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Hidden heroes of the health revolution Sanitation and personal hygiene

      Since the mid-1800s, there has been a significant improvement in the public health of people living in the U.S. and Europe. It's proposed that changes in personal and domestic hygiene practices played an essential, but understated role in achieving this improvement. A corollary of this hypothesis is that sanitation and personal and household hygiene practices are responsible for much of the good health we enjoy today; and any significant decline in hygiene standards will result in increased health problems. This hypothesis will be critically analyzed in this chapter. Before examining the evidence, it' s worthwhile to understand the challenges and technologies that apply in such an examination, as well as the recognized criteria for judging the relevance and adequacy of the evidence.
      “Health” can be measured using indices for “good” health (e.g., lives saved, illness avoided) or, on the other hand, the antithesis of good health (e.g., death, disease). Here we'll “measure” community health by three commonly used guides:
      • 1.
        General population mortality rates;
      • 2.
        Infant and child mortality rates;
      • 3.
        Life expectancy and death statistics.
      It's suggested that during the 19th century, “sanitarians” in Europe and the U.S. awakened a sanitary consciousness among the common people and popularized cleanliness. This, in turn, led in whole or in part to the decline of such serious endemic diseases as infant diarrhea (a leading cause of death among children), typhus, trachoma, and certain skin diseases. If the hypothesis is true, this contribution cannot be dismissed as trivial. If it can be shown that such things as soap and water lowered the incidence of infant diarrhea, the direct contribution of personal hygiene to infant survival will become self-evident. Furthermore, if it can be shown that cleanliness interacts with other health determinates, such as nutrition and overcrowding, then changes in personal cleanliness must also have had an indirect impact on many other diseases, such as trachoma and typhus.
      If the logic ends up being so compelling and the contribution so potentially important, how could the role of personal hygiene in improving health have been “understated” and “ignored”? The answers to this question illustrate the perceptions and scientific challenges that must be overcome in this type of analysis.
      This lack of understanding could be partly due to ignorance of health revolution itself. If one doesn't know it occurred, then one doesn't really care about its underlying causes. And, most people just don't have the instinct to distinguish between “health then” and “health now.” For example, in 1952 polio was viewed as a national emergency when there were 14 cases of paralytic polio per 100,000 people. In comparison, those living in the era around 1900 witnessed 4,429 babies per 100,000 dying from infant diarrhea per year, which at the time might not have been considered exceptional! If polio was a scourge whose elimination brought honors to those responsible, how much more credit should be given to those who controlled a disease that was 300 times more tragic? Yet, we have forgotten the latter and don't even remember what they did.
      It could be partly due to the low profile of the sanitary era itself. Today, we are so well attuned to the almost daily miracles of medical, surgical, and pharmacological interventions, anything done a century ago is a curiosity at best and primitive as a general rule. Only medical historians and demographers truly appreciate the health revolutions of the 19th century and pre-World War I sanitation. Further, such enterprises as water treatment and sewage disposal seem mundane. Today, they pale beside the “real” advances like kidney transplants and computer-assisted tomography. How can anyone get excited about soap, laundry detergents, and garbage collection when open-heart surgery is practically routine? Despite the period's hidden or ignored identity, the sanitary era was a significant contributor to the health revolution. Let's explore this era in more depth.

      Advances in Sanitation

      One of the more important contributors to the health revolution was the technological-sociological-environmental phenomenon known today as “the sanitary era” or the “public health campaign.” However, getting past the filth took great efforts since sanitary practices weren't given nearly the same value or importance as they are today.
      Today, clean people and surroundings are so much the norm that it is difficult to imagine an era when they weren't. Clean air and water are assumed to be a civic right. Litter-free streets and garbage disposal are traditional responsibilities of local government. Showers, toilets, baths, soaps, detergents, laundries, dishwashers, and vacuum cleaners are common features in our homes. All are associated with good health, good manners, good rearing, good housekeeping, and civilization itself! But today's accepted standards of environmental and personal hygiene are very recent concepts.
      In the middle 1800s, a wave of disgust against environmental filth swept through Western civilization. The sanitarians of those years believed, quite mistakenly, that disease was caused by “miasmas,” foul smelling emissions from decaying organic matter. For example, swamps and poorly drained farmlands smelled bad in thesummer, just when people living near them became sick. Therefore, the sanitarians reasoned that the bad air, or mal-aria, must have been responsible for the illness. They took heroic steps to clean up the miasma sources—water, sewage, factories,and homes.Sanitarians of the mid-1800s believed, quite mistakenly, that disease was caused by “miasmas,” smelly emissions from decaying organic matter.
      The sanitarians had experimental proof that controlling bad smells would control disease. Although their reasoning was wrong, their efforts paid off in health benefits. For example, they drained the swamps—coincidentally eliminating the breeding ground of the mosquito carriers. They installed sewage disposal systems, thus breaking the relentless cycle of cholera epidemics. Proper disposal of garbage helped control insects and rodents, which are reservoirs and carriers of disease. It has been claimed that the major decline in mortality observed during the late 1800s and the early 1900s was due to innovations in environmental sanitation.

      Sydenstricker E. Health and Environment. (New York: McGraw-Hill Book Co., Inc.; 1933).

      Advancements in sanitation worked hand-in-hand with science and social and political activism to move this cause forward.

      Science and Social/Political Activism

      The triad “filth, poverty, disease” appears so frequently in the writings of the 1800s that it's easy to see how they became associated as a cause-effect relationship. Chadwick was particularly interested in this association since he was the secretary to Great Britain's Poor Law Commission. It was his job to deal with the causes and consequences of poverty.
      In 1840 England, socially sensitive citizens believed that disease was “caused” by poverty. Thus, they advocated control of illness among the poor by providing grants of money to control poverty. Chadwick disagreed with the sequence of events and consequently with the remedial strategy. In 1842, he claimed that filth leads to disease and that disease, in turn, leads to loss of income and poverty.

      Chadwick E. Report on the Sanitary Condition of the Laboring Population of Great Britain. (London: Her Majesty's Stationery Office; W. Clowes and Sons; 1842. reprinted by Edinburgh University Press, 1965)

      What was his remedy for poverty? The government taking action to improve the sanitary status of the laboring class, which would improve their health and protect their earning power.
      Whether or not Chadwick's socioeconomic arguments had merit, his epidemiological arguments came exactly when the country was ready to receive them. Knowledge about the cause of disease was still in its infancy, but Chadwick lived and wrote at a time when the branches of several streams of scientific and social/political activism were cresting. Together, these streams were sufficient to result in the establishment of public health as a governmental responsibility in Great Britain and the U.S.

      Vital Statistics

      One of the streams that contributed to the acceptance of Chadwick's advocacy was the development of vital statistics as a science. This permitted the objective measurement of the consequences of sanitary reform. What could be a more convincing argument regarding the success of a governmental health program than the measurement of lives saved and years added to life?
      In England the establishment of vital statistics is credited to Chadwick and William Farr. In the U.S., Lemuel Shattuck is given credit. However, an intriguing piece of historical detective work by David and Abraham Lilienfeld traces the work of all three (and most statistician-sanitarian epidemiologists in the 19th century) to Pierre-Charles Louis, a French physician.
      • Lilienfeld D.E.
      • Lilienfeld A.M.
      “Epidemiology: A Retrospective Study,”.
      Some claim that the French sanitary movement of the early 1800s was inspiration for the rest of the world. Indeed, the first public health journal, The Annales d'Hygiene, originated in France in 1829.

      Origins of Disease

      Another stream was the attempt to identify specific agents of origin for diseases. Coincidentally, during Chadwick's active period in sanitary reform, the following three classic studies on the epidemiology and control of infectious disease were published:
      • John Snow showed that cholera was transmitted by a contaminated water supply.
        • Snow J.
        On the Mode of Communication of Cholera.
        He effectively terminated a London epidemic by persuading the local board of Guardians to remove the handle of the water pump in question.
      • William Budd demonstrated that typhoid fever was not caused by bad odors, but rather by a disease agent carried via sewage to water and milk.
        • Budd W.
        Typhoid Fever: Its Nature, Mode of Spreading, and Prevention.
      • Ignaz Semmelweis showed in an 1861 publication that puerperal fever was transmitted by physicians who did not sanitize their hands between patients.
        • Semmelweis I.P.
        “The Etiology, the Concept and the Prophylaxis of Childbed Fever,”.

      Social and Political Activism

      Another stream was the liberal-humanitarian zeal that characterized early-19th-century England and was exemplified in writer Charles Dickens's crusade against child labor. Prison reform (including bathing facilities, whitewashed walls, ventilation, and separate rooms for the sick) is associated with John Howard—considered by Charles Edward Amory Winslow to be the first of the pioneer English sanitarians. The social-sanitary campaign to protect industrial workers resulted in a series of 19th-century legislative acts—the early forerunners of today's labor and occupational health laws. There's no doubt that the sanitary revolution was, in part, a response to humanitarian concern for the lack of resources for proper hygiene.

      Sanitary Pioneers and Theories

      The pioneers of the sanitary era were all active prior to 1850—Edwin Chadwick, John Snow, William Budd, and John Simon in England; Ignaz Semmelweis in Austria; and Lemuel Shattuck in Boston. They maintained that illness and death were associated with unsanitary conditions or practices, and they all advocated sanitary reform. Among the sanitary reformers, some supported the “miasma” theory of transmission and some were “contagionists.” Arguments among the advocates of these epidemiologic theories continued for decades—even after the germ theory of disease had been well-accepted.
      From a practical point of view, all of the sanitarians recognized the relationship between filth and disease. The evolution of epidemiological reasoning from 1849 to 1878 is well described by Winslow.
      • Winslow C.E.A.
      The Conquest of Epidemic Disease.
      The sanitary reformers were joined in the next decade by Florence Nightingale and Joseph Lister, who reformed medical and surgical care. Louis Pasteur and Robert Koch subsequently provided scientific evidence that the sanitarians' aims—though not always their reasoning—were realistic.

      Legislation

      The payoff for the sanitarians' efforts was legislation. Six years after Chadwick's report was published, a General Board of Health was established in England in 1848. In 1855, Sir John Simon became the Central Medical Officer of this board. He was instrumental in the passage of a series of laws providing the basic taxation and regulatory powers necessary to implement the aims of the sanitarians (see below).
      Figure thumbnail fx1
      In the same period across the ocean, Shattuck's report of 1850 became the basis of American public health.
      • Clarkson L.
      Death, Disease and Famine in Pre-Industrial England.
      Winslow called Shattuck's report “for breadth and clarity of prophetic vision… the most remarkable document in the history of Public Health.”
      • Winslow C.E.A.
      The Evolution and Significance of the Modern Public Health Campaign.
      In addition to recommending the establishment of state and local boards of health, Shattuck outlined the following:
      • vital-statistics gathering
      • tuberculosis control
      • alcoholism control
      • air pollution control
      • mental-health care
      • education reform
      • housing development
      • public bathhouse availability
      • routine physical examinations
      By 1869, Massachusetts established the first State Board of Health, and within nine years 16 other states followed.
      • Clarkson L.
      Death, Disease and Famine in Pre-Industrial England.

      Other Developments

      During the sanitary era, the world was also introduced to milk pasteurization, autoclave sterilizers for hospitals, chemical germicides, and municipal water treatment systems. For example, Figure 3-1, Figure 3-2, Figure 3-3 illustrate advances in water treatmant and distribution in the U.S.
      Figure thumbnail gr1
      Figure 3-1Reduction in Death Rate for Typhoid Fever, Pittsburgh E. Sydenstricker, Health and Environment (New York: McGraw-Hill 1933).
      Figure thumbnail gr2
      Figure 3-2Death Rates for Typhoid Fever, U.S. U.S. Bureau of the Census, Historical Statistics of the United States, Colonial Times to 1970, Bicentennial Edition, Part 1, Washington, D.C., 1975.
      Figure thumbnail gr3
      Figure 3-3Availability of Filtered Water to Urban Populations M. P. Ravenel, ed., A Half Century of Public Health: Jubilee Historical Volume of the American Public Health Association (New York American Public Health Association, 1921).
      The bacteriological discoveries of Louis Pasteur and Robert Koch provided a scientific rationale for the experimental programs of the sanitarians. Western civilization became convinced that infectious disease was not inevitable. The health revolution was in full swing by the turn of the 20th century.
      • Winslow C.E.A.
      The Conquest of Epidemic Disease.
      An 1840s proposal of Chadwick was the collection and conveyance of sewage away from cities.
      Similar to Asian practices, he envisioned that sewage could be processed for sale to farmers for use as fertilizer. Unfortunately, the availability of more convenient forms of fertilizers, such as guano from South America and synthetic fertilizers, led to the sewage being discharged into water bodies, which led to a history of problems until sewage treatment became effective.

      W.H. McNeill, Plagues and Peoples (New York: Quality Paperback Book Club, 1976).

      Advances in Personal Hygiene

      In the years leading up to the health revolution, the custom of bathing wasn't a part of Western civilization. Indeed, except for the social relaxation of the aristocracy, religious rites, or miraculous healing, bathing was not readily accepted in most countries where the temperature was less than tropical.
      This medical officer's report to Chadwick around 1840 wasn't at all unusual:

      Chadwick E. Report on the Sanitary Condition of the Laboring Population of Great Britain. (London: Her Majesty's Stationery Office; W. Clowes and Sons; 1842. reprinted by Edinburgh University Press, 1965)

      “I attended a man, woman and five children, all lying ill in one bedroom, and having only two beds amongst them. The walls of the cottage were black, the sheets were black, and the patients themselves were blacker still. It was indeed a gloomy scene…”
      While we might occasionally experience such scenes as above today in the U.S., they would really be public health curiosities, not common occurrences. Personal cleanliness is now an accepted value of society. But when and how did the personal hygiene transformation come about? This section will examine the transformation and show how personal hygiene habits changed before health improvements arrived.

      The Reformers

      The beginning of the personal hygiene transformation was brought about by the sanitary reformers, and again by legislation. The pioneers of the sanitary era weren't only advocates for improving environmental hygiene and public health infrastructures, they were also fervent advocates of personal hygiene. John Simon, for example, was always concerned with “organic decomposition—especially human excrement”—as well as “the less riotous forms of uncleanliness” (distinguished from “accumulated obvious masses of filth”). He was also concerned that the average Englishman hadn't “reached any high standard of sensibility to dirt.” Even more important than his legislative enactments was the need for “Education… the one far-reaching reformer,” and “hygiene rules, not less important to mankind than the rules which constitute local authorities.”
      • Simon J.
      English Sanitary Institutions.
      In 1833, the reformers convinced the British government to reduce the soap tax, which was three pence per pound. In 1853, William E. Gladstone repealed the soap tax altogether, and British and Scottish soap production increased from 25,000 tons in 1801 to 83,000 tons in 1851 and 100,000 tons in 1872.
      • Kingzett C.T.
      The History, Products, and Processes of the Alkali Trade Including the Most Recent Improvements.
      • Wilson G.
      Handbook of Hygiene and Sanitary Science.
      Domestic use of soap in England was equivalent to 3.6 lbs. per person in 1801, increased to 8 lbs. in 1861, and almost doubled again by 1891.
      • Fleck A.
      “Technology and Its Social Consequences,” in A History of Technology, Volume 5: The Late 19th Century.
      In 1846, John Coventry, a British surgeon, published an article entitled, “The Mischiefs of Uncleanliness and The Public Importance of Ablution.”
      • Coventry J.
      “On the Mischiefs of Uncleanliness and the Public Importance of Ablution,”.
      He complained that the medical publications of the period made “very meager contributions to the subject of hygiene.” After providing a “scientific” explanation of the importance of clean skin, and tracing the “large amount of disease and misery to uncleanliness,” he recommended that public baths be provided for the laboring classes in England. These baths were similar to those available in Scotland and some cities on the continent.
      • Coventry J.
      “On the Mischiefs of Uncleanliness and the Public Importance of Ablution,”.
      An 1867 lecture by Dr. Edward Dillon Mapother to the Royal College of Surgeons in Dublin states: “I believe that health would be preserved and life prolonged if we ourselves were as assiduously ‘groomed’ as our horses.”
      • Mapother E.D.
      Lectures on Public Health, Delivered at the Royal College of Surgeons.
      Figure thumbnail fx2
      Child being bathed by New York City Department of Health Little Mother's League. (Reprinted with permission of NYC municipal Archives.)
      Edwin Chadwick used the practical argument that:
      “Skin cleanliness augments the nutritive effects of food… It should be preached to the poor, as an additional inducement to skin cleanliness, that the same food which is required to make four dirty children thrive, will serve to make five thrive whose skins are daily washed and kept clean.”
      • Mapother E.D.
      Lectures on Public Health, Delivered at the Royal College of Surgeons.
      These historical anecdotes, such as the one from Chadwick, are plentiful and sometimes even amusing, but the sanitary reformers were quite serious. For whatever reasons that motivated them—health, esthetics, fear of dirt, or scientific insight—they extended their sanitary obsession beyond water, sewage, swamps, and ventilation to dirty people and vermin-infested clothing. They used the same weapons for this personal hygiene battle as they did for cleaning up the physical environment, namely legislation, preaching, and teaching. Their successes, however, were harder to measure and longer delayed. It's easier to terminate an epidemic by dismantling a pump than it is to control endemic disease by changing a lifestyle. Still, they persevered, and during the next 150 years, the sanitary consciousness and habits of Europe, the U.S., and elsewhere were gradually but fundamentally altered.

      The Introduction of Baths and Bathing

      Europe

      In George Ryley Scott's history of baths and bathing, he explained that Victorian citizens really couldn't bathe, even if they wanted to, unless they enjoyed cold streams and polluted rivers.
      • Scott G.R.
      The Story of Baths and Bathing.
      In addition, there wasn't running water, heating fuel was expensive, soap was hard to get (or make), and there weren't facilities for personal hygiene. Bathing could be done in wash basins with some effort, but it wasn't part of the folk culture. Few private houses, even of the aristocracy, possessed “bathrooms.” The rich and titled gathered at Turkish baths or spas, but did more socializing than bathing.
      Figure thumbnail fx3
      English Regency shower (circa 1810).
      Until the middle 1800s, “the great unwashed” remained that way for two reasons: lack of desire and lack of opportunity to do anything about it. During the same time in Paris and Brussels, people could “hire” a warm bath in their own homes. Entrepreneurs provided portable bathtubs and hot water, with the tubs carried in a cart from the bathing establishment to the home, and then carted away again after use. In 1840, the cost of this service was equivalent to three English shillings.
      • Scott G.R.
      The Story of Baths and Bathing.
      With a British laborer earning 10 to 18 shillings a week, clearly only the wealthy could afford this service.
      Some British employers did make sporadic attempts to “protect the health as well as the morals of their workers by influencing their personal cleanliness habits.”

      W.H. McNeill, Plagues and Peoples (New York: Quality Paperback Book Club, 1976).

      In some factories and mines, hot wastewater from steam engines and smelters was poured into large basins so workers could take warm baths. In fact, some of these wastewater baths became so popular that factory owners opened them to the public and profited from the admission fees.
      In 1844, a movement was started in London to provide bathing and laundering accommodations for the working classes, who had very limited access to hot water, bathtubs, sinks, or a place to bathe. A bathhouse and laundry was built, and became an immediate success!
      Chadwick describes two such enterprises:
      “Some families subscribe a shilling each month, which entitles them to five baths weekly. Men and women bathe on alternate days and a bath keeper for each attends for an hour and a half in the evening…”

      Chadwick E. Report on the Sanitary Condition of the Laboring Population of Great Britain. (London: Her Majesty's Stationery Office; W. Clowes and Sons; 1842. reprinted by Edinburgh University Press, 1965)

      “In Westminster… the establishment… (was reported). . . of similar tepid swimming baths where only three pence is charged to persons of the working class. As many as 2,000 and 3,000 of this class have resorted to these baths in one day. ..”

      Chadwick E. Report on the Sanitary Condition of the Laboring Population of Great Britain. (London: Her Majesty's Stationery Office; W. Clowes and Sons; 1842. reprinted by Edinburgh University Press, 1965)

      In 1846, the English government passed the “Public Baths and Wash-Houses Act” for the “health, comfort and welfare” of the population. This was the forerunner of a series of statutes and amendments that sanctioned building loans to local governmental units for bathing facilities. The maximum charge for a second-class cold bath was one penny; a hot bath cost two pence.

      Encyclopedia Britannica, Article on Baths: http://search.eb.com, 1911.

      By 1890, the prices had increased—a cold bath could be purchased for two pence and a warm bath for six pence. A clean towel came with the admission price, but a small bar of soap cost one penny more.
      • Paton J.
      “Remarks to the Association for Improving the Condition of the Poor,”.
      The movement spread to other countries in Europe, with France passing similar public bath legislation in 1850. Then Germany, Switzerland, Austria, Italy, and Belgium followed suit.
      Use of London Bathhouses
      • In the 1860s, among the 10 baths in London, there were 1,001,041 baths taken in a given year, and 321,474 women used the laundry facilities.
        • Mapother E.D.
        Lectures on Public Health, Delivered at the Royal College of Surgeons.
      • Between 1896 and 1897, two million people in England used the facilities.

        Encyclopedia Britannica, Article on Baths: http://search.eb.com, 1911.

      • Between 1904 and 1905, this number grew to 6,347,158. It' s not known how many of these millions were repeaters, i.e., whether six million bathed once that year or 120,000 bathed every week. But it is known that only 18% were females.

        Encyclopedia Britannica, Article on Baths: http://search.eb.com, 1911.

      The glorious breakthrough in personal hygiene that should have come soon after 1846 took much longer than expected. An 1879 medical officer complained: “A healthy desire for bathing, not having yet been awakened in the wage-earning class, what guarantee has anyone for concluding that the baths, when provided, would be used? Just as one man can bring a horse to water, but a down cannot make it drink, it would be a comparatively simple feat to erect baths, but an exceedingly arduous one to get the uncleanly to use them . . .”

      F. Vacher, “Cheap Baths for the People,” The Sanitary Record 129, February 28, 1879.

      Why wouldn't more of the public take advantage of the baths? First, public baths were only built in towns and boroughs that requested them. For nearly 50 years, most towns and boroughs ignored this opportunity. It wasn't until the 1890s that there was anything close to a spurt of enthusiasm for the program on a countrywide scale in England. Second, the bathing facilities were usually located in the slums of town. The majority of people equated public baths (not the recreational swimming pools) with public workhouses. According to contemporary critics, public baths were “as far from one's conception of a haunt of pleasure as it was humanly possible to make them. They were drab and dreary. Furthermore, they stank of officialdom and patronage.”
      • Scott G.R.
      The Story of Baths and Bathing.

      United States

      The history of baths and bathing in the U.S. up through the mid-1800s was not much different than in Western Europe at that time. With no running water in homes, bathing was largely left to occasional dips in ponds or streams.
      • Furnas J.C.
      The Americans: A Social History of the United States, 1587-1914.
      Washing parts of the body and bathing started to come into the home during the mid-1800s via the kitchen and then rooms off the bedchamber, though indoor plumbing in any building was still extremely rare.
      • Larkin J.
      The Reshaping of Everyday Life: 1740-1840.
      From a story of American public baths published in 1896, the sanitary hero in the U.S. was Dr. Simon Baruch.
      • Fisk H.E.
      The Introduction of Public Rain Baths in America—A Historical Sketch.
      He advocated “rain baths” or showers as early as 1889, and he recommended they be established in schools, asylums, and in the poorer districts of large cities. His purpose was to “popularize bathing and protect the community against many diseases, without a large outlay of the people's money.” By 1890, the public bath movement gained a foothold in the U.S.
      The following is a quote from the Journal of the American Medical Association, October 1892:
      “If prevention be better than cure, then, to fund a great public bath would confer a grander blessing than to erect a hospital. To provide an institution which should bring refreshment and vigor to the overworked, healing to the sufferer, warmth, comfort, and self-respect to the victim of squalor, poverty and neglect, would be to raise a cenotaph more glorious than ever from Attic or Etruscan hands arose. ”
      • Shepard C.H.
      “Public Baths: A Preventive of Disease,”.
      Japan
      Hygiene in Japan from the mid-1600s to mid-1800s contrasted sharply with that in the U.S. and Europe, which would have played an important role in reducing disease. A visitor's account from the late 1600s to early 1700s reports: “ . . . it is an invariable custom of both nobles and commoners to wash their hands every time after using the privy . . .” Other customs resulting from a strong avoidance of anything dirty, such as boiling water for tea, cooking food, separate eating utensils for everyone in the household, and removal of footwear when entering homes and buildings reduced viral and bacterial contamination, impeding the spread of disease. Public baths, which began to appear in the 1500s, also would have reduced the spread of disease.
      • Hanley S.B.
      “Urban Sanitation in Preindustrial Japan,” in Health and Disease in Human History: A Journal of Interdisciplinary History Reader.
      China
      Commercial baths were reported in Hangchow, China, as far back as 1072. During a stay in Hangchow in the 1260s, Marco Polo noted as many as three thousand commercial bathing establishments. Used by middle and lower classes, residents frequented them almost daily. Upper classes had a custom of taking a bath every ten days in the privacy of their own homes.
      • Gernet J.
      Daily Life in China on the Eve of the Mongol Invasion 1250-1276.

      The Big Transformation

      Unfortunately, the public baths and laundries in the U.S. and England didn't have much impact on personal hygiene and health. However, they did influence, to some extent, the personal hygiene practices of hundreds of thousands, perhaps millions, who wouldn't otherwise have bathed. But the largest part of the population remained unaffected. Any modification of community mortality and morbidity rates by public baths would, necessarily, be slow and very difficult to ascertain.
      The big transformation in personal hygiene didn't occur until running water could be provided to homes from municipal treatment and distribution systems. Along with water-heating devices, plumbing, baths and sinks, building improvements, and drainage systems, running water permitted the installation of true bathrooms in middle-class homes and the prospering labor class.
      In England, home bathing and laundering became a social norm in the years immediately before and after World War II; in the U.S., it might have happened slightly earlier. Although these occurrences cannot be pinpointed, we wouldn't be too far off in identifying the years from 1890 to 1910 as the period of significant personal hygiene transformation in the English-speaking countries of Europe and North America.
      Figure thumbnail fx4
      Late Victorian bathtub (circa 1870-1910).

      The Growth in Availability of Hygiene and Cleaning Products

      Events in the U.S. illustrate the availability of hygiene-related products to the masses. Advertisements, as well as washing machines and soap data, all point to the high level of interest in hygiene in pre–World War I America. The best pictures of the late 1800s and its hygienic maturation are found in the pages of the early Sears catalogues. The company was founded in 1895, and by 1897, the Sears catalogue listed three columns of advertising for soaps (both laundry and toilet), bluing, ammonia, and borax.
      From the 1897 Sears Catalog:
      Procter and Gamble's Ivory soap sold for $0.07 per bar or $6.75 for a case of 100. China Soap's advertisement stated:
      “China Soap. Far exceeds any soap on the market. Best in the world for the laundry. Is bought by thousands and preferred to any other for the toilet. Better than Ivory; 100 eight oz. cakes to a box, $3.50.”

      Sears, Roebuck and Co. catalogues, Chicago, 1897, 1902, 1930.

      Again, the Sears catalogues present reasonable evidence that personal hygiene played a sufficiently important role in pre-World War I America (Figure 3-4, Figure 3-5, Figure 3-6). The purpose was to attract serious commercial attention. In Depression America, hygiene was evidently one of the big consumer interests (Figure 3-7, Figure 3-8).
      Figure thumbnail gr4
      Figure 3-4Sears, Roebuck and Co. catalogues, Chicago, 1902, 1930.
      Figure thumbnail gr5
      Figure 3-5Sears, Roebuck and Co. catalogues, Chicago, 1902, 1930.
      Figure thumbnail gr6
      Figure 3-6Sears, Roebuck and Co. catalogues, Chicago, 1902, 1930.
      Figure thumbnail gr7
      Figure 3-7Sears, Roebuck and Co. catalogues, Chicago, 1902, 1930.
      Figure thumbnail gr8
      Figure 3-8Sears, Roebuck and Co. catalogues, Chicago, 1902, 1930.
      Jean LemMon describes the little-known history of home laundering. According to him, prior to the availability of hot running water, commercial laundry soap, and mechanical washers, the task of keeping a household's linens clean was grim and laborious.

      J. LemMon, contributing ed., Maytag Encyclopedia of Home Laundry: A Completely Authoritative Guide to Doing the Wash, Buying Automatic Washers and Dryers, Conserving Energy, a Modern Laundry Center for Your Home, 5th ed. (New York: Western Pub. Co., 1982).

      The following changes that occurred in the U.S. in the 1800s eventually made the laundering task much easier.
      Figure thumbnail fx5
      Soap production also increased dramatically during this time. In the late 1800s, the U.S. government began collecting information on the combined value of soap and candle production (Figure 3-9). Soap production began to be split out in 1904. From 1904 to 1916, the value of soap production in the U.S. increased more than 500% (Figure 3-9). Soap sales continued to increase until around 1940. From 1940 to 1970, synthetic soap (detergent) sales rose steadily as laundry products converted from soap to detergents. The development of detergents (synthetic soaps) was driven by the shortage of fat and oil supplies for making soaps during WWI and WWII. Another driver was the military's need for a cleaning agent that would work in mineral-rich seawater and cold water.
      Figure thumbnail gr9
      Figure 3-9Soap and Candle Production, U.S. Manufactures of the United States: 1860 (Washington, D.C.: Government Printing Office, 1865). Compendium of Eleventh Census: 1890, Part III (Washington, D.C.: Government Printing Office, 1897). Census of Manufactures: 1914, The Soap and Detergent Industry (Washington, D.C.: Government Printing Office, 1917). Biennial Census of Manufactures: 1921, The Soap and Detergent Industry (Washington, D.C.: Government Printing Office, 1924).
      In addition, there were dramatic increases in the growth of laundry appliances. Annual home laundry appliance shipment rates increased more than eight times between 1916 and 1920 (Figure 3-10). After 1945, newly built houses used to accommodate the huge waves of immigrants were almost universally supplied with indoor plumbing, flush toilets, sinks, laundry facilities, and bathtubs or showers. Figure 3-11 shows the dramatic increase in shipments of both home laundry appliances and dishwashers in the U.S. in the post-World War II era.
      Figure thumbnail gr10
      Figure 3-10Home Laundry Appliance Shipments Association of Home Appliance Manufacturers, Total Home Laundry Appliances, Washington, D.C., 2002.
      Figure thumbnail gr11
      Figure 3-11Home Laundry and Dishwashing Appliances Association of Home Appliance Manufacturers, Total Home Laundry Appliances, Automatic Washers, Dishwashers, Washington, D.C., 2002.
      Additional evidence of advancement at the personal hygiene level in the U.S. is indicated by figures on toilet soap production from 1909 to 1987 (Figure 3-12), which show increasing per capita production.
      Figure thumbnail gr12
      Figure 3-12Toilet Bath Soap Production/Consumption. U.S. data: Census of Manufactures: 1914, The Soap and Detergent Industry (Washington, D.C.: Government Printing Office, 1917). Biennial Census of Manufactures: 1921, The Soap and Detergent Industry (Washington, D.C.: Government Printing Office, 1924). Census of Manufactures: 1923, Soap (Washington, D.C.: Government Printing Office, 1925). Census of Manufactures: 1925, Soap (Washington, D.C.: Government Printing Office, 1927). Census of Manufactures: 1927, Soap (Washington, D.C.: Government Printing Office, 1929). Census of Manufactures: 1931, Soap (Washington, D.C.: Government Printing Office, 1933). Census of Manufactures: 1939, Drugs, Medicines, Toilet Preparations, Insecticides, and Related Products, Soap and Glycerin (Washington, D.C.: Government Printing Office, 1941). Census of Manufactures: 1947, Volume II: Statistics by Industry (Washington, D.C.: Government Printing Office, 1949). U.S. Bureau of the Census, U.S. Census of Manufactures: 1954, Volume II: Statistics by Industry, Part 1: General Summary of Major Groups 20 to 28 (Washington, D.C.: Government Printing Office, 1957). U.S. Bureau of the Census, Census of Manufactures: 1963, Volume II: Statistics by Industry, Part 1: Major Groups 20 to 28 (Washington, D.C.: Government Printing Office, 1966). U.S. Bureau of the Census, Census of Manufactures: 1967, Volume II: Industry Statistics, Part 2: Major Groups 25 to 33 (Washington, D.C.: Government Printing Office, 1971). U.S. Bureau of the Census, Census of Manufactures: 1972, Volume II: Industry Statistics, Part 2, SIC Major Groups 27 to 34 (Washington, D.C.: Government Printing Office, 1976). U.S. Bureau of the Census, Census of Manufactures: 1977, Volume II: Industry Statistics, Part 2, SIC Major Groups 27 to 34 (Washington, D.C.: Government Printing Office, 1981). U.S. Bureau of the Census, Census of Manufactures: 1987, Industry Series, Soaps, Cleaners, and Toilet Goods, Industries 2841, 2842, 2843, and 2844 (Washington, D.C.: Government Printing Office, 1988). U.S. Census Bureau, Soap and Other Detergent Manufacturing, 1997 Economic Census, Manufacturing, Industry Series, Washington, D.C., 1999. Population numbers: U.S. Census Bureau, http://eire.census.gov/popest/archives/state/st_stts.php. Japan data: Japan Soap and Detergent Association, 2001. Ministry of Health, Labour, and Welfare (Japan) www.mhlw.go.jp/english/database/db-hw/populate/popl.html, accessed on February 18, 2003. India data: Indian Soap and Toiletries Makers' Association, 2001. www.library.uu.nl/wesp/populstat/populframe.html, accessed on February 18, 2003.
      Other countries show similar trends in the use of toilet and bath soaps. Figure 3-12 shows per capita toilet and bar soap consumption for India and Japan. Toilet and bath soap use in India has been steadily increasing. The same is true for Japan, though bar soap use per capita has been decreasing from around 1990, when liquid soap was introduced.

      Linking Personal and Household Cleanliness with Health

      Validations and Methodologies

      Even those who know about the sanitary era and its revolutionary impact on death and disease over a century ago in the U.S. and Western Europe virtually ignore its personal hygiene aspect. This is probably because improvements in personal hygiene are not dramatic and are difficult to document. For example, it is relatively easy to pinpoint the installation of a sewer system, the establishment of a milk pasteurization program, or the completion of a swamp drainage operation. On the other hand, it is almost impossible to pinpoint behavioral changes, like personal hygiene habits. Bathing and laundering practices are sociocultural activities that were adopted at uneven rates among diverse populations over long periods of time.
      In evaluating the contributions of personal hygiene to historical health changes and current health status, it is important to consider that many other social, behavioral, environmental, and medical changes have taken place concurrently. All of these other changes could reasonably be expected to modify the incidence of the same diseases whose control we are attributing to hygiene. An irrevocable fact of health history is that the use of any of the following—vaccines, soap, pasteurization, plumbing, autoclaves, showers—may interact with the introduction and use of the others, which makes their specific individual contributions hard to unravel.

      Interventional and Observational Study Designs

      Studies employing either interventional or observational designs provide other means of investigating hygiene and health relationships. An interventional study is one in which a study investigator imposes an intervention and observes changes in disease incidence. Intervention studies can be conducted on the same group of people, where disease incidence is compared before and after the intervention. Or it can be compared among groups of people who are randomized to either the intervention method or no change in practices. The strengths and limitations of intervention studies should be assessed by considering the methods used to design and conduct them. Such methods can include randomization, assessment and control of confounding factors, blinding, and other pertinent validity issues.
      In an observational study, groups of people are observed or questioned concerning practices or exposures (i.e., without an imposed intervention) and assessed for subsequent changes in disease incidence. Observational studies report disease incidences in populations following certain hygiene practices.
      To resolve our contention that cleanliness and personal hygiene changes actually contribute to the dramatic changes in the health status of populations, four separate but converging lines of evidence are employed:
      • Plausibility of the hypothesis from an epidemiological point of view.
      • Historical evidence that specific and documentable changes in personal hygiene practices during the last century and a half had an impact on several major components of mortality and morbidity.
      • Evidence from multiple populations, which shows that the health status of different geographic regions can be closely related to certain indices of personal hygiene and cleanliness.
      • Evidence from interventional and observational studies.

      Plausibility of the Hypothesis

      The most that can be expected from historical information, studies of populations in different geographic regions, or interventional and observational studies are associations. Perhaps it is an association between soap consumption and diarrhea decline, or between laundering frequency and typhus control. To many people, association between two variables is the same as causality. To the scientist—and in particular to the epidemiologist who studies the distribution and determinants of health in populations—association between two factors is just a first step. Before the epidemiologist can say, with any degree of confidence, that a given factor caused a given disease (or in our case, that a given factor was responsible for the control of a disease), she or he must climb a ladder of logic and reinforcement.
      This isn't intended to be a short course in epidemiology, but the point is so important, we really cannot proceed to a critical analysis of our basic hypothesis without making this point clear: Observed associations between personal hygiene practices and improved health are not enough to prove that one causes the other.
      The other rungs of the logic ladder are the following set of criteria (not prioritized) that have been suggested as an aid for distinguishing between noncausal and causal associations:
      • Hill A.
      The Environment and Disease: Association or Causation?.
      • Strength of the Association—What is the magnitude of association between the two variables? How often could such an association occur by chance alone (statistical significance)?
      • Consistency of the Association—Has the same association between a hygiene practice and health impact been shown among different populations? At different times? In different geographic regions? Using different research designs?
      • Specificity of the Association—Is this a unique association or is the same effect attributable to different causes? Does the cause produce one effect?
      • Time Dependence—Did the “outcome” occur after the “cause” was introduced? Was there enough delay between “cause” and “outcome” to suggest true association? How can we be sure, when two factors are associated, that one is the cause and the other the effect? Can they both be effects of a third, unsuspected cause? If the cause is removed or reversed, does the outcome also change?
      • Biological Plausibility—Are the two associated factors logical candidates for a biological “cause and effect” association? Is there a biological mechanism consistent with the hypothesis?
      • Biological Gradient—Is there evidence of a dose-response relationship between the number of infectious organisms and transmission or occurrence of disease?
      • •.
        Experimental Evidence—Do the studies describe changes in health when hygienic measures are introduced?
      A fuller discussion of tools to characterize epidemiological relationships between two or more factors, and the occurrence of an effect is presented elsewhere, including examples of the application of these criteria.
      • Aiello A.E.
      • Larson E.
      “Causal Inference: The Case for Hygiene and Health,”.
      These criteria are not meant to be used as “hard-and-fast rules” for either accepting or rejecting causal relationships.
      • Hill A.
      The Environment and Disease: Association or Causation?.
      One of the implications of holding steadfast to these criteria and ignoring other basic scientific principles would be the pitfall of basing causality on findings from studies that are methodologically flawed. Hence, the criteria should not be applied in the absence of rigorous evaluation of the scientific quality of each study.

      Impact of the Health Revolution on Infant Mortality

      The most dramatic impact of the health revolution was its influence on the mortality of infants and children. We examine infants' and children's morbidity and mortality rates because children are more susceptible to many diseases than adults. Prior to 1915, the most important cause of infant death in the U.S. was diarrhea—the most common cases being cholera infantum and teething disease. Cause-specific mortality data prior to 1900 are hard to come by for several reasons. The causes of infant death, as recorded in 19th-century death certificates, are difficult to interpret, and diarrhea is often reported in diverse terms.
      Figure thumbnail fx6
      Children near an apartment building. (Reprinted with permission of NYC municipal Archives.)
      Infant mortality begins a sharp decline in the U.S. around 1890 (Figure 3-13). To further illustrate this fact, diarrhea mortality in Baltimore among children less than two years old consistently dropped every decade from 1870 (265/100,000) to 1920 (90/100,000).
      • Howard W.T.
      Public Health Administration and the Natural History of Disease in Baltimore, Maryland, 1797-1920.
      This trend of declining infant mortality rates has continued in more modern times (see Figure 2-5 in the previous article, “The Health Revolution: Medical and Socioeconomic Advances”).
      Figure thumbnail gr13
      Figure 3-13Changes in Infant Mortality: U.S. F. E. Linder and R. D. Grove, Vital Statistics Rates in the United States, 1900-1940 (Washington, D.C.: Bureau of the Census, Department of Commerce, 1943). Massachusetts U.S. Bureau of the Census, Historical Statistics of the United States, Colonial Times to 1970, Bicentennial Edition, Part 1 (Washington, D.C.: Bureau of the Census, Department of Commerce, 1975). Illinois I. D. Rawlings, The Rise and Fall of Disease in Illinois (Springfield, MA: State Department of Public Health, 1927). Newark, NJ S. Galishoff, Safeguarding the Public Health: Newark, 1895-1918 (Westport, CT: Greenwood Press, 1975).
      Figures 3-14 a, b, and c illustrate the trends for the leading causes of infant mortality by comparing 1916, 1940, and 1998. Diarrhea and related diseases were the number-one killer in 1916. Six of the top causes of infant deaths were infectious diseases. Even as late as the 1940s, six of the top-ten causes of infant death (which included diarrhea) were of an infectious nature, whereas by 1998 mortalities due to infectious diseases were only two of the top-ten causes (in addition to having much lower rates compared to 1916 and 1940).
      Figure thumbnail gr14
      Figure 3-14Top Ten Causes of U.S. Infant Mortality, 1916,1940,1998. 1916 and 1940 data: F. E. Linder and R. D. Grove, Vital Statistics Rates in the United States 1900-1940 (Washington, D.C.: Bureau of the Census, Department of Commerce, 1943). 1998 data: U.S. Census Bureau, Statistical Abstract of the United States, 2001, revised on June 4, 2002, http://www.census.gov/prod/2002pubs/01statab/vitstat.pdf.
      Nutrition, pasteurization, and personal hygiene all played important roles in improving the health of infants and children. In fact, the dramatic decrease in infant mortality in the U.S. from about 150–250 per 1,000 live births prior to 1890 to about 70 per 1,000 live births in 1930 can be attributed mainly to the decline of diarrheal diseases that are prevented by proper nutrition, milk pasteurization, and personal hygiene. However, discussion is needed about the degree of impact that nutrition and pasteurization had on infant mortality and health improvement in general.
      Figure thumbnail fx7
      Children at lunch. (Reprinted with permission of NYC municipal Archives.)
      Nutrition, pasteurization, and personal hygiene all played important roles in improving the health of infants and children.

      The Role of Nutrition

      Nutritional improvements have been cited by Thomas McKeown as major factors contributing to the decline of infant mortality. However, he reached this conclusion by deductive reasoning rather than direct evidence.
      • McKeown T.
      The Role of Medicine: Dream, Mirage, or Nemesis?.
      His hypothesis might account for the general decline of infant mortality through the 1800s, but he didn't provide data to account for the sharp decline in infant mortality between 1890 to 1915.

      The Role of Pasteurization

      The role of pasteurization, on the other hand, is a public health classic. Mazÿck Ravenel describes its role. Pasteurization benefits are much more plausible than “nutrition.” Also, pasteurization was introduced closer in time to the decline in mortality at the turn of the century. However, pasteurization wasn't generally introduced into the U.S. until the early 1900s, and it wasn't really accepted until a few years later.
      • McKeown T.
      The Role of Medicine: Dream, Mirage, or Nemesis?.
      The few available data on milk consumption suggest that 1910 to 1920 was the earliest time period with sufficient consumption of pasteurized milk to have a noticeable impact on the infant mortality rate.
      • Galishoff S.
      Safeguarding the Public Health in Newark, 1895-1918.
      Thus, pasteurization and nutrition cannot account entirely for the marked infant mortality decline between 1890 to 1910.

      The Role of Personal Hygiene

      As mentioned earlier, the steep decline in infant mortality began in 1890, a period in which neither nutrition or pasteurization would be expected to account for it. Considering data from the states of Massachusetts and Illinois, as well as areas within the City of Newark, New Jersey, declines of about 20 to 60% occurred by 1910 (Figure 3-13). Personal hygiene changes are a reasonable explanation, as indicated by the rapid growth in soap production in this time period (Figure 3-9). Handwashing and bathing decrease the potential transmission to infants of diarrhea agents, which can liberally contaminate the skin of people who don't wash their hands after defecation.
      These declines have continued, as illustrated by infant mortality rates in Massachusetts prior to 1890 compared to today in the U.S. as a whole (see Figure 2-5 in the previous article). In the mid-1800s, 130 to 170 babies out of every 1,000 died in the first year of life. Today, that loss has been reduced more than 25 fold!
      These data are an indication that hygiene may have played a role in the decline in death rates and disease prevention during this time period.

      The Interrelationship Between Health and Hygiene Around the World: The Case of Infant Mortality

      Another way to analyze the relationship between personal hygiene and health is to examine geographical data. If we can show a correlation between hygiene practice and health status among populations in different countries and climates, who have different social systems and diets, and even do so over time, we can help strengthen the link between hygiene and health. Moreover, we will further support this endeavor by showing that the same personal hygiene habits are associated with the same disease problems in all of these areas.
      In each country, health determinants—genetics, environment, diet, lifestyle, and politics—are unique and combine to show various health outcomes. Thus, any common thread (e.g., soap and detergent use) if measured in each country, would require controlling for the various baseline risk factors specific to each country. At the very least, it' s possible to study areas where the infant mortality is either lower, higher, or equal to that experienced in 19th-century America. Then the hypothesis that soap use and personal hygiene are associated with beneficial health outcomes can be tested.
      Examples relating soap and washing powder consumption around the world to infant mortality rates are presented in Figures 3-15 a and b, which demonstrate a relationship between increased consumption of these products and lower infant mortality rates. Figure 3-15a represents an attempt to correlate soap and washing powder consumption in 1971-73 and infant mortality rates in 1970 for 36 countries for which these data are available. Figure 3-15b shows the same relationship for 35 countries in 1990 where similar data are available. Interestingly, historical data for the period 1832-1854 in England and Wales on infant mortality in comparison to soap production fit in well with the multinational data from the 1970s and 1990s (Figures 3-15a and b).
      Figure thumbnail gr15
      Figure 3-15aRelationship of Soap and Washing Powder Consumption to Infant Mortality Rates, 1970. Soap and washing powder data: United Nations, World Industry Since 1960: Progress and Prospects (New York: UN Industrial Development Organization, 1979). Population data for 1970: United Nations, World Industry Since 1960: Progress and Prospects (New York: UN Industrial Development Organization, 1979). Infant mortality: UNICEF, www.childinfo.org/areas/childmortality/infantdata.php. England/Wales: B. R. Mitchell, Abstract of British Historical Statistics (Cambridge, MA: Cambridge University Press, 1962). Figure 3-15b. Relationship of Soap and Washing Products Consumption to Infant Mortality, 1990. Soap and washing powder data: United Nations, 1997 Industrial Commodity Statistics Yearbook: Production Statistics (1988-1997), Department of Economic and Social Affairs, Statistics Division, (New York: United Nations, 1999). Population data for 1990: United Nations, World Population Prospects: Population Database, esa.un.org/unpp/. Infant mortality: UNICEF www.childinfo.org/areas/childmortality/infantdata.php. England/Wales: B. R. Mitchell, Abstract of British Historical Statistics (Cambridge, MA: Cambridge University Press, 1962).
      Another way to look at these types of data is to examine relationships that exist between infant mortality and soap and detergent consumption spanning a wide time period within a single geography. Figures 3-16a and 3-16b show such a relationship in data from Canada, Japan, and India.
      Figure thumbnail gr16
      Figure 3-16aRelationship Between Soap and Detergent Shipments and Infant Mortality, Canada, 1927-1974 F. H. Leacy, ed., Historical Statistics of Canada, 2nd ed. (Ottawa: Statistics Canada, 1983). Figure 3-16b. Relationship Between Soap and Detergent Consumption and Infant Mortality, Japan and India:. Japan Source of bath and hand production: Japan Soap and Detergent Association, 2001. Source of population data: Ministry of Health, Labour, and Welfare (Japan), www.mhlw.go.jp/english/database/db-hw/populate/popl.html, accessed February 18, 2003. India Source of detergent and toilet soap/bath consumption: Indian Soap and Toiletries Makers' Association, 2001. Source of population data: www.library.uu.nl/wesp/populstat/populframe.html, accessed February 18, 2003. Infant mortality data: U.S. Bureau of Census, International Database, http://www.census.gov.
      These are rudimentary correlations that must be interpreted with great caution; but the fact that any relationship at all exists between infant mortality decreases and increasing shipment or production of soaps and detergents across geographies in the same time period, across time in the same geography, and even across time and geographies is encouraging.
      In societies where the bathing and laundering practices are well established, many of the infectious illnesses related to inadequate hygiene are under control. In certain at-risk groups, such as the immunocompromised, and in lesser-developed countries where environmental and personal hygiene measures are economically out of reach, the diseases are still very prevalent. Furthermore, though differences in the extent of other advances, such as nutrition and milk pasteurization, can be temporally related to some of these diseases, those advances alone probably don't explain the dramatic differences in mortality and morbidity witnessed among the geographic regions in question.

      Other Associations Between Hygiene and Disease

      Similar associations can also be documented between historical changes in cleanliness and declines in other diseases, such as typhus and trachoma, though the data for these conditions are more fragmentary. Improved levels of personal and environmental hygiene, particularly hand hygiene and laundering, and to a lesser extent dishwashing, cleaning, and disinfection of hard surfaces, would lower the chance of spread of these diseases. For example, in the U.S. there have been no major epidemics of typhus since 1893—the last small outbreak occurred in 1921. Trachoma was a troublesome problem to public health officials between 1890 and 1915 among the immigrant populations and the coal miners of Appalachia. In some counties of Tennessee, West Virginia, and Kentucky, the incidence rate was 10 to 15% of all persons examined. The condition was brought under control by classical public health strategies: exclusion of infected children from school, personal hygiene instruction by public health nurses, educational programs, sanitation, and hospitalization where necessary.
      • Bailey C.A.
      Trachoma in East Tennessee and Northern Georgia.
      • Clark T.
      Trachoma in Virginia and West Virginia.
      • McMullen J.
      Trachoma in Eastern Kentucky.
      • Oakley J.H.
      • Moore D.
      • Kolb L.
      Trachoma in Kentucky.
      In endemic areas, mass treatment campaigns with antibiotics reduce frequency. However, without improvement of general sanitary conditions, reinfection occurs and the disease regains its original high levels of frequency.

      Evidence of Links Between Hygiene and Health

      We've looked at trends and data that show the link between hygiene and health, but now current epidemiological evidence supports this link from a critical evaluation of 30 interventional studies and 24 observational studies.
      • Aiello A.E.
      • Larson E.
      What Is the Evidence for a Causal Link Between Hygiene and Infections?.
      As mentioned earlier, an interventional study is one in which a study investigator imposes an intervention and observes changes in disease incidence. Intervention studies can be conducted on the same group of people, where disease incidence is compared before and after the intervention. Or, disease incidence can be compared among groups of people who are randomized to either the intervention method or no change in practices. In an observational study, groups of people are observed or questioned concerning practices or exposures (i.e., without an imposed intervention) and assessed for subsequent changes in disease incidence.
      Despite methodological strengths and limitations, the weight of evidence from the studies collectively indicate a significant reduction in infectious illness attributed to changes in hygiene practices or behaviors. The reduction in infections was appreciable and generally greater than 20%. Most of the observational studies reported a strong association between risk factors related to inadequate hygiene and infection. The consistent findings in both the intervention and observational studies support the conclusion that hygiene interventions other than infrastructure implementation are important for preventing infections.
      While these results may not be surprising or “new,” they are nevertheless important because they demonstrate that even in an era of unprecedented cleanliness and improved public health infrastructure, there's a continued, measurable, positive effect of personal and community hygiene. However, attributing a specific hygiene intervention to a reduction in illness is difficult since it' s virtually impossible to isolate the effects of specific hygiene measures. Therefore, the magnitude of reduction in illnesses attributed to a specific intervention or practice alone cannot be assessed through these studies. Other studies can be consulted for evidence for a causal link between hand hygiene and infections.
      • Bryan J.L.
      • Cohran J.
      • Larson E.
      “Handwashing: A Ritual Revisited,”.
      • Larson E.
      Skin Hygiene and Infection Prevention: More of the Same or Different Approaches?.
      • Larson E.
      Hygiene of the Skin: When Is Clean too Clean?.
      Personal Hygiene and Its Impact on Typhoid
      As far as back as 1890, personal hygiene could be seen playing a positive role in the prevention of typhoid fever in nurses and among females in other occupations in the U.S. In an obscure table from the 1890 U.S. census, a statistician summarized the proportions of deaths due to typhoid fever.
      Proportion of deaths due to typhoid fever per 1,000 deaths from all causes (Females, 1890)

      Government Printing Office, Compendium of Eleventh Census:1890, Washington, 1895, as cited in: V.W. Greene, Cleanliness and the Health Revolution, The Soap and Detergent Association, 1984.

      Tabled 1
      Laundresses32.18
      Nurses44.57
      Servants48.50
      All Occupations51.48
      Milliners, Dressmakers69.43
      Teachers72.89
      Mill and Factory Operators87.89
      From this table, one could speculate:
      • Nurses didn't succumb to typhoid fever because of sanitary training.
      • Servants weren't susceptible because they worked for employers who compelled them to practice personal hygiene.
      • Laundresses were lowest on the list because their hands were always immersed in hot, soapy water!

      Bringing Back Infection

      Just as personal and environmental sanitation practices improve mortality and reduce morbidity rates, the reverse is also true—as hygiene practices become worse, health declines. During wars and the resultant formation of large groups of individuals living in displaced refugee conditions, hygienic facilities and practices become disrupted, generating epidemics and the rapid spread of infectious diseases. The Polish ghettos, which were established in 1940 as a consequence of World War II, clearly illustrate this fact.
      One-and-a-quarter-million persons lived in the most unsanitary conditions. They inhabited dwellings without heat, water, or plumbing; lacked soap, disinfecting materials, drugs, linens, shoes, and clothing; had a scarcity of hospitals, bathing establishments, laundries, and a greatly depleted number of physicians and medical personnel. From an average of 10 per 1,000 in the immediate prewar years, the Jewish mortality rate rose to 137/1,000 in September 1941! Many people died from starvation, violence, tuberculosis, pneumonia, and typhoid.

      J. Apenszlak, ed., The Black Book of Polish Jewry (American Federation for Polish Jews, Inc., 1943).

      As an example of the role of disease, Figure 3-17 illustrates the return of typhus fever in Warsaw after almost two decades of decline.
      Figure thumbnail gr17
      Figure 3-17The Return of Typhus Fever J. Apenszlak, ed., The Black Book of Polish Jewry, American Federation for Polish Jews, Inc., 1943.
      It' s widely recognized from more recent events that wars and conditions in refugee camps, during which hygienic facilities and practices become disrupted, inevitably generate epidemics and the rapid spread of infectious diseases.
      • Peterson E.A.
      • Roberts L.
      • Toole M.J.
      • Peterson D.E.
      The Effect of Soap Distribution on Diarrhoea: Nyamithuthu Refugee Camp.
      • Rudland S.
      • Little M.
      • Kemp P.
      • Miller A.
      • Hodge J.
      The Enemy Within: Diarrheal Rates Among British and Australian Troops in Iraq.
      • Kalipeni E.
      • Oppong J.
      The Refugee Crisis in Africa and Implications for Health and Disease: A Political Ecology Approach.
      • Dodge C.P.
      Health Implications of War in Uganda and Sudan.
      • Diaz T.
      • Achi R.
      Infectious Diseases in a Nicaraguan Refugee Camp in Costa Rica.
      • Cavallo J.D.
      • Niel L.
      • Talarmin A.
      • Dubrous P.
      Antibiotic Sensitivity to Epidemic Strains of Vibrio cholerae and Shigella dysenteriae Type 1 Isolated in Rwandan Refugee Camps in Zaire.

      Conclusions

      When it comes to health, we are clearly better off today than in those imaginary “good old days.” Every possible indicator used to measure health verifies this. For example, we live longer today, get sick less often, have healthier children with a better chance to survive to old age, eat better, and are even physically stronger than any other generation that left a documentable history behind.
      Clearly, the health revolution has had a dramatic impact on our lives. For example, Figure 3-18 shows that the total mortality experience for children in the U.S. decreased by 22-fold between 1900 and 1998.
      Figure thumbnail gr18
      Figure 3-18Age-Specific Mortality Rates, U.S. National Center for Health Statistics, United States, 2003; F. Linder and R. D. Grove, Vital Statistics Rates in the U.S. 1900-1940 (Washington, D.C.: U.S. Government Printing Office, 1947).
      And it's getting better every day. For nearly the last 100 years, the prospects for living for every age group, including infants, toddlers, young adults, the middle aged, and senior citizens, have improved in the U.S.
      However, while improvements continued in many other countries around the world in the latter part of the 20th century, there are still regions of the world where significant improvements can be made (Figure 3-19).
      Figure thumbnail gr19
      Figure 3-19Infant Mortality by Region UNICEF Statistics for Child Mortality: http://www.childinfo.org/cmr/revis/db1.htm, accessed March 30, 2003.
      The World Health Organization reported that for 2000, 3.1% of deaths (1.7 million) around the world were due to unsafe water, sanitation, and hygiene. Combining the years of life lost due to premature mortality and years lost due to disability—a statistic referred to as “disability-adjusted life years” (DALY)—these risk factors accounted for 3.7% of worldwide DALYs, or 54.2 million DALYs.
      World Health Organization
      “Reducing Risks, Promoting Healthy Life,” in World Health Report.
      Thus, improvement in these risk factors could protect millions of years of healthy, productive lives.
      By every criterion that we choose to measure community health status—infant mortality, general mortality, age-adjusted mortality, life expectancy, epidemics, or endemic disease incidence—we can demonstrate the impact of the health revolution in numerous societies that kept health records.
      Numerous factors on multiple levels determine the health status of a population. Intervention on one or more of these levels may affect community health. For example, it may be possible to modify determinants, such as host susceptibility, environment, lifestyle, socioeconomic status, and availability or accessibility of personal and community health services.
      During the last century in the U.S. and Western Europe, the following profound changes occurred in all of these determinants:
      • 1.
        Sanitary engineers cleaned up the water supply, drained the swamps, improved refuse disposal, and built sewage-disposal systems (i.e., they changed the environment).
      • 2.
        The discoveries of the epidemiologists and the bacteriologists provided a scientific basis for disease prevention and treatment using vaccines and antibiotics (i.e., they changed host susceptibility).
      • 3.
        Governments became involved in the training and licensing of health-care professionals and hospitals (i.e., they changed availability and accessibility of personal and community health services). Health departments with police and taxation powers were organized. Health services became available to people as a right rather than a charity.
      • 4.
        There was a revolution in personal hygiene practices (i.e., changes in lifestyle). Soap consumption increased, public bathhouses and laundry facilities were made available, and houses and tenements were provided with running water, sinks, bathtubs, and toilets.
      • 5.
        Economies began an upward trend in prosperity that followed industrialization (i.e., changes in socioeconomic status).
      Historical and epidemiologic trends in personal hygiene and community health were reviewed in this chapter. Such personal hygiene practices as bathing and laundering gradually became popular among the masses in Europe and the U.S. in the few decades before the turn of the 20th century and became an established social-behavior feature of the U.S. and England during the quarter century 1890-1915. This sociocultural modification was temporally correlated with declines in infant diarrhea—the leading cause of infant mortality during those years, as well as such diseases as typhus and trachoma.
      In some societies where social, economic, and public health infrastructure has aided creating an environment where high levels of hygiene products and education are widely available, many of the infectious illnesses related to inadequate hygiene are under control, although these diseases are still prevalent in certain risk groups. Furthermore, although several other advances, such as milk pasteurization and improved nutrition, can be etiologically and temporally related to some of these diseases, the causal evidence (e.g., temporal sequence, consistency, biologic plausibility) is consistent with the hypothesis that personal hygiene is one other factor that helped to determine the decline. This may be one of the more silent victories of public health and continues to be an important disease prevention strategy, even in this “modern” era when the “gospel of germs” has waned in popularity.
      • Tomes N.
      The Making of a Germ Panic, Then and Now.
      Our new health challenges are highlighted in Figure 3-20 , which lists the leading causes of death across all ages in the U.S. in 1900 and 1998. Figure 3-20 illustrates the phenomenon that we are all too familiar with today—the prominent rise of chronic diseases.
      Figure thumbnail gr20
      Figure 3-20Leading Causes of Death, U.S., 1900,1998 National Center for Health Statistics, Centers for Disease Control and Prevention. Leading Causes of Death, 1900-1998; www.cdc.gov/nchs/data/dvs/lead1900_98.pdf, accessed August 2001.
      Consequently, we're dealing with two sides of the same coin. A major reason for the lack of chronic diseases in the past is simply that very few people lived long enough to incubate illnesses that take decades to manifest themselves. If you die at age 40 from tuberculosis, your coronary arteries don't have time to become clogged with atherosclerotic plaques.
      This doesn't mean we should tolerate our current health problems as a “new fate,” but we must continue the health revolution and solve the chronic diseases like our predecessors solved the infectious ones. At the same time, we must prevent the “good old days” from returning in places where they are a distant past. Even as we learn how to prevent and treat heart disease, cancer, and stroke, we can't presume that our current freedom from plague and pestilence is assured. We didn't get where we are without some effort, and new and reemerging infections are always present. In fact, numerous new and emerging infections have been identified in the last two decades, such as Ebola virus, west nile virus, hanta virus, and human immunodeficiency virus (HIV).
      As demonstrated in the preceding sections, hygiene improvements at the individual and community levels, such as sanitary living conditions and practices and potable water and sewage facilities, have played a major role in reducing morbidity and mortality from infections, particularly those transmitted by the fecal-oral and direct contact routes. However, even in developed countries where there's access to improved water supply and sanitation, such infections continue to be a problem, especially in high-risk settings in which susceptible individuals gather, such as child-care and elder-care centers. In developing countries, infections carry an even greater burden of morbidity and mortality, especially in areas where public health infrastructure and medical care are inadequate or unavailable. At the beginning of 2000, approximately one billion individuals globally lacked adequate water supply and more than two billion lacked access to adequate sanitation. The majority of people that don't have access to these basic infrastructures live in developing countries.

      World Health Organization and United Nations Children's Fund, Assessment Report: Global Water Supply and Sanitation, 2000 (www.who.int/water_sanitation_health/monitoring/jmp2000.pdf).

      The Global Water Supply and Sanitation Assessment 2000 Report provided by the World Health Organization lists the following three key hygiene behaviors that are of the greatest likely benefit to health, particularly in developing countries:

      World Health Organization and United Nations Children's Fund, Assessment Report: Global Water Supply and Sanitation, 2000 (www.who.int/water_sanitation_health/monitoring/jmp2000.pdf).

      • 1.
        Handwashing with soap (or ash or other aid)
      • 2.
        Safe disposal of children's feces
      • 3.
        Safe water handling and storage
      In the next article, we will explore personal hygiene and household cleaning practices today, along with their impact on public health.

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