The Allegheny and the Monongahela Rivers are turbid at all times, and after a rain or in the spring, so muddy that a platinum wire cannot be seen more than a quarter of an inch from the surface. In addition to this, investigations have shown that the rivers commonly carry in solution the soluble chemical products of the mills along their shores,—organic and inorganic, acid and alkali; oils, fats, and other carbon compounds; dead animals,—rats, cats and dogs; flesh-disintegrated and putrescent; as well as the offscourings of iron and steel mills, tanneries and slaughter houses, and similar industries. But this is not all. Seventy-five up-river towns,—with an estimated population of 350,000 inhabitants,—in the Allegheny or tributary valleys; and in the Monongahela a long string of towns, Swissvale, Homestead, Braddock, Rankin and McKeesport, all furnish their supply of common sewage as a further contamination of the already dirty water with its long list of disease-breeding bacteria.
These conditions have existed since Pittsburgh came into prominence as an industrial center. Typhoid has been endemic. The duration of this "plague" in Pittsburgh, unbelievable though its sufferance may appear in view of the facts already given, is a matter of history and record. For thirty-five years, up to the beginning of 1908, the city was in the grip of a scourge which has been in the words of the most recent treatise on typhoid[10], "one of the black records in the sanitary history of our country." Here and there clamorous, indignant voices were raised against it; but public sentiment had become so callous that it only spasmodically and halfheartedly demanded the carrying into operation of a tardy system of filtration. In the meantime, those who could not afford to buy distilled or spring water, continued to drink this filth.
[10] Whipple, Typhoid Fever, p. 158.
With what result? For the last twenty-five years, an average death rate of 102.3 per 100,000 population; since 1889 never below 107; for the last nine years an average of 130; and last year, the year of the completion of Pittsburgh's filtration plant, 131.5 deaths and 1,115 cases for every 100,000 inhabitants. A black record this, in the face of uncontrovertible evidence from other cities, both in this country and abroad, that the purification of the water supply should blot out at least seven-ninths of the typhoid fever. In contrast with Pittsburgh's high mortality, the average for other large American and European cities since 1898 may be seen from the following list:
| Pittsburgh | 130.0 |
| Allegheny | 104.4 |
| Washington | 59.0 |
| Philadelphia | 54.7 |
| Baltimore | 35.3 |
| San Francisco | 30.5 |
| St. Louis | 30.3 |
| Chicago | 27.3 |
| Boston | 24.5 |
| New York | 18.2 |
| Paris | 17.4 |
| London | 11.7 |
| Vienna | 5.2 |
| Berlin | 4.2 |
The very even distribution of typhoid in Pittsburgh,—another indication pointing to infected water as the chief cause,—is seen in the map on page [927], on which each dot represents a case of typhoid within the year,—July 1, 1907, to June 30, 1908, the period covered by the main part of this study.
The second map shows the relative mortality, by wards, for the same period.
The following chart shows the relative rise and fall from year to year in cases and deaths during the past twenty-five years, and is based on estimates of population provided by the United States Census Bureau. The morbidity figures are taken from the United States census prior to 1901, and from the Pittsburgh Bureau of Health records following that year.