America’s First Great Epidemics From Lead in Water Pipes

tags: Flint, Lead contamination

Karen Clay is an Associate Professor of Economics and Public Policy at Carnegie Mellon University and a Research Associate at the NBER. She is the author of The Evolution of a Nation: How Geography and Law Shaped the American States with Daniel Berkowitz (Princeton University Press 2012). Werner Troesken is a professor of economics at the University of Pittsburgh and faculty research associate at the National Bureau of Economic Research (NBER). He has been a National Fellow at the Hoover Institution and a Julian Simon Fellow at the Property and Environment Research Center in Bozeman, Montana. His books include Water, Race, and Disease (MIT Press, 2004); The Great Lead Water Pipe Disaster (MIT Press, 2006).

During the 1890s and early 1900s, epidemics of water-related lead poisoning occurred all across the United States and Europe. Looking at how and why they happened, how they were handled, and what their effects might have been provides an important backdrop for understanding the recent events in Flint.

One of the worst cases happened in Lowell, Massachusetts, after officials switched from one source of water to another that was even more corrosive. Within a few years, hundreds of Lowell residents who were drinking this water began to exhibit the unmistakable signs recognized in this era as lead poisoning, such as wrist drop and a blue gum line. In one fatal case, the poisoned individual had been drinking tap water that contained lead levels 1,300 times greater than the current EPA standard for more than two years. In England, not just the introduction of water from new sources but acid rain from industrialization and coal consumption helped draw lead into the water, causing further outbreaks.1

Lowell was not an isolated event in this time, just as water-related lead poisoning in Flint, Michigan and Washington, D.C. are not unique today. Lead service pipes, the pipes linking street mains to homes and buildings, were pervasive. Of the 50 largest cities in the United States in 1900, all but six or seven employed lead piping to some degree; it could be mandated by local building codes. Why? Though lead was not cheap, engineers chose it because it was durable, and in comparison to iron, less vulnerable to corrosion. They were right: most of those lead pipes in use in 1900 are still in use today. And they were right in another way, as well: only when water supplies became highly acidic or alkaline did lead levels in the water really surge.2

Historically, engineers did not fully understand this and so simply pointed to the experience of other cities where “lead pipes have been used safely … for years.”3 Given that, the logic seemed clear: “Lead pipes can be used safely here as well.” But a city with a chemically neutral water supply, which was the assumed baseline, provided a misleading indicator of safety for a city whose supply was highly acidic or alkaline. Moreover, into the early twentieth century, few cities regularly monitored their water supplies for undue lead levels, so problems only came to be discovered upon sudden mass outbreaks of lead poisoning. Even these only included adults; this period’s experts missed entirely the serious and long-term damage done to children. As a result, one of us has documented cities in the United States and England whose tap water, though with lead levels 10 to 800 times the modern EPA standard, was considered safe by observers at the time.4

A small but growing group of economic historians have begun to study and quantify the effects of water-related lead exposure on a variety of outcomes in this period, including crime, infant mortality, educational attainment, intelligence, and long-term labor market outcomes.5 The results of this research are startling. They suggest the use of lead pipes in areas with highly acidic water supplies increased infant mortality by 10 to 25 percent, and in some Massachusetts cities with unusually corrosive supplies, by a factor of three or four.6 Children who grew up in areas with corrosive water supplies and lead service pipes earned a lower wage later in life, had lower educational attainment, scored lower on military intelligence exams, were less likely to own a home in mid-life, and were less mobile.7 The effects were especially pronounced among lower socioeconomic groups.8Effects this large might, at first glance, seem implausible. But if one considers what just how much lead was leaching into so many water supplies throughout the early decades of the twentieth century, then these consequences look far more tenable.

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