The Great Lead Water Pipe Disaster

Published by EH.NET (June 2007)

Werner Troesken, The Great Lead Water Pipe Disaster. Cambridge, MA: MIT Press, 2006. x + 318 pp. $30 (cloth), ISBN: 978-0-262-20167-4.

Reviewed for EH.NET by Robert A. Margo, Department of Economics, Boston University.

Werner Troesken (Professor of History at the University of Pittsburgh ) is the kind of scholar who makes the rest look dull and unproductive. In The Great Lead Water Pipe Disaster, his second MIT Press monograph in two years (with many journal articles in between), Troesken examines the historical origins of a serious environmental hazard ? the use of lead pipe in water delivery. Lead, not to put too fine a point on it, is bad news if ingested in sufficient quantities ? which, as these things go, is pretty minute. Unfortunately, water running through lead pipe can pick up the metal along the way. In a hazy sort of way, the hazards of lead pipe have been known for a very long time but the specific relationship between dosage and harm proved much more elusive to scientists. If this were not enough, industry self-interest obfuscated the science at crucial junctures. This is hardly a story unique to lead, as a glance at the history of environmental regulation would tell.

Following a “Prologue” that sets the stage, Great Lead is divided into eight substantive chapters, a conclusion, and three technical appendices. Chapter One begins by reminding the reader that a toxin small enough to be invisible to the naked eye might still have horrible consequences. Lead, according to Troesken, is such a toxin. Cities throughout the world in the mid-to-late nineteenth century installed lead service pipes to deliver water to the masses. Historically, lead levels in water were many orders of magnitude ? 500 times, approximately ? as large as maximum current standards as set by the U.S. Environmental Protection Agency. Troesken asks a simple question as in: “Hello? Is Anyone Home?” It is not like our ancestors, recent or otherwise, were completely ignorant of lead’s toxicity. Why did they install lead service pipes? Equally strange, why did it take so long for some cities (Cape Town, South Africa, and Glasgow, Scotland, the subject of Chapter 9, being two examples) to dismantle their lead water systems? The book makes the following arguments. First, depending on location, historical levels of lead did have serious health consequences, principally (if not exclusively) for the unborn, young children, and pregnant women. Second, the adverse effects of lead varied with the chemical characteristics of the water supply. Third, public health officials tended to judge adverse effects by looking at adults, and here the effects were confusing to discern unless lead levels were off the charts, so to speak. Fourth, lead pipes were used because they were cheap. Fifth, the legal system allocated liability to consumers, who were supposed to take care not to become sick by drinking lead-infused water ? except that consumers, according to Troesken, rarely knew enough to know what they were drinking; and when they did, often could not take appropriate preventive steps.

Chapter Two reviews the scientific literature on lead poisoning. Like most of the other chapters, it opens with an historical anecdote. Erasmus D. Fenner was a New Orleans physician who tried to marshal evidence that lead pipes were harmful in colic outbreaks in the Big Easy. He was unable to do so, according to Troesken, because he lacked a scientific model to explain his correlations. What did Fenner need to know? First, lead if ingested is more harmful in infants and children than in adults. Second, at high dosages, there are symptoms of lead poisoning that are plainly visible; but at low to moderate dosages, which cumulatively can be harmful, lead poisoning can be very difficult to detect, largely because it can produce contradictory symptoms. Third, lead is bad for one’s health because it mimics calcium and zinc in the body and can thus throw off physiological processes like nerve conduction.

Chapter Three considers just how much lead was present in municipal tap water at the turn of the twentieth century. One reference standard would be today’s EPA maximum recommended dosage; by this standard, lead levels ca. 1900 were astronomical. Another standard is the amount of lead in diachylon pills, an over-the-counter “remedy” to induce abortion. To reach the manufacturer’s recommended dosage of diachylon to achieve the intended result, a resident of Attleborough, Massachusetts ca. 1900 would only have to drink 12 ounces of tap water per day. Exactly what one should make of such a comparison is not immediately clear to me but in one of the technical appendices (see below) Troesken presents econometric evidence from turn-of-the-century Massachusetts towns positively linking water lead levels to infant mortality rates (see below). Chapter Four studies eclampsia, a convulsive disease specific to pregnancy, very dangerous to the woman and her unborn child. Historically eclampsia was a serious medical problem but only recently have medical researchers been able to show that prior exposure to lead can increase the risk of the disease. Chapter Five continues the survey of the historical evidence on lead poisoning arguing that significant fractions of the adult population ca. 1900 (10-12 percent in the case of Massachusetts) harbored unhealthy levels of lead in their bodies.

Chapters Six and Seven focus on legal matters. Chapter Six elucidates the doctrine of protective power, which held that lead water pipes were safe because the interior of the pipes developed a protective coating that prevented the lead from dissolving in the water. The doctrine, however, was faulty as a general rule. Water alkalinity and acidity are important chemical facets but even with a good deal of prior information it can be extremely difficult to predict ex ante whether lead pipes will be a problem. Chapter Seven notes that courts routinely held consumers liable for drinking lead-contaminated water even though on Coasian grounds one would suspect that water companies were the least cost suppliers of alternative piping. Troesken also claims that consumers were poorly informed about the hazards of lead in any specific case, as were plumbers, and other relevant service providers. Being well-informed might not be useful anyway because municipal governments often mandated the use of lead.

Chapter Eight examines the history of lead pipes in Glasgow, Scotland. At the start of the nineteenth century, Glasgow had a terrible water system, to put it mildly, and things only got worse as the city grew from industrialization. The city fathers eventually settled on a plan to build an aqueduct from Loch Katrine. The water from this source was exceptionally pure but also very soft. Everyone was so pleased with the new water supply that, a few lone voices aside, no one noticed (or cared) that once Katrine water hit the service pipes in Glasgow, lead levels rose to dangerous levels. Glasgow residents had to suffer until 1979 before the authorities dosed the water with lime, thereby correcting the lead problem. Glasgow, Troesken argues, is a telling counter-example to anyone who believes that municipal authorities, unlike private owners, will always internalize public health externalities associated with water delivery. Chapter Nine sums up by calling on cliometricians to focus their attention on inorganic toxins of which lead is but one, albeit telling, example.

Great Lead has a great many virtues. It is, above all, impeccably researched and exceedingly well-written. Perhaps because he has spent so much time in a history department, Troesken is acutely aware of the value of the telling anecdote in attracting readers beyond the usual suspects. The book is also a poster child for interdisciplinary research, much beloved these days by deans and provosts. In particular, Chapter Two evinces a glowing mastery of the underlying science; surely Troesken knows more about water plumbism than any other historian alive (and probably, a good many medical doctors).

I am a trifle less enthusiastic about the econometrics, the details of which are reported in the technical appendices. Consider Appendix A, which presents cross-sectional evidence linking infant mortality to lead pipe use in Massachusetts cities at the turn of the twentieth century. Troesken rightly points out that OLS is a problem because of omitted variable bias, and he corrects for this with instrumental variables. Now, as someone who spends many sleepless nights trying to come up with one usable IV I am more than mildly impressed with Troesken’s ability to generate three: a dummy for who paid for the service line (water company versus property owner), the number of water meters per one hundred miles of water mains, and a dummy for whether the local water company had been “municipalized” (switched from private to public ownership). I do not question that these instruments are relevant ? they predict lead use ? but to be valid they cannot have direct impacts on infant mortality, and this is far from obvious, particularly because the specification (p. 210) does not have a lot of control variables. Because of this I do not know whether one should place a lot of stock in the IV estimates, which are larger in magnitude but (predictably) less precise than the OLS estimates. I do not want to seem overly critical here because Troesken does include many robustness checks, and is unusually upfront in acknowledging data and other problems.

More philosophically, it is not at all clear to me why we need cliometrics linking infant mortality rates to lead pipes in the first place. That is because we know from Chapter Two’s exhaustive coverage of the relevant science that lead is harmful in dosages vastly smaller than was characteristic of turn of the century urban water systems. What if Troesken had run his regressions and found “nothing” ? either a zero coefficient or (a la the IV’s) statistical imprecision? Would we conclude that residents of Attleborough had nothing to fear from their drinking water? Not withstanding Troesken’s (somewhat far-fetched) suggestion in Chapter Two that this might have been the case (for example, if residents didn’t drink the water in sufficient quantities to cause illness), I don’t think so. This is not to say that econometrics has no place in Troesken’s “new environmental history” ? far from it. But rather than link lead pipes to infant mortality I would have liked to see a regression relating lead to wages or housing prices (more economics, in other words). In particular, if housing prices were lower (or wages higher) in cities with lead pipes this would cause me to raise my eyebrows at some of Troesken’s claims about consumer ignorance in Chapter Seven. I would have also liked to have seen an analysis linking fertility to lead pipes, a pattern that Troesken hints might be historically relevant (and to my mind rather more interesting than the link with mortality) but which is not investigated formally.

Quibbles aside, Great Lead is an excellent book, essential reading for anyone involved in demographic history, or the history of environmental regulation, water or otherwise.

Robert A. Margo is the editor of Explorations in Economic History.