Higher prior exposure to water-borne lead among male World War Two U.S. Army enlistees was associated with lower intelligence test scores. Exposure was proxied by urban residence and the water pH levels of the cities where enlistees lived in 1930. Army General Classification Test scores were six points lower (nearly 1/3 standard deviation) where pH was 6 (so the water lead concentration for a given amount of lead piping was higher) than where pH was 7 (so the concentration was lower). This difference rose with time exposed. At this time, the dangers of exposure to lead in water were not widely known and lead was ubiquitous in water systems, so these results are not likely the effect of individuals selecting into locations with different levels of exposure.
Economics and Human Biology
I12: Health Production
Q53: Air Pollution; Water Pollution; Noise; Hazardous Waste; Solid Waste; Recycling
N32: Economic History: Labor and Consumers, Demography, Education, Health, Welfare, Income, Wealth, Religion, and Philanthropy: U.S.; Canada: 1913-
N52: Economic History: Agriculture, Natural Resources, Environment, and Extractive Industries: U.S.; Canada: 1913-