Lead is still present in drinking water in many communities, where it can leach from lead pipes in homes, apartment buildings and municipal water system, or from brass fittings or solder used in plumbing. Another 25,000 to 30,000 tons of lead enters the U.S. environment each year from hunting and shooting-range ammunition, fishing-line weights, discarded batteries and electronic waste, said Mark Pokras at Tufts University.
Coal-burning power plants in developed nations also generate some lead in emissions and more so in ash, and the steep rise in coal power in China has boosted levels worldwide because regulations are more lax. Larger lead particles fall to the ground within about 200 meters of the source (including tailpipes, by the way), but the smaller particles, about 0.5 micron in size, can remain airborne for a week before they settle out. According to Flegal, lead particles from China have been found in rainfall in Santa Cruz, Calif.
Many steps can be taken nationwide to further reduce lead levels. Tougher emissions laws can be imposed. Lead paint, still sold in China, for example, can be banned in that country, or for import by other countries. Lead pipes and old lead paint can be removed. A high tax could be imposed on products containing lead, and lead in ammunition and fishing weights could be replaced with substitutes—although materials such as tungsten have not performed well in bullets. A different view about prevention is needed, too. For years, U.S. regulators have focused primarily on reducing lead poisoning, and they have succeeded. “So now we have to stop thinking about the problem as a small number of people who have an acute exposure, and start thinking about the problem as a large number of people who have a chronic exposure,” Schwartz said.
Cost analyses might help push regulators into action, Reyes said. “Perhaps we will find that an X-amount of reduction in lead exposure equates with an X-amount of rise in test scores” [which has been shown in Massachusetts], she said. “Or perhaps we will find that a certain amount of reduction equates with a certain reduction in health-care costs.”