Howard Mielke is a toxicologist at the Medical School of Tulane University in New Orleans. He described March 21, 2017 as “a sad day for the children of the U.S.” in response to news that the Environmental Protection Agency (EPA) plans to eliminate two programs that protect children from exposure to lead in paint. One program supports public education on risks of lead-based paint and trains contractors to do remodeling projects without releasing lead into the atmosphere from old paint; the second provides grants to states and Indian tribes to deal with these risks in their jurisdictions. These programs currently cost $16 million and have 73 full-time employees.
Tools for Critical Thinking in Biology is about various kinds of evidence that scientists use to answer questions and test hypotheses. Evidence can take many forms, from systematic observations to results of experiments to comparisons and correlations. Some questions that scientists ask have implications for public policy, including questions about the effects of lead exposure on health. In Chapter 5, I use two main questions to illustrate the possibilities and pitfalls of inferring causation from comparisons and correlations: Do cell phones cause brain cancer? Does lead exposure in childhood make individuals more likely to commit crimes later in life? In the first case, a correlation between cell phone use and brain cancer is not convincing evidence that cell phone use causes brain cancer (see my book for an explanation). In the second case, scientists have found a host of correlations between lead exposure and rates of violent crime about 20 years later: in different countries of the world, different states and cities of the U.S., and different neighborhoods of New Orleans. Together with detailed studies of the impact of lead exposure on brain development, these correlations imply that early exposure to lead has adverse, longterm consequences for the health of children. In particular, children exposed to lead in childhood have lower IQs, a greater risk of attention deficit / hyperactivity disorder and other behavioral problems, and a greater likelihood of being arrested for violent crimes later in life.
Children in the U.S. have been exposed to lead from two main sources: paint and gasoline. Use of lead in gasoline was phased out in the 1970s. Lead-based paint was outlawed for residential use in 1978, although its use had declined substantially after a peak in the 1920s. Nevertheless, many older homes in poor neighborhoods of cities have flaking and chipping paint containing lead. This is why the EPA has supported the removal of paint from older homes in a careful process that doesn’t produce lead-filled dust that can be inhaled by children, as well as adults and pets.
President Trump released a budget on March 15, 2017 that proposed cuts across the government with the exception of the departments of Defense, Homeland Security, and Veterans Affairs. The EPA was targeted for the largest percentage cut of 31.4%, for a total decrease of $2.6 billion. In this context, elimination of two programs to protect children from exposure to lead-based paint seems like small potatoes: $16 million is less than 1% of the total cut proposed for the EPA budget. Trump’s plans will harm the environment in many ways, but this small part of his plans seems particularly petty and mean-spirited. The evidence is strong that lead exposure is harmful to kids and society; this has been recognized for a long time and led to elimination of lead from paint and gasoline 40 years ago; the cost to continue remediation efforts is minuscule. Perhaps Congress will recognize these facts and reject this and other parts of Trump’s agenda that adversely affect the environment and human health.