Positive outcomes from U.S. lead regulations, continued challenges, and
lessons learned for regulating emerging contaminants
Abstract
Albeit slow and not without its challenges, lead (Pb) emissions and
sources in the United States (U.S.) have decreased immensely over the
past several decades. Despite the prevalence of childhood Pb poisoning
throughout the 20th century, most U.S. children born in the last two
decades are significantly better off than their predecessors in regards
to Pb exposure. However, this is not equal across demographic groups and
challenges remain. Modern atmospheric emissions of Pb in the U.S. are
nearly negligible since the banning of leaded gasoline in vehicles and
regulatory controls on Pb smelting plants and refineries. This is
evident in the rapid decrease of atmospheric Pb concentrations across
the U.S over the last four decades. One of the most significant
remaining contributors to air Pb is aviation gasoline (avgas), which is
minor compared to former Pb emissions. However, continual exposure risks
to Pb exist in older homes and urban centers, where leaded paint and/or
historically contaminated soils+dusts can still harm children. Thus,
while effective in eliminating nearly all primary sources of Pb in the
environment, the slow rate of U.S. Pb regulation has led to legacy,
secondary sources of Pb in the environment. More proactive planning,
communication, and research of commonly used emerging contaminants of
concern that can persist in the environment long after their initial use
(i.e., PFAS) should be prioritized so that the same mistakes are not
made again.