Getting the Lead Out: A Career-Long Perspective onLeaded Gasoline, Dust, Soil, and Proactive Pediatric Exposure Prevention

Howard W. Mielke, Ph.D. Affiliation, Department of Pharmacology,
Tulane University School of Medicine, New Orleans, LA, USA
Sara Perl Egendorf, Ph.D., Researcher, NYC Compost Project Hosted
by Earth Matter, New York, NY
“The right to search for truth implies also a duty; one must not conceal
any part of what one has recognized to be true.” Albert Einstein.
Engraved on a bench at the Albert Einstein Memorial, National
Academy of Sciences, Washington, DC.

This commentary considers the long arc of lead (Pb) poisoning from
antiquity to the 21st century. While Pb exposure is commonly
attributed to paint or water, this article aims to discuss the
underrecognized impacts of air Pb and soil Pb and to address
controversial misconceptions related to these exposure sources. The
Roman Aristocracy experienced lead poisoning mainly from the
ingestion of foods, lead cookware, and lead-contaminated water and
wine, but by the 20th century, lead exposure occurred by ingestion
and inhalation. The introduction of tetraethyl lead (TEL) additives in
gasoline was approved in 1925 in the US and produced an
exponential increase in inhalable air lead exhaust particles through
the 1970s. These five decades of widespread lead aerosol exposure
were enabled by the Lead Industries Association (LIA), which
confounded pediatricians, healthcare providers, and government
agencies by promoting lead-based paint as the primary agent of
childhood lead exposure. Empirical evidence of lead poisoning,
environmental exposures, and proactive lead prevention in the
general population was impossible until analytical instruments became
commonly available for clinical studies and environmental
measurements in the 1960s and 1970s. Soil studies in Baltimore,
Maryland, beginning in the mid-1970s, indicated that lead particles
exhausted from vehicles fueled by leaded gasoline excessively
contaminated urban soils compared with non-urban soils. The invisible
lead-contaminated air fouled multiple exposure routes via inhalation
and ingestion. In addition to misunderstandings about sources of lead
exposure, misinformation currently abounds regarding the timeline of
banning lead in gasoline. The US Center for Disease Control (CDC)
lists the ban as beginning in 1996. The banning of leaded gasoline
first occurred in Japan starting in 1972, and after a 1984 Senate
Hearing, the US Congress agreed on a rapid phasedown. A US
Environmental Protection Agency (EPA) timeline confirmed that most
leaded gasoline was banned by the end of 1986. Banning leaded
gasoline was associated with sharp declines in the US population’s
blood lead, which prompted global efforts to ban leaded gasoline.
The eventual result was a complete global ban on highway use of
leaded gasoline achieved in August 2021. Leaded gasoline is still
used in piston-engine aircraft and the US EPA is proceeding to
complete the ban on lead additives in fuel. Using precautionary
principles to recover lead-contaminated urban environments and
prevent new toxicant exposures are essential challenges and
opportunities for present and future generations.