Exposure from Food
By Michael Kashtock, Ph.D.
Edited by Sebastian Cianci
The U.S. Food and Drug Administration (FDA) has sought to limit or ban the presence of lead in food at various
points in history dating back to the pas-
sage of the Federal Food, Drug, and
Cosmetic Act (“the Act”) in 1906. In the
100-plus years since the Act was signed into law, great progress has
been made in reducing dietary intake of lead. In fact, most people in
the U.S. can eat what they like, when they like, without concern
about ingesting lead. However, FDA occasionally encounters a prod-
uct for which lead exposure is an issue. This article provides an
overview of efforts to reduce lead levels in foods and presents the re-
cently addressed example of certain Mexican-style candies with high
lead levels as an illustration of the need for targeted industry educa-
tion and enforcement actions.
Many people would be surprised to learn that until the post-World War II era,
nearly all apples sold in the U.S. were treated with lead in the form of lead arsenate.
This was done to protect the fruit from the codling moth, whose larvae would bore
into the apples. Left unchecked, the larvae would damage large portions of the
apple crop. The treated apples were subjected to an acid-wash process to remove
residues of lead arsenate and make the apples safe to consume. FDA monitored
lead levels in apples and apple products closely during this era to ensure the lead
arsenate was being sufficiently removed. Eventually, other pesticides were developed to control the codling moth.
Two significant indirect sources of lead in the typical U.S. diet through much of
the 20th century were leaded gasoline and lead-soldered cans. Vehicles using leaded
gasoline produced emissions that contained lead. These emissions accumulated in the environment and added
significant amounts of lead to food
crops and to the fields in which feed animals grazed. In 1973, in response to lead
reduction standards issued by the Environmental Protection Agency, the U.S.
began to phase out leaded gasoline. This
resulted in a significant drop in the environmental lead burden and in turn lowered levels of lead in the average U.S.
Another important step in reducing
dietary lead levels began in the late
1970s with the food industry’s gradual
conversion from lead-soldered cans to
welded cans. This conversion was completed by the industry in 1991, and FDA
formally banned the sale of food packed
in lead-soldered cans in 1996.
By the early 1990s, data from FDA’s
Total Diet Study showed that lead levels
in the U.S. food supply had been dramatically reduced. For some age and
gender groups, lead levels had decreased
by more than 95% over a 20-year period. To put this into a larger public
health context, by the mid-1990s, dietary lead levels for all age and gender
groups had been minimized to the point
that they did not significantly contribute
to blood lead levels associated with
In the 1990s, FDA undertook additional efforts to ban or restrict uses of
lead in association with food, including
lowering the limit for lead in bottled
water, lowering the action level for
leachable lead in ceramicware, setting an
enforcement level for lead in wine, and
prohibiting the use of lead foil seals for
wine bottles. However, subsequent Total
Diet Study data did not indicate additional significant decreases in lead levels.
This leveling off suggests that the efforts
to reduce exposures to lead by switching
from leaded gasoline and lead-soldered
cans effectively targeted the most significant, addressable sources of dietary lead
exposure. Current dietary lead exposure
in the general population likely reflects
lead present in food at background lev-