mirex, hexachlorobenzene, oxychlordane, toxaphene, and others. However, several
organochlorines are still registered for use, including lindane, endosulfan, methoxy-
chlor, dicofol, and pentachlorophenol.
Some organochlorines have been targeted for global elimination under the recently
signed Stockholm Convention on Persistent Organic Pollutants. The treaty is an
international effort to phase out harmful chemicals that persist in the environment
and can be transported around the world. Many organochlorines fall into this cate-
gory. The initial list of twelve chemicals targeted by the treaty included nine organo-
chlorine pesticides that have already been banned in the United States. The United
States has not yet ratified the Stockholm Convention largely due to resistance from
the current presidential administration regarding the process of listing new POPs that
are still in use in the United States.^36
The EPA can manage the risks of currently used pesticides by setting strict tolerance
limits to keep residues within the range required by the FQPA. The dietary risk contri-
butions of dicofol and endosulfan, for example, could be managed this way. But for a
banned chemical, such as dieldrin or heptachlor, EPA tolerances are already set at zero.
Unavoidable residues caused by environmental contamination are legal and are gov-
erned by ‘‘action levels’’ set by the FDA. An action level defines a level of contamina-
tion that may render a food injurious and warrants keeping it off the market.
Current action levels for banned organochlorine insecticides are relatively high; the
action level for dieldrin is 0.1 ppm. High action levels for the banned organochlorines
sanction serious residue problems, such as those observed in winter squash. As long
as it remains legal, squash growers will continue to sell products that contain significant
dieldrin and heptachlor residues. If these action levels were lowered, say to 0.01 ppm,
growers would have an incentive to seek out uncontaminated land for food crops that
absorb organochlorines as effectively as squash does. The FDA depends on the EPA for
risk assessments on pesticides. To provide a basis for setting more health-protective
action levels for the banned organochlorine pesticides, the two agencies need to work
together. Under the FQPA, ensuring a wider safety margin for these residues should be
ahighpriority.^37
Status of Carbamate Exposures
Despite the clear advice from its own scientific advisory panel and innumerable
other expert bodies, the EPA has stuck by its decision to exclude other cholinesterase-
inhibiting pesticides from the revised and final OP-CRA. A preponderance of
scientific evidence supports the inclusion of the carbamate insecticides in any cholin-
esterase inhibition-based cumulative risk assessment.
Excluding carbamates has consequences. Farmers use insecticides from these two chem-
ical families interchangeably, often for resistance management purposes. In most crops,
carbamates leave residues about as frequently as OPs and often at comparable levels.
Unless the EPA includes both OPs and carbamates in future cumulative risk assess-
ments, and imposes comparable risk mitigation measures across all OPs and carbamates
Pesticides in Food | 93