Environmental Engineering Reference
In-Depth Information
cides such as aldrin, chlordane/heptachlor, lindane, dieldrin, chlordecone,
and DDT; organophosphorous insecticides such as dichlorvos and methyl
parathion; fungicides such as captan, chlorothalonil, hexachlorobenzene,
PCP,
o
-phenylphenol, and 2,4,6-trichlorophenol. Most pesticides identified
as actual or potential animal carcinogens are still registered for use in the U.S.
Most information linking pesticides and human cancers has come from
epidemiological studies of farmers/farm workers/farm families. Males typ-
ically have higher-than-expected rates of cancers of the lymphatic and
hematopoietic systems, lip, stomach, prostate, brain, testes, soft tissues, and
skin. Females are reported to have an excess of lymphatic, hematopoietic,
lip, stomach, and ovarian cancers. There is strong evidence that selected
organochlorine, organophosphorous, and arsenical insecticides, and triazine
and phenoxyacetic acid herbicides may play a role in human cancer.
Organochlorine insecticides have been epidemiologically linked with
leukemia (DDT, methoxychlor), non-Hodgkin's lymphoma, lymphoma
(DDT, chlordane, toxophene), and lung cancer (chlordane). DDT exposures
have also been linked with soft tissue sarcomas and pancreatic, breast, and
liver cancers. Organophosphorous insecticides have been linked with leuke-
mia (crotoxyphos, dichlorvos, Famphur) and non-Hodgkin's lymphoma
(diazinon, dichlorvos, malathion). Phenoxyacetic acid herbicides such as 2,4-
D have been linked with non-Hodgkin's lymphoma and prostate cancer.
As indicated previously in this section, potentially carcinogenic pesti-
cides have been, or are being, used indoors; are present as a consequence of
subterranean termiticidal applications; may be released from treated prod-
ucts (wood preservatives, pet collars, natural fibers and fabrics); or may be
passively transported indoors on shoes and clothing. Because pesticides
degrade slowly indoors, the potential exists for chronic exposures to low
concentrations of a number of potentially carcinogenic pesticides. Cancer
risks may, as a consequence, be increased in both children and adults.
Because of the nature of exposure pathways and increased sensitivity to
chemical exposures, children may be at special risk.
c. Childhood cancer.
Children may be exposed to pesticides through
their diet, parental pesticide use both inside and outside the home, and a
“toxics brought home” phenomenon associated with parental occupational
exposure. In a study conducted in the U.S. and Canada, acute nonlympho-
blastic leukemia among children up to age 18 was observed to be strongly
associated with occupational paternal pesticide exposure of >1000 days, with
much higher risks for children under age 6. In a similar U.S. study among
children under age 10, the use of a household pesticide
once/week by
either parent during the pregnancy of the affected child was observed to
significantly increase the risk of acute lymphocytic leukemia. A higher risk
was observed when either parent used a garden pesticide or herbicide
≥
≥
once/month. In both studies, pesticide exposures inside the home appeared
to be responsible for increased risk of developing leukemia. It has also been
