February 9, 2004 (ENS): A new study finds agricultural
workers who perform thinning - removing young buds from
orchard trees to increase the size of the remaining
fruit - face a greater likelihood of pesticide exposure
than other farm workers.
The researchers found that workers who thinned orchards
were more likely to have detectable levels of pesticides
in their house and vehicle dust as compared to agricultural
workers who did not perform orchard thinning.
The study also found that children of thinners were
more likely to have detectable levels of pesticide metabolites
in their urine than children of non-thinners.
These findings support the theory that agricultural
workers may track pesticides home on their clothing
"Most previous pesticide exposure research on
farm workers has focused on pesticide handlers, such
as pesticide mixers, loaders and sprayers, but this
study suggests that more research is needed regarding
exposure patterns among other types of farm workers
as well," said Dr. Gloria Coronado, lead author
of the study and a scientist in Fred Hutchinson's Cancer
Prevention Program in Seattle.
Orchard thinners are thought to be at higher risk for
pesticide exposure because thinning usually takes place
in the spring, when crops are being sprayed to prevent
Such workers also have substantial physical contact
with fruits, leaves, twigs and branches that may contain
In addition, unlike pesticide handlers, thinners are
not required by the U.S. Environmental Protection Agency
to use protective equipment or undergo safety training.
The project, conducted in Eastern Washington's Lower
Yakima Valley, involved 571 farm workers in 24 communities
and labor camps who were interviewed about their pesticide
It revealed some 20 percent more thinners had pesticide
residue in their home and vehicle dust as compared to
The researchers also found that the presence of a dimethyl
urinary pesticide metabolite called DMTP was present
in children of thinners 10 percent more than in children
"Unfortunately, we do not know the extent to which
ongoing, low level exposure to pesticides leads to adverse
health consequences," said project leader Dr. Beti
Thompson of Fred Hutchinson's Public Health Sciences
Division. "However, knowing exposure pathways helps
us plan interventions to reduce exposure risk, which
is particularly important for young children."
The study appears in the February issue of the journal
"Environmental Health Perspectives," a publication
of the National Institutes of Health.