Illnesses Linked to Pesticide Use
WebMD News Archive
Calvert also tells WebMD, "I think it would be important to do
surveillance wherever malathion is sprayed." However, much will have to
change before that occurs. Only eight states currently have government-run
pesticide surveillance programs of any type today, although up to 30 states
require the reporting of suspected pesticide-related illnesses.
Of the 230 reported cases of problems, 107 were discounted due to a lack of
information or because the symptoms being reported were incompatible with
pesticide exposure. Without specific laboratory or environmental tests, the CDC
does not classify any cases as a "definite" result of exposure, and no
reports met this requirement. The balance, 123 cases, were thought to be either
"possibly" or "probably" related to the malathion. These people
experienced multiple problems, from nausea, diarrhea, and vomiting to problems
with breathing, burning eyes, blurred vision, and skin rashes.
Malathion is also sprayed in Florida and other states to kill mosquitoes. It
was used most recently in New York City to combat an outbreak of encephalitis
caused by mosquitoes.
But the effects of the medfly spraying cannot be applied to malathion used
for mosquitoes, Calvert contends. "The concentrations are pretty much
equivalent. The difference is with the medfly, the application persists longer.
The aerosol [for mosquitoes] dissipates in one hour. With medfly, the bait can
persist for one to 30 days. We think, on average, it persists for four days.
There is more opportunity for skin exposure." In addition, it isn't known
whether the bait contributes some toxicity to the malathion. "The
researchers weren't able to tease out what was causing" the symptoms,
according to Calvert.
People should tell their physician if they have ever been exposed to
pesticides in the environment or from their occupations so they can match
symptoms to possible exposure, Calvert says. An acute reaction to exposure can
include rapid tearing of the eyes, runny nose, and increased sweating.
"If it is a pretty heavy exposure, it can be fatal," Calvert says.
"The problem with pesticide exposure is often the signs and symptoms are
nonspecific. They might be diagnosed as upper respiratory infections and acute
gastroenteritis," the symptoms of which include nausea, vomiting, and
abdominal pain. If exposure is suspected, blood tests can be done to look for
reduction of an enzyme called cholinesterase, he adds.