A federal review of the health effects
of malathion, released 12-May-2000, says the insecticide sprayed
around New York City and many other cities, to kill
disease-carrying mosquitoes, contains
"suggestive evidence" that high doses of the
chemical may cause cancer in laboratory
animals. There is no current evidence that it poses a
threat to people when used properly.
The Environmental Protection Agency, in
more than 1,000 pages of preliminary analysis of malathion posted on its Web site at www.epa.gov, found no evidence that would indicate a need for tighter restrictions on the chemical, which is widely used in agriculture, consumer backyard products
and mosquito control.
In particular, the agency concluded that
when malathion is sprayed in the very low
concentrations that are used to kill mosquitoes, there is no health threat to people. The
agency did conclude that an independent
scientific advisory panel should take a closer look at studies in laboratory mice and
rats hinting that malathion might cause
some kinds of tumors when consumed in
high doses, but the report also noted that
malathion is rarely encountered in concentrations beyond a trace.
In some city neighborhoods, the spraying
operation last year caused more public concern than the West Nile virus, the disease it
was aimed at eliminating. The virus, which
is transmitted by some mosquitoes, can in
rare instances cause deadly encephalitis, a
swelling of the brain.
Last year, seven people died of West Nile
encephalitis in and around New York City, and 60
others developed serious infections. There
was no documented rise in health problems
from the spraying.
"No pesticide is 100 percent safe, and they
have to be used in accordance with labeled
directions," said Stephen L. Johnson, a deputy assistant E.P.A. administrator who is in
charge of the agency's pesticide program. "But," Mr. Johnson added, "we have concluded that we don't have any level of
concern with regard to food or drinking
water or the use of malathion in a program
to control mosquitoes, boll weevils or medflies."
As is normal procedure, the E.P.A. is accepting public
comments on its findings for 60 days,
then will issue a revised report and
take public comments once again
before publishing its final conclusions.
Malathion is one of 43 organophosphate pesticides approved for use in
the United States. These chemicals,
related to nerve gas, kill insects by
disrupting the action of their nerve
cells. Some, including malathion,
have been known to cause neurological problems in people in high doses.