Science Rejects Anti-Pesticide Claims

Science Rejects Anti-Pesticide Claims

Logomasini Op-Ed for Heartland Institute in the Environment News
September 24, 2003

Public health officials across the country are considering widespread spraying of pesticides to control the mosquito-borne <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" />West Nile virus.  Anti-pesticide environmentalists claim spraying will devastate bird populations and other wildlife, but sound science shows the pesticides are safe and necessary.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" />

West Nile Kills

West Nile virus and other factors in the natural environment pose greater threats to birds and wildlife than pesticide spraying.

According to the Centers for Disease Control, West Nile virus has killed birds from at least 138 species, including some that are endangered.  In the Midwest last year, 400 great horned owls were found dead from West Nile.  Researchers estimate that for each dead bird reported, there are probably 100 to 1,000 unreported cases--meaning as many as 40,000 to 400,000 great horned owls may have succumbed to West Nile virus last year alone.

In 2001, anti-pesticide environmentalists claimed data from New York showed more birds were dying from “toxins,” including pesticides, than from West Nile virus.  Science writer Steven Milloy examined their data and found the toxins killing the New York birds were mostly naturally occurring.

According to Milloy, the New York data recorded the deaths of 3,216 birds.  More than one-third of them (1,263) died from West Nile virus, and another 1,100 died from botulinum. The New York data reported 219 pesticide-related bird deaths, of which 30 were from intentional poisonings of pest birds and 100 were from illegal use of pesticides for intentional killing of birds.  Just 27 bird deaths were attributed to lawn care products.

More recently, the Audubon Society claimed 80,000 dead birds examined by New York in subsequent years showed that pesticides, primarily lawn care products, killed most of the birds.  It is unclear whether Audubon is claiming to have reviewed the data for all 80,000 birds or for only a sample of that population.  New York officials have not released the data in any report, nor has any research involving the data been peer reviewed.

The researcher who conducts bird pathology evaluations for New York, who reportedly gave the data to the Audubon Society, has told the press he doubts pesticide spraying will do much harm to birds--at least not as much as does the West Nile virus  The U.S. Environmental Protection Agency says spraying poses a negligible risk to birds.

Aquatic Life Largely Unaffected

Some environmentalists also claim aquatic life is at grave risk from pesticide use.  When a massive lobster die-off occurred in Long Island Sound in 1999, environmentalists and lobstermen claimed New York City’s malathion spraying had reached the waters and caused the die-off.

The die-off, however, began before New York sprayed, and federally funded research conducted over a period of several years has been unable to link the lobster die-off to pesticides.  The University of Connecticut’s Dr. Richard French explained in a 2001 report: “There is no quantitative evidence of pesticide toxicity. ...All the indications based on pathological evaluation of the American Lobster in LIS [Long Island Sound] suggest that the mass mortality of lobsters in 1999 was the effect of a natural disease.”

Long Island is at the far southern end of the lobsters’ range, and the Sound’s waters were unusually warm in 1999 and for years before.  Researchers speculate the lobsters may have succumbed to natural environmental stresses that made the shellfish more susceptible to parasites and other diseases.

New York’s regional problem has not stopped the lobster industry from growing.  According to figures from the National Marine Fisheries Service, the biggest national lobster catch occurred in 1999--the year New York suffered its massive die-off. Since 1950, the U.S. lobster catch has been increasing consistently, with occasional “slow” years that have not affected the upward trend.

New York’s lobster population is more variable.  The average annual lobster catch between 1950 and 1989 was less than a million pounds. The catch increased dramatically in the 1990s, reaching more than three million pounds by 1992 and a pinnacle of more than nine million pounds in 1996.  The yields for 1999 (seven million pounds) and 2000 (three million) are higher than for any year before 1990.

While such facts matter little to the anti-pesticide crowd, they are important information for public health officials and other policymakers.  Charges that pesticides threaten birds and wildlife have been found repeatedly to be wrong.