RESIDENTS FOR ENVIRONMENTAL ACTION AND COMMUNITY HEALTH

PRESENTATION TO THE FORT WAYNE BOARD OF PARK COMMISSIONERS

MAY 19, 2003

CONTACTS:

DIANE DICKSON 456-9724

DAVID SHEARER 458-9554

COMMUNITY RESPONSE TO WEST NILE VIRUS

Since this fall, Residents for Environmental Action and Community Health (REACH) have been working with city and county officials to implement the most effective, economical and least toxic methods of controlling West Nile virus (WNv). We have been pleased to be included on the BEST team WNv task force, under the able leadership of Dianne Hoover.

Based on our research of other cities, the most effective strategies to reduce human cases of WNv have been people-based, community programs focusing on surveillance, source reduction and public education.

Connecticut, most of New York state, Cambridge MA, Washington, D.C., Fort Worth Texas, Shaker Heights and Chagrin Falls, Ohio, and Medina and Geauga counties, Ohio, are part of a growing number of communities who have virtually stopped pesticide spraying after adopting vigorous education programs and comprehensive source reduction strategies.

Source reduction is the elimination of standing water and the killing of mosquito larvae with chemical or biological pesticides (larvaciding). The U.S. Centers for Disease Control and Prevention’s evaluation of source reduction is that it "remains the most effective and economical method of providing long-term mosquito control."

Adulticiding is the killing of adult mosquitoes using Ultra Low Volume (ULV) truck fogging of pesticides to kill adult mosquitoes. Adulticiding doesn’t kill enough mosquitoes to be effective, and is not safe to human health or the environment.

Washington, D.C. and Fort Worth, Texas have instituted no-spray mandates due to the low efficacy, kill-offs of non-target species, and potential health risks to persons affected with respiratory problems and compromised immune systems.

SURVEILLANCE AND SOURCE REDUCTION

Monitoring is an essential part of an effective mosquito management program. Communities that have focused on larval mosquito surveillance have applied larval controls in a wide variety of natural and man-made habitats. Data collected in a Geographic Position System (GPS) is used to map and monitor breeding areas, and can be analyzed over time. This cumulative surveillance information will also provide the necessary data to make informed decisions related to control timing, duration, frequency and effectiveness.

The mosquito that spreads WNv breeds primarily in urban areas in small, stagnant pools of water rich in organic matter, such as old tires, rain gutters, buckets, etc. Loren Eck, the director of Allen County Vector Control, estimated over 60% of human cases of WNv were associated with mosquitoes breeding in tires. Sewer catch basins have also been identified as sources for mosquito larvae.

The Washington, D.C. Department of Health has found larvaciding to be more effective over a period of time than adulticiding. In 2001, about 3,500 catch basins were treated with a biological larvacide. In 2002, it was increased to 10,800. Additionally, health officials applied larvacides and went door-to-door to help residents eliminate standing water in an eight-square block radius around positive mosquito pools. As a result of these efforts, adult mosquito hatches were significantly reduced in 2002.

The mosquito counts in Shaker Heights, Oh, were reduced from the highest in the state in 2001 to the lowest after larvaciding the sewer catch basins in 2002. Additionally, significant reductions in adult mosquito counts through early-season larvaciding have been documented in Nassau and Suffolk Counties in New York in 2000.

Bacillus thuringiensis (Bt), is a biological pesticide that contains naturally occurring soil bacteria in different strains that target specific insects. Bti (Bacillus israelensis) and Bts (bacillus sphaericus) are used against mosquito larvae. Bt’s are widely used in organic farming, and are not known to be toxic to humans, animals, birds, fish or most beneficial insects. Bt is significantly less costly than chemical larvacides, and can be applied to lakes, ponds, drainage ditches, and sewer catch basins to stop mosquito eggs from hatching.

PUBLIC RELATIONS AND EDUCATION

A Connecticut serosurvey suggested that prevention measures implemented in 2000 might have contributed to the low incidence of disease among humans, in spite of intense epizootic activity (dead birds and infected mosquito pools.) Prevention activities included spring larvaciding of catch basins. Public education was aimed at eliminating breeding sites, and encouraging personal protection. Adulticiding was negligible. The people surveyed in the study were highly aware of WNv; most took some protective measures, and almost 50% used mosquito repellant.

Surveys done in Connecticut, Florida, Maine and by the Harvard School of Public Health have shown that the regular utilization of TV and radio public service announcements is one of the most effective ways to educate residents about WNv prevention. Newspaper articles, targeted mailings, automated phone messages and direct door-to-door contact with residents in neighborhoods experiencing WNv positive events are other effective means of communication.

SPRAYING – IS IT EFFECTIVE?

Studies done with caged mosquitoes have shown that spray applications are spotty, because vegetative cover and buildings reduce spray penetration. The spray must come in direct contact with the insect in order to kill it. Many mosquitoes evade the fog or leave the treated area, and reinfestation occurs within 24 hours.

According to one of the nation’s foremost experts on pesticide spraying, only a miniscule amount of the pesticide spray actually gets to the target organism.

At a forum on West Nile virus held in Cleveland in May, Cornell University entomologist Dr. David Pimentel said that only about .01% of the pesticide actually reaches the target organism. That leaves 99.9% of the spray going off into the environment where it can have detrimental effects on public health and ecosystems. At best, mosquito populations are reduced by 10%.

"Truck spraying with pesticides is a waste of time and is done for political and cosmetic purposes," said Pimentel.

Even if spray trucks fogged our neighborhoods and parks every 7 to 12 days, the mosquitoes left behind and the subsequent hatches of new mosquitoes would continue to pose the risk of WNv transmission.

Spraying for mosquitoes may give many residents a false sense of security. The risk of someone being infected with West Nile might increase if fewer people decide not to use insect repellant because they thought the problem had been handled.

Dr. Paul Reiter, chief of the Entomology Section of the Dengue Branch of the CDC, has said, "We know very little about the real efficacy of aerosols, of ground-base ULV. The real impact of the sprays on the mosquito in the environment has been very rarely monitored, or very little evaluated."

HEALTH RISKS

We at REACH do not feel that the benefits of using pesticides outweigh their risks. Pesticides are not safe. And it is against federal law to make any claims of safety, even if used as directed. Children are especially sensitive to low levels of pesticide exposure.

There are short and long-term human health risks associated with mosquito sprays -- acute upper respiratory disease and possible links to neurological disorders and breast cancer.

Exposure to sumithrin, the active ingredient in Anvil, has resulted in contact dermatitis and asthma-like reactions. Children with a history of allergies or asthma are particularly sensitive. Other symptoms of acute toxicity due to inhalation include sneezing, nasal stuffiness, headache, nausea, tremors, facial flushing and swelling, and burning and itching sensations.

There is enough evidence in the medical literature to prompt concern about the chronic hazards of exposure to sumithrin, which is a synthetic pyrethroid. Studies have linked sumithrin to disruption of the endocrine system. When tested, it has demonstrated significant estrogenicity, and has been shown to increase breast cancer tumors.

Piperonyl butoxide (PBO) is a synergist used to increase the potency of the spray formulation. Studies have linked PBO exposure to liver cancers in rats and mice, and is classified by the EPA as a "possible human carcinogen."

There is growing concern worldwide with the adverse effects that endocrine disruptors cause in both humans and wildlife. A panel organized by the World Health Organization, the International Labour Organization and the United Nations Environment Programme has recently issued a report linking endocrine disruptors to a wide range of human health problems, including impaired physical and mental development in young children, increases in breast and prostrate cancer, decreases in sperm counts, and abnormal reproductive development in wildlife species.

ECOLOGICAL EFFECTS

Many people think that Anvil, the pesticide spray used in Allen County last summer, doesn’t persist in the environment. The claim that the pesticide dissipates quickly is based on the ideal conditions of direct sunlight. While pyrethroids generally break down within one to two days in direct sunlight, in areas with limited sunlight they can persist for months. The chemical is deposited in forested areas, and in countless other places that lack direct sunlight. Much of it is tracked into people’s homes where it can be inhaled, ingested or absorbed through the skin.

The European Union will withdraw sumithrin and other synthetic pyrethroids from the European market by July 2003 because they have not been proven safe for people, and are highly toxic to honeybees and fish.

RECOMMENDATION:

In the absence of scientific evidence that adulticiding reduces the risk of West Nile virus transmission to humans, we at REACH feel that the hazards of the pesticides pose too great a risk to humans and the ecosystem. We do not think our residents should be put in the direct line of the spray trucks while enjoying the parks at dusk. Nor do we think it is safe for children to be exposed to pesticide residues on playground and picnic table equipment or on athletic fields.

We respectfully recommend to the Fort Wayne Board of Park Commissioners and the Department of Parks and Recreation to adopt a no-spray policy in the city parks. Educating park users about personal protection measures, providing insect repellant, eliminating standing water wherever possible, and using Bt larvacides are methods that have successfully reduced people’s risk of being bitten by mosquitoes infected with West Nile virus in many other communities around the country.

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