[T]wo environmental organizations have joined forces to fight the spraying of mosquito-killing pesticides in parts of Addison and Rutland counties.
The Environment and Natural Resources Clinic at Vermont Law School filed an appeal for Toxics Action Center disputing a permit granted to spray in towns straddling the two counties on the western edge of the Green Mountain National Forest.
Vermont’s Department of Environmental Conservation gave approval last month to a plan for spraying malathion and permethrin — known as “adulticides” because they kill mature mosquitoes — in the Brandon-Leicester-Salisbury-Goshen-Pittsford Insect Control District.
The Toxics Action Center initiated the appeal process on behalf of some residents living within the district who argue the adulticides are powerful nerve agents that can cause developmental disorders and other ailments in humans.
“These are chemicals that you don’t want to inhale and you don’t want to eat,” said Chris Fastie, an ecologist in Salisbury who opposes adulticide spraying in the district.
Mason Overstreet, an attorney with the Environment and Natural Resources Clinic, filed a notice of appeal last week with the state’s environmental court.
In an interview Tuesday, he said the DEC had failed to adequately “evaluate the impact (of spraying) on water quality and non-target aquatic organisms” under the terms and conditions of the state’s Pesticide General Permit. He also said the action thresholds — the mosquito count that would trigger use of pesticides — as outlined in the district’s application are not rigorous enough.
Malathion is considered to have low toxicity to mammals, but is “highly toxic” to bees, some fish and amphibians and “moderately toxic” to birds, according to the National Pesticide Information Center. The center classifies permethrin as “highly toxic” to fish and bees. Although not classified as toxic to humans, the chemical can make people feel nauseous, and cause breathing difficulties and headaches when inhaled.
Two neighboring mosquito control districts formed by towns in southern Addison and northern Rutland counties, in the Otter Creek floodplain, contain thousands of acres of wetlands — ideal breeding grounds for mosquitoes. To control the insect hatch, both districts — BLSG and the Lemon Fair district encompassing Bridport, Cornwall and Weyridge — have sprayed bacterial based larvicides that attack mosquito and black fly larvae in aquatic breeding grounds. Only the BLSG district has sought to spray adulticides.
The BLSG district is headed by Brandon dentist Benjamin Lawton, who said in an interview Thursday that he learned about the dangers of mosquitoes firsthand when his wife contracted Eastern Equine Encephalitis in 1989. That same year, a photo of Gov. Madeline Kunin swatting mosquitos in Leicester was featured in news stories about Vermont’s mosquito plague as far afield as Los Angeles, causing the legislature to appropriate funds for mosquito control and prompting Lawton and other area residents to form the state’s first insect control district.
Lawton stressed that adulticide was only one step in the district’s integrated pest management plan. The district has had to supplement larvicide treatment with less expensive adulticide in recent years to stretch limited state funds, he said. Lawton added that it would be impossible to treat all mosquito breeding sites in the thousands of acres of swamp even with adequate larvicide. The district only sprays adulticides at night when mosquitos are most active and bees and other pollinators are not as likely to be flying around, according to Lawton.
The Agency of Agriculture has worked closely to train members of the district in how to identify different types of mosquitoes and understand ecological factors, such as hatch dates, that affect treatment, according to Patti Casey, who coordinates the state’s vector management program.
The agency administers grants to the districts, which member towns then supplement with their own funds. However, the districts are largely “self-governing” as far as how they choose to combat mosquitoes, Casey said.
She pointed out that unlike the state’s vector program — which tracks and manages disease-carrying mosquitoes — the two insect control districts deal with “nuisance” pests. The agency conducts weekly surveys of mosquito populations throughout Vermont, testing for the presence of West Nile virus and Eastern equine encephalitis. The Department of Health uses this information to assess whether a state response needs to be initiated to prevent an outbreak of mosquito-borne diseases, according to public health veterinarian Natalie Kwit.
West Nile virus has been found in mosquitoes across the state, said Kwit. Last year, 2.1 percent of mosquito pools sampled around the state contained West Nile virus, according to the Department of Health’s annual report, and three residents contracted the virus.
Mosquitoes that carry Eastern equine encephalitis are not as prevalent statewide, but concentrate in “acidic hardwood swamps,” according to Kwit. The Otter Creek floodplains that span thousands of acres in both the Lemon Fair and BLSG Insect District contain just such swamps. In 2012, two people in southern Addison and northern Rutland counties contracted and died from equine encephalitis, prompting the last statewide response by the Department of Health, she said.
Salisbury resident Chris Fastie said in an interview that he does not oppose use of larvicides as a mosquito management tool, but feels spraying adulticides in the district violates the “clean, green neighborhood” valued by area residents. He also questioned the efficacy of the adulticide program, saying the district’s practice of spraying pesticides from trucks only hits a “narrow swath” along the road amidst the district’s largely rural area.
Fastie said that the spraying repeatedly exposes residents to low doses of pesticides throughout the summer while only having its intended mosquito-killing effect for the couple of hours the mist is airborne.
“By morning, there’s probably going to be just as many mosquitoes by the road that have flown in,” he said.
Wally Bailey, also a resident of Salisbury, questioned in an interview the criteria used by the district to determine when to spray adulticides in an area. He said the chemicals had already been sprayed three times this year, although disease-carrying mosquitoes don’t come out until later in the summer and mosquitoes had not yet become abundant.
“This is Vermont, people expect some mosquitoes,” said Bailey. “If you live by a lake, you’re going to have mosquitoes.”
Bailey said that opting out of spraying reduced his exposure as his house is far enough back from the road to minimize pesticide drift, but expressed concern for residents in more densely populated village centers who could not so easily escape the mist. He said he also worries about the impact spraying could have on fish in the region’s abundant rivers and lakes.
“What we really would like to see is more funding for larvicide and less use of that toxic chemical,” he said.
