Environmentalist challenges mosquito-control agencyWritten by Patrick Timmis | | firstname.lastname@example.org
Local environmental advocate Susan Searles and her team have distributed about 11,000 pamphlets around Toledo as part of their “Say Nay to Spray” campaign.
The main thrust of Searles’ argument is that the pesticides sprayed by Toledo Area Sanitary District (TASD) — the city mosquito-control agency — are dangerous to wildlife, pets, children and adults. The agency responds that its chemicals carry minimum risk and do not harm residents or the environment.
Searles wrote in an online article that pesticides are linked to childhood epidemics like cancer and asthma. She maintains the chemicals are deadly to bees, which are vital to pollination of fruits and vegetables. Pesticides also indirectly poison insect predators, such as birds, bats and amphibians, when they eat infected mosquitoes, she wrote.
Searles challenged the effectiveness of pesticide spraying, writing that it does not work for more than a day or two. Studies from the Centers for Disease Control and Prevention seem to conclude that mosquitoes develop immunity to the chemicals after a time, she wrote.
“Then with fewer predators, the mosquitoes multiply faster than they did originally. The logical conclusion is that mosquito sprays are counterproductive, actually increasing the number of mosquitoes, because of the kill-off of their predators,” she wrote.
Addressing the common concern that mosquitoes carry West Nile virus (WNV), she said on average only one in 150 people infected with WNV becomes seriously ill, and that person typically is either very old or already very sick.
“So it’s a very small population that WNV is affecting,” she said in an interview, “and the hazards of the spray are such that it’s not fair … to fumigate and pesticide the majority of the population because a very small percentage have that risk.”
The chemical chlorpyrifos — used in spraying mosquitoes — is found in the vast majority of Americans; such pesticides damage the immune system, rendering people more susceptible to WNV, she said.
Her concerns extend beyond the ordinary application of pesticides.
“It’s a security issue,” she said.
If a TASD truck crashed and the chemical tank was punctured, she said, this spray — which she said was originally developed by the Nazis in concentrated form as a chemical weapon — could infiltrate the population.
“It would be a disaster, a complete disaster,” she said. “Not to mention terrorists breaking into TASD and wreaking havoc.”
Searles has repeatedly brought the issue before the city councils of Toledo, Sylvania and Maumee, and plans on meeting with the county’s Health Department next week. So far, she has not been able to convince lawmakers to enact a ban because of a lack of community pressure on lawmakers. This is why she said she has distributed more than 10,000 flyers advising residents how they can opt out of being sprayed. Her blog site is http://sites.google.com/site/saynaytospray/
Searles stressed that she has no malice toward TASD itself and has found the agency’s employees to be as courteous and accommodating as possible.
“I don’t want to shut them down,” she said. “I want them to turn to a nontoxic approach — which is advocated by the Centers for Disease Control — which is not spraying, but helping communities eliminate the standing water which breeds mosquitoes. It’s that simple.”
“It’s not our goal to come to work and spray a lot of pesticide,” said Lee Mitchell, TASD’s biologist. “I’d be perfectly happy not to have to spray anything to kill mosquitoes, but that simply is the tool that we have at the present time. I would love to see a different technique than we’re using.”
Mitchell said sumithrin and chlorpyrifos, the pesticides TASD uses, are not perfect. Ideally, each droplet would be a heat-seeking missile that never missed the insects. In a perfect world, there would be no pesticide residue on fruits or vegetables, but in today’s mass-produced agricultural system, that’s not realistic, he said.
But Mitchell maintains that the actual risks are minimal and the cases of real harm in Lucas County basically nonexistent. When TASD sprays, it was only two-thirds of an ounce of pesticide per acre. That translates to two tablespoons, Mitchell said, and most homeowners only live on about half an acre.
According to the Virginia Department of Health, “Sumithrin has very low toxicity to humans. Short-term or accidental exposure to very high levels of sumithrin can affect the nervous system, causing effects such as incoordination, tremors or tingling and numbness in the area of skin contact.
Since sumithrin is applied at very low concentrations, most people would not be expected to experience any adverse health effects.”
Chlorpyrifos, which TASD applies at night, is more dangerous. According to the Agency for Toxic Substances and Disease Registry, short-term oral exposure to low levels of chlorpyrifos can cause dizziness, fatigue, runny nose or eyes, salivation, nausea, intestinal discomfort, sweating, and changes in heart rate. Short-term oral exposure to much higher levels of chlorpyrifos can cause paralysis, seizures, loss of consciousness and death.
The chemical was banned for use by homeowners by the U.S. Environmental Protection Agency. Mitchell said the main reason for the ban was misuse by people who sprayed their own homes with the chemical.
“Most people don’t have a degree in entomology, so when it comes to killing a bug, anything beyond using a flyswatter or something pretty basic has the potential to be a problem.”
Mitchell said the most likely way for someone to be orally exposed to the pesticide is to eat fruits or vegetables that have been sprayed. But he said the residue would likely be minimal and recommended that people wash their food before eating it, citing USDA guidelines.
Mitchell said employees would be the first to experience illness because of contact with the gas, but that hasn’t happened.
“All we do is one thing, so we have to be pretty focused on that one thing and not screw it up,” he said. “So because we have trained employees we’re able to keep people safe, and we’ve never had a lawsuit in Lucas County because of ill health or disease or employees filing suit that we’ve somehow adversely affected their health.”
TASD has also never seen a bird or bee tested positive for death by pesticide. Bees have been dying because of parasites and a new disease affecting the whole bee industry that is not pesticide related, Mitchell said.
“We’ve worked with beekeepers in Lucas County for years and years and years, and we’ve never had anyone accuse us of killing bees.”
The reason TASD uses multiple kinds of pesticide — sumithrin and chlorpyrifos for adults and BTI, Abate and Tire Abate to kill larvae in the water — is to fight the mosquitoes’ ability to build resistance, Mitchell said. TASD’s efforts are aided by the out-of-county mosquitoes, without any genetic fortifications against the chemicals, that fly into the area attracted by city lights. They breed with Lucas County mosquitoes and impede the resistance process, he said.
Mitchell said the mosquito population is dropping as the summer goes on, but mid-July to mid-September is the hotspot for West Nile Virus. Five pools of mosquitoes Mitchell has captured have tested positive for WNV this summer — a typical rate, he said.
TASD also has some natural recommendations, including eliminating standing water and stocking ponds with Gambusia, a small mosquito-eating fish TASD will deliver for free.
Anyone who wishes to opt out of spraying can contact TASD and request the removal form. Mitchell said the “Say Nay to Spray” campaign — which he said would be intimidating to someone without the context of a scientific background — has resulted in about 30 people opting out so far this year.
“I’m surprised we haven’t gotten more calls because of those pamphlets,” he said. “A lot of that I would attribute to just the trust factor, since we’ve been here a long time. We’ve been here 65 years. Our employees live in the community. My kids grew up in this community.”