Aerial Application of Pesticides after 16 years- Groups Take Action
(Beyond Pesticides, August 10, 2006)
On Tuesday evening, Pylmouth County, Massachusetts conducted the state's first aerial fumigation in 16 years, spraying more than 6,000 pounds of the pyrethroid pesticide, Sumithrin, over 159,000 acres where the Eastern equine encephalitis virus was detected recently in human-biting mosquitoes and a horse.
According to the Boston Globe, State health officials said the spraying, which began at 7:55 p.m., was necessary to control the virus that is spreading quickly in the robust mosquito population produced by heavy spring rains. The virus has killed a horse in Lakeville and has been found in 33 samples of mosquitoes in Plymouth and Bristol counties, including a human-biting species. Around Southeastern Massachusetts, residents prepared by closing windows, turning off air conditioners, and keeping children indoors.
The major hotbed for breeding is reported to be the Hockomock Swamp in this semi-rural region which is in its third year of high EEE activity. There were four human cases and two deaths in both 2004 and 2005. Last year, all four people in the state infected by EEE were from Plymouth County. The elderly and young are especially vulnerable. A 5-year-old Halifax girl and an elderly Kingston man died of the disease last year when 28 of the 45 mosquito samples tested positive for the virus came from within the county.
Late tuesday, the Jones River Watershed Association, which was unsuccessful in halting the spraying, sought a temporary restraining order against the state in Brockton Superior Court, saying the decision to spray deviated from a protocol developed after the state last sprayed in malathion in 1990. They will appear in court Friday with affadavits.
Adult mosquito spraying is known to be the least effective management method of controlling mosquitos. According to experts, the threat of mosquito-borne diseases such as EEE and WNv are best managed through an integrated program that does not expose vulnerable populations of the society to pesticides, including children, pregnant women, the elderly and people with compromised immune systems. The most effective program to protect the public focuses funds and resources on removing breeding areas, killing mosquitoes that carry the virus before they start flying, and mass public education on prevention and precaution.
The Centers for
Disease Control (CDC) recommends several important management techniques
for evaluating the efficacy of adult mosquito control spraying, including
determining the pre- and post spray vector mosquito densities inside
and outside control area, and the vector mosquito infection rates pre-
and post-spray inside and outside the control area; to determine if
the spraying is in actuality reducing the disease risk. CDC also recommends
monitoring to determining whether the mosquitos are becoming resistant
to the pesticide. They also outline several management techniques for
impoundments and marshes that do not include adulticiding. See
Epidemic/Epizootic West Nile Virus in the United States: Guidelines
for Surveillance, Prevention, and Control.
However, there is no recommendation to monitor the impacts on non-target species, such as birds and bats, that naturally control mosquito populations to determine if spraying is reducing predators and causing a population explosion of mosquitos. Activists joined together in Massachusetts to put out bedsheets in their yards to catch non-target species impacted by the spraying for a local entomologist to study.
In New Orleans, they are battling mosquitos in their hard to reach water bodies, thousands of swimming pools, with a natural predator—the western mosquito fish (Gambusia affinis). The fish can eat up to a hundred mosquito larvae a day, and unlike aerially sprayed pesticides, they do not impact humans, and they can replenish themselves. See National Geographic for more on this story.
Beyond Pesticides advocates for full disclosure of both the risk of contracting diseases and the risks of pesticides exposures (see below). We advise communities to adopt a preventive, health-based mosquito management plan and has several resource publications on the issue, including the Public Health Mosquito Management Strategy: For Decision Makers and Communities. Additonal materials such as safer repellents, mosquito control pesticides, public service announcements, and community policies throughout the nation can be found online at http://www.beyondpesticides.org/mosquito or by contacting Beyond Pesticides.
Sumithrin, the pesticide in the product Anvil, is a synthetic pyrethroid and a neuropoison that acts on the nervous system of insects. Symptoms of exposure for humans include dizziness, headache, fatigue and diarrhea. In laboratory tests, sumithrin has damaged the liver and the kidneys, caused anemia and increased the incidence of liver cancer. In breast cancer cells, sumithrin increases the expression of a gene that is involved with proliferation of cells in the mammary gland. Sumithrin is also a suspected endocrine disruptor, it can mimic certain activities of the sex hormone estrogen and keep another sex hormone from binding to its normal receptors. Thousands of cat poisonings and some dog poisonings have been reported following the use of some sumithrin- containing flea control products. Low concentrations of sumithrin (as low as one part per billion) kill fish and other aquatic animals and it is highly toxic to bees.
Butoxide (PBO) the synergist in the Anvil product PBO acts as a
synergist by inhibiting the activity of a family of enzymes called P450s.
These enzymes have many functions, including breakdown of toxic chemicals
and transformation of hormones. Symptoms of PBO exposure include nausea,
diarrhea, and labored breathing.
EPA classifies PBO as a “possible human carcinogen” because it caused liver tumors and cancers in laboratory tests.