The Board of Health approved this year's mosquito control program.
PITTSFIELD, Mass. — Insecticide spraying is a necessary "tool in the arsenal" against the risk of mosquito-borne illness, but one whose use must be weighed carefully, according to local Board of Health officials.
"I think all of us are concerned about potential exposures," said Dr. Cynthia Geyer. "But I think the board has been very careful about when to apply an adulticide."
The board on Wednesday approved the Berkshire County Mosquito Control Project's action plan for 2014, but will continue to monitor the program and must vote to authorize periodic spraying throughout the summer season. BCMCP is asking for approximately $240,000 from the commonwealth for efforts in participating area municipalities. Six other communities — Clarksburg, Hinsdale, Otis, Stockbridge, Tyringham and Sheffield — are members of the BCMCP, one of nine mosquito control districts that account for 193 out of 351 towns and cities in Massachusetts. Statewide control in 2014 is expected to total $11.6 million.
BCMCP uses a system called Integrated Pest Management, a multitiered approach to mosquito population reduction.
This includes strategic application of larvicide for source reduction at identified breeding areas, along with selective truck based adulticide spraying in high risk areas or where mosquitoes have tested positive for West Nile virus or eastern equine encephalitis. Staff set and monitor traps for measuring populations and testing samples for the viruses, and based on these factors recommend spraying efforts for the Board of Health's approval in neighborhoods and parks considered a risk. The department also conducts some ditch maintenance and public awareness activities in an effort to reduce standing water around residences.
As part of its efforts in 2013
, the program applied 136 gallons of an adulticide called Duet, a potent combination of the pyrethroid insecticides Sumithrin and Prallithin, over 27,792 acres in the seven participating Berkshire County communities.
During a public input period, Pittsfield resident Kathy Lloyd challenged the use of this product, citing studies demonstrating risks to both humans and other wildlife. Lloyd raised particular issue not with the often controversial pyrethroids, but with piperonxyl butoxide (PBO), a non-insecticidal booster ingredient in the chemical mixture added to increase their effects by inhibiting immune system response to the other toxins in the spray.
"About a pint [ingested] will kill you," said Lloyd, "This is an unsafe substance to spray in our neighborhoods and in our wildlife."
Lloyd said that although PBO generally breaks down into innocuous substances in under 24 hours in direct sunlight, under some conditions it can remain in the surrounding environment substantially longer, with untold effects. She cited a 2011 Columbia University study
and another from Duke University
demonstrating a connection between PBO exposure and childhood cognitive development, along with data on negative effects on wildlife reproduction, and possible cancer causing properties that have yet to be researched in humans.
"Animal studies have shown that it has ties to thyroid and liver cancer," Lloyd told the board, "It's a Group C carcinogen, and this is being sprayed in our neighborhoods, and in our wetlands."
Additionally, a 2006 study
conducted in the Boston area found aerosol plumes of from truck based spraying failed to contact the target mosquito groups, and concluded that "may not effectively reduce the force of transmission of WNV."
"I beg you to cancel this program, and find another way," said Lloyd.
Board members acknowledged concerns about toxic exposure, but said their charge is to balance those concerns against the threat of acute illness.
"You have to weigh the potential risk of exposure to the potential risk of catching an infection," said Geyer, "You always have to weigh those concerns in the context of overall public health policy."
"It's not an easy decision to introduce chemicals into the environment," agreed board member Jay Green. "But at the same time. ... the risk associated with contracting these diseases is frightening."
"It's very closely targeted and monitored," added Department of Health Director Gina Armstrong of the program, who noted that residents in spray areas are notified in advance via the CodeRed system and can opt their property out of the program by calling BCMCP at 413-447-9808.
"With EEE especially the rate of death frightens me," said Green, who expressed faith in the program to administer the toxins only when considered crucial to public health. "We have it as a tool in our arsenal, to use, conservatively, and tactfully, and methodically."
Mosquito samples from Pittsfield continued to test positive for EEE and West Nile during the late summer and early fall, according to a Sept. 20 press release from the Department of Health, though there were no human cases of infection. Statewide, one human case of EEE
was recorded in 2013, in Norfolk County. In total there have been 23 cases in Massachusetts in the past decade, with nearly a third of them fatal, particularly those patients who were above the age of 60.
Public health records
indicate there were six recorded cases of West Nile virus infection in Massachusetts in 2013, all in more populous eastern counties with more robust mosquito control programs, though Berkshire County had one non-fatal case
BCMCP will next go before the city's Parks Commission on May 20 to obtain that board's endorsement to conduct annual larvicide and adulticide application in select park spaces throughout the city as deemed necessary.