Members of the Governor's Pesticide Council have decided to continue spraying the pesticide malathion to kill mosquitoes, despite complaints from critics who say it can cause chronic health problems.
The panel also told the Maryland Department of Agriculture to improve public education on the state's mosquito control program and how to keep mosquitoes from breeding, and to be sure to notify communities when spray trucks will be in their neighborhood.
The state began revamping the mosquito control program a few months ago, after critics claimed that it relied heavily on malathion and was nearly silent on prevention.
Cyrus Lesser, program chief, has said that money saved by using an estimated one-third less malathion next summer will go toward public education.
Ruth Berlin, the Annapolis psychotherapist who has been leading the fight against malathion, said she was disappointed. "I'm not done," she said.
Ms. Berlin said doctors linked her chronic health problems to exposure to malathion used to eradicate the Mediterranean fruit fly in California when she was living there.
She, her lawyer, Judith Billage of Annapolis, and Del. Marsha G. Perry of Crofton asked the council last month to recommend dropping malathion from the mosquito control program unless there was a "serious documented health hazard such as an outbreak of malaria or encephalitis."
There has not been a case of mosquito-borne encephalitis linked to a local mosquito population in Maryland since 1989, according to state officials.
Amy E. Brown, the panel's chairwoman and pesticide coordinator of the University of Maryland's cooperative extension service, said the panel lacked the authority to second-guess the federal Environmental Protection Agency, which has allowed the pesticide on the market for decades.
Malathion is being studied for re-registration.
Ms. Berlin said the advisory panel disregarded studies done outside the pesticide industry that may tie malathion to a variety of health risks.
Because of Ms. Berlin's protests, the state has changed the mosquito control program for Annapolis and Anne Arundel County. For the first time, communities will be allowed to choose whether to be included in the program or to be included without malathion.
Anne Arundel had been the only jurisdiction in the state in which 600 communities were automatically included unless they chose otherwise.
More than 30 communities have requested more information about malathion, and all of the approximately 200 others that signed up for mosquito control want the entire program, including malathion, said Kevin Sweeney, who runs the mosquito control program for Anne Arundel County.
The state uses larvicide, predatory fish and a false hormone to destroy young mosquitoes before turning to malathion to kill the adult insects.
This year, it used about 405 gallons of malathion in Anne Arundel County.