Aerial spraying for Eastern Equine Encephalitis will begin after 8 p.m. tonight and Saturday, weather permitting.

If the temperature, wind and rain cooperates, an aircraft with ultra-low volume sprayers will disperse a pesticide with the product Anvil 10+10 over the area to reduce public health risks from EEE viral exposure. The Department of Public Health notified local health departments that the town of Canton has had a EEE positive bird-biting mosquito sample. There is no change to the risk levels for Canton or surrounding towns at this time. The emergence of EEE in more mosquitoes in Easton triggered the decision to spray. It is not done in the beginning of mosquito season because of the pricetag.

"To spray beforehand would just be too expensive as it costs about a million dollars per spray," said Norton Health Agent Leon Dumont.

In addition to Norton, towns being sprayed are Acushnet, Berkley, Bridgewater, Carver, Dighton, East Bridgewater, Easton, Freetown, Halifax, Hanson, Kingston, Lakeville, Middleborough, Pembroke, Plympton, Raynham, Rehoboth, Rochester, Taunton and West Bridgewater.

According to the Massachusetts Department of Environmental Protection, the pesticide 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. Studies in animals have not reported effects on reproduction, birth defects, or cancer when animals were exposed to Sumithrin. The primary mode of action for Sumithrin is to target the nervous system. There are no data directly on whether Sumithrin causes cancer, birth defects, or reproductive effects in people. The US EPA has determined that Sumithrin is unlikely to be carcinogenic to humans.

Sumithrin is highly toxic to honeybees, fish and other aquatic life forms. Sampling of surface waters and biota will be conducted in conjunction with aerial application spraying. To reduce such risks, EPA has established specific precautions on the label including restrictions that prohibit the direct application of Sumithrin in the daylight when bees and aquatic lifeforms are active. It is also restricted to open water or within 100 feet of lakes, streams, rivers, or bays. However, spraying will take place up to the shores of surface water bodies.

A decision has been made by senior state environmental and public health authorities to incur this risk to aquatic biota in the interests of getting the most effective control of disease carrying mosquitoes and thereby reducing the likelihood of these infected mosquitoes biting humans and transmitting the EEE virus to them. 

You can reduce/eliminate your exposure risk to the insecticide by staying indoors during spraying. The active ingredients of the pesticide product as it is used for aerial application for mosquito control generally break down quickly and do not leave a toxic residue. To reduce potential exposure, however, follow these tips:

• If the immediate area of your home is being sprayed, keep windows closed and fans off. Shut off air conditioners unless they have a setting for recirculating indoor air. In very hot weather, make sure you open the windows or turn fans and air conditioners back on soon after the aerial spraying is completed.
• Rinse any homegrown fruits and vegetables with water.
• Keep pets indoors during spraying to minimize their risk of exposure. Pets that remain outdoors could be exposed to small amounts of pyrethroids, but would not be expected to experience adverse health effects from the spraying. 
• If possible, shelter or cover outdoor holding areas for particularly sensitive animal groups such as fish or other contained aquatic biota. 
• If skin or clothes or other items are exposed to the sprayed pesticide, wash with soap and water.
• If the spray gets in your eyes, immediately rinse them with water or eye drops, and call your doctor.
• Because Anvil breaks down quickly in sunlight and water, and considering dilution factors, no special precaution or waiting periods are recommended for outdoor swimming pools or beaches.