Worcester, Middlesex Counties Delay Aerial Mosquito Spraying

MILFORD, MA — Aerial spraying was delayed in communities in Worcester and Middlesex counties until Monday afternoon. Spraying was originally planned for Sunday but weather conditions delayed the process. This weekend, a Fairhaven woman was the first person in Massachusetts to die from Eastern equine encephalitis virus this year, according to social media posts from her family and her husband's union.

The spraying comes after 37 communities in the state were labeled at high or critical risk for the Eastern equine encephalitis (EEE) virus.

There are 17 communities scheduled to be sprayed, many of which are in the MetroWest. The communities include:

• Framingham
• Ashland
• Grafton
• Westborough
• Northborough
• Worcester
• Milford
• Berlin
• Hopkinton
• Marlborough
• Upton
• Millbury
• Northbridge
• Shrewsbury
• Sudbury
• Sutton
• Southborough

The sprayings could last several evenings.

The second human case of EEE was reported in Grafton on Aug. 16, elevating the risk level for several neighboring communities. EEE is a rare but serious and potentially fatal disease. The first two human cases of EEE in Massachusetts since 2013 were announced on August 10 and August 16 and are an indication of the current significant risk of EEE in the commonwealth.
While spraying doesn't completely eliminate the risk and presence of mosquitoes it is a tool against the spread of the EEE virus. DPH officials still urge residents to limit time outdoors in the evenings and wear bug spray.

The pesticide used is called Anvil 10+10, the Department of Public Health described the pesticide as, "A product extensively tested and used in both ground-level and aerial spraying in the U.S. to control mosquitoes. Anvil 10+10 contains two ingredients: Sumithrin and Piperonyl butoxid. Sumithrin is an ingredient similar to the natural components of the chrysanthemum flower which is also found in other pesticide products used indoors, in pet shampoos, and tick control treatments." The DPH said Sumithrin is rapidly inactivated and decomposes with exposure to light and air, with a half-life of less than one day in the air and on plants. In soil, it degrades rapidly. "Sumithrin has proven to be extremely effective in killing mosquitoes worldwide for over 20 years. Piperonyl butoxide serves to increase the ability of Sumithrin to kill mosquitoes," the DPH said.

There are no health risks expected during or after spraying and according to the DPH, there is no evidence that aerial spraying will exacerbate certain health conditions such as asthma or chemical sensitivity. You don't have to take any special precautions but you can reduce exposure by staying indoors during spraying. Aerial spraying is not expected to have any impacts on surface water or drinking water.