Helicopters Will Buzz Boston Marathon Route To Check For Radiation

WAYLAND, MA — Don't worry if you see a helicopter flying very low over the next few days — it's just a nuclear security check.

The U.S. Department of Energy’s National Nuclear Security Administration will be flying helicopters as low as 150 feet in the air above the Boston Marathon route ahead of Monday's race. The flights began on Wednesday, according to the agency.

"NNSA’s Nuclear Emergency Support Team (NEST) aircraft will measure expected background radiation as part of standard preparations to protect public health and safety on the day of an event," the agency said in a news release.

The radiation checks will be conducted with a twin-engine Bell 412 helicopter equipped with special sensors. The chopper will be checking the route in a grid over the next few days, and flights will only take place during daytime hours, the agency said.

"These surveys are a normal part of security and emergency preparedness activities. NNSA is making the public aware of the upcoming flights so citizens who see the low-flying aircraft are not alarmed," NNSA said.

The 2022 Boston Marathon begins Monday morning in Hopkinton. The race route traces Route 135 through Ashland, Framingham and Natick before heading northeast along Route 16 in downtown Wellesley.