Massachusetts public health officials are looking into safety and compliance issues at an MIT lab containing a deactivated electron accelerator.

The state's Radiation Control Program says in an Oct. 17 letter obtained by The Associated Press that it has opened an investigation into the university's Bates Research and Engineering Center in Middleton following a complaint.

Former Massachusetts Institute of Technology researcher Babak Babakinejad says he's concerned he and other workers were exposed to low levels of radiation from the accelerator, which was used for scientific experiments until being shut down in the early 2000s.

Babakinejad is a critic of the university's Open Agricultural Initiative, which is based at the lab.

MIT confirmed state officials visited the site last Tuesday in response to the allegations and that it's cooperating.

A state public health spokeswoman declined to comment.