WAYNESBURG, Pa. (AP) -- The Pennsylvania prison system is putting in place new policies on mail handling, visits and detection of drones after a month in which about 50 staff reported symptoms that may have been caused by exposure to toxic chemicals.
Gov. Tom Wolf announced it Wednesday.
Pennsylvania's 25 prisons have been on lockdown for a week while officials investigate the spate of illnesses.
The cause is suspected to be a clear, odorless substance known as synthetic marijuana that can be concealed in the paper of books and letters.
Inmate mail will be processed outside of the prisons, except legal mail.
The state is expanding its detection of drones and use of body scanners. Visiting room staff will be doubled and photos and vending machines won't be allowed for 90 days.