PORTLAND, Maine — Sen. Susan Collins is joining a pair of Democratic senators to call for a review of the Environmental Protection Agency’s operation of air quality monitoring networks.

Collins, a Maine Republican, is joining Rhode Island Democratic Sen. Sheldon Whitehouse and Delaware Democratic Sen. Tom Carper on the request. They say they want the Government Accountability Office to conduct a “top-to-bottom review” of the EPA’s air quality monitoring work.

The senators say the review should include a look at whether the monitoring networks provide enough good-quality data to help protect vulnerable populations from air pollution.

The senators say emissions carried on prevailing winds from Midwestern smokestacks often end up in downwind states on the East Coast, such as their own.