U.S. EPA moves Stark from non-attainment to attainment for two previous National Ambient Air Quality Standard reports.

The Canton-Massillon area is now achieving air quality standards it was previously unable to meet, according to the U.S. Environmental Protection Agency.

The agency redesignated the area as being in line with the National Ambient Air Quality Standard. It was unable to meet two previous tests, but data obtained from 2009 through 2011 now shows conditions improving.

Officials credited a reduction in emissions from the Marathon Petroleum Refinery, other industries and motor vehicles and the use of cleaner fuels for the improvements.

The area has had healthy levels of fine particle matter since 2008.

In addition to “confirming” that air quality here has improved, Air Pollution Control Division Administrator Terry Dzienis of the Canton Health Department said the designation clears the way for new industries to build here. The Canton Health Department is responsible for monitoring air quality for Stark County.

Stark County was forced to implement rules to control emissions because it wasn’t meeting standards in 1997 or 2006. A report for 2012 standards has not yet been issued. Dzienis said part of the reason the county wasn’t able to meet standards in 2006 was due to malfunctioning equipment.

Fine particulate matter is a mixture of microscopic solids, like soil and dust particles and metals, and liquid droplets. Exposure to fine particulate matter can lead to premature death from heart or lung disease.

In April, the American Lung Association, which has much more stringent air-quality ratings, gave the area a failing grade on its “State of the Air 2013” report card because of smog and particle pollution, but noted that it had made great strides to improve air quality.

Dzienis said at the time that the grade was “open to interpretation.”