The U.S. Environmental Protection Agency has set a stronger standard for soot.
The EPA this week lowered the maximum concentration for fine particulate matter by 25 percent.
The agency says the new standard will prevent thousands of premature deaths and produce $46 billion in net health benefits in the next eight years.
Since 2000, the EPA says fine particulate matter has decreased 42 percent in outdoor air.
The agency confirms that all 55 of West Virginia’s counties meet the new standard.
Most U.S. counties already meet the standard. Heavily industrial states such as Pennsylvania and Ohio have several counties that will have until 2032 to meet the new limit for soot.