Washington: The US Environmental Protection Agency has announced that it is tightening federal air pollution standards by setting more stringent ozone limits for the first time in a decade. "EPA today met its requirements of the Clean Air Act by signing the most stringent eight-hour standard ever for ozone, revising the standards for the first time in more than a decade," the EPA said in a statement yesterday.

The rules on smog-forming ozone restrict the amount of nitrogen oxides and other compounds that are allowed to be released by power plants, motor vehicle exhaust, industrial facilities and other man-made sources, the EPA said. The primary and secondary eight-hour ozone thresholds are now 0.075 parts per million (ppm), compared with the previous standard set in 1997 at 0.08 ppm.

"Because ozone is measured out to three decimal places, the standard effectively became 0.084 ppm: areas with ozone levels as high as 0.084 ppm were considered as meeting the 0.08 ppm standard, because of rounding," the EPA explained. EPA Administrator Stephen Johnson said the new guidelines will help protect public health and the environment.

"By meeting the requirement of the Clean Air Act and strengthening the national standard for ozone, EPA is keeping our clean air progress moving forward," Johnson said.

EPA said it estimated the value of health benefits of the stricter regulations at between USD two billion and USD 19 billion, with the cost of implementing the new standards estimated between USD 7.6 billion and USD 8.5 billion.

Source : PTI