The Wall Street Journal: Trump administration won’t tighten existing ozone standards

The Trump administration plans to retain a national limit of 70 parts per billion for the pollutant ozone, the standard set by the Obama administration five years ago after business groups fought tougher standards.

The Clean Air Act requires the Environmental Protection Agency to review ozone, soot and a handful of other named pollutants every five years, with a mandate to consider only the latest science on public health and not the cost of implementation.