The EPA Is Limiting Data Collection on a Harmful Air Pollutant

Published Apr 30, 2019

In 20 US states EPA no longer uses the technology best supported by science to monitor NOx pollution.

What happened: In 20 US states (mostly on the US East Coast) and in Washington DC, the Environmental Protection Agency (EPA) no longer requires the use of a “gold standard” to measure the amount of nitrogen oxides (NOx) escaping from industrial facilities and polluting our air. In the rule’s text, the EPA admits that by not using the technology best supported by science, there will be less high-quality data available to monitor how much NOx pollution is escaping from hundreds of the nation’s largest industrial facilities.

Why it matters: Policies based in science that protect public health are only as effective as their informing scientific data. When the EPA decides that poorer data collection methods should be codified into policy, it becomes difficult for the agency to fulfill its mission to protect human health and the environment. The Clean Air Act sets strict standards for NOx in a similar manner as it does for particulate matter and lead because NOx pollution is known to be incredibly harmful to both humans and the environment. It can increase the risk for asthma, can cause severe coughing and wheezing, and is one of major components of smog. Fossil-fuel electric utilities – the facilities that are specifically targeted by this change in regulation – are known to be one of the most prominent sources of NOx pollution in the air. Only by measuring air pollution well do we have any chance of protecting people and the environment from its harms.


Learn more about how the EPA modified a 1998 rule to allow industrial facilities to use less scientifically valid methods to monitor for NOx pollution, a rule that is partially responsible for the reduction of NOx gases by 82% from these industrial facilities in the last 20 years.