Nitrogen Oxide Standards Not Strong Enough

Nitrogen oxides are a group of harmful gases spewed by tailpipes and smokestacks. They form when fossil fuels are burned and pose serious health threats.

So serious in fact, that the Clean Air Act requires a limit be set on the amount of nitrogen oxides in our air. This limit is called an ambient air quality standard. By law, ambient air quality standards are supposed to be based solely on what is needed to safeguard our health.

And right now, the U.S. Environmental Protection Agency is reviewing the latest science to see if current ambient air quality standards for nitrogen oxides fully safeguard our health. The agency just released a draft science assessment reviewing hundreds of studies. The overarching conclusion of all these studies is that nitrogen oxide standards need to be strengthened considerably.

While current standards limit annual average nitrogen oxide concentrations to no more than 53 parts per billion, recent studies have found that short-term (1 hour to 24 hour) concentrations much lower pose serious health impacts. Here's some specific findings from the science assessment:

• Recent studies provide strong scientific evidence that nitrogen oxides are associated with a range of respiratory effects, even where the range of 24-hour average concentrations are below the current standard of 53 parts per billion.
• There is a suggestive link between nitrogen oxides and premature death, although additional research is needed to explain the link.
• The new body of epidemiological data provides strong evidence of associations with increased emergency room visits and hospital admissions for respiratory causes, especially asthma and emphysema, and short-term ambient exposure to nitrogen oxides.
• There is strong evidence of partially irreversible decreased lung function growth and lung function capacity among children with long-term exposure to nitrogen oxides from traffic.

The science assessment found that concentrations as low as 5 parts per billion over a 24-hour period adversely affect our health, especially the health of our children. Yesterday in Denver, the 24-hour average nitrogen oxide concentration was 19 parts per billion.

So what does this all mean? It means that we have our work cut out for us. It also means that we have all the more reason to be pushing for a shift from our reliance on fossil fuels toward clean, renewable sources of energy and transportation.