Tablet Opinion

Richard Greene: Dallas-Fort Worth air quality improving

Having served in the Environmental Protection Agency for a number of years, I often encounter folks who express concern that DFW air quality is “really bad” and getting worse.

Their impressions are almost always the result of what they read or hear in media reports about ozone levels and related health issues. They are usually snapshots of incidents that qualify as newsworthy.

As such, they are incomplete. This statement is not so much a criticism of news coverage as it is to recognize how complex the issues are and how limited the space is to explain them comprehensively.

Then there is a lot of political noise that gets mixed in along with positions expressed by environmental groups on one end of the discussion and business interests on the other.

I don’t have enough space here to do justice to the entire subject of air quality in our region, but I can address, with some factual data, the two concerns cited above.

First, the EPA uses a five-category classification system — marginal, moderate, serious, severe and extreme — to define areas with unhealthy ozone levels.

The DFW area’s air quality under the latest federal standard is classified as moderate, a two on the five-point scale. Planning is underway to remove the region from the classification altogether by the 2018 compliance deadline.

Second, EPA informs us in their latest reports that “Air quality has improved continuously across the U. S. since the Clean Air Act was amended more that two decades ago.”

That improvement is especially impressive in Texas, as the state has recorded a 24 percent reduction in ozone levels since 2000 as compared to the average 12 percent reduction in all states.

What’s even more telling in this achievement is that Texas, among the fastest-growing states, has benefited from the largest reduction in ozone of them all.

Closer to home, during the past 20 years while the DFW area was becoming the fastest growing urban area in the country, ozone levels have been reduced by about 20 percent.

Ozone forms in the atmosphere when air pollutants are combined with high temperatures in bright sunshine and there is little or no wind. By the middle of last week, we were about two-thirds of the way through this year’s ozone season, with no countable exceedance of the current standard at any of the region’s 20 air monitors.

Higher numbers are likely before the summer is over. Weather continues to be the greatest force in all of this, and it’s the one thing that can’t be regulated by any government.

The principal pollutants leading to ozone formation are nitrogen oxides (NOx), and we get about 70 percent of those harmful substances from vehicles operating in our region.

Industrial sources such as power plants, cement plants and oil and gas operations combine to account for about 15 percent.

Here’s some really good news about the reductions of these emissions: In 1999, NOx levels in the region totaled about 550 tons per day. This year we will experience about 160 tons, a decrease of more than 70 percent even with very substantial increases in vehicle miles traveled every day.

Most of that improvement is due to cleaner engines and fuels. As older vehicles are replaced with newer models, we get closer and closer to full compliance with federal air quality standards.

Improved air quality results in longer, healthier lives. A little research on the extensive websites of federal and state environmental agencies will provide optimism and assurance that the nation is on the right track in this long journey to clean air.