By Matt Johnson
As a kid, I remember ozone being a good thing. There was a layer of it in the stratosphere that protected us from the sun’s ultraviolet rays, but it was being destroyed by our use of chlorofluorocarbons like those found in aerosol sprays (remember aerosol deodorants?). But ozone*, a molecule of three oxygen atoms, is quite harmful to humans at ground level, which is why the Clean Air Act requires the EPA to set limits on it.
One of the most persistent and pervasive public health threats from air pollution, particularly for children in urban communities, is ozone (aka “smog”) because ozone is the prime ingredient with other noxious chemicals. Ozone is one of the leading causes of asthma and other respiratory distress, with both short and long term health problems from breathing unhealthy air at concentrations as low as 40 to 60 parts per billion (ppb). Yet some of our communities in Texas get smog pollution over 100 ppb – nearly twice the levels deemed safe by medical experts.
This summer, for the first time since ground level ozone monitoring began, Houston — in the heart of Harris County, the heaviest industrialized area in the nation for oil refineries and chemical and petrochemical plants— did not exceed the 1-hour ozone limit, although one exceedance occurred in Brazoria County, marking the fewest 1-hour exceedances in the HGB region since ozone monitoring began. In addition, DFW did not exceed the 1997 8-hour ozone limit. I recently sat down with Neil Carman, Clean Air Program Director, to explain the significance of these achievements, what exactly they are, and why we need to continue to reduce ozone.
TGR: Neil, first of all, what is the “1-hour” and “8-hour” standard?
NC: Simply put, these refer to ozone concentrations averaged over time. The Clean Air Act requires the EPA to establish standards for harmful pollutants, such as ground level ozone. Collectively these are called “National Ambient Air Quality Standards” (NAAQS) and when an area does not meet these standards, we refer to those as “non-attainment” areas because they have not attained the standards sufficient to protect humans. There are a few non-attainment areas in Texas, most notably the large Houston region (8 counties) and DFW region (10 counties). In 1997, EPA adopted the first 8-hr ozone standard of 80 ppb to replace the older 1-hr standard of 125 ppb in 1979. EPA has gradually phased out the 1-hr standard since most cities have been able to meet it, except Houston, Los Angeles and a few others.
TGR: So what happened in Texas this year with ozone levels?
NC: We had two major Clean Air Act milestones in Texas this year. First, the Houston area of eight counties is on track to fully meet the old 1-hr ozone NAAQS by having only a single 1-hr ozone exceedance for the first time on record compared to prior years when it had dozens. Second, the DFW area of ten counties is on track to finally attain the old 8-hr ozone NAAQS by having lower 8-hr ozone exceedance levels than previous years.
These air quality milestones prove that the Clean Air Act works for over ten million people living in the two largest urban areas of Texas!
Although, both Houston and DFW still need to comply with the current 8-hr ozone NAAQS set in 2008 at 75 ppb, but 2014 ozone levels show progress here as well.
TGR: If the air in Houston and DFW is still foul and harmful, why is attainment of these older standards such a big deal?
NC: Because industry and elected officials in the Texas Legislature and Congress have complained loudly for decades that the Clean Air Act does not work down here, and, more specifically, that Houston would never meet the old 1-hour ozone standard of 125 ppb. But in 2014, Houston and Harris County, for the first time since ozone monitoring began over 35 years ago, did not observe a single exceedance of the old 1-hr NAAQS despite the heavy concentration of industry. That is like a miracle!
To put this in context, the whole Houston region used to observe 40-50-60 days over the 125 ppb standard when the smog was really horrible! In 1999, Houston beat Los Angeles in exceedance days 52-41 and made headlines in the Houston Chronicle and L.A. Times. It was unthinkable that any city in the U.S. would top L.A. for more days with 1-hour violations but it happened in 1999 and two more years shortly after that.
Houston would still be in official nonattainment of the 1-hour ozone standard except in 2005 the EPA revoked the 1-hour standard since the 8-hour standard is in effect.
This is a really big deal because I heard the same mantra year after year in Houston in the 1990s that the area is so polluted that it will never be in attainment and compliance with the old 1-hour NAAQS. Now we can say that the Clean Air Act works really well and even polluted Houston has complied fully with the old 1-hour ozone NAAQS.
TGR: Now that progress is being made in these areas, however, the EPA has just announced a new ozone standard. What should people know about that?
NC: The previous EPA Clean Air Science Advisory Committee on Ozone (CASAC) had in fact recommended to the Bush EPA administrator Stephen Johnson (in 2007) that the proposed new ozone NAAQS should be less than 75 ppb based upon hundreds of medical studies. CASAC recommended no higher than 70 ppb.
We all thought the new ozone NAAQS would be set at 70 ppb but the Bush EPA set it at 75 ppb in March 2008 despite the unanimous recommendation of the 25 scientists on the EPA CASAC panel at the time.
Once Obama was elected in 2008, the new Obama EPA promised to revisit the Bush EPA ozone NAAQS of 75 ppb and appeared that it would be strengthened to 70 ppb but the Obama White House and Office of Management and Budget (OMB), punted to keep it at 75 ppb.
EPA, under court order, has now issued a new proposed ozone standard by, and will issue a final rule by October 1, 2015.
EPA is likely to propose a range of 60-70 ppb for 8-hours (based on the CASAC panel’s health recommendations) and 3-year average (4th highest), and lower the current ozone level of 75 ppb set in 2008 to no higher than 70 ppb for 8-hours.
TGR: What would that mean for Texas, assuming that the new standard is lower than 70 ppb?
NC: Texas now has two areas, DFW (10 counties) and Houston-Galveston-Brazoria (8 counties), classified by EPA in ozone nonattainment. A new EPA standard will rely on three years of ozone monitoring data gathered from 2014 to 2016 and EPA will make new designations in 2017.
Setting a new ozone standard at 70 ppb means Texas will add, besides the DFW and Houston areas with 18 counties, a group of new nonattainment areas of 11-12 counties. That would include San Antonio (five counties), potentially Longview-Tyler-Marshall (four counties), and Waco-Temple-Killeen (two to three counties).
Texas will have at least 32-38 counties in nonattainment. DFW area may expand to 12-15 counties.
Setting a new ozone standard at 65 ppb means Texas will have more ozone nonattainment areas. Additional areas may include: Beaumont-Port Arthur (3), San Antonio (5), Longview-Tyler-Marshall (4), Waco-Temple-Killeen (2-3), Austin (5), Corpus Christi (1-2), Victoria (1), and El Paso (1). Texas will have at least 41-43 counties in nonattainment.
TGR: Wouldn’t weather affect ozone levels, causing some areas that are borderline to go over or stay under?
NC: Yes. If we have more cooler, wet ozone seasons in 2015 and 2016, Texas could have fewer areas proposed in nonattainment designations than we thought in 2013.
TGR: What about the claim by the TCEQ that lowering the ozone standard will not be worth it? Essentially, that ground level ozone at the current standard is not harmful to humans now?
NC: This claim has been widely discredited by the scientific and medical communities. TCEQ made similar false claims in 1996-97 with the adoption of the first 8-hour standard. As I said, back in 2008 there was a unanimous recommendation by independent scientific and medical experts that the standard should be no higher than 70 ppb, and there is a mountain of studies to back this up.
To put it another way, the 75 ppb was never a scientifically tenable standard. It was a political compromise and now the EPA has to do the right thing and set the ozone standard at a level that science tells us it should be to protect human health.
TGR: What can people do to support a better ozone standard?
NC: First, stay informed. The Sierra Club will be monitoring and reporting on this process as it has been for years. The Lone Star Chapter will share information through our website, newsletter, and elsewhere.
Second, there will now be a 60-day period when the public can comment on the proposed new ozone standard. This is a great opportunity for people to voice their support for a standard based on science. There will be opportunities to send in your comments and also share your support at public meetings. I suspect there will be a hearing in Dallas sometime next year on the new standard.
Third, spread the word. If you are concerned about asthma, other lung diseases, and health problems that ozone makes worse, tell your friends, neighbors, and family. The more people understand that lower ground level ozone levels saves lives, the more likely our elected officials will do the right thing and support better standards.
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*Ozone is not emitted directly into the air. It is created by chemical reactions between nitrogen oxides (NOx) and volatile organic compounds (VOC) most often during hot summer days. These pollutants come from many sources, such as burning coal and car exhaust.