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Thursday, March 27, 2014

Houston’s air-quality issues: Interlinking problems

Monitoring Air Pollution

Finding ways to develop effective pollution-reduction strategies

Accurate air pollution monitoring – the focus of much of research scientist Alex Cuclis' work for HARC - is essential to efforts to clean the air in Houston and other locations in Texas.

Houston has long had a reputation as the city with the worst air-quality problems in Texas and, at various times, some of the worst in the country.

Accurate and complete measurements arm regulators, researchers, business officials and public-health advocates with information needed to develop effective pollution-reduction strategies.

Houston has long had a reputation as the city with the worst air-quality problems in Texas and, at various times, some of the worst in the country. Three key issues have been, and continue to be, central to efforts to achieve cleaner air in the metropolitan region.

Ozone – A corrosive form of oxygen, ozone forms in sunlight from reactions among various air pollutants, including volatile organic compounds (VOCs) and nitrogen oxides, emitted by industries, cars and many other sources. The main ingredient of smog, breathing ozone is a respiratory irritant associated by scientists with health impacts including lung damage, asthma attacks, heart disease and early death. Houston's once nation-leading ozone levels have declined over the past decade, but ozone has remained the metro area's biggest air-quality challenge. Houston has never achieved a national health standard for ozone. An Environmental Protection Agency report released in February attributed ozone-linked health problems to levels lower than the current standard. The Houston Chronicle reported at the time that the report "sets the stage for tighter restrictions for ozone that even some environmentalists say may be impossible for the eight-county Houston region to achieve on a consistent basis." Such restrictions, the newspaper reported, would trigger new pollution-reduction requirements in several other Texas cities, as well.

Particles – Houston does not violate the national health standards for particle pollution but has come close to violation status on occasion over the years. An EPA decision is expected by the end of this year on whether the Houston region meets or violates the standards. A violation ruling would prompt Texas officials to develop regulatory control strategies. The smallest particles, generated by various pollution sources, can travel deep into people's breathing passages and lungs. (Nitrogen dioxide, linked to ozone formation, is also sometimes a precursor for tiny particles to form.) Particle pollution has been linked by researchers to health impacts including premature death among people with heart or lung disease, nonfatal heart problems, asthma attacks, decreased lung function and increased respiratory problems, according to the EPA. A Houston Chronicle analysis last year concluded that more than 80,000 children in Houston attend school near freeways or other major roads, where they may be exposed to ultra-fine particles in vehicle exhausts, as well as nitrogen oxides, carbon monoxide and potentially cancer-causing pollutants from diesel models' tailpipes.

Air toxics - Airborne toxic chemicals, or "air toxics" as they are commonly known, have been a perennial issue in Houston for decades, especially in specific locations near industry, such as the Manchester neighborhood on Houston's east side, where HARC recently assisted a pollution-monitoring project carried out by three environmental groups (see “Alex Cuclis: Working for better air pollution monitoring”). Air toxics, emitted by industrial facilities, motor vehicles and many other sources, include chemicals linked to cancer, neurological damage and an array of other potential health impacts, which they may cause by themselves or in combination with other pollutants. Some air toxics are VOCs and also contribute to ozone formation. Concerns voiced about air toxics in Houston since the 1970s were exemplified by a 2006 study, funded by Houston Endowment and carried out by researchers at several local institutions. The researchers at Rice University, Baylor College of Medicine, Texas Southern University, University of Houston Law Center and the University of Texas Medical Branch in Galveston recommended "immediate action" to reduce ambient levels of four substances – benzene, 1,3-butadiene, formaldehyde and diesel-emitted particles. A Rice scientist said local concentrations of the four pollutants that were detected then posed "a dangerously high risk of cancer and other health problems" for some residents.

In a recent legal development pertinent to all three of those air-quality issues in Houston, the EPA announced last month that it had settled a lawsuit by Air Alliance Houston, Texas Environmental Justice Advocacy Services (TEJAS) and other environmental groups, agreeing to review the agency's decades-old methods for estimating emissions from refineries.

HARC does not engage in issue-related advocacy work and therefore was not a party to the environmental groups' lawsuit, but Air Alliance, publicizing the settlement, echoed numerous statements by HARC's Cuclis about remote-sensing pollution measurements in noting that such research has pointed to apparent underestimates of industrial facilities' air pollution with EPA-approved methods.

Larry Soward, board president of Air Alliance and a former member of the Texas Commission on Environmental Quality, wrote about the settlement that "many believe refinery emissions nationwide are vastly under-reported – with actual emissions 10 to 100 times greater than EPA estimates - and this long-overdue review will very likely reveal higher pollution levels in Houston and nationwide. If the emissions levels are indeed under-reported, it should also result in more protective standards limiting the amount of hazardous air pollutants that refineries release into the air throughout the U.S."