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Soot is an Underrated Threat, Scientists Say

Soot gets less attention in Texas than the big daddy of air pollution, ozone. But scientists say that it is a growing threat for Texans, and the Environmental Protection Agency is tightening standards.

Robert J. Griffin, a soot expert at Rice University in Houston, in his on-campus lab on Wednesday, June 20, 2012.

HOUSTON — In a laboratory at Rice University, a small machine hums, drawing in outside air through a tube and analyzing its soot content.

“We can tell when someone walks by with a cigarette,” said Robert Griffin, an associate professor in the department of civil and environmental engineering.

Non-smokers also breathe in soot, sometimes known as particulate matter. It is a type of pollutant that increasingly concerns scientists as they uncover new links to heart and lung problems.

In Texas, soot has received less attention than ozone, the top statewide air-pollution issue. Environmentalists partly attribute that to insufficient monitoring. They fear areas with wildfires, heavy truck traffic or manufacturing facilities may be especially vulnerable.

“We’ve had very little monitoring — not just in Texas but around the country,” said Ilan Levin, the Austin-based associate director of the Environmental Integrity Project, which has recently sued operators of two Texas coal-fired power plants over their soot emissions.

Most major Texas cities are in compliance with current federal standards for soot. But the Environmental Protection Agency announced last month that it would tighten requirements by up to 20 percent for a certain type of particulate matter. The standards are due to be finalized by December.

The EPA does not expect any Texas counties to be out of compliance with the new regulations by 2020, the year they take full effect. But Barry Lefer, an associate professor of atmospheric science at the University of Houston, said that Houston could fall short of the new standards in the shorter-term, depending on how strict they are.

On Monday around midday, hourly measurements for fine particles — which scientists say are especially dangerous for the lungs and less understood than coarse ones — showed concentrations in Beaumont-Port Arthur and the Houston area that were substantially higher than those in West Texas. (Dust-prone El Paso County is the only part of Texas that currently does not meet federal standards for coarse particles.)

The Texas Commission on Environmental Quality says it knows of 89 monitoring stations around the state for various types of particulate matter. Scientists say that is not enough. However, the stations are expensive: setting up a monitoring site and operating it for a year can cost anywhere from $12,000 to $240,000, the TCEQ says.

In September 2013, NASA will launch a four-week campaign to analyze air quality over Houston using satellites and airplanes. Griffin and Lefer will assist in the work, and expect a better picture of particulate matter to emerge, including its links to ozone, which is sometimes created by the same pollution ingredients.

“The particulate matter folks used to think ozone was completely separate, and vice-versa,” Lefer said. Over the course of his career, he added, “I’ve seen the merging of these two worlds.”

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