Professor sheds light on the issue of Houston’s air quality

Professor sheds light on the issue of Houston’s air quality

Houston’s air quality has been national
news to the point that the Houston Chronicle recently reported
that it is affecting recruiting by Houston businesses and
institutions. Terry Shepard, vice president for public affairs,
discussed the issue with Matthew Fraser, assistant professor
of environmental science and engineering. Fraser is co-principal
investigator of the Gulf Coast Aerosol Research and Characterization
Program, a 16-month study funded by the U.S. Environmental
Protection Agency.

Shepard: How do scientists react to headlines like “Houston passes L.A. in smog” or “Los Angeles
retakes lead in air pollution”?

Fraser: Do we think that they are technically correct?
No. What we like to do is look at the trend of ozone and
various other pollutants. I have a graph showing what Los
Angeles and Houston have been doing for the last 20 years
as far as the number of days they violate the ozone regulations.
That’s a better way of doing it than just a single
year’s data within the trend. (See graph.)

Shepard: Looking at the graph, it appears that Houston’s
number of ozone violation days are actually somewhat fewer
than in the 1980s. The difference seems to be that Los Angeles
has improved more and faster.

Fraser: Yes. Houston has slowly improved air quality
in the last 20 years. Los Angeles has improved dramatically.
In 1990, Los Angeles decided that the best way to reduce
ozone concentration was to control emissions of NOX, nitric
oxide. Texas pursued the NOX waiver and has not aggressively
pursued NOX emissions. Controlling NOX requires modifications
of many combustion sources—cars, chemical refineries,
power plants, even home water heaters—to aggressively
reduce NOX emissions.

Shepard: So, the reality is considerably more complex
than headlines or sound bites would indicate. What is the
reality of today’s Houston air quality?

Fraser: Houston has a serious problem with ozone
concentrations. That’s what people commonly refer to
as smog—a nonscientific term that comes from combining
the words smoke and fog. However, ozone is only one compound
in the hundreds of compounds that have serious effects on
people. We have an ozone problem. We also have a problem
with fine particulate matter, which causes hazy days with
reduced visibility.

Shepard: Houston violates the EPA ozone standard. Don’t
some other cities violate multiple standards?

Fraser: Yes. There are six pollutants that the EPA
has identified and set air-quality criteria for. They are
ozone, carbon monoxide, sulfur dioxide, nitrogen dioxide,
particulate matter and lead. Los Angeles has historically
violated—routinely violates—standards in ozone,
particulate matter, carbon monoxide and, occasionally, nitrogen
dioxide. There are about 180 other compounds—hazardous
air pollutants, such as benzene and asbestos—of which
the health effects are less well understood. There are no
EPA benchmarks for these, and they are regulated by a separate
set of criteria.

Shepard: If the EPA has standards on six pollutants,
why does ozone get all the headlines?

Fraser: Nationally, about 100 million people live
in areas that exceed the ozone standard—areas that
the EPA considers unhealthy. That’s about one-third
of the country’s population. The next largest violations
are for particulate matter and there you’re talking
less than 20 million people. So it’s just the sheer
numbers.

Shepard: Is ozone more harmful than other pollutants?

Fraser: It depends on how you look at it. There are
definite known health hazards for ozone—things like
irritated lungs, coughing, wheezing, upper respiratory infection—but
there also are hazards with other pollutants.

Shepard: On balance, how does our air compare to
that of L.A. or other big cities?

Fraser: We have really bad episodes. In the last
two years, we’ve had higher levels of ozone per year
than anywhere in the world, so we have really bad episodes.
It’s just the episodes of stagnation, when it’s
hot and sunny and the wind doesn’t blow. We violate
the EPA standard 50 days out of 365 days—about once
a week. Once a week, somewhere in Houston, the air is considered
unhealthy.

Shepard: Is that year-round or mostly in summer?
Put another way, does this affect students who are gone
in the summer?

Fraser: Most of the violations are in June, July
and August, when school is out. But we do have violations
at other times during the year. This year, our first episode
was in February.

Shepard: When you are recruiting, what do you tell
people about coming to live here?

Fraser: I think that when you are thinking about
where you want to live, you look at a variety of things:
art, theater, shopping, restaurants, the weather, the cost
of housing. How do you weigh those things? If you don’t
have an upper respiratory problem, air quality is one of
many factors. Of course, if you have existing respiratory
problems, Houston may not be for you. There are things you
can do to actively reduce your exposure to ozone. If you
are concerned about ozone, when there is an ozone warning,
you can avoid going outside and stay inside in an air-conditioned
building. I would tell people not to run outdoors on those
days in the afternoon. Just try to change your schedule.

Shepard: Why does staying inside in air conditioning
help avoid ozone?

Fraser: Ozone is a very reactive compound. When you
bring it indoors, it reacts with your carpet and everything
it comes into contact with in your home, including air conditioning.
Indoor air has minimal ozone.

Shepard: Is the air better in different parts of
the city or does ozone travel pretty freely?

Fraser: It depends on which way the wind is blowing.
The worst is when there is stagnation.

Shepard: What would it take to improve our air?

Fraser: The TNRCC [Texas Natural Resource Conservation
Commission], the agency in charge of air quality operations,
is in the process of submitting an implementation plan for
how they can get our air quality to meet all of the federal
air-quality standards. They are coming up with ideas for
legislation on vehicles and industries. Beginning in 1970
we had a series of containment deadlines—the original
one was 1977—that were constantly pushed back. But
there is a feeling now that it’s been pushed back enough,
and we need serious air-quality solutions. A lot of people
think that the new deadline, 2007, is firm. If we don’t
meet air-quality standards by that date, there will be serious
consequences.

Shepard: Who will be affected by the changes?
Fraser: Industry, in the regulated community, is most affected
because they have to change their practices. They are already
up against the deadline. In order to get air pollution control
equipment installed and operating properly for the eight-county
area, it’s going to affect about 1,300 industrial facilities.
Industries know they have to change. The legislation is
already in process.

Shepard: What about cars?

Fraser: Cars in Texas that are bought now are significantly
better than they used to be. But federal standards are getting
much more strict, so by 2004, the cars we are driving now
will not be in compliance. SUVs have less stringent emissions
standards, although there are future plans to improve that.
Half of the cars we buy today will be on the road in 2006,
which is when we have to make compliance. So it’s really
hard because a lot of people say that we need to have cleaner
cars, but it takes a while for those cars to get into use.

Shepard: You’re a scientist, not a politician.
But what’s your sense of the political will to turn
things around?

Fraser: I think there has been a shift. When the
business community realized that we were having a problem
attracting employees to Houston, they were much more willing
to make the sacrifices to reduce emissions in their industries.
Especially now that the problem has achieved national prominence.

Shepard: Is this a public relations problem or a
real problem?

Fraser: We have a real problem that goes deep. It’s
going to be very difficult. Everybody, not only industry,
but also the average person, is going to be affected somehow.