Although Houston’s pollutant and ozone levels have improved over the last 25 years, the region’s air quality is still not meeting the Environmental Protection Agency’s standards, experts say.
According to the Texas Commission on Environmental Quality, from 2000 to 2016, the Houston-Galveston-Brazoria population increased by 44 percent, while ground-level ozone levels improved by 29 percent.
Stuart Mueller, operations manager for Harris County Pollution Control Services, said TCEQ released rules in the early 2000s regarding nitrogen oxides and organic compounds—which can be precursors to ozone formation—that contributed to the decline in ozone.
The American Lung Association’s 2018 State of the Air Report—which was released April 18 and studied Houston air between 2014 and 2016—found that Houston reported its fewest unhealthy ozone days ever since the study has been conducted.
Despite this progress, Houston is still not meeting EPA standards.
“We are getting this uptick in pollution—not anywhere near the levels that we saw 10, 15 years ago—but it isn’t on that same steady decline that we had been seeing,” said Stephanie Thomas, a Houston-based organizer and researcher for Public Citizen, a nonprofit political advocacy organization.
Houston-Galveston Area Council experts anticipate, under the EPA’s 2008 standards and based on previous years’ emissions, the EPA will reclassify Houston as “serious” this summer, meaning the region’s air quality has not improved enough to meet EPA standards.
“We have a ways to go [to improve air quality in Houston],” H-GAC Air Quality Manager Shelley Whitworth said.
Contributing factors
The Clean Air Act, a federal law passed in 1970 to control air quality, makes it a requirement for the EPA to issue standards known as the National Ambient Air Quality Standards for six criteria pollutants, according to the EPA’s website.
Experts have said two of the most critical to Houston are particulate matter and ground-level ozone. Different from stratospheric ozone—which is found naturally in the atmosphere—ground-level ozone is created from natural and man-made chemical compounds and pollutants, according to the TCEQ.
TCEQ Media Relations Specialist Andrew Keese said the TCEQ uses its network of ozone monitors across the Greater Houston area—including one off Telge Road south of the Grand Parkway—to track emissions.
Another factor is increased traffic on roadways, said Alan Clark, director of transportation planning for H-GAC.
“When we adopt a new plan, when we fund new projects—particularly those that are of significant regional impact—we have to perform an explicit air quality analysis, using the TCEQ’s process for measuring emission impacts to show, to demonstrate, that we will continue to be on track to meet the emissions reductions required in that [plan],” he said.
Effects and solutions
Despite progress toward cleaner air, Houston has never reached attainment—the acceptable standard—for ground-level ozone, according to the TCEQ.
The EPA measures ozone in terms of parts per billion and changed acceptable standards from 75 ppb to 70 ppb in 2015. Data collected from 2013 to 2015 measures ozone levels in Harris County at 79 ppb, according to a 2016 TCEQ report submitted to the EPA.
“Having higher than the standard levels of ozone can actually be harmful to our health,” Thomas said. “Ozone creates a number of respiratory issues, and children are especially vulnerable as well as the elderly and people who have pre-existing conditions.”
Although Houston’s ozone levels have dropped from highs of 230-250 ppb in the late ’90s, there is still work to be done to identify problem areas, officials said.
Considering the progress the city has made, Whitworth said Houston’s inability to meet the standard for ozone proves other solutions need to be looked at.
Thomas said TCEQ has a number of programs that could help reduce vehicle emissions, including the Texas Emissions Reduction Plan. The program helps companies and government agencies apply for funding for cleaner vehicles.
“If you are driving a truck that is 20 years old, you are going to be contributing significantly more air pollution than a truck that is a year old,” she said.
Latrice Babin, deputy director of Harris County Pollution Control Services, said she agrees mass transit can help.
“When you drive your vehicle, when you idle your vehicle—all of those things contribute to the soup that is ozone and the air quality of our area,” she said.
The department receives about 1,500 pollution complaints annually that it investigates, about half of which involve air quality, Babin said.
“Air permits are in place for industrial facilities, but each person has to do their little bit,” she said.
Additional reporting by Shawn Arrajj
