Many of the primary sources of pollution in Greater Houston converge in east Harris County. The Houston Ship Channel passes through the area, major highways intersect it, and petrochemical plants and refineries border its neighborhoods.

Juan Flores has lived with this reality for most of his life in Galena Park, east of Houston. He is raising a family there.

“I’m in the point of my life when if stuff smells, I don’t smell anything anymore,” he says as he stands by the ship channel, surrounded by smokestacks and massive chemical storage tanks.

“Any new threats,” he says, “it’s a scary scenario.”

The state is considering changes that could increase levels of a toxic gas believed to be responsible for some of the highest cancer risks in the country — particularly in east Harris County, where its production is concentrated.

The Texas Commission on Environmental Quality is proposing raising the acceptable threshold for long-term exposure to ethylene oxide from 1 part per billion to 4 parts per billion. The agency says the proposed new standard is a level that “any person could breathe during the course of a lifetime and not experience a significant increased risk of adverse health effects.” Public comments are due by Sept. 26 .

Environmentalists fear the higher standard could mean a rise in emissions of the toxic gas, with consequences beyond Texas.

In 2016, the EPA determined that ethylene oxide might be as much as 60 times more carcinogenic than previously thought and that 0.0001 parts per billion exposure for a lifetime was could be enough to increase the cancer risk of one in one million. Two years later, it used the higher estimates to determine cancer risks by census tract.

The TCEQ and some in the industry say the federal agency overestimated the risk.

Ethylene oxide is a flammable gas with a sweet odor, primarily produced in Texas and Louisiana; nearly half the country’s emissions of the chemical come from Texas. If it mixes with air and is heated, it can quickly become explosive.

It’s used to sterilize medical equipment and as a building block for other chemicals to make products such as antifreeze, plastics and adhesives.

If the new standard is finalized, the TCEQ will use it when reviewing new facilities’ air permits.

Familiar smells

East Harris County residents are used to smelling the chemicals, especially when it rains; to hearing alarms at night that signal workers they need to shelter in place; and to seeing the billows of smoke rising into the air, says Flores, who also does community outreach for Air Alliance Houston, an environmental advocacy group.

Corey Williams, the alliance’s research and policy director, said the facilities producing ethylene oxide in Harris County “seem to have a disproportionate impact on a handful of census tracts of Deer Park and La Porte,” two east Harris County communities. Because no air monitoring is being done, “we have no idea what the actual ambient concentrations are,” Williams said.

Twelve Harris County facilities reported to the EPA that they processed more than 25,000 pounds or used more than 10,000 pounds of ethylene oxide in 2017. Another four facilities reported to local authorities that they stored ethylene oxide on site in their 2015 chemical inventories. Eleven of the combined 16 facilities are in the Pasadena area.

Communities north of this cluster of plants have some of the highest cancer risks in the state, according to the EPA. In one census tract in La Porte, the risk is 312 cases per 1 million people, attributed to ethylene oxide. Nationwide, nearly a quarter of all communities with cancer risks over 100 cases in 1 million people are in Texas, which the EPA deems unacceptable.

Prolonged exposure to higher concentrations of ethylene oxide can irritate the eyes, nose, and lungs. It can also damage the brain and nervous system and cause lymphoid and breast cancer.

The toxic gas can linger in the air for weeks, according to the EPA, and can be spread to other neighborhoods with prevailing winds, especially at higher temperatures.

People who have lived near a facility releasing ethylene oxide into the air for their entire lifetimes face greater risk, the EPA says. This is especially true for children, as ethylene oxide can damage DNA.

Harris County Commissioner Adrian Garcia, whose precinct covers these communities, said these are some of the most vulnerable, with among the lowest income levels, largest share without health insurance and highest rates of diagnosed cancer

"Many families in the precinct are dealing with generational cancer," he said, "children are being diagnosed with the same cancer the parents were diagnosed with."

Garcia didn't know about the increased risk of ethylene oxide, he said.

While he doesn't want to demonize the industry, he said, "it's hard to sit back and ignore that there's something that needs to be done," and that includes working with the industry. Harris County could become a model for the rest of the state and country of how public health can work in conjunction with industry.

The Indorama Ventures Oxide and Glycols plant in Clear Lake, operated by Celanese, was the largest emitter of ethylene oxide in the county in 2017, releasing more than 6,000 pounds of the toxic gas. The plant, however, is in full compliance with state and federal regulations, wrote Richard Jones, head of corporate communications for Indorama Ventures PCL.

The American Chemistry Council’s members“operate according to permits intended to protect surrounding communities and minimize impacts to human health and the environment,” said Jon Corley, a council spokesman.

But Flores, the Galena Park resident, doesn’t believe the TCEQ has the communities’ best interests in mind. Critics say the agency is too industry-friendly.

Industry pushes back

Nationwide, concerns over ethylene oxide have risen after the EPA released the new cancer risk assessments by census tract last year.

Since then, Sterigenics, a medical sterilizer plant in Willowbrook, Ill., was shut down and the state has passed the country’s toughest ethylene oxide laws.

In Georgia, residents and some lawmakers have called for investigations, better monitoring of the gas and shutting down plants there.

But the industry is pushing back. The American Chemistry Council has asked the EPA to correct the risk value and says that the 2016 risk assessment for ethylene oxide is not the first to be called into question by the scientific community, government or industry, Corley wrote in an email.

Jennifer Jinot, who worked on the EPA health assessment on ethylene oxide, said it was twice reviewed by an independent panel of scientific experts, who endorsed the agency’s major conclusions and analytical approaches.

It all comes down to the type of model used by each agency, with TCEQ claiming its is the most accurate and some scientists and environmental groups saying the opposite.

Either way, said Elena Craft, senior director for climate and health at Environmental Defense Fund, “you can debate what someone’s baseline cancer risk is for these endpoints, but the point of it is that we know these compounds cause cancer, why would we establish the least protective health threshold we think we can get away with when the implication is that millions more people might get cancer because of it?”

But the TCEQ doesn’t agree. Progress on protecting public health cannot be made on what it calls flawed science, Andrew Keese, an agency spokesman, said.

“Otherwise,” he said, “public, government, and industry efforts and resources are wasted on addressing unrealistic risks created by flawed science.”

Decision due by 2020

What happens in Texas could play a role in the federal agency’s decision, due by 2020, on the standards and regulations for ethylene oxide emissions for some types of facilities.

An EPA spokesperson said the agency “will consider all of this information, along with additional public input in making a decision on the appropriate approach for calculating risks in its rulemakings.”

Several groups, including the Sierra Club’s Lone Star chapter, are fighting the state for public records on studies, data and calculations TCEQ relied on.

Michael Honeycutt, the TCEQ’s top toxicologist, “is advising on science policy for the entire country,” Craft said. “If his agency is able to push through and ramrod this risk assessment on ethylene oxide, the result is that they wouldn’t regulate ethylene oxide to reduce exposure to it.”

Honeycutt is also the chairman of the EPA’s Science Advisory board, and has previously fought EPA efforts to put stricter controls on certain pollutants, including ozone and mercury.

“It is a big mess with huge implications,” said Neil Carman, a former TCEQ air inspector who now works with the Sierra Club’s Lone Star chapter. He fears that once approved, it could weaken cancer-risk protections for other chemicals and translate into more pollution.

But the American Chemistry Council sees the TCEQ proposal as a possible alternative to the EPA’s “flawed risk.”

Regardless of the ultimate range, Corley wrote, the council doesn’t foresee any weakening of national emissions standards.

In the meantime, Indorama, who owns the ethylne oxide unit in Clear Lake, said it will continue to closely monitor regulatory discussions between the EPA and TCEQ.

“We find no issue with being asked to comply with whichever standard we are required to meet,” Jones said. “Our focus is to be fully compliant with all regulatory permits and to be a good steward of our facility in the community.”

Data editor Matt Dempsey contributed to this report.

perla.trevizo@chron.com