Questions over how natural gas drilling affects air quality have raged across North Texas this year, with much of the focus on toxins including benzene and toluene. But more questions are coming up about a chemical more associated with paint and construction materials than drilling: formaldehyde.
Drilling rigs do not emit formaldehyde, but it is a byproduct of the combustion engines used in the compressor stations that pump gas from wells to transmission lines. The Environmental Protection Agency published a draft report in June declaring formaldehyde a carcinogen and has a hand in regulating its emissions.
Environmental scientists say the danger of formaldehyde in the air is twofold. Some researchers believe that at lower levels, it accelerates the formation of ozone, the main ingredient of smog. At higher levels, formaldehyde becomes a direct health risk, irritating the eyes, nose and throat, and causing wheezing.
Formaldehyde had rarely come up in discussions about drilling until this summer, when Dish Mayor Calvin Tillman announced that he was selling his home because of concerns that natural gas operations around the tiny town were affecting his kids' health. Tillman said both of his sons had awakened at night with nosebleeds.
"When I put out the message that my kids were getting nosebleeds, I got a ton of e-mails back saying, 'It's formaldehyde,'" Tillman said. He asked the Texas Commission on Environmental Quality to look into it.
Michael Honeycutt, the state agency's director of toxicology, said Tillman's was the first request he could recall for formaldehyde testing related to gas drilling. If formaldehyde emissions from compressor stations were a serious problem, he said, the agency would surely find high levels in Dish, which is near multiple compressor stations.
The agency took 23 one-hour samples around Dish in June. The highest reading was 4.8 parts per billion by volume. The 2008 state average for formaldehyde was 2.44 parts per billion, according to state documents.
The state agency's long-term screening level for formaldehyde was 8.9 parts per billion by volume. That's the level at which officials believe that health problems are possible if someone were exposed continuously for 70 years.
Honeycutt noted that the formaldehyde levels in Dish were comparable to the amount naturally produced in the human body.
"Median level you would expect to find in a person's breath is 4 parts per billion. That's about the same range we found in the Dish monitoring," Honeycutt said.
Dish paid for its own air testing in July and found no elevated levels of formaldehyde, Tillman said. He said he is still concerned that the state's testing reported levels higher than would be expected in a rural community.
Around the same time state investigators were collecting samples in Dish, the industry-funded Barnett Shale Energy Education Council was conducting its own air tests in the region. Ed Ireland, the council's executive director, said the testing was done to dispel concerns about emissions from natural gas drilling.
Along with usual suspects like benzene and toluene, the council opted to test for formaldehyde near two compressor stations.
"I think it may have been the intent of the Barnett Shale Energy Education Council and the producers to get ahead of the curve on that and test for it," Douglas Cantor of Titan Engineering said in July when the report was released.
The council touted the findings as proof that drilling contributes some contaminants into the air but not at levels that should cause health concerns. Ireland said he believes that is true for formaldehyde as well as the other chemicals included in the study.
But one finding in the report raised some eyebrows. Titan recorded unusually high levels of formaldehyde near a Fort Worth compressor station near Lake Arlington. The highest reading was 126.9 parts per billion by volume, more than triple the 41 parts per billion that the state environmental agency considers a potential health concern for short-term exposure.
The report concluded that the high level was from an "unidentified low-elevation source" not related to natural gas operations.
"We may go back and try and investigate where it was coming from, but that wasn't part of that study," Ireland said.
The high formaldehyde reading caught the attention of Eduardo Olaguer, director of air quality research at the Houston Advanced Research Center. Olaguer and a team of researchers from several universities had been studying how formaldehyde and other chemicals exacerbate the formation of smog around Houston.
In an e-mail to the Star-Telegram, Olaguer said the level of measured formaldehyde in the air can differ depending on the measurement tool used. The research in Houston led Olaguer and his colleagues to conclude that the area's refineries and other industry sources are emitting "10 to 100 times more formaldehyde than anyone had previously suspected." If true, cutting back on those emissions would do more to reduce ozone in the region that previously assumed.
A similar situation could be taking place in the Barnett Shale, Olaguer said. He voiced his concerns to the EPA at a public hearing in August in Arlington. He also encouraged a closer look at the industry-backed study.
"The high measured levels should be taken very seriously and investigated further to understand where those levels come from," Olaguer told the Star-Telegram.
Honeycutt said the state is working with Olaguer and other researchers to see whether formaldehyde may be a bigger issue related to ozone formation than previously believed. He said he doesn't see evidence that the level of formaldehyde in the region is anywhere near the higher levels that could cause immediate health concerns.
"With regard to direct human health effects, I don't know where we would expect to find higher levels than Dish," Honeycutt said. "We've done monitoring there and the levels we found are background levels, so that just kind of speaks volumes."
Terry Clawson, a spokesman with the Texas Commission on Environmental Quality, said the agency plans to return to North Texas this month for follow-up formaldehyde testing. The agency plans to conduct new tests in Dish as well as test near Lake Arlington, Clawson said.
Aman Batheja, 817-390-7695