Early air tests near Sterigenics offer ‘snapshot’ of toxic emissions

Workers install air monitoring equipment in Cobb County (Courtesy of Cobb County)

Workers install air monitoring equipment in Cobb County (Courtesy of Cobb County)

The first test results from air samples taken near the Sterigenics facility in Cobb County were made public Monday, but experts cautioned that much more data is needed before they can draw conclusions about concentrations of the carcinogenic gas ethylene oxide in the area.

The samples were collected while plant operations were suspended during the installation of new emissions controls. The results will be used as a baseline for comparison once the plant is operating at full capacity and air testing resumes sometime next month.

A majority of the samples — about 80 percent — did not show detectable levels of ethylene oxide, the gas legally used to sterilize medical equipment and emitted by the Sterigenics facility. Emissions from the plant have caused widespread concern and protests in recent months, with some residents calling for the facility to be shut down because of potential health effects.

At the other end of the spectrum, one air sample reading was hundreds of times above the threshold federal regulators use to calculate long-term elevated cancer risk.

Dyron Hamlin, a principal at the company carrying out the air testing, said the highest reading was “a bit of an anomaly” but not outside the range of what he considers “background” levels. Since the federal government reclassified ethylene oxide as a carcinogen in 2016, air tests across the country indicate the chemical is more pervasive than previously thought.

“I can’t necessarily say that it’s atypical,” Hamlin said of one test result showing 7.9 micrograms of ethylene oxide per cubic meter.

The federal Environmental Protection Agency says exposure to anything over 0.02 micrograms of per cubic meter over many years could pose an elevated cancer risk.

“This is a very small snapshot,” Hamlin said of the test results, adding that more testing is needed.

Sterigenics declined to comment.

The testing is being carried out at a cost of $130,000 by GHD, an international environmental consulting firm, on behalf of Smyrna, Atlanta and Cobb County. The results were shared during a meeting of an air quality oversight committee made up of mostly local officials.

Emrys Treasure, an Atlanta resident, said the test results were a good start but he still had concerns.

“I think it shows a good faith effort on the part of Atlanta, Cobb and Smyrna to collect real data, which is what we asked for,” he said. “There was a huge missed opportunity in getting this deployed prior to the (plant’s) suspension of operations … but at least we have something that resembles baseline.”

Meanwhile, the state announced the ethylene oxide test results for additional air samples it took in south DeKalb County, miles away from any known source. A previous sample taken in June showed a level 15 times higher than the EPA's threshold.

On Monday, the state Environmental Protection Division released the results of three more tests from the same locationnone of which showed detectable levels of ethylene oxide.

“It is not unexpected to see variability in these results and EPD is conducting a long-term sampling study to account for that variability,” said spokesman Kevin Chambers. “EPD will continue to take samples from south DeKalb and will be adding data from a rural site in south Georgia in addition to air monitoring in Smyrna and Covington, which will begin in the next two weeks.”