Toxic gas used in petrochemical manufacturing has been detected at levels a thousand times higher than what is considered safe in Louisiana.

The chemical in question is ethylene oxide, an extremely flammable and colorless gas with a slightly sweet smell. It has a variety of industrial uses, including the production of products like antifreeze, detergents, fibers, and bottles. It’s also used to sterilize medical and food production equipment.

Researchers at Johns Hopkins University recently tested levels of ethylene oxide in the air of southeastern Louisianna using two vans fitted with different but highly sensitive technologies to measure the gas in real-time. 

This part of the state includes “Cancer Alley,” a stretch along the Mississippi River between New Orleans and Baton Rouge that has very high rates of cancer and other health issues among its residents. By coincidence, it also has a significant number of petrochemical plants that pump out all kinds of industrial chemicals, including ethylene oxide. 

Long-term exposure to concentrations of ethylene oxide over 11 parts per trillion is considered problematic to human health due to its ability to directly damage DNA and increase the risk of cancer.

Shockingly, this study found levels as high as 40 parts per billion in areas close to industrial facilities. The concentrations were also found to be way higher than the estimates created by the Environmental Protection Agency.

“We expected to see ethylene oxide in this area. But we didn’t expect the levels that we saw, and they certainly were much, much higher than EPA’s estimated levels,” Peter DeCarlo, senior author and an associate professor of Environmental Health and Engineering at Johns Hopkins University, said in a statement. 

“We’d drive through the industrial areas and saw concentrations hitting 40 parts per billion, which is more a thousand times higher than the accepted risk for lifetime exposure,” DeCarlo said.

The researchers warned that people living near facilities that manufacture and use ethylene oxide could be at a higher risk of cancer. 

“Our findings have really important implications for community residents, especially infants and children. Ethylene oxide has been shown to directly damage DNA, meaning that exposures that occur in early life are more dangerous,” said Keeve Nachman, associate professor of Environmental Health and Engineering and the co-director of the Risk Sciences and Public Policy Institute.

The new study was published in the journal Environmental Science & Technology.