Levels of Carcinogenic Chemical Near Ohio Derailment Site Far Above Safe Limit
www.theguardian.com
EPA scientists assessed a dioxin cancer risks threshold in 2010, but a federal cleanup is only triggered at far higher levels
Newly released data shows soil in the Ohio town of East Palestine – scene of a recent catastrophic train crash and chemical spill – contains dioxin levels hundreds of times greater than the exposure threshold above which Environmental Protection Agency (EPA) scientists in 2010 found poses cancer risks.
The EPA at the time proposed lowering the cleanup threshold to reflect the science around the highly toxic chemical, but the Obama administration killed the rules, and the higher federal action threshold remains in place.
The chemicals are highly persistent and can accumulate and stay for years in the environment or human bodies. Among other health issues, the compounds are linked to cancer, diabetes, heart disease, nervous system disorders and other serious health problems. Soil and food contamination are considered to be among the most common exposure routes.
Regulators establish the toxicity of dioxins in a soil sample by calculating the “toxicity equivalence” of all dioxins in the soil compared with the most toxic dioxin compound, called 2,3,7,8 TCDD. East Palestine soil showed levels of “2,3,7,8 TCDD toxicity equivalence” of 700 parts per trillion (ppt). The level at which the EPA will initiate cleanup action in residential areas is 1,000 ppt.
However, the cleanup triggers are much lower in many states – 90 ppt in Michigan, and 50 ppt in California.
Moreover, EPA scientists in 2010 put the cancer risk threshold for dioxins in residential soil at 3.7 ppt, and the agency recommended lowering the cleanup trigger to 72 ppt.
“When you run the numbers and do your best state-of-the-art risk calculations, that’s the number you get for the cancer risk,” said Stephen Lester, a toxicologist who has researched dioxins for 40 years and is science director for the Center for Health, Environment and Justice. “That’s why dioxins are described as one of the most toxic chemicals ever created.”
The rules were ultimately killed ”for political reasons”, Lester said. Exposure to that level of dioxin is probably widespread, and making the change would create fallout that would be extremely difficult for the government to manage, he added.
Levels of carcinogenic chemical near Ohio derailment site far above safe limit
EPA scientists assessed dioxin cancer risks in 2010, but the federal cleanup threshold is still far below those recommendations
EPA scientists assessed a dioxin cancer risks threshold in 2010, but a federal cleanup is only triggered at far higher levels
Newly released data shows soil in the Ohio town of East Palestine – scene of a recent catastrophic train crash and chemical spill – contains dioxin levels hundreds of times greater than the exposure threshold above which Environmental Protection Agency (EPA) scientists in 2010 found poses cancer risks.
The EPA at the time proposed lowering the cleanup threshold to reflect the science around the highly toxic chemical, but the Obama administration killed the rules, and the higher federal action threshold remains in place.
The chemicals are highly persistent and can accumulate and stay for years in the environment or human bodies. Among other health issues, the compounds are linked to cancer, diabetes, heart disease, nervous system disorders and other serious health problems. Soil and food contamination are considered to be among the most common exposure routes.
Regulators establish the toxicity of dioxins in a soil sample by calculating the “toxicity equivalence” of all dioxins in the soil compared with the most toxic dioxin compound, called 2,3,7,8 TCDD. East Palestine soil showed levels of “2,3,7,8 TCDD toxicity equivalence” of 700 parts per trillion (ppt). The level at which the EPA will initiate cleanup action in residential areas is 1,000 ppt.
However, the cleanup triggers are much lower in many states – 90 ppt in Michigan, and 50 ppt in California.
Moreover, EPA scientists in 2010 put the cancer risk threshold for dioxins in residential soil at 3.7 ppt, and the agency recommended lowering the cleanup trigger to 72 ppt.
“When you run the numbers and do your best state-of-the-art risk calculations, that’s the number you get for the cancer risk,” said Stephen Lester, a toxicologist who has researched dioxins for 40 years and is science director for the Center for Health, Environment and Justice. “That’s why dioxins are described as one of the most toxic chemicals ever created.”
The rules were ultimately killed ”for political reasons”, Lester said. Exposure to that level of dioxin is probably widespread, and making the change would create fallout that would be extremely difficult for the government to manage, he added.
