On Feb. 3, a Norfolk Southern train derailed in East Palestine, Ohio, with 11 tank cars carrying hazardous materials and five tank cars carrying 115,580 gallons of vinyl chloride, according to CNN. A response team then ignited the hazardous materials to control the spill.
Vinyl chloride is often used to make PVC. Its combustion products are phosgene and dioxin, of which phosgene was used as a chemical weapon in World War I, and dioxin is a persistent environmental pollutant that can remain in the ground and body for years. They are all carcinogens.
People in East Palestine and throughout other outlying states, including Connecticut, have closely watched the incident. Officials are concerned that these toxic substances are entering the water cycle, the atmosphere and the soil, thus affecting health.
Animal studies done by the Department of Health and Human Services have shown that exposure to 50 ppm of vinyl chloride in the air increases the risk of liver cancer.
Cody Smith is an assistant professor of pharmacology and toxicology at UConn. He explained he does not expect people to be exposed long enough to the chemicals to bear the worst side-effects.
“I don’t think anyone’s going to be exposed long enough or at high enough levels to actually be concerned with liver cancer,” Smith said.
David Grant is also a professor of pharmacology and toxicology at UConn. He concurred with Professor Smith’s assessment.
“Most of the chemicals in the train cars were relatively volatile, unstable compounds. Their biological and environmental half-life is relatively short. So they’re not going to stay around too long,” Grant said.
“I don’t think anyone’s going to be exposed long enough or at high enough levels to actually be concerned with liver cancer.”Cody Smith, assistant professor of pharmacology and toxicology at UConn
Another, riskier practice, Grant noted, would be to bury these hazards in the ground.
“That’s one reason why the remediation team didn’t do that. It’s better to burn these types of chemicals and get rid of them than to bury them in the ground and have them potentially leach into the groundwater or someone’s basement,” Grant said.
Kristina Wagstrom is an associate professor of environmental engineering at UConn. She explained how complex the situation is in terms of cleanup and the options available to agencies on how to do so.
“They were trying to come up with the best solution to a bad problem. And none of the solutions were perfect,” commented Wagstrom.”If vinyl chloride got into the soil and the groundwater, it was going to be a very big problem that would take a very long time to clean up. By combusting it, they made things that were slightly less toxic than releasing the original compounds into the air. I think that was the logic.”
Wagstrom also pointed out that if the vinyl chloride was not burned, there would be a risk of explosion, which would have a greater impact.
“That’s why they did a controlled combustion, it was partially to keep from having that happen. This probably resulted in less vinyl chloride being released directly because, with the controlled burn, they can make sure that everything’s combusting as it’s released,” Wagstrom said.
At present, the concentration of vinyl chloride will become lower and lower with atmospheric volatilization and will not pose a threat to residents of Connecticut.
“You could calculate how much vinyl chloride and how much of all of those chemicals were there, and then if you dilute that amount in that space of air, you could calculate the approximate concentration, and you could come up with how significant that concentration might be. And I would bet you would find that the concentration would be so low that it’s probably a very, very, very low risk to anyone here in Eastern Connecticut,” Grant said.
Another concern for environmentalists is that it may take a very long time for nature to degrade these toxic chemicals fully. According to estimates from the Ohio Department of Natural Resources, more than 43,000 animals have died in and around East Palestine in the three weeks directly following the train derailment. Dark clouds and acid rain have also been reported in Ohio and surrounding areas after the VCM burn. However, Grant had a more optimistic view of the environmental situation.
“If the environment is healthy, if it’s diverse, typically the environmental problem will eventually go away. There’s so much redundancy in our environment, many species that can recover very quickly. Some species are very sensitive. So they might be initially eliminated, but gradually, they will likely come back, especially in a stream or an aquatic ecosystem like this, where there’s fresh water coming in all the time and new species drifting in the water. So it’ll take a while, but if the environment is healthy, it will probably recover,” Grant said.
The method of transporting hazardous materials has always been a highly controversial issue. According to the CT mirror, there are over 1,700 derailments in the U.S. each year. In Connecticut, those chemicals are traveling on our highways, albeit in smaller truck-sized loads, but they are no less likely to cause explosions or damage if they’re involved in an accident.
“If vinyl chloride got into the soil and the groundwater, it was going to be a very big problem that would take a very long time to clean up. By combusting it, they made things that were slightly less toxic than releasing the original compounds into the air. I think that was the logic.”Kristina Wagstrom, associate professor of environmental engineering at UConn
For Grant, it is a risk vs. cost problem with no single optimal solution.
“Companies that use these chemicals could potentially make them on-site. And then there would be less transportation, but that would be very costly for someone who needs vinyl chloride to make it themselves, and it might even make the potential risk worse because now you’ve got vinyl chloride all over the country being made in a factory somewhere and people don’t even know it,” Grant said.
The professors also expressed their opinions in response to the social impact of this incident.
“There are still some questions on the overall impact, and this is going to be something that gets looked at for years to come. As far as transport within the environmental matrix, the dioxins that might have formed from the combustion and how they may have deposited, that still needs to be looked at,” said Wagstrom.
“I think for Connecticut, the biggest thing that will come out of this is that the railroad industry will need to be more diligent in monitoring the safety of their transportation system. They will likely have to make sure those trucks and wheels under the train cars are inspected more frequently. And hopefully, stricter oversight of hazardous chemical transportation will be enacted from this, so that the railroad industry is more responsible and do a better job in preventing this in the future,” Grant said.