The release of toxic chemicals from a derailed freight train in East Palestine, Ohio, prompted the evacuation of residents last week amid fears of an explosion following the February 3 incident. U.S. authorities asked residents of the neighborhood to return home on February 8, although there are still signs of dead wildlife and unpleasant chemical odors in the area.
Is it safe to move back at this point?
Although U.S. officials said it's safe, some experts disagree. "Both vinyl chloride and dioxins are much heavier than air. In other words, they tend to precipitate on the lower ground or aquatic system and move very slowly. Staying away from the area will be a wise choice for local residents in a short period of time," Jin Xin, a chemical engineering expert from the China University of Petroleum, told GDToday on February 18.
Vinyl chloride causes immediate, irreversible damage to the respiration system
Vinyl chloride is a colourless gas at room temperature, according to the U.S. Department of Health and Human Services (HHS) and the Centers for Disease Control (CDC). However, Jin stated that the gas does burn easily. It’s unstable and has a mild sweet odor at high temperatures.
According to the U.S. National cancer institute (NCI), vinyl chloride is produced as a combustion product in tobacco smoke as well. "Hazardous chemicals like vinyl chloride will immediately cause irreversible damage to our respiration system, particularly under a high local concentration close to the incident," Jin explained.
Public information provided on the U.S. Environmental Protection Agency (EPA) website shows that burning vinyl chloride will produce dioxin, a contaminant formed during producing some chlorinated organic compounds. Moreover, dioxins are highly toxic and can cause cancer, reproductive and developmental problems, damage the immune system, and interfere with hormones.
Is burning vinyl chloride a proper method to deal with toxic chemicals?
U.S. officials said the controlled burn of vinyl chloride could send phosgene into the air. Phosgene is a highly toxic gas that can cause vomiting, breathing trouble and hydrogen chloride while irritating people's skin, eyes, nose, and throat.
CBC News reported 3,500 dead fish as local waterways, including the Ohio River, were contaminated. Apart from animal death, Jin said that the damage to people’s eyes and skin should also be highlighted.
In the meantime, establishing reliable safety protocols and improving poorly maintained infrastructure are among the top priorities of local authorities to bring the situation under control.
"The so-called controlled release is probably not a doable option as it will risk firefighters' life once getting too close to the center of the accident.”
Jin suggested that making use of photoactive powders such as titania and alkaline species to neutralize the chemicals could be a good idea to constrain the spread out and reduce the risk to lowest levels.
How long will it take to get back to normal?
U.S. authorities lifted the evacuation on February 8, five days after the disaster. Then, U.S. EPA later reported safe concentration levels, so residents of eastern Palestine were told the air was now safe.
Apparently, there are some information discrepancies between the various sources. Two weeks after the tragic incident in East Palestine, Ohio, residents are still waiting for a concrete response from U.S. authorities.
Jin said that it is complicated to give a rough estimate on the possible lifespan without knowing the exact amount of vinyl chloride and other hazardous chemicals being transported and stored on-site, which worries Americans and people worldwide.
He also believes that people should pay close and continuous attention to the species in valleys and rivers in the coming months or even years, with high winds blowing the chemicals away.
Author | Clarice
Video | Zoey
Editors | Wing, Steven, Jasmine, James