I've been following this as a matter of personal interest. My tox coursework is long in the past and I'm not working in the field, so apply whatever measure of skepticism you would for any anon...
Exemplary
I've been following this as a matter of personal interest. My tox coursework is long in the past and I'm not working in the field, so apply whatever measure of skepticism you would for any anon Internet response.
The article is vague and not a great source, but most of the conclusions it reports are plausible. I do take issue with the claim that all 8.5 million pounds of chemicals went up in a plume of dust which spread widely over great distances.
Most of that mass underwent combustion in fires and in a "controlled" burn. That's actually not good news. Good general discussion here.
The open burning of vinyl chloride is a nightmare, not just because it produces immediately hazardous phosgene gas. Academic paper abstract here. At medium to high temperatures (200 - 800°C), burning chlorinated organic materials tends to create extremely toxic and carcinogenic chlorinated polycyclic aromatic hydrocarbons. Those include the poison of poisons, 2,3,4,5-tetrachlorodibenzodioxin (usually called TCDD or just "dioxin"). As a direct toxin, TCDD is lethal at doses in the low milligrams. As a persistent chemical in the food chain, even parts per trillion can accumulate to do grave harm over a lifetime. TCDD is hard to measure accurately. It breaks down from exposure to sunlight, so surface sampling isn't very effective. I found myself scratching my head at some of the reported sampling techniques the EPA was using, months after the initial incident.
There's an ongoing struggle in the toxicology literature on determining effects from mixed chemical exposures. The jury is still out, but I wouldn't be surprised if there are dire long term effects on people exposed to the mix of volatile chemicals that was known to be on the train. Butyl and ethylhexyl acrylates are known sensitizers, which can also trigger allergic sensitivity to other chemicals present concurrently. It's likely there will be excess asthma and skin rashes among the people exposed, potentially severe and lifelong.
I don't think the offered $600 million compensation is anywhere near adequate for the potential harm done. Even if the company bankrupted itself, it probably wouldn't provide sufficient money. That's what regulation is supposed to prevent, and that's what the current government structures aren't adequate to enforce.
Edit: If you really want to dig into why dioxins and related chlorinated PAHs are nasty, there's a good review paper here. They interfere with a fundamental DNA transcription controller in ways that inhibit metabolism and promote cancer, across most animal species.]
I've been following this as a matter of personal interest. My tox coursework is long in the past and I'm not working in the field, so apply whatever measure of skepticism you would for any anon Internet response.
The article is vague and not a great source, but most of the conclusions it reports are plausible. I do take issue with the claim that all 8.5 million pounds of chemicals went up in a plume of dust which spread widely over great distances.
Most of that mass underwent combustion in fires and in a "controlled" burn. That's actually not good news. Good general discussion here.
The open burning of vinyl chloride is a nightmare, not just because it produces immediately hazardous phosgene gas. Academic paper abstract here. At medium to high temperatures (200 - 800°C), burning chlorinated organic materials tends to create extremely toxic and carcinogenic chlorinated polycyclic aromatic hydrocarbons. Those include the poison of poisons, 2,3,4,5-tetrachlorodibenzodioxin (usually called TCDD or just "dioxin"). As a direct toxin, TCDD is lethal at doses in the low milligrams. As a persistent chemical in the food chain, even parts per trillion can accumulate to do grave harm over a lifetime. TCDD is hard to measure accurately. It breaks down from exposure to sunlight, so surface sampling isn't very effective. I found myself scratching my head at some of the reported sampling techniques the EPA was using, months after the initial incident.
There's an ongoing struggle in the toxicology literature on determining effects from mixed chemical exposures. The jury is still out, but I wouldn't be surprised if there are dire long term effects on people exposed to the mix of volatile chemicals that was known to be on the train. Butyl and ethylhexyl acrylates are known sensitizers, which can also trigger allergic sensitivity to other chemicals present concurrently. It's likely there will be excess asthma and skin rashes among the people exposed, potentially severe and lifelong.
I don't think the offered $600 million compensation is anywhere near adequate for the potential harm done. Even if the company bankrupted itself, it probably wouldn't provide sufficient money. That's what regulation is supposed to prevent, and that's what the current government structures aren't adequate to enforce.
Edit: If you really want to dig into why dioxins and related chlorinated PAHs are nasty, there's a good review paper here. They interfere with a fundamental DNA transcription controller in ways that inhibit metabolism and promote cancer, across most animal species.]