美国国家公共电台 NPR--Scientists find high levels of hazardous chemicals in the air around Ohio town（在线收听）

Scientists find high levels of hazardous chemicals in the air around Ohio town

Transcript

NPR's Leila Fadel talks to Texas A&M professor Weihsueh Chiu, about independent researchers, who have found higher-than-average levels of some hazardous chemicals around the train derailment.

LEILA FADEL, HOST:

Now, scientists are also concerned about high levels of hazardous chemicals in the air around East Palestine. Texas A&M professor Weihsueh Chiu leads a team that's been looking for answers, and he's with us now. Good morning. Thanks for being on the program.

WEIHSUEH CHIU: Good morning. Pleasure to be here.

FADEL: So what are you finding? We heard these very scared residents just now. Is the air safe to breathe like the EPA is saying?

CHIU: So we've been conducting some mobile sampling, which means that we can drive around the town and look at air quality throughout different parts of the town, not just at a couple of fixed locations, like EPA has monitoring stations. So our first set of sampling data we released last night. It shows that for four particular chemicals of concern, benzene, xylene, tyrosine and vinyl chloride - and vinyl chloride is a carcinogen that was being carried on the train - our measurements were consistent with EPA's and were below levels of exposures of concern for exposures up to a year or more. And we didn't - furthermore didn't find any hot spots for those chemicals.

FADEL: So what does that mean? Are people safe to drink the water, to breathe the air? What does it mean for people in East Palestine?

CHIU: So we're still conducting additional analysis. We're only focused on the air, so I can't comment on the water and soil at the moment. But there is one issue of the chemical acrolein, which we had previously noted some of the EPA data were above levels that were considered of minimal risk for longer-term exposures. Additionally, one limitation of EPA's data is that their analytical method can't detect levels low enough to really fully provide that assurance of safety. In other words, the detection limits for that particular chemical, acrolein, is higher than what would be considered a minimal level of risk.

FADEL: And what would that chemical, acrolein, do to people's health long term if it continues to be high - higher levels in the air?

CHIU: So acrolein is a respiratory toxicant. It means it affects the respiratory system - the nose, the throat and the lungs. And over long periods in animal studies, it's caused - low levels have caused problems in the - particularly the nasal passages. And also, a couple years ago, there was a new rodent study that found that it caused nasal tumors over lifetime exposures. However, you know, we did conduct mobile sampling data on acrolein, as well, although our mobile sampling data can't be directly compared to those minimal risk levels. So we instead compared to other locations, specifically downtown Pittsburgh, where Carnegie Mellon, which is part of our team, has been sampling. We found that levels in East Palestine for acrolein range from about five times lower to about three times higher than downtown Pittsburgh. Those levels also tended to be concentrated in sort of the southern and eastern parts of town closer to the accident site.

FADEL: So if you could just help us out for nonscientists, what this means for a regular person living near the derailment, if you find higher levels of this chemical and lower levels in other parts, should they be concerned? What should they be doing? How long should you be testing?

CHIU: Well, so this is a rural area. So you wouldn't expect levels to be similar to, like, downtown Pittsburgh.

FADEL: Right.

CHIU: Now, you know, but the levels aren't uniformly higher, you know, like 10 times higher than Pittsburgh or something like that. So I wouldn't say there's a cause for immediate concern, but I do think there needs to be continued follow-up and periodic testing to ensure that levels do go down with continued cleanup and, as well, that to confirm whether the levels are really concentrated in that part of town or whether, you know, it's something that is variable from day to day.

FADEL: And what should residents be looking out for in the coming weeks and months? What's the greatest danger - or what you're looking at is the greatest danger?

CHIU: So in terms of air pollution, I think another thing people are concerned about is whether there may be chemicals in the air that no one's measuring. And so that's another thing that we're trying to address with our mobile sampling. And - because our particular instrument can search more broadly for a wider range of chemicals. And we hope to have some of that data analyzed soon to see whether there are some chemicals in the air that nobody has been monitoring for and again, help, you know, redirect maybe some resources to focus on some of those additional chemicals.

FADEL: And very quickly, how concerned should people in East Palestine be about your findings?

CHIU: I have confidence in EPA, FEMA and other federal, state and local officials in addressing what I think Donald Rumsfeld popularized the idea of known - there are known knowns, known unknowns and unknown unknowns. So I worked at EPA for 14 years, and I know that everyone there is dedicated to protecting public health and will definitely address all the known knowns. What I'm hoping we're doing in some - and that other people can do is to help fill in some of those known unknowns and unknown unknowns - that people in East Palestine are clearly concerned about their continued health. We want to fill in some of those gaps to ensure that people can get their lives back to normal.

FADEL: Texas A&M professor Weihsueh Chiu, thank you so much.

CHIU: Thank you very much.

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