The agency assumed, for instance, that every plane at an airport would be idling on a runway burning an entire tank of fuel, that the cancer-causing components would be present in the exhaust and that residents nearby would breathe that exhaust every day over their lifetime.
This seems to support their assertion that the modeled risk is unreasonable. But that unfortunately doesn't tell us what it actually is. Also, I'd love to know: was it EPA scientists making these assumptions in their models? If so, then why? The cynical part of me wants to say that it's to create exactly this scenario: They can dismiss the results as unreasonable, and since that's the only version they ran, they don't have reasonable numbers to give us.
These appear to be complex hydrocarbon byproducts of plastic, so it's extremely difficult to model what they are or their actual behavior. The EPA basically use a combination of analog substances and "stuff they think might be similar" and then add the risks together to make a score.
The EPA analysis is much more useful than any of these articles. I don't think the analysis itself supports the breathless claims in the news article. I do ultimately agree that this feels odd, though: while I don't think any of these materials are actually that likely to cause cancer, it seems a bit strange to be approving fuel additives with this much uncertainty in analysis. But, I don't work in hydrocarbons so maybe this is normal.
https://www.documentcloud.org/documents/23863526-epa-hq-oppt...
That's not how probabilities work. The average person might be expected to get 1.3 cancers over their lifetime (assuming they don't die early), but that doesn't guarantee that every person exposed to it will get cancer.
> The average person might be expected to get 1.3 cancers
Same same, expect and guaranteed are only loosely the same in English. The weatherman expects rain.
Suppose you get a bunch of people to flip 3 coins. You'd expect the average person to get 1.5 heads, but it would be inaccurate to say "every person would be expected to get heads".
Edit, actually it's a full screen ad that's really difficult to get around
https://www.propublica.org/article/epa-approved-chevron-fuel...
This is so bad. I didn't wake up expecting to have to be politically active today. The EPA needs to do its job. :(
