Map of life expectancy at birth from Global Education Project.

Wednesday, April 15, 2009


I was planning to go no with the medication adherence thing and now you've got me all distracted. Anyway . . .

Yes, there is still lead in the soil near heavily trafficked roads because there used to be lead in gasoline prior to 1970. I did a little bit of a lit search and I was somewhat surprised to find that most of the recent research on this has been done outside of the U.S. where there is still lead in gasoline or has been until much more recently. This study done in Florida in 1996 shows that yup, it's still there, and at levels considered hazardous by the EPA. I do know anecdotally that in many densely populated areas, there have been efforts at mitigation. BTW another source is the paint on highway overpasses, which used to contain lead and which they would just sandblast off when they went to repaint. These areas undoubtedly constitute hot spots.

Second, I hadn't heard about differential risk for women from near highway pollution but then again, when you catch me at the right moment I'll admit that I don't know everything. Just offhand -- and I'm talking out of the wrong orifice here -- it would be a bit hard to sort out because women have differential rates of smoking, hypercholestrolemia, baseline heart disease etc. and that all gets mixed together in epidemiological models with highway exposure. It may well be that women have a higher raw relative risk, simply as a function of lower baseline risk therefore pollution can make a bigger contribution to overall risk. But I'm just blowing smoke to give you an indication of how tricky these analyses can be. If you have a reference, let me know.

And Stephanie, all I can say is, there are a lot of factors that go into where we choose to live and you certainly shouldn't panic, but 150 yards is awfully close. Those gross particles that you clean off your windowsill -- black carbon -- aren't in themselves as dangerous as fine and ultrafine particles, but they are an indication that the bad stuff is there.

As for cancer, as far as I know the epidemiology isn't as well established as the cardiovascular risk, but it's certainly biologically plausible. The UFP contain nasty chemical components including polycyclic aromatic hydrocarbons (PAH) and oxidative free radicals, and variations on PAHs which are halogenated or contain dioxin bonds, etc. All this stuff is known to be carcinogenic and probably causes other forms of DNA and cellular damage as well. Personally, I would prefer to live somewhere else. (I'll have to get used to your new last name . . .)


C. Corax said...

These three links may all refer to the same study. Sorry I there's repetition. If I were on campus, I could probably access some scholarly articles, but I'm on vacation, so no access.

C. Corax said...

Let me try that again:

Cervantes said...

That study doesn't seem to be saying that women are at disproportionate risk, it just happened to study women. In this case the endpoint was COPD, rather than cardiovascular disease. Overwhelmingly, the cause of COPD is smoking, so this would likely be an additive effect -- but if you can COPD from highway pollution without even being a smoker, all the more reason to steer clear!

kathy a. said...

EPA declares carbon monoxide and other gasses health risks: