Wildfires, Pollution and Health (And Other Interesting Links)

I was watching an interesting report on CNN this morning about how many Southern California residents have reported various respiratory symptoms, likely due to wildfire induced particulate matter in the air. It's probably obvious to most people that forest fire related smoke will have adverse health consequences. Even so, its worth trying to get a sense of whether this holds up in the data and what the magnitude of the effect really is.

Some interesting research on the 1997 forest fires in Indonesia provides insight into these issues. This paper by Seema Jayachandran suggests that the fire led to a 17% increase in childhood (here under-2) mortality rates. The effect was larger in poor Indonesian districts, again something that most would expect a priori. Frankenberg and co-authors find effects among adults as well. Exposed individuals had more difficulty with activities of daily-living and were more likely to report respiratory symptoms.

A quick, but important digression: Forest fires are a good way to study the effects of pollution on health. First, variation in forest fire intensity is plausibly exogenous. The location and intensity of forest fires are essentially "random" conditional on typical region and individual level controls. Second, for more recent events, there are usually very good atmospheric measurements of particulate matter, which allows the economist/epidemiologist/statistician to directly estimate the effect on salient pollution factors on health.

I think the existing research can be extended on several margins. For example, what are the long term effects of those exposed in utero. That is, how do kids who survive the insult do later in childhood and later in life? What is the biology behind this? Another interesting question stems from Jayachandran's finding that the impacts of pollution decline with increasing regional wealth. It's worth trying to tease apart why this is so: What is it about richer regions that shields their residents from the effects of dirty air? Do the wealthy live in houses with better ventilation? Are they more mobile?

More stuff: how much does an individual's productivity decline as a result of pollution? Finally, conditional on income, can we use information on the choices people make to avoid exposure to pollution say something about an individual's own valuation of his/her health status?

As unfortunate as the So-Cal fires are, perhaps some good can come out of the fact that it can generate some rich research. I'll be interested to see how the current state of the pollution literature will be advanced.

Other Interesting Links:

1) Kenneth Chay and Michael Greenstone have written some of the seminal papers on pollution and infant health. You can find some of them here and here. I like these papers because they are extremely rigorous. That kind of stuff makes for good graduate student reading.

2) Interesting post at the Freakonomics blog about the potentially substantial benefits to malaria eradication on health and economic outcomes.

3) Do grants increase research productivity? Check out this paper if you are interested in finding out the answer.