Living near freeways is bad for your health. Of course, you get exposed to particulates when driving on freeways as well.
Researchers at the Keck School of Medicine of the University of Southern California (USC), in collaboration with international partners in Spain and Switzerland and colleagues in California, have found that exposure to air pollution accelerates the thickening of artery walls that leads to cardiovascular disease.
The study, published this week in the journal PloS ONE, is the first to link outdoor air quality and progression of atherosclerosis in humans. Researchers found that artery wall thickening among people living within 100 meters (328 feet) of a Los Angeles highway progressed twice as quickly as those who lived farther away.
This result is an argument for electric cars, tougher regulations on coal electric plants, and accelerated retirement of old belching diesel trucks that were manufactured under easier regulations.
Here's an excerpt from the full paper which you can read in full.
We examined data from five double-blind randomized trials that assessed effects of various treatments on the change in CIMT. The trials were conducted in the Los Angeles area. Spatial models and land-use data were used to estimate the home outdoor mean concentration of particulate matter up to 2.5 micrometer in diameter (PM2.5), and to classify residence by proximity to traffic-related pollution (within 100 m of highways). PM2.5 and traffic proximity were positively associated with CIMT progression. Adjusted coefficients were larger than crude associations, not sensitive to modelling specifications, and statistically significant for highway proximity while of borderline significance for PM2.5 (P = 0.08). Annual CIMT progression among those living within 100 m of a highway was accelerated (5.5 micrometers/yr [95%CI: 0.13–10.79; p = 0.04]) or more than twice the population mean progression. For PM2.5, coefficients were positive as well, reaching statistical significance in the socially disadvantaged; in subjects reporting lipid lowering treatment at baseline; among participants receiving on-trial treatments; and among the pool of four out of the five trials.
Moving more freight to trains would also cut pollution since trains use much less diesel fuel per ton of freight moved. Also, trains lend themselves to electrification. A fully electrified train system with major bottlenecks sped up would move freight with far less harm to human health both due to less pollution and fewer deaths and injuries in accidents.
| Share | | Randall Parker, 2010 February 14 06:38 PM Pollution Health |
I am always baffled by the sight of joggers grimly pounding the pavement alongside busy highways. Wouldn't it be a lot more pleasurable just to sit at home and smoke a pack of Kools in front of the television? Certainly the end result is the same.
I wonder if they controlled for traffic noise, which itself must accelerate atherosclerosis.
Another statistical manipulation masquerading as clinical research. The 'researchers' took data from 5 clinical studies looking at various cardiovascular treatments, and retrospectively tried to correlate air pollution with changes in coronary wall thickness. The wall thickness data seems valid, but the air pollution exposure 'measurements' are worthy of climate researchers, as they basically took addresses and a bunch of assumptions about how an address predicts air pollution and built a 'model' that generated the 'air pollution data'. Note that NO air pollution measurements were actually performed during this study.
Most importantly, out of over 1400 subjects in the 5 (actual) clinical trials, only 23 (1.5%) were deemed to have high air pollution exposure (i.e., be living within 100 m of a highway). Once I saw that figure I didn't waste any more time trying to figure out how they massaged the data to make the numbers statistically significant.
Does air pollution cause heart disease? Maybe, maybe not, but this article does nothing to add to real knowledge.
This is interesting. Maybe it should go into the file of Anemic Statistics. Alas, they had to use the tools they had.
Controlling for income would have been good as the authors note. But they used only prior studies and no doubt lacked that data. The population living near busy freeways and highways probably has low income. That is certainly my memory of Los Angeles.
The authors are candid about the weaknesses. The combined sample size from all five studies was not big, and the number very close to the roads was anemic - there's that word again. Only volunteers were used, the exposure numbers relied partly upon modeling, and only 245 subjects had not moved for six years.
etc, etc, etc.
About thirty years ago my son did an experiment in Los Angeles. He measured airborne particle count and size, day of the week and time of day to see if weekends were significantly different. In our neighborhood they were not. I believe they would have been if all homeowners were cutting their own grass. But most used gardeners who came only on weekdays. And the homeowners who cut their own grass almost always did it on the weekend.
He got a nice prize for project originality.
Nobody lives near railroad tracks? Riiight.
Micha Elyi,
I always wonder at the motive of someone who attacks a straw man rather than attacking what I wrote. So what's your motive?
I said a shift of freight from trucks to trains will cut pollution because trains use less fuel per ton of freight.
I also said trains lend themselves to electrification. It is much harder to electrify trucks except for short haul routes (e.g. the electric trucks that the ports of Long Beach and LA are going to use).
parker, so people who live near windfarms are adversely affected also, where's that study? I put one up but it was large blocks of print with no pictures so I doubt badour read it, did you?
th,
I live near windfarms. What are the problems with them?
The ones I know about are infrasound, which is intrinsic to the technology, and poor choices for locating transmission lines, which are not.
Plus, my electric rates have been going up as fast as the windmills, but I am unsure of any causal link.
badour, your rates should be 43cents/kwh, engineer/poet advises us that the horse-drawn wagon with the block of ice is the future, sea breezes and sunshine will power the world, you'll learn to love the wait, or maybe you already do.