A couple of new findings tell an unsettling story about the health effects of living near freeways–and that “near” is a lot farther away than you might think.
Finding #1: Pregnant women living near highways or busy roads are more than twice as likely give birth “very preterm” at 30 or fewer weeks. They are also 30 percent more likely to give birth to plain old “preterm” at 31 to 37 weeks. The mechanism isn’t clear, but it could involve oxidative damage to the child’s DNA and other stuff that sounds really bad. The lead scientist for this study suggests the culprits might be horrible airborne compounds called “polycyclic aromatics” that are a component of auto pollution.
This is addition, of course, to asthma and cancer and heart disease all the other great stuff–including generally shortened life spans–that traffic pollution has been shown to do to the human body.
Finding #2: Living “close” to a freeway means being right next to it, right–like overlooking it pressed up against one of those ugly noise walls? Sadly, no. Researchers at UCLA have found that a large freeway’s pollution plume extends as much as a mile and a half from the roadway–in this case, I-10. “This distance is 10 times greater than previously measured daytime pollutant impacts from roadways and has significant exposure implications.” Those nasty carcinogenic ultrafine particles–not to mention polycylic aromatics–don’t obey the nicities of staying in those close to the roadway. No, the call is coming from inside the house for plenty of rich people in Santa Monica and other communities around the country. Even if you’d never be one of those poor unhealthy schlubs who lives next to a freeway — practically speaking, you’re probably already one of those poor unhealthy schlubs who lives next to a freeway.
Says one of the researchers: “The study raises more questions about the significant health outcomes caused or exacerbated by freeway traffic.” Yeah, that sounds about right.
Research like this really highlights theimportance of diversifying away from auto travel in our cities, and doing so on the double. It’s lunacy to poison densely populated areas in two- and three-mile wide swaths.
The answers aren’t even all that complicated. Electric cars will help, and this another argument for creating incentives for consumers to migrate over to them, if and when they’re ready for the big time. Investing in electrified freight rail (”Steel Interstate” style) to start getting more trucks off the road would be another important element. Also, congestion pricing in cities and a dedication of resources to expanding and improving rail and transit on a scale similar to China and Spain–which is to say “huge.”
Now, just go do it kthxbai.
July 9th, 2009 at 2:42 pm
Good god, as a New Yorker, this is real disturbing. I had figured that my early morning workouts were exposing me to less pollution, but this study apparently shows this not to be the case at all. I had no idea the pollution thresholds were so wide - my leafy NW Bronx hood clearly falls within the danger zone. Given how densely developed and populated the NYC metro area is and the sheer number of high speed parkways and highways that slice through our communities, there are probably very few safe locations until you hit the far exurbs.
I would be curious to see how the study defines a freeway/highway, as the soot and ozone levels coming off of the interstate are bound to be vastly higher than those from an automobiles-only parkway. And conversely, there are probably of plenty of congested two or four lane arterials that are exposing residents to tons of nasty pollution.
July 9th, 2009 at 2:56 pm
James,
Yeah, the UCLA study was particularly focusing on the plume of a major Interstate — but clearly the effect is not contained to freeways.
On the practical side, the effect is more pronounced in winter than summer. So dark winter mornings might be a time to exercise indoors.
-Jebediah
July 9th, 2009 at 3:23 pm
I am afraid that this study might frighten people to move their families away from cities (which have more interstates), which would require more highways for them to commute back into the city.
July 9th, 2009 at 4:08 pm
James, you should keep in mind that NYC’s wind patterns are way different from LA’s. Ultimately the answer is going to be measuring smog to a finer grain around LA, so that by measuring it in Brooklyn you can know where you stand, instead of just guessing from how close you are to traffic.
The actual paper is here, for all you stats geeks.
July 9th, 2009 at 6:05 pm
How about the health effects of living near a major railroad?
Although I’m already pretty certain that the effects would be negligible (even for a non-electrified line), it’d be nice to see it formally written up.
July 9th, 2009 at 10:48 pm
[...] Freeway Air Pollution Is So Much Worse Than You Thought from INFRASTRUCTURIST A couple of new findings tell an unsettling story about the health effects of living near freeways–and that “near” is a lot farther away than you might think. Finding #1: Pregnant women living near highways or busy roads are more than twice as likely give birth “very preterm” at 30 or … [...]
July 10th, 2009 at 12:45 am
andrew, I have to point out that freight trains can derail and spill hazardous chemicals. So there can be very immediate health effects; though overall I doubt they can measure up to the effects of highways.
July 10th, 2009 at 8:14 am
The japanese got it right: a tight electrified train network with last mile done with bicycles or walking…
July 10th, 2009 at 9:11 am
Did you know that warmer water causes drowning deaths? It’s true. Virtually no one drowns in Lake Erie in the winter. Then, when the water heats up in the summer, there is a spate of drowning deaths.
Also,
http://en.wikipedia.org/wiki/Correlation_does_not_imply_causation
There are some awful areas of NYc with grinding poverty and lousy health outcomes that are nowhere near any highways, then there is the Upper East Side, Northeast Queens, etc. with lots of highways, and happy healthy kids.
July 10th, 2009 at 9:23 am
[...] The Infrastructurist notes a new study on freeway pollution: [...]
July 10th, 2009 at 10:09 am
One of the principles that separates real scientists from laypeople is that real scientists understand that correlation does not prove causation.
This is a “epidemiological” study, sociology rather than biology. Sociologists like to think of themselves as scientific, but most of them seem to be engaged in popular mythology.
For those of you who think this study proves something, please pause for a moment and consider if perhaps there might be other factors that lead to the poorer health of the people living near freeways. Everyone knows property near busy freeways is old and dilapidated. And most of the people who live in these areas are poor. Might, for instance, the fact that these buildings and homes contain high levels of asbestos, lead paint, decades of rat and cockroach dander be a factor? Or the fact that people in these poorer neighborhoods typically eat a lot more fast food and exercise a lot less than those in the leafier suburbs? Or the fact that smoking, alchohol and drug use is much more prevalent in these types of neighborhoods? Or that these people have less access to health care and are much less likely to seek out prenatal care than people in other parts of the city? Don’t ‘cha just think that maybe some of these factors also play a role?
July 10th, 2009 at 10:26 am
Eric, must you always be the contrarian of the comments section? First, the study, nor Jeb’s summary of it, never implied that highway pollution is killing us all off daily.
And now your examples. Awful areas of NYC that are nowhere near highways but still have lousy health outcomes? I’d like to know what area of NYC is “nowhere near” significant amounts of auto traffic. In addition, you have to take into consideration the quality of the tap water in the area, as well as a myriad of other factors. Again, the study isn’t calling highway pollution the leading cause of all health issues.
As for your comment about “happy healthy kids” in Upper East Side, well of course they’re happy and healthy, because they’re rich! But that doesn’t mean they haven’t been affected by pollution. Unless you’re an infant, pollution doesn’t always have a noticeable effect on you right away. It’s more of a “death by a thousand cuts” problem. Auto pollution is a compliment to the many other things that harm us.
July 10th, 2009 at 10:46 am
Conclusion from the study:
“Exposures to local traffic-generated air pollution modeled with CALINE4 for the whole
pregnancy elevated the risk of preterm birth and preeclampsia in Southern California women. A 42% increased risk of preeclampsia was observed for the highest quartile of modeled traffic related PM2.5 exposure during the entire-pregnancy. For preterm birth, the exposure-response relation was strongest for very preterm births with potentially serious consequences for the newborn. These results provide further evidence that traffic-related air pollution is associated with adverse reproductive outcomes.”
Anecdotal evidence about NYC aside, I think this study clearly shows associated risk with a particular factor. Feel free to draw your own conclusions, of course.
July 10th, 2009 at 11:21 am
Tom J - part of the point about addressing health inequity is addressing the linked factors. So if something is done to mitigate urban air pollution, you can be sure that the “related” factors you point out — like poor quality housing and the perception of other neighborhood stresses — will improve too. T
his doesn’t mean the results of one study are accurate or not: it just means that, when taken along with numerous other studies, they can be a powerful tool for actual social and policy changes.
And there’s nothing more scientifically valid than change.
July 10th, 2009 at 11:31 am
My questions may betray my inexperience in making send out of medical research stats, but does anybody know what the percentages are for preeclampsia, very preterm, and preterm births in the baseline population that the study is using for comparison? I read the study, and although there is mention at the beginning of what the likelihood of these birth complications is in (what I believe is) the general population, it’s not stated clearly that these are the numbers that their “30 percent,”"42 percent,” etc. increased risk determinations are based on.
The paper also states that more than half a million infants (out of how many?) are born prematurely each year in the U.S., but the researchers don’t break this down into pop. percentages for the three stages of “preterm” that they use in the study, so we don’t really know how likely each one is to occur in populations not living within major emissions danger zones. I think any health researcher reading this paper would want to know that, and they shouldn’t have to go to the CDC to find that out.
Obviously, no matter what, these percentages are horrifying - especially to a pregnant woman living in a city like Houston - but I think these obviously significant results make it even more important to be clear just how common these birth disorders/outcomes are in less affected populations, so we know what this really means for those of us who are in danger.
July 10th, 2009 at 11:48 am
Tom and Eric: read the actual study, not just the summary. It’s only 39 pages. They did, in fact, control for confounding factors. IOW, this is real science, not just advocacy. See the link in my earlier comment.
September 9th, 2009 at 5:22 pm
[...] time that highway air pollution has many harmful effects. As we noted a few weeks ago, it can cause premature births and DNA damage. Also among the established effects are heart attack and stroke. But a new study sheds light on [...]