I asked a colleague of mine from the Somerville Transportation Equity Partnership, Wig Zamore to respond to Thera's email because he has been looking at the health effects of bicycling on busy roadways.  We work together on the CAFEH studies examining health impact of near roadway pollutants               ( http://sites.tufts.edu/cafeh/ ).  Wig has co-taught a course at Harvard School of Public Health that focuses on active transportation (biking) and mobile pollution.  His response to Thera's concerns may be of interest to others on the listserv.

Ellin


---------- Forwarded message ----------
From: wig zamore <wigzamore@gmail.com>
Date: Tue, Nov 5, 2013 at 7:02 AM
Subject: Re: [H+T--Friends] AQ Impacts vs Active Transport Benefits
To: Ellin Reisner <reisnere51@gmail.com>, Thera Black <blackvt@trpc.org>


Hi Ellin and Thera,
 
I can supply some papers that may be helpful.  In general most environmental health scientists are pro "active transportation".  Although some active transportation epidemiology has used regional pollutants such as PM2.5 in their analyses (Barcelona for example), the better question is whether primary transportation emissions such as ultrafine particles, particle bound polycyclic aromatics and transition metals are a health risk to joggers and bicyclists.  These are a result of local conditions and not so much of regional pollution.  You can have a very clean region but be next to a very busy roadway and have elevated risk.  With traffic generally, you can think in terms of a few common sense metrics - how large is the volume (I5 in Olympia is up to 140,000 vehicles per day, SR101 considerably less and I do not have local street volumes), how close are people (10 meters, 100 meters, a kilometer), how much time do people spend there (home is worse than work and school, etc.), are there meteorological issues such as inversions, and finally are there street canyons or geographic features that might trap the pollution.  With bicyclists, the issue is ventilation.  Cyclists have about 4 to 6 times the effective dose as non-active travelers in the same corridors.  Their breathing rates and metabolic rates are higher and the ultrafines are inhaled more deeply.
 
For residents within 100 meters of a very busy roadway, good rules of thumb are that cardiovascular mortality risk, lung cancer risk, and childhood asthma risk are greater than 50% higher than cleaner locations in the same communities.  Autism risk appears to be more than 100% higher for children whose mothers spent their whole pregnancies in such locations, or even a little higher for those children who spent their first year of life in high traffic exposure locations.  In general these exposures occur to about 5% to 10% of urban populations and probably somewhat less in smaller cities.  For active transportation participants, including bicyclists, the most obvious risks are cardiovascular.  For susceptible populations, for example men who are proactively exercising after heart attack survival, the oxygen crisis stress levels in the heart muscles ( as measured by the ST segment of an electrocardiogram) may be doubled in the presence of diesel emissions.  Similarly, heart attacks may be more common for everyone (3X) after high traffic exposures and may be a little higher for bicyclists (4X).   Even so these events are relatively uncommon - people are not dropping like flies.  Time of day makes a difference too.  Cyclists should avoid highway and arterial adjacent travel during rush hours, where it is possible to do so.  Ditto for very busy intersections.
 
My personal advice would be to be to push active transportation as much as possible but to offer alternatives to the highest exposure routes when and where it is possible to do so. 
 
I have a breakfast meeting but will send along to Thera some relevant papers a little later today.
 
Regards, Wig Zamore
 
Email or 617-625-5630 (24/7 secure land line, no cell)
 
 


On Tue, Nov 5, 2013 at 12:24 AM, Ellin Reisner <reisnere51@gmail.com> wrote:
Wig,

Do you have any suggestions for good articles on this or presentations that can be sent to Thera Black?

Ellin

---------- Forwarded message ----------
From: Thera Black <blackvt@trpc.org>
Date: Mon, Nov 4, 2013 at 4:00 PM
Subject: [H+T--Friends] AQ Impacts vs Active Transport Benefits
To: "h+t--friends@ryoko.chrispy.net" <h+t--friends@ryoko.chrispy.net>


Greetings, all - I’m reaching out to Health and Transportation listserv members in the hopes someone can point me in a productive direction.

 

I have a planning commission that is struggling with the public health benefits/impacts of compact, walkable urban development. On the one hand they understand and appreciate the active transportation benefits associated with this built form. On the other hand, the epidemiologist on the commission argues that the increased impacts of air pollution in an urban area more than offsets the benefits associated with active lifestyle and so is working to prohibit urbanization measures along our key transit corridors – density, mix of uses, transit oriented development.

 

I can find reams of articles on the benefits of active transport. And I can find scholarly articles about transportation-related air quality impacts on public health. What I cannot find is anything that brings the two together in a way that sheds light about these considerations in combination – air quality impacts trumping active transport benefits (or vice versa). This is further complicated by the studies she is referencing which were done in major metropolitan areas. We are a small, low-density metro area with a population of about 175,000 between three cities. Our principal arterials carry anywhere from 10,000 – 18,000 vehicles per day. We have very little “urban” land use form and are trying to more effectively stimulate that kind of private sector investment along our premier transit corridors where we have the beginnings of walkable, mixed-use neighborhoods taking shape.

 

Are you aware of any research that has looked at the trade-offs between active transport and air quality impacts that might be useful in this regard?

 

Any insights are appreciated – thank you!

 

Thera

 

Thera Black

Thurston Regional Planning Council

2424 Heritage Court SW, Ste A

Olympia, WA  98502

360.956.7575 ext 2545

www.trpc.org

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--
Ellin Reisner, Ph.D.
reisnere51@gmail.com




--
Ellin Reisner, Ph.D.
reisnere51@gmail.com