Traffic kills brain cells

File this under Cars R Coffins: A new study adds to the body of evidence that exposure to air pollutants from vehicle exhaust makes people stupid.

Consider the evidence so far:

  • Low cognitive function in older women is associated with proximity to car traffic (Ranft et al. 2009)
  • In middle aged adults, lower cognitive performance is associated with exposure to car fumes (Chen and Schwartz 2009)
  • School children exposed to car exhaust do poorly on standardized tests (Suglia et al. 2008)
  • Children exposed to car exhaust have lower IQs (Perera et al. 2009)
  • The prevalence of autism is associated with proximity at birth to urban freeways (Volk et
    al. 2010
    )

  • Brain autopsies on people from infamously polluted Mexico City reveal amyloid β-peptide deposits, which are generally associated with Alzheimers patients, and unusual inflammation in the brain tissue and blood vessels in the brain (Calderón-Garcidueñas et al. 2008)
  • And earlier Mexico City study shows similar findings with dog brains – markers for dementia and inflammation in the brain (Calderon-Garciduenas et al. 2003).


Willow Road morning traffic

Last year, researchers at the University of Southern California specifically extracted vehicle exhaust particulate matter (PM) from collected air samples along the 110 freeway in Los Angeles. This is the microfine ‘soot’ that even the cleanest of hydrocarbon burning vehicles emit, and the scientists and their grad student slaves focused specifically on ultrasmall ‘nano’ PM to see what happens when rodents are exposed to this stuff. Doing this isolates poorly understood nano-particles from the better known gaseous poisons of exhaust such as carbon monoxide.

Exposure was through inhalation by live rats and also by directly applying the vehicle exhaust nanoparticles directly to brain cell cultures. The USC researchers discovered exhaust nanoparticles are easily absorbed into brain tissue and are toxic to brain cells. They saw the poisons inflame and damage brain cells and inhibit brain tissue growth in cell cultures. Furthermore, they saw the exhaust particles damages brain blood vessels, causing cognitive decline through reduced blood flow into the brain.

There’s evidence that these ultrafine automotive poisons can be transported directly to the brain via the olfactory nerves. Our mucous membranes are designed to clear somewhat larger dust particles; nanoparticles spewed into the atmosphere by our motor transportation have a clear path to all parts of our bodies. Even if you don’t breath, you’re hosed.

Vehicle exhaust nanoparticles damage brain cells, damage blood supply to the brain, inhibit brain cell growth, make children stupid, and accelerate age related cognitive impairments.

More –> Environmental Health Perspectives Glutamatergic Neurons in Rodent Models Respond to Nanoscale Particulate Urban Air Pollutants In Vivo and In Vitro by Todd E. Morgan, David A. Davis, Nahoko Iwata, Jeremy A. Tanner, David Snyder, Zhi Ning, Winnie Kam, Yu-Tien Hsu, Jeremy W. Winkler, Jiu-Chiuan Chen, Nicos A. Petasis, Michel Baudry, Constantinos Sioutas, Caleb E. Finch. I encourage you to click through on the links I provided above to the related research as well.

Via California Watch and Wend Magazine.

14 Comments

  1. Wow… This is a remarkable collection of evidence. This is for sure a great argument to lift into the higher chambers. Well written!

  2. Sadly this doesn’t seem like it’s helped by our personal decision to bike. Yes, it’s one less car, but in the process we are exposing ourselves to even more exhaust. Or at least I assume so. I certainly am more aware of inhaling fumes from traffic when I’m on my bike then when I’m in a car. So we may be decreasing the general level of pollution, but increasing the amount that the existing pollution affects us. This seems kind of like the dilemma faced on high ozone days around here. We’re advised to keep driving and out door physical activity to a minimum because cars exacerbate the problem and outdoor physical activity increases our exposure. Do people really sit inside, twiddling their thumbs on high ozone days? I think not. And do people who normally drive find alternative transport, to the detriment of their own health? Unlikely. Seems like automotive-related pollution is a self-perpetuating problem unless some general shift in attitude occurs.

  3. Does anyone else find the Zipcar ads on this post more than a bit ironic?

  4. I bike through heavy traffic as well, and I’m very aware of the fumes I breath in during my daily commute. You’re right: a shift in attitude is needed.

  5. Why would the air a cyclist breathes be worse than the air inside a car?

  6. I’m aware pollutants dissipate rapidly (probably something like the inverse cube of the distance from tailpipe since it’s a volume) and I’m (usually but not always) out of the direct stream of traffic, but I’m also breathing more and usually have more exposure time as well. I can drive down 101 from Menlo Park to San Jose in about 40 minutes with minimal effort; cycling Central Expressway going all out takes me about an hour and 15 minutes.

  7. I’m aware pollutants dissipate rapidly (probably something like the inverse cube of the distance from tailpipe since it’s a volume) and I’m (usually but not always) out of the direct stream of traffic, but I’m also breathing more and usually have more exposure time as well. I can drive down 101 from Menlo Park to San Jose in about 40 minutes with minimal effort; cycling Central Expressway going all out takes me about an hour and 15 minutes.

  8. And the air inside your destination is cleaner than the air in your car, or the air outdoors?

    In other words, isn’t exposure time 24 hours per day?

  9. And the air inside your destination is cleaner than the air in your car, or the air outdoors?

    In other words, isn’t exposure time 24 hours per day?

  10. That answers so many questions! I’ve always suspected that driving has some deleterious effect on the human brain, causing the higher functions to atrophy until all that was left was the brain stem and its autonomic processes. Then the victim develops both a typical shuffling gait and an intense desire to replace those lost brain tissues by consuming the brains of his friends, neighbors, spouses, family pets, etc. Braaaaains!

    Driving turns us into zombies!

  11. long time reader, first time post. i too have wondered about the detrimental effects of car pollution on daily cyclists. at least 2 studies suggest that we need not worry, however, and to sleep easy at night, i’m going to accept them at face value 🙂

    1.

    Sci Total Environ. 2001 Nov 12;279(1-3):131-6.Differences in cyclists and car drivers exposure to air pollution from traffic in the city of Copenhagen.
    Rank J, Folke J, Jespersen PH.
    SourceUniversity of Roskilde, Department of Environment, Technology and Social Studies, Denmark. jr@ruc.dk
    AbstractIt
    has frequently been claimed that cycling in heavy traffic is unhealthy,
    more so than driving a car. To test this hypothesis, teams of two
    cyclists and two car drivers in two cars were equipped with personal air
    samplers while driving for 4 h on 2 different days in the morning
    traffic of Copenhagen. The air sample charcoal tubes were analysed for
    their benzene, toluene, ethylbenzene and xylene (BTEX) content and the
    air filters for particles (total dust). The concentrations of particles
    and BTEX in the cabin of the cars were 2-4 times greater than in the
    cyclists’ breathing zone, the greatest difference being for BTEX.
    Therefore, even after taking the increased respiration rate of cyclists
    into consideration, car drivers seem to be more exposed to airborne
    pollution than cyclists.

    2.Environ Health Perspect. 2010 Aug;118(8):1109-16. Epub 2010 Jun 11.Do the health benefits of cycling outweigh the risks?Johan de Hartog J, Boogaard H, Nijland H, Hoek G.SourceUniversity of Utrecht, Institute for Risk Assessment Sciences, Utrecht, the Netherlands. J.J.deHartog@uu.nlAbstractBACKGROUND: Although
    from a societal point of view a modal shift from car to bicycle may
    have beneficial health effects due to decreased air pollution emissions,
    decreased greenhouse gas emissions, and increased levels of physical
    activity, shifts in individual adverse health effects such as higher
    exposure to air pollution and risk of a traffic accident may
    prevail.Objective: We describe whether the health benefits from the
    increased physical activity of a modal shift for urban commutes outweigh
    the health risks.DATA SOURCES AND EXTRACTION: We have
    summarized the literature for air pollution, traffic accidents, and
    physical activity using systematic reviews supplemented with recent key
    studies.DATA SYNTHESIS: We quantified the impact on
    all-cause mortality when 500,000 people would make a transition from car
    to bicycle for short trips on a daily basis in the Netherlands. We have
    expressed mortality impacts in life-years gained or lost, using life
    table calculations. For individuals who shift from car to bicycle, we
    estimated that beneficial effects of increased physical activity are
    substantially larger (3-14 months gained) than the potential mortality
    effect of increased inhaled air pollution doses (0.8-40 days lost) and
    the increase in traffic accidents (5-9 days lost). Societal benefits are
    even larger because of a modest reduction in air pollution and
    greenhouse gas emissions and traffic accidents.CONCLUSIONS: On
    average, the estimated health benefits of cycling were substantially
    larger than the risks relative to car driving for individuals shifting
    their mode of transport.

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