Researchers look for link between air pollution and brain disease

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• John Yang:

  New research is raising important questions about the effect of air pollution, not only on our lungs but on our brains. It's what one study called an urgent public health concern. The issue how much and to what extent are airborne contaminants linked to neurological diseases like Alzheimer's? Jeffrey Brown has more.

• Jeffrey Brown:

  Research in this area has been building for years with many links now seen but much still uncertain. Dr. Deborah Cory Slechta focuses her studies on environmental health and the brain at the University of Rochester Medical Center, and she joins us now. Thanks for being with us. You know, you and others see a growing public health issue here. Explain the the the concern. I mean, how does air pollution impact the brain and possibly lead to neurological disease?

• Deborah Cory-Slechta:

  Well, we've known that air pollution has effects on the heart and the lung for a very long time. But it's really only been in about the past ten years that attention has been directed to its effects on the brain. And over that period of time, there's been a growing body of scientific evidence showing associations between exposures to air pollution in a a real wide variety of neurological diseases and disorders that is included neurodevelopmental disorders like autism, attention deficit hyperactivity disorder, as well as neurodegenerative diseases like Alzheimer's disease, Parkinson's disease, etc.. How that's happening, we still don't fully understand. But the fact that it seems to have such a impact on such a variety of neurological diseases and disorders suggests that instead of acting on what are the really unique characteristics of each of those diseases and disorders, air pollution is acting on the features that are shared across these neurological diseases and disorders.

• Jeffrey Brown:

  Well, so to be clear at this stage, it's a question of association of pollution to neurological problems, but not yet clear causation. Is that fair?

• Deborah Cory-Slechta:

  I think there is a growing body of experimental data linking or directly showing causal relationships. Air pollution is a very complicated exposure. It's really a mixture of gases and particles, and those particles carry other toxins on them, metals and organics that get into the brain. And so what we really don't understand. One of the things we don't understand is what are the contaminants that are getting into the brain via those air pollution particles that are responsible for these neurological diseases and disorders.

• Jeffrey Brown:

  As you're studying this, who do you consider most at risk, whether it's by age or by living conditions or geography? Who are you most worried about?

• Deborah Cory-Slechta:

  Well, I think we don't fully have the answers to that yet. So one of the things we don't yet understand with respect to, for example, neurodevelopmental disorders is what is the period of greatest vulnerability? Is it preconception or is it in utero first, second, third trimester, early brain development? We don't know the answers. And with respect to neurodegenerative diseases, one has to remember that this is actually a lifetime exposures are neurodegenerative diseases being caused by a cumulative exposure over the lifetime, or is it exposures that are occurring later as maybe the blood brain barrier begins to break down, gets a little bit leaky? We don't have answers to those questions as of yet. We really need to understand what the contaminants are that are in air pollution that are causing these because then we could go and basically set regulatory policies that might assist in preventing those exposures.

• Jeffrey Brown:

  Are there things you do advise to individuals to in terms of behavior or care in this regard?

• Deborah Cory-Slechta:

  Well, I don't know that there's much an individual can do. This is really going to be at a national level. We do regulate right now levels of air pollution with specifically what we call PM 2.5 and PM10. Those are particle sizes, but we know that it's actually the smallest particle size, the ultrafine particles, the nanoparticles that are the most problematic, they are the what carry those toxicants into the body and we don't regulate those right now. We don't have a system in place to fully assess the data of those kinds of exposures. And so a lot more effort is going to be needed to address this Ultrafine particle component.

• Jeffrey Brown:

  Deborah Cory-Slechta, thank you very much.

• Deborah Cory-Slechta:

  Thank you.