Q&A: Sverre Vedal

Thursday, December 1, 2011

Professor Sverre Vedal (DEOHS) will deliver the Fall 2011 Distinguished Faculty Lecture on December 12 at 3:30 in T-625: Air Pollution--Can It Really Be That Bad For Us? Catherine Shen spent some time with Sverre to learn about his research.

Q: (SPH) How did you come to the field of air pollution research?
A: (Sverre Vedal) It really happened by chance. In a med school seminar, I did a lot of quantitative stuff and liked the link between the quantitative and how it could meaningfully improve health. I did a respiratory epidemiology fellowship in Boston that was the single most important academic step I took, using statistics with a group involved in air pollution epidemiology in the US in the early days. I eventually joined a University of British Columbia group in an academic pulmonary role and got NIH grants to do air pollution studies. What I do is a nice marriage of quantitative methods, epidemiology, and my medical and pulmonary background.

Q: What are the biggest challenges in the field of air pollution?
A: Fortunately, the field is well supported with infrastructure and funds. However, one challenge is coming up with original and insightful approaches about how to examine the effects of air pollution. Sometimes the tendency in the field is to do "me too" work and just get a paper published.

There has been a strong link between policy needs and biomedical air pollution research, so what is studied is largely what is needed to make policy. The "criteria pollutants" cited by the EPA (particles, sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone and lead), because they are central to federal air quality regulations, have led to the bulk of the air pollution research being directed at those pollutants. My particular focus has been on ozone and particulate matter. But what we breathe is much more complicated than just these few pollutants; we breathe a combination of many pollutants in many forms. The approach of our new UW Center for Clean Air Research is to take a more realistic multi-pollutant approach rather than dealing with one pollutant at a time.

Q: What are some significant findings?
A: Vancouver, BC, where I spent many years in the earlier part of my career, has the cleanest air of any urban area in North America. It has the lowest levels of both ozone and particulate matter. However, even though it has the cleanest air, Vancouver is no different from LA, New York City, or Chicago in our being able to detect effects of air pollution on the most serious health effects, including death. How can this be? It's a paradoxical observation.

We do have some clues as to what is going on, however. We know that half of all deaths are caused by cardiovascular disease, so air pollution must somehow affect the cardiovascular system rather than just the lung. We've learned a lot from work being done on the short-term effect of different pollutants on people and animals. For example, from work done here at UW, we know that diesel exhaust affects blood vessel diameter and blood pressure. Within minutes of exposure to diesel exhaust, the vessels narrow.

There are three main hypotheses about how air pollution causes these systemic effects:

  1. The most popular is that air pollution causes lung inflammation that somehow spills over into the bloodstream and affects the heart.
  2. Very fine particles can get through the lungs and pass into the bloodstream without being filtered.
  3. Air pollutants trigger receptors in the lung that connect with the autonomic nervous system, affecting heart rate and rhythm and also inflammation. However, people's receptors vary a lot in sensitivity, which probably has a genetic basis and may explain why some people would be sensitive to very low levels. We are currently studying genetic variation among people to gain insight into who is most susceptible to exposure and why.

I lean towards the third theory.

Q: What do you do for fun?
A: I run about three times a week and do some back-country skiing. I read a lot. James Joyce and Vladimir Nabokov are two of my favorite authors. I recently read a really interesting book called The Lost and Forgotten Languages of Shanghai. It's a novel about a Chinese man who grew up in the US, returns to China, and is very successful—but suffers brain damage and loses his ability to speak Chinese, although he can still speak English. It's about what language means to relationships and to life.