Alvine Lecture Series: Air Pollution and Human Health

The Charger Bulletin

By Brent Higgins
Guest Contributor

Overwhelming is an understatement, especially when acknowledging the deluge of variables that could have an effect on Ms. Bell’s data sets. On the overhead was a long string of what looked like frat house graffiti gone wrong- later determined to be a Baysian Hierarchical Model that accounted for a barrage of real world variable statistics. The model included information such as time of day, day of the week, temperature, and levels of different sizes of air particulate. Just the title of the lecture alone: “Air Pollution and Human Health” committed itself to a plethora of what ifs and if and only ifs.

Michelle C. Bell represents an army of scholarly elites expanding our understanding of the world through Sisyphusian endeavours neither wholly inglorious nor murmured in the streets. Her historical research began with the “Great Smog of 1952” when London air was trapped under a dense natural fog. The effect was so severe that visibility for a pedestrian was reduced to less than an arm’s length. Even pictures taken in broad daylight looked nightly. A correlation between exposure to sulphur dioxide and the number of health consequences and deaths was acknowledged with the Clean Air Acts of both the United States and the United Kingdom in the 70s.

As a result of the Clean Air Acts today’s scientists researching air pollution are “looking at a much smaller signal.” This decrease in larger, coarser particulate has been met with an increase in finer, combustion related particulate. This finer particulate is denoted PM2.5 for an aerodynamic diameter under 2.5 micrometers or about 30 times smaller than that of a human hair. The larger coarse dirt or dust particulate around PM10 is more common in developing cities with a lot of construction like those of China and India. Depending on weather conditions PM10 can settle to the ground within a couple of hours but PM2.5 is capable of remaining airborne for weeks and is only really removed when it rains. An interesting remark made about the federal stipulations was that they shortcut by only accounting for particulate size and avoid more intensive characteristics like chemical structure, acidity, water content and shape.

Due to the small size of fine particulate and its dependency on a daunting number of external factors that are difficult to quantify, the exact nature of PM2.5 with regards to bodily absorption rates and health effects remains elusive. Ms. Bell stated a better understanding of the nature of these chemicals present in the air can be achieved provided the time needed for more data collection. Of course it would also help to have more innovative but yet precise instruments capable of dissecting the air into quantifiable datasets. “…Come see me in four more years.” Michelle C. Bell concluded with a slight humour. More data is exactly what she intends to acquire.