On Wednesday, October 26, 2011, Laurentian SETAC held its first Ottawa Pub Night of the season with speaker Dr. Dalibor Breznan from Health Canada, who spoke about the toxicology of urban particulate matter. An enthusiastic crowd gathered at the Clock Tower Brew Pub in Ottawa to hear Dr. Breznan’s presentation entitled “Toxicology of Urban Particulate Matter: In Vitro and In Vivo Bioassays”. The evening began with the set-up and display of HealthCanada’s impressive promotional science booth. Jason Rancourt, Manager of Science Promotion and Intellectual Property at HealthCanada, gave an introductory message promoting science at HealthCanada. Throughout the course of the evening, Mr. Rancourt answered questions at the Health Canada booth. Dr. Breznan’s talk explained that air pollution is a growing concern for the population, with deaths from acute and chronic exposure predicted to rise in the coming decades. One of the contributors to air pollution is urban particulate matter. After an informative introduction, the talk shifted into outlining the health effects of particulate matter on humans. Air pollution has been linked to altered pulmonary reflexes and inflammation, cancer, lower birth weight in infants, as well as development and worsening of acute and chronic conditions such as cardiovascular diseases and stroke. This emphasised the importance of studying the health effects of particulate matter and of reducing particulate matter levels in the environment. The research conducted by Dr. Breznan and the Inhalation Toxicology Lab at Health Canadacontributes to the knowledge of the effects of particulate matter. They developed a high-throughput in vitro cell bioassay test suite that is a good predictor of the in vivo response of animal cells to particulate matter. This high-throughput screening tool allows for quicker results to help model the results for some compounds, a necessary step due to the thousands of particulate matter chemicals whose effects are still unknown. They also determined during their in vitro testing that the toxicity profiles of particulate matter with different compositions are also dependent on the cell types assayed and cytotoxicity tests used, emphasizing the importance of conducting the testing using a panel of assays and different cell types, in order to obtain a more robust profile for the particle effects. As well, studying the cytotoxic responses to particulate matter of different cell types in a co-culture showed an increase in inflammation factors in comparison with exposures of individual cell types, demonstrating the importance of cellular interactions in modulating the effects of particulate matter. As a result of Dr. Breznan’s work, it is hoped that there will be a better understanding of the factors that influence the biological potency of air pollution particles, and of the effects the particles have on human health. Overall, the night was entertaining and informative and the audience was enlightened and well-fed. - Submitted by Stacey Saucier
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