An example of how the environment may contribute to health disparities: Estimates of mortality that could be prevented if Interior and Northern British Columbia had the same air quality as Vancouver Dr. Catherine Elliott 1 and Dr. Ray Copes 2 Canadian Public Health Association Conference June 2008, Halifax, Nova Scotia 1 Community Medicine, University of British Columbia 2 British Columbia Centre for Disease Control, Environmental Health Division

Objectives To highlight the concept: environmental health inequity To illustrate the differences in ambient fine particulate matter between British Columbia’s Lower Mainland and Interior and Northern communities To estimate the mortality attributable to this unequal exposure

Environmental Health Inequity Disproportionately high human health outcomes result from inequitable distribution of environmental hazards. Includes physical, chemical, biological pollution as well as the built environment Northridge et al. AJPH 2003;29(2)

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Fine particulate matter health outcomes PM 2.5 PM  m

SOURCE: BC Ministry of Water, Land and Air Protection, Air Resources Branch, Distribution of fine particulate matter pollution in British Columbia

Mean Annual PM 2.5 in Northern and Interior BC

Methods Risk Assessment Approach – to estimate the mortality burden, given the currently available information. Mortality attributable to ambient air pollution is estimated based on attributable risk for each increment in PM 2.5 above an a priori low level

Attributable Mortality Estimates of attributable mortality are based on: –Measured annual mean PM 2.5 concentration –The reference PM 2.5 that we set –Mortality count in the region –The relationship between mortality and PM concentration from the literature

Results

Estimated Mortality Attributable to Ambient PM 2.5 above the level in Attainable (reference exposure level, Vancouver: 5.79 ug/m3)

Estimated Mortality Attributable to Ambient PM 2.5 above Background (Terrace as the reference exposure level, 3.39 ug/m3)

Estimate of mortality burden of long-term exposure to ambient air quality in Northern and Interior BC Reference Exposure Level Annual Mortality Central (Low, High) InteriorNorth Attainable Vancouver (5.79 ug/m3) 32 (5,79)25 (4,63) Background Terrace (3.39 ug/m3) 179 (27,443)53 (8,130)

Annual mortality attributable to PM2.5 compared with other contributing and immediate causes of death in Northern Health Cause of Death Annual Mortality Air pollution25 (4,63) Smoking attributable mortality*319 Alcohol related mortality168 Cardiovascular disease297 Stroke/CVA82 Chronic Pulmonary Disease73 Diabetes61 Drug Induced57 Influenza and Pneumonia51 * Smoking attributable mortality does not include environmental tobacco smoke (second-hand smoke).

Annual mortality attributable to PM2.5 compared with other contributing and immediate causes of death in Northern Health Cause of Death Annual Mortality Air pollution32 (5,79) Smoking attributable mortality*1217 Alcohol related mortality463 Cardiovascular disease1415 Stroke/CVA437 Chronic Pulmonary Disease283 Influenza and Pneumonia228 Diabetes187 Drug Induced173 * Smoking attributable mortality does not include environmental tobacco smoke (second-hand smoke).

Limitations Risk Assessment Methodology: provides an estimate of attributable mortality incremental to the reference PM 2.5 concentration. We did not include different susceptibilities to particulate matter in our analysis.

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Conclusion If ambient air pollution were reduced to Vancouver levels, then approximately 57 (range 9-142) deaths each year in the Northern and Interior Health Authorities would be avoided.

Acknowledgements Dr. Ray Copes, Scientific Director, Environmental Health, BCCDC NCCEH Dr. Bob Fisk, BC Ministry of Health Natalie Suzuki, BC Ministry of the Environment

Questions?

End of presentation

Northern and Interior British Columbia

Concentration Response Functions Study Concentration Response Function (95% CI) Six Cities Study, original (Dockery et al 1993)13 (4.2,23) Six Cities Study, HEI reanalysis (Krewski et al 2000)14 (5.4,23) Six Cities Study, extended reanalysis (Laden et al 2006) 16 (7,26) ACS, original (Pope et al 1995)6.6 (3.5,9.8) ACS, HEI reanalysis (Krewski et al 2000)7.0 (3.9,10) ACS, extended reanalysis (Pope et al 2002, 2004)6.2 (1.6,11) Values used in this analysis Pope et al 2002, 2004; Mean value of six major studies***; Laden et al 2006 Low 1.6 Central 10.5 High 26 CRFs are expressed as percentage increased mortality per 10ug/m 3 increase in PM 2.5

Inversions and trapping

Methods II: Model to derive number of cases attributable to ambient air pollution PM 2.5 (ug/m 3 ) Concentration Response Function (derived from RR) Air Quality Standard

Reference exposure level Measured PM 2.5 level Number of cases attributable to increase in exposure by 10 ug/m3 PM 2.5 (ug/m 3 ) Methods II: Model to derive number of cases attributable to ambient air pollution A B Mortality 1121