Chronic health risks in retail buildings and their dependence on ventilation rates and filtration efficiencies

Abstract

Background-Inhalation exposures to indoor pollutants in non-residential environments contribute largely to total daily exposures. Prioritizing pollutants to be controlled by energy-intensive methods (i.e.ventilation and filtration) is key to reducing the total chronic disease burden and achieve energy efficiency in retail buildings. Objective-Our objective was to model exposure to indoor pollutants measured in retail environments for customers and employees, and assess the role of ventilation and filtration in mitigating this exposure. Methods-Measured concentrations of pollutants in 140 stores in the U.S., available methods (IND and ID approaches) and toxicological data were employed in Monte Carlo simulations to calculate disability-adjusted-life-years (DALYs). Indoor emission factors for pollutants were calculated to assess the change in health risks under 9 scenarios of ventilation rates and filtration efficiencies. Results were compared with DALYs found in residences. Results-The estimated average DALYs due to PM2.5 and acrolein exposure contributed the largest to annual health impacts, with an estimated 122 DALYs per 100,000 persons, divided equally between PM2.5 and acrolein.Carbon tetrachloride, formaldehyde and ozone accounted for the vast majority of the cancer health effects, contributing for a total of 10 DALYs per 100,000 persons annually. Increasing the filtration efficiency, while reducing infiltration rate to a minimum, is found to be the most energy efficient method to decrease DALYs from PM2.5 exposure. As for acrolein, increasing the ventilation rates in the retail stores could not drive acrolein concentrations below the OEHHA chronic REL. Comparing the findings from this study to DALYs reported by Logue et al. (2012) for residences revealed that PM2.5 and acrolein are two common contaminants of concerns. Conclusions-This study found that polluatnt control startegies should focus on mitigating exposure to PM2.5 and acrolein. Cumulative health burden from all indoor pollutants contributed to 146 DALYs per 100,000 persons annually.