Exposure to Black Carbon (BC) and the Secondary Aerosol (p-SO₄^2– and p-NO₃^‒) Components of Fine Particulate Matter (PM_2.5), and Cardiopulmonary Morbidity in Jeddah, Saudi Arabia

Abstract: This study assessed the morbidity risk for respiratory (RDs) and cardiovascular diseases (CVDs) from the exposure to black carbon (BC), p-SO₄^2–, and p-NO₃^‒ measured in PM_2.5 collected from Jeddah. The 24 h PM_2.5 sampling was done at three sites for 6 weeks quarterly from 8 April 2013 to 18 February 2014, with concurrent hospital data collection. Though the data were collected more than a decade ago, the results are still applicable to the current middle east region and beyond. The relative risk (RR) for CVDs and RDs was computed in a single pollutant GLM time-series model using moving averages (MAs) and presented with 95% confidence intervals (CI). Overall, the morbidity risk was highest in outpatients. The risk of RDs was highest in younger age groups with age group 0–14 years being the most vulnerable, while the risk of CVDs was highest in age groups above 30 years. BC: The risk of RDs was highest in outpatient females of 0–14 years at all MAs; 1.483 (1.035, 2.123) to 2.501 (1.522, 4.112), and males of 31–45 years; 1.758 (1.134, 2.725) to 1.895 (1.142, 3.145) at MAs 5–7. The risk of CVDs was highest in age group 61–75 years but with a marginal statistical significance. p-SO₄^2–: The risk of RDs was highest in males of 31–45 years; 1.173 (1.066, 1.291) to 1.256 (1.126, 1.400) at MAs_3–7. The risk of CVDs was also highest in age group 31–45 years; 1.078 (1.004, 1.157) to 1.090 (1.010, 1.177), with higher risk estimates in males; 1.084 (0.986, 1.191) to 1.120 (1.013, 1.239) at MAs 4–7. p-NO₃^‒: No significant risk was observed for RD morbidity. The overall risk of CVDs was significant in outpatients with an age group of 61–75 years at all MAs; 1.204 (1.014, 1.429) to 1.316 (1.096, 1.579); females, 1.221 (0.987, 1.511) to 1.428 (1.123, 1.816); and males, 1.205 (1.022, 1.421) to 1.258 (1.052, 1.505). This is the first study to assess the cardiopulmonary risk from BC, p-SO₄^2–, and p-NO₃^‒ exposure in Jeddah. A high morbidity risk was observed in all age groups, accentuating the effects of elevated air pollution in Saudi Arabia and beyond. Females of 0–14 years were more at risk for RDs morbidity while the CVDs morbidity risk was relatively higher in males in age groups above 30 years.