Differential Impact of Exposure to PM2.5 Composition and Contributing Sectors on Anemia Prevalence Amongst Children Under age five in India

Abstract

Anemia, a condition of low red blood cell count and diminished hemoglobin levels, is highly prevalent in India. India has one of the highest anemia prevalence approx. 60% among children under age five (U5) in the world. Ambient PM2.5 exposure has been identified as a potential risk factor for anemia via systemic inflammation. Moreover, whether the impact varies with PM2.5 composition and sources contributing to such components is not known. Here, we examine the differential impact of exposure to ambient PM2.5 components on anemia prevalence among children U5 in India using exposure data from the CMAQ model and satellite-derived PM2.5, health data from the NFHS-IV. Here we focus on the exposure to PM2.5 components such as Black Carbon, Organic Carbon, nitrate (NO3), ammonium (NH4), sulfate, soil, and others, during the early life period. We use multilevel models adjusted for the risk factors - smoking, cooking fuel, BMI, wealth, and residence to assess the impact of PM2.5 components on anemia prevalence among children. At the ecological level, for every IQR increase in ambient PM2.5 exposure, the odds ratio for average anemia prevalence is 1.19 (95% UI: 1.17,1.22). For each IQR of NO3, anemia prevalence increased with an odds ratio of 1.26 (95% UI: 1.24,1.29). For the corresponding increase in NH4, others, BC, OC, SO4, and soil, anemia prevalence increased by odds ratio 1.19 (95% UI: 1.17,1.21), 1.16 (95% UI: 1.14, 1.18), 1.15 (95% UI: 1.13, 1.17), 1.11 (95% UI: 1.09, 1.13), 1.12 (95% UI: 1.11,1.13), and 1.10 (95% UI: 1.08,1.11), respectively. Sectorally, the domestic sector has the highest impact, followed by the unorganized sectors, road dust, agriculture waste, industry, etc. Our results will support the policymakers to target specific sectors that are contributing to exposure to PM2.5 and its components and, in turn, causing lethal health impacts. Keywords- Anemia, PM2.5, LMICs