Research

 PM2.5 exposure profile of a participant

Preliminary Findings

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• Personal PM2.5 exposures in the range of 85± 117 µg/m3

• Wintertime personal exposures (152±120 µg/m3) ~300% higher than Summer (49±35 µg/m3) 

• Slum residents have higher exposures than non-slum and slum resettlement colony residents

• Informal sector employees and housewives have  higher exposures than formal sector employees

• Cooking, Heating, Passive Smoking, and  Worship – Activities with higher exposures

Study Findings

1. Association of Long-Term Exposure to Fine Particulate Matter and Cardio-Metabolic Diseases in Low- and Middle-Income Countries: A Systematic Review

        Key findings:

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• 17 articles were included for final review, and these studies were from Brazil, Bulgaria, China, India, and Mexico.

• Outcome assessed were hypertension, type 2 diabetes mellitus and insulin resistance, and cardiovascular disease (CVD)-related emergency room visits/admissions, death, and mortality.

• Largely a positive association between exposure to PM2.5 and CMDs was found, and CVD mortality with effect estimates ranging from 0.24% to 6.11% increased per 10 μg/m3 in PM2.5.

• CVD-related hospitalizations and emergency room visits increased by 0.3% to 19.6%. Risk factors like hypertension had an odds ratio of 1.14, and type 2 diabetes mellitus had an odds ratio ranging from 1.14–1.32.

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  2.  Ensemble averaging based assessment of spatiotemporal variations in ambient PM 2.5

      concentrations over Delhi, India, during 2010-2016

      Key findings:

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• Overall cross-validated prediction accuracy of the model was 80% over the study period with high spatial model accuracy and predicted annual average concentrations ranging from 87 to 138 μg/m3.

• Annual average root mean squared errors for the ensemble averaged predictions were in the range 39.7-62.7 μg/m3 with prediction bias ranging between 4.6-11.2 μg/m3.

• Our findings indicate important seasonal and geographical differences in particulate matter concentrations within Delhi over a significant period of time, with meteorological and land use features that discriminate most and least polluted regions.

• This exposure assessment can be used to estimate dose response relationships more accurately over a wide range of particulate matter concentrations.

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  3.  Exposure to Particulate Matter Is Associated With Elevated Blood Pressure and Incident

      Hypertension in Urban India  

      Key findings:

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• Median annual and monthly exposure at baseline was 92.1 μg/m3 (interquartile range, 87.6–95.7) and 82.4 μg/m3 (interquartile range, 68.4–107.0), respectively.

• We observed higher average systolic BP (1.77 mm Hg [95% CI, 0.97–2.56] and 3.33 mm Hg [95% CI, 1.12–5.52]) per interquartile range differences in monthly and annual exposures, respectively, after adjusting for covariates.

• Additionally, interquartile range differences in long-term exposures of 1, 1.5, and 2 years increased the risk of incident hypertension by 1.53× (95% CI, 1.19–1.96), 1.59× (95% CI, 1.31–1.92), and 1.16× (95% CI, 0.95–1.43), respectively.

• Observed effects were larger in individuals with higher waist-hip ratios.