Mortality Associated with Ambient PM2.5 Exposure in India: Results from the Million Death Study.

BACKGROUND: Studies on the extent to which long-term exposure to ambient particulate matter (PM) with aerodynamic diameter ≤2.5µm (PM2.5) contributes to adult mortality in India are few, despite over 99% of Indians being exposed to levels that the World Health Organization (WHO) considers unsafe. OBJECTIVE: We conducted a retrospective cohort study within the Million Death Study (MDS) to provide the first-ever quantification of national mortality from exposure to PM2.5 in India from 1999 to 2014. METHODS: We calculated relative risks (RRs) by linking a total of ten 3-y intervals of satellite-based estimated PM2.5 exposure to deaths 3 to 5 y later in over 7,400 small villages or urban blocks covering a total population of 6.8 million. We applied using a model-based geostatistical model, adjusted for individual age, sex, and year of death; smoking prevalence, rural/urban residency, area-level female illiteracy, languages, and spatial clustering and unit-level variation. RESULTS: PM2.5 exposure levels increased from 1999 to 2014, particularly in central and eastern India. Among 212,573 deaths at ages 15-69 y, after spatial adjustment, we found a significant RR of 1.09 [95% credible interval (CI): 1.04, 1.14] for stroke deaths per 10-µg/m3 increase in PM2.5 exposure, but no significant excess for deaths from chronic respiratory disease and ischemic heart disease (IHD), all nonaccidental causes, and total mortality (after excluding stroke). Spatial adjustment attenuated the RRs for chronic respiratory disease and IHD but raised those for stroke. The RRs were consistent in various sensitivity analyses with spatial adjustment, including stratifying by levels of solid fuel exposure, by sex, and by age group, addition of climatic variables, and in supplementary case-control analyses using injury deaths as controls. DISCUSSION: Direct epidemiological measurements, despite inherent limitations, yielded associations between mortality and long-term PM2.5 inconsistent with those reported in earlier models used by the WHO to derive estimates of PM2.5 mortality in India. The modest RRs in our study are consistent with near or null mortality effects. They suggest suitable caution in estimating deaths from PM2.5 exposure based on MDS results and even more caution in extrapolating model-based associations of risk derived mostly from high-income countries to India. https://doi.org/10.1289/EHP9538.

Deaths from acute abdominal conditions and geographical access to surgical care in India: a nationally representative spatial analysis.

BACKGROUND: Few population-based studies quantify mortality from surgical conditions and relate mortality to access to surgical care in low-income and middle-income countries. METHODS: We linked deaths from acute abdominal conditions within a nationally representative, population-based mortality survey of 1·1 million households in India to nationally representative facility data. We calculated total and age-standardised death rates for acute abdominal conditions. Using 4064 postal codes, we undertook a spatial clustering analysis to compare geographical access to well-resourced government district hospitals (24 h surgical and anaesthesia services, blood bank, critical care beds, basic laboratory, and radiology) in high-mortality or low-mortality clusters from acute abdominal conditions. FINDINGS: 923 (1·1%) of 86,806 study deaths at ages 0-69 years were identified as deaths from acute abdominal conditions, corresponding to 72,000 deaths nationally in 2010 in India. Most deaths occurred at home (71%) and in rural areas (87%). Compared with 567 low-mortality geographical clusters, the 393 high-mortality clusters had a nine times higher age-standardised acute abdominal mortality rate and significantly greater distance to a well-resourced hospital. The odds ratio (OR) of being a high-mortality cluster was 4·4 (99% CI 3·2-6·0) for living 50 km or more from well-resourced district hospitals (rising to an OR of 16·1 [95% CI 7·9-32·8] for >100 km). No such relation was seen for deaths from non-acute surgical conditions (ie, oral, breast, and uterine cancer). INTERPRETATION: Improvements in human and physical resources at existing government hospitals are needed to reduce deaths from acute abdominal conditions in India. Full access to well-resourced hospitals within 50 km by all of India's population could have avoided about 50,000 deaths from acute abdominal conditions, and probably more from other emergency surgical conditions. FUNDING: Bill & Melinda Gates Foundation, Dalla Lana School of Public Health, Canadian Institute of Health Research.

Geospatial analysis on the distributions of tobacco smoking and alcohol drinking in India.

BACKGROUND: Tobacco smoking and binge alcohol drinking are two of the leading risk factors for premature mortality worldwide. In India, studies have examined the geographic distributions of tobacco smoking and alcohol drinking only at the state-level; sub-state variations and the spatial association between the two consumptions are poorly understood. METHODOLOGY: We used data from the Special Fertility and Mortality Survey conducted in 1998 to examine the geographic distributions of tobacco smoking and alcohol drinking at the district and postal code levels. We used kriging interpolation to generate smoking and drinking distributions at the postal code level. We also examined spatial autocorrelations and identified spatial clusters of high and low prevalence of smoking and drinking. Finally, we used bivariate analyses to examine the spatial correlations between smoking and drinking, and between cigarette and bidi smoking. RESULTS: There was a high prevalence of any smoking in the central and northeastern states, and a high prevalence of any drinking in Himachal Pradesh, Arunachal Pradesh, and eastern Madhya Pradesh. Spatial clusters of early smoking (started smoking before age 20) were identified in the central states. Cigarette and bidi smoking showed distinctly different geographic patterns, with high levels of cigarette smoking in the northeastern states and high levels of bidi smoking in the central states. The geographic pattern of bidi smoking was similar to early smoking. Cigarette smoking was spatially associated with any drinking. Smoking prevalences in 1998 were correlated with prevalences in 2004 at the district level and 2010 at the state level. CONCLUSION: These results along with earlier evidence on the complementarities between tobacco smoking and alcohol drinking suggest that local public health action on smoking might also help to reduce alcohol consumption, and vice versa. Surveys that properly represent tobacco and alcohol consumptions at the district level are recommended.