Publication Year: 2021

Daily nonaccidental mortality associated with short-term PM2.5 exposures in Delhi, India

Abstract

Background: 

Ambient particulate matter of aerodynamic diameter less than 2.5 microns PM2.5) levels in Delhi routinely exceed World Health Organization (WHO) guidelines and Indian National Ambient Air Quality Standards (NAAQS) for acceptable levels of daily exposure. Only a handful of studies have examined the short-term mortality effects of PM in India, with none from Delhi examining the contribution of PM2.5.

 

Objectives: 

We aimed to analyze the association between short-term PM2.5 exposures and daily nonaccidental mortality in Delhi, India.

 

Methods: 

Using generalized additive Poisson regression models, we examined the association between daily PM2.5 exposures and nonaccidental mortality between June 2010 and December 2016. Daily exposures to PM2.5 were estimated using an ensemble averaging technique developed by our research group, and mortality data were obtained from the Municipal Corporations of Delhi and the New Delhi Municipal Council.

 

Results: 

Median exposures to PM2.5 were 91.1 µg/m3 (interquartile range = 68.9, 126.2), with minimum and maximum exposures of 21.4 µg/m3 and 276.7 µg/m3, respectively. Total nonaccidental deaths recorded in Delhi during the study period were 700,512. Each 25 µg/m3 increment in exposure was associated with a 0.8% (95% confidence intervals [CI] = 0.3, 1.3%) increase in daily nonaccidental mortality in the study population and a 1.5% (95% CI = 0.8, 2.2%) increase in mortality among those with 60 years of age or over. The exposure-response relationship was nonlinear in nature, with relative risk rising rapidly before tapering off above 125 µg/m3. Meeting WHO guidelines for acceptable levels of exposure over the study period would have likely averted 17,526 (95% CI = 6,837, 25,589) premature deaths, with older and male populations disproportionately affected.

 

Discussion: 

This study provides robust evidence of the impact of short-term exposure to PM2.5 on nonaccidental mortality with important considerations for various stakeholders including policymakers and physicians. Most importantly, we find that reducing exposures significantly below current levels would substantially decrease the mortality burden associated with PM2.5.

Read more

The limits of opportunism: the uneven emergence of climate institutions in India

Introduction

India’s centrality to global mitigation efforts makes it an important point of inquiry in studies of climate governance. However, we understand little of how climate change has been institutionalized in India’s decision-making processes. We capture the emergence and decline of climate institutions over three decades, showing how political conditions have shaped institutional form. The politics of opportunism has animated institutional development. It resolves the tension between India’s global leadership ambitions and a deeply entrenched, equity focused narrative frame that rejects incurring large mitigation costs. Climate institutions have therefore been layered upon existing bodies and processes to create room for the organic, bottom-up growth of policies that meet development objectives while promoting mitigation. While this structure limits polarization around climate action, it also inhibits strategic intent, particularly because strong cross-governmental institutions have been unable to take root.

Read more

Net-zero emission targets are a hollow pledge

Introduction

India needs a path that shows how a focus on opportunities for low-carbon development is more likely, in practice, to deliver emissions reductions than abstract future 2050 pledges

Give young environmentalists a voice

Introduction

India has always argued that climate is linked to development choices, livelihoods and equity. Don’t ask activists to narrow down their concerns