Effect of global atmospheric aerosol emission change on PM_2.5-related health impacts

ABSTRACT

Background: Previous research has highlighted the importance of major atmospheric aerosols such as sulfate, through its precursor sulfur dioxide (SO₂), black carbon (BC), and organic carbon (OC), and their effect on global climate regimes, specifically on their impact on particulate matter measuring ≤ 2.5 μm (PM_2.5). Policy regulations have attempted to address the change in these major active aerosols and their impact on PM_2.5, which would presumably have a cascading effect toward the change of health risks.

Objective: This study aimed to determine how the change in the global emissions of anthropogenic aerosols affects health, particularly through the change in attributable mortality (AN) and years of life lost (YLL). This study also aimed to explore the importance of using AM/YLL in conveying air pollution health impact message.

Methods: The Model for Interdisciplinary Research on Climate was used to estimate the gridded atmospheric PM_2.5 by changing the emission of SO₂, BC, and OC. Next, the emissions were utilized to estimate the associated cause-specific risks via an integrated exposure–response function, and its consequent health indicators, AM and YLL, per country.

Results: OC change yielded the greatest benefit for all country income groups, particularly among low-middle-income countries. Utilizing either AM or YLL did not alter the order of benefits among upper-middle and high-income countries (UMIC/HIC); however, using either health indicator to express the order of benefit varied among low- and low-middle-income countries (LIC/LMIC).

Conclusions: Global and country-specific mitigation efforts focusing on OC-related activities would yield substantial health benefits. Substantial aerosol emission reduction would greatly benefit high-emitting countries (i.e. China and India). Although no difference is found in the order of health outcome benefits in UMIC/HIC, caution is warranted in using either AM or YLL for health impact assessment in LIC/LMIC.

KEYWORDS:

• Black carbon
• organic carbon
• sulfur dioxide
• attributable mortality
• years life lost

Responsible Editor Peter Byass, Umeå University, Sweden

Responsible Editor Peter Byass, Umeå University, Sweden

Author contributions

XS and KU conceptualized the study design. SSP, KS, TK and TN contributed to the data generation as well as interpretation of results. XS conducted the necessary calculations for burden of disease estimation. XS and KU drafted the manuscript. All authors have read and approved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Ethics and consent

Not applicable.

Paper context

Policies have been utilized to target the decrease of atmospheric aerosols, which presumably will affect PM concentration and the consequent associated disease burden. This study demonstrated that OC-reduction would have the greatest health benefit among most, if not all, of the countries. Although the prospective benefits due to the reduced disease burden have been generally positive, caution should be warranted when conducting health impact assessment, particularly for LICs/LMICs because the order of health benefits may vary.

Supplementary Material

Supplemental data for this article can be accessed here.

Additional information

Funding

This research was supported by the Environment Research and Technology Development Fund [S-12, 5-1751] of the Environmental Restoration and Conservation Agency.