The recent Air Pollution Special Issue (Science 385) does a laudable job highlighting the global scientific community’s ability to quantify air pollution and its impacts and translate findings into policy-relevant recommendations. We contend, however, that it gives insufficient consideration to one of the oldest and leading sources of health-damaging pollution: cooking and heating with solid fuels (wood, dung, charcoal, coal, crop residues). ~3 million deaths yearly are attributable to the resulting household air pollution, which also contributes to climate change (1).
How bad is the air pollution associated with solid fuel use? Of ~12,000 PM2.5 measurements made in households or on individuals using solid fuels, 1% were at or below the annual WHO Interim Target 1 guideline value of 35 µg/m3 (2). None attained the guideline value of 5 ug/m3. In other words, we expect that none of the 3 billion people without access to clean household energy experience air quality that satisfies the WHO guideline.
Advances in lower-cost sensing, as discussed in Apte et al (Science 385, 380-385), have enabled better resolved air pollution estimates and novel justice-focused analyses. They have not been widely applied in rural communities, especially indoors among households using solid fuels. Similarly, the goal of universal clean air, as discussed by Huang et al (Science 385, 386-390), cannot be met without commitment to reducing inequities in the impacts of household air pollution in low- and middle-income countries (LMICs).
Cleaner biomass alternatives—gas and electricity—have been available for decades and are commonplace among wealthier households in LMICs and widely in developed nations. While access to these cleaner technologies is increasing, their exclusive use lags in LMICs due to cost, availability, and reliability of supply (3). Global momentum to ban fossil fuel use has affected support for scaling clean household energy in LMICs, even while fossil fuels continue to power the economies of developed nations and the homes of their citizens. Without drastic policy measures to enable near-term clean energy transitions, which likely includes LPG, we run the risk of exacerbating exposure and health inequities among vulnerable communities (4).
Policies reducing HAP have many benefits: decreased exposure of household members by eliminating solid fuel use (5); reduced community exposures by removing many point sources; and improved air quality for entire airsheds (6). Efforts to improve measurement of HAP exposures and of rural air pollution similarly serve multiple purposes: they provide an important baseline of pollution people actually experience; they enable calibration of model- or satellite- based pollution estimates; and they enable accountability studies of policies that may improve ambient air (e.g. programs transitioning from biomass to gas or electricity).
No global health discourse on air pollution can be complete without adequate emphasis on household air pollution exposures that impact the poorest three billion with limited bargaining power for energy or health equity. We implore continued emphasis on this public health risk in every forum concerned with air pollution and health.
References
1. Health Effects Institute. “State of Global Air 2024.” Special Report.(Boston, MA:Health Effects Institute., 2024.
2. M. Shupler, K. Balakrishnan, S. Ghosh, G. Thangavel, S. Stroud-Drinkwater, H. Adair-Rohani, J. Lewis, S. Mehta, M. Brauer, Global household air pollution database: Kitchen concentrations and personal exposures of particulate matter and carbon monoxide. Data in Brief 21, 1292–1295 (2018).
3. E. Puzzolo, D. Pope, D. Stanistreet, E. A. Rehfuess, N. G. Bruce, Clean fuels for resource-poor settings: A systematic review of barriers and enablers to adoption and sustained use. Environmental Research 146, 218–234 (2016).
4. C. F. Gould, R. Bailis, K. Balakrishnan, M. Burke, S. Espinoza, S. Mehta, S. B. Schlesinger, J. R. Suarez-Lopez, A. Pillarisetti, In praise of cooking gas subsidies: transitional fuels to advance health and equity *. Environ. Res. Lett. 19, 081002 (2024).
5. M. Johnson, A. Pillarisetti, R. Piedrahita, K. Balakrishnan, J. L. Peel, K. Steenland, L. J. Underhill, G. Rosa, M. A. Kirby, A. Díaz-Artiga, J. McCracken, M. L. Clark, L. Waller, H. H. Chang, J. Wang, E. Dusabimana, F. Ndagijimana, S. Sambandam, K. Mukhopadhyay, K. A. Kearns, D. Campbell, J. Kremer, J. P. Rosenthal, W. Checkley, T. Clasen, L. Naeher, and the Household Air Pollution Intervention Network (HAPIN) Trial Investigators, Exposure Contrasts of Pregnant Women during the Household Air Pollution Intervention Network Randomized Controlled Trial. Environ Health Perspect 130, 097005 (2022).
6. S. Chowdhury, S. Dey, S. Guttikunda, A. Pillarisetti, K. R. Smith, L. Di Girolamo, Indian annual ambient air quality standard is achievable by completely mitigating emissions from household sources. Proc Natl Acad Sci USA 116, 10711 (2019).
by Ajay Pillarisetti1*, Sumi Mehta2, Kalpana Balakrishnan3
1 School of Public Health, University of California, Berkeley; Berkeley, USA
2 Vital Strategies; New York, USA
3 Department of Environmental Health Engineering, Faculty of Public Health, Sri Ramachandra, Institute of Higher Education and Research; Chennai, India
rejected as a letter to the editor at Science