Health Impacts of HAP Exposure
Burning biomass (wood, dung, charcoal, and crop waste), coal, and kerosene fuels in traditional or unvented stoves for cooking, heating, and lighting results in high levels of household air pollution. Despite reductions in the proportion of the global population exposed to household air pollution — a decrease of 30% from 1990 to 2015 — 1.3 billion people are still exposed to household air pollution and it is a leading environmental risk factor with detrimental health outcomes .
Household air pollution remains a leading risk factor for disease and premature death worldwide.
Estimate: household air pollution responsible for 2.9 million premature deaths in 2015 .
Household air pollution is a leading risk factor for disease and death, especially among women and children.
Evidence of health outcomes in children associated with exposure to household air pollution from traditional/unvented biomass-burning stoves and open fires, compared with those using clean stoves and fuels, comes from randomized controlled trials and observational studies and include:
- A 73% increased risk of acute lower respiratory infections (ALRI) in children, the leading cause of child death globally, based on 26 studies of household air pollution and ALRI outcomes [4-6]
- Higher risk of all-cause mortality in children under five years by 27% , based on five studies in Tanzania, India, Indonesia, and South Africa .
- Lower birthweight by an average of 86 grams  and 35% greater risk of low birthweight (<2,500 grams), based on 13 studies in Guatemala, Peru, Serbia, Zimbabwe, Ghana, Pakistan, India, the Gaza Strip . Low birthweight is important since it increases the risk of newborn mortality 2-5 fold compared to that in normal birthweight infants .
- A 29% increased risk of stillbirth, based on five studies in India and Pakistan .
- In Guatemala, children with enclosed combustion chambers suffered 33% less physician-diagnosed pneumonia than those children who lived in households with wood-burning chimney stoves .
- Another Guatemala study found that children six to seven years old with reduced in utero exposure to household air pollution had improved neurological development, as compared to children whose mothers used open wood fires .
- In Nigeria, pregnant women who received ethanol cookstoves had lower diastolic blood pressure and hypertension by 4.5 to 7%, compared to pregnant women using firewood or kerosene stoves .
Randomized controlled trials show that switching to clean fuels or low-polluting improved stoves can decrease household air pollution and potentially reduce its adverse health impacts, including low birthweight in newborns, respiratory infections in children, and increased blood pressure in pregnant women.
Health Benefits of Reducing HAP
- Reduced particle pollution in kitchens
- Reduced incidence of pneumonia in young children
- Lowered blood pressure in pregnant women
- Decreased risk of pneumonia among children
- Reduced duration of respiratory infections in children
- Reduced blood inflammatory biomarkers (which may increase the risk of obstetric complications) in pregnant women
- Improved neurological development in children
"I have seen firsthand the importance of access to energy and clean cookstoves... it must play a central role in our work to ensure the realization of human needs and fundamental rights."ANTÓNIO GUTERRES - Secretary-General of the United Nations
What are successful interventions?
To successfully reduce household air pollution, households must exclusively and consistently use clean fuels and improved stoves with low emissions. Clean cooking interventions may achieve greater health benefits if other factors are addressed in addition to promoting clean fuels and improved stoves. Strong interventions should ensure the availability of fuels, reliable cookstoves, long-term service, and replacement options.
Successful interventions encourage the use of clean cookstoves consistently and exclusively. The transition from burning high emission biomass or kerosene to burning cleaner pellets requires pellet production facilities, pellet stoves, and a community interest in changing some cooking practices to accommodate a pellet stove. This multifaceted solution requires coordination among different parts of a system and multiple sectors. The international development community can help by aligning the necessary policies and sectors to make investments more effective and sustainable.
Policies to Reduce HAP
Strong policies help create system-wide change
System-wide policies of clean fuel subsidies, tariffs, financing, bans, and standards may encourage households to switch to clean fuels and address other sources of air pollution. Greater health benefits are expected to result from strategies that target multiple sources of air pollution and offer community-wide solutions.
Policy initiatives that improve energy access can encourage communities to use clean fuels, such as propane, ethanol, biogas, processed biomass, and well-implemented, low-emission biomass stoves. In addition, policies such as subsidies and bans incentivize clean cooking and fuel use. For example, Indonesia, Kenya and Nigeria removed kerosene subsidies and increased propane subsidies, encouraging citizens to choose cleaner energy sources.
Though reducing household air pollution requires system-level interventions and strong community support, countries like Indonesia, Kenya and Nigeria are paving the way forward. The international development community and developing country governments must continue to provide opportunities for households to stay healthier through their use of cleaner energy sources.
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- GBD 2016 Risk Factors Collaborators, Global, regional, and national comparative risk assessment of 84 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. The Lancet, 2017. 390: p. 1345-1422.
- Institute for Health Metrics and Evaluation (IHME). GBD Compare. 2017 [cited 2017 September 16, 2017]; Available from: https://vizhub.healthdata.org/gbd-compare/.
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- Bruce, N., Perez-Padilla, R., Albalak, R. World Health Organization Report: The health effects of indoor air pollution in developing countries. 2002; Available from: http://www.who.int/indoorair/publications/health_effects/en/.
- Bruce, N.G., et al., Control of household air pollution for child survival: estimates for intervention impacts. BMC Public Health, 2013. 13 Suppl 3: p. S8.
- Amegah, A.K., R. Quansah, and J.J. Jaakkola, Household air pollution from solid fuel use and risk of adverse pregnancy outcomes: a systematic review and meta-analysis of the empirical evidence. PLoS One, 2014. 9(12): p. E113920.
- Katz, J., et al., Mortality risk in preterm and small-for-gestational-age infants in low-income and middle-income countries: a pooled country analysis. Lancet, 2013. 382(9890): p. 417-25.
- Smith, K.R., et al., Effect of reduction in household air pollution on childhood pneumonia in Guatemala (RESPIRE): a randomised controlled trial. Lancet, 2011. 378(9804): p. 1717-26.
- Dix-Cooper, L., et al., Neurodevelopmental performance among school age children in rural Guatemala is associated with prenatal and postnatal exposure to carbon monoxide, a marker for exposure to woodsmoke. Neurotoxicology, 2012. 33(2): p. 246-54.
- Alexander, D., et al., Randomized Controlled Ethanol Cookstove Intervention and Blood Pressure in Pregnant Nigerian Women. Am J Respir Crit Care Med, 2017. 195(12): p. 1629-1639.