Control of household air pollution for child survival: estimates for intervention impacts

Abstract

Background Exposure to household air pollution (HAP) from cooking with solid fuels affects 2.8 billion people in developing countries, including children and pregnant women. The aim of this review is to propose intervention estimates for child survival outcomes linked to HAP. Methods Systematic reviews with meta-analysis were conducted for ages 0-59 months, for child pneumonia, adverse pregnancy outcomes, stunting and all-cause mortality. Evidence for each outcome was assessed against Bradford-Hill viewpoints, and GRADE used for certainty about intervention effect size for which all odds ratios (OR) are presented as protective effects. Results Reviews found evidence linking HAP exposure with child ALRI, low birth weight (LBW), stillbirth, preterm birth, stunting and all-cause mortality. Most studies were observational and rated low/very low in GRADE despite strong causal evidence for some outcomes; only one randomised trial was eligible.Intervention effect (OR) estimates of 0.64 (95% CI: 0.55, 0.75) for ALRI, 0.71 (0.65, 0.79) for LBW and 0.66 (0.54, 0.81) for stillbirth are proposed, specific outcomes for which causal evidence was sufficient. Exposure-response evidence suggests this is a conservative estimate for ALRI risk reduction expected with sustained, low exposure. Statistically significant protective ORs were also found for stunting [OR=0.79 (0.70, 0.89)], and in one study of pre-term birth [OR=0.70 (0.54, 0.90)], indicating these outcomes would also likely be reduced. Five studies of all-cause mortality had an OR of 0.79 (0.70, 0.89), but heterogenity precludes a reliable estimate for mortality impact. Although interventions including clean fuels and improved solid fuel stoves are available and can deliver low exposure levels, significant challenges remain in achieving sustained use at scale among low-income households. Conclusions Reducing exposure to HAP could substantially reduce the risk of several child survival outcomes, including fatal pneumonia, and the proposed effects could be achieved by interventions delivering low exposures. Larger impacts are anticipated if WHO air quality guidelines are met. To achieve these benefits, clean fuels should be adopted where possible, and for other households the most effective solid fuel stoves promoted. To strengthen evidence, new studies with thorough exposure assessment are required, along with evaluation of the longer-term acceptance and impacts of interventions.

Prenatal exposure to particulate matter (PM2.5) and low birth weight in a Sri Lankan birth cohort

“…Balakrishnan et al (2017) reported a decrease of 4 grams (95% CI:1.08 g, 6.76 g) decrease in birthweight and 2% increase in prevalence of low birthweight (OR, 1.02; 95% CI, 1.01-1.04) with a 10-μg/m 3 increase in PM2.5. Results from other meta-analyses also found increased prevalence of LBW between 10% to 45%, associated with HAP exposure (17,19,21,(33)(34)(35)(36)(37). Similarly, a recent meta-analysis conducted by Sun et al (2016), found significant association between 10μg/m 3 increment of ambient PM2.5 and increased odds of LBW (39).…”

Quantifying risks and interventions that have affected the burden of lower respiratory infections among children younger than 5 years: an analysis for the Global Burden of Disease Study 2017

“…A pair of systematic reviews and metaanalyses found that exposure to household air pollution from solid fuel use increased the risk of pneumonia among children younger than 5 years. 34,35 A pair of randomised controlled trials found little statistical evidence of a reduction in pneumonia incidence with provision of chimneys 36 or cleaner burning cookstoves, 37 and several more studies investigating household air pollution and childhood pneumonia are in progress. 38,39 This suggests that the provision of chimneys or cleaner burning practices does not result in a sufficient reduction of air pollution to translate into a reduction in health effects.…”

One‐Off Subsidies and Long‐Run Adoption—Experimental Evidence on Improved Cooking Stoves in Senegal

“…1 1Exposure to particulate matter induced by biomass cooking affects health in various ways and may lead to acute respiratory infections, stunted growth in children, pneumonia, chronic bronchitis in women, chronic obstructive pulmonary disease (COPD), cataracts and other visual impairments, cardiovascular diseases, lung cancer, tuberculosis and perinatal diseases (see, e.g., Ezzati and Kammen 2002; Dherani et al 2008; Hosgood et al 2010; Po, FitzGerald, and Carlsten 2011; McCracken et al 2012; Bruce et al 2013; Amegah, Quansah, and Jaakkola 2014; Smith et al 2014).…”