Associations between Indoor Air Pollution and Acute Respiratory Infections among Under-Five Children in Afghanistan: Do SES and Sex Matter?

Abstract

Background: Low-income families often depend on fuels such as wood, coal, and animal dung for cooking. Such solid fuels are highly polluting and are a primary source of indoor air pollutants (IAP). We examined the association between solid fuel use (SFU) and acute respiratory infection (ARI) among under-five children in Afghanistan and the extent to which this association varies by socioeconomic status (SES) and gender. Materials and Methods: This is a cross-sectional study based on de-identified data from Afghanistan’s first standard Demographic and Health Survey conducted in 2015. The sample consists of ever-married mothers with under-five children in the household (n=27,565). We used mixed-effect Poisson regression models with robust error variance accounting for clustering to examine the associations between SFU and ARI among under-five children after adjusting for potential confounders. We also investigated potential effect modification by SES and sex. Additional analyses were conducted using an augmented measure of the exposure to IAP accounting for both SFU and the location of cooking/kitchen (High Exposure, Moderate, and No Exposure). Results: Around 70% of households reported SFU, whereas the prevalence of ARI was 17.6%. The prevalence of ARI was higher in children living in households with SFU compared to children living in households with no SFU (adjusted prevalence ratio [aPR]= 1.10; 95%CI: 0.98, 1.23). We did not observe any effect modification by SES or child sex. When using the augmented measure of exposure incorporating the kitchen’s location, children highly exposed to IAP had a higher prevalence of ARI compared to unexposed children (aPR 1.17; 95% CI: 1.03, 1.32). SES modified this association with the strongest associations observed among children from the middle wealth quintile. Conclusion: The findings have significant policy implications and suggest that ARI risk in children may be reduced by ensuring clean cookstove as well as clean fuels and acting on the socio-environmental pathways.

Acute Respiratory Infection of under-five children associated with place of food cooking in Ethiopia: Multilevel Analysis of 2005-2016 Ethiopian Demographic Health Survey data

“…Regarding child related risk factors associated with ARI, risk of having ARI is 26%, 34% and 51% less likely respectively among children of aged 2-3 years, 3-4 years and 4-5 years compared to children of below one year which suggests the exposure of children for cooking induced indoor air pollutants decreases with age. The nding complies with a prior study in urban areas of Oromia region, Ethiopia [36]; in Wondo-Genet district, southern Ethiopia [19] and in Afghanistan [37]. This could be because of the few time the older children spend with their mothers in the house [37], and the higher number in younger children could be associated with the underdeveloped epithelial linings of the lungs and weaker immune system of younger children compared with the older counterparts [37][38][39].…”

Effect of indoor air pollution on infant and child-mortality in Myanmar: Evidence from the first Demographic and Health Survey

“…Previous studies reported comparable results that SFU and exposure to IAP increase the risk of infant and child mortality in LMICs (17)(18)(19)(20)(21)(22). Evidence suggests that the combustion of SFU emits multiple pollutants such as fine particles, carbon monoxide, formaldehyde, and many more toxic chemicals, which increase the risk of mortality from ALRIs, asthma, and pneumonia among infant and young children exposed to these pollutants (3,6,7,(23)(24)(25)(26)(27)(28)(29). Exposure to these toxic pollutants also increases the risk of low birth weight, stillbirth, and preterm birth, including acute and chronic health problems, all of which are considered as leading causes of child mortality (20,22,30,31).…”

“…Previous studies emphasized to consider cooking place along with SFU for examining the association between IAP and child-mortality because cooking inside the house with solid fuels maximizes the concentrations of airborne toxic pollutants in the household and ambient air (20,23,32,33). Following the previous study, we employed an inclusive SFU exposure measure combining both SFU and cooking place and found stronger associations of high exposure to IAP with infant and child mortality (23). Consistent with our study, previous studies showed that children were exposed to higher concentration of pollutants from SFU because of high proximity to pollutants and spending much time in the kitchen during heating and cooking, which intensifies the risk of child mortality from ALRI including other adverse health outcomes (17,23,24).…”

“…Third, information related to birth and death of the children was reported by mothers that may introduce recall bias, but it is unlikely that the mother would incorrectly report the birth and death of their children. Fourth, there might be a source of exposure measurement error as we used two proxy measures such as SFU and combining SFU and cooking place to measure the associations between IAP exposures (23) and under-five child mortality. However, this is the available robust and established measurement of exposures for IAP because DHS does not objectively measure the level and duration of IAP exposures (23,32).…”

“…Fourth, there might be a source of exposure measurement error as we used two proxy measures such as SFU and combining SFU and cooking place to measure the associations between IAP exposures (23) and under-five child mortality. However, this is the available robust and established measurement of exposures for IAP because DHS does not objectively measure the level and duration of IAP exposures (23,32). Further studies may include questions related to ventilation in the kitchen, duration of cooking, proximity to the kitchen, or heating areas for the better measurement of children's exposure to IAP.…”