Household air pollution and under-five mortality in India (1992-2006)

Revisiting Factors Influencing Under-Five Mortality in India: The Application of a Generalised Additive Cox Proportional Hazards Model

BACKGROUND

Despite the implementation of various preventive measures, India continues to experience an alarmingly high under-five mortality rate (U5MR). The most recent nationwide data on U5MRs has provided an opportunity to re-examine the associated factors of U5MRs using advanced techniques. This study attempted to identify the associated determinants of U5MRs via the generalised additive Cox proportional hazards method.

METHODS

This study analysed the fifth round of unit-level data for 213,612 children from the National Family Health Survey (NFHS-5) to identify the risk factors associated with U5MRs, employing a generalised additive Cox proportional hazards regression analysis.

RESULTS

The children who had a length of pregnancy of less than 9 months had a 2.621 (95% CI: 2.494, 2.755) times greater hazard of U5MRs than the children who had a gestational period of 9 months or more. The non-linear association with U5MRs was highest in the mother's age, followed by the mother's haemoglobin, the mother's education, and household wealth score. The relationships between the mother's age and the mother's haemoglobin level with the U5MR were found to be U-shaped.

CONCLUSIONS

This study highlights the importance of addressing maternal and socioeconomic factors while improving access to healthcare services in order to reduce U5MRs in India. Furthermore, the findings underscore the necessity for more sophisticated approaches to healthcare delivery that consider the non-linear relationships between predictor variables and U5MRs.

Air Pollution and Mortality in India: Investigating the Nexus of Ambient and Household Pollution Across Life Stages

Air pollution in India is a foremost environmental risk factor that affects human health. This study first investigates the geographical distribution of ambient and household air pollution (HAP) and then examines the associated mortality risk. Data on fine particulate matter (PM2.5) concentration has been extracted from the Greenhouse Gas Air Pollution Interactions and Synergies (GAINS) model. HAP, mortality and socio-demographic data were extracted from the National Family and Health Survey-5, India, 2019-2021. Regression models were applied to see the difference in age-group mortality by different pollution parameters. The districts with PM2.5 concentration above the National Ambient Air Quality Standard (NAAQS) level of 40 μg/m3 show a higher risk of neonatal (OR-1.86, CI 1.418-2.433), postneonatal (OR-2.04, CI 1.399-2.971), child (OR-2.19, CI 0.999-4.803) and adult death (OR-1.13, CI 1.060-1.208). The absence of a separate kitchen shows a higher probability of neonatal (OR: 1.18, CI 1.074-1.306) and adult death (OR-1.06, CI 1.027-1.088). The interaction between PM2.5 levels above NAAQS and HAP leads to a substantial rise in mortality observed for neonatal (OR 1.19 CI 1.051-1.337), child (OR 1.17 CI 1.054-1.289), and adult (OR 1.13 CI 1.096-1.168) age groups. This study advocates that there is a strong positive association between ambient and HAP and mortality risk. PM2.5 pollution significantly contributes to the mortality risk in all age groups. Children are more vulnerable to HAP than adults. In India, policymakers should focus on reducing the anthropogenic PM2.5 emission at least to reach the NAAQS, which can substantially reduce disease burden and, more precisely, mortality.

Population modifiable risk factors associated with neonatal mortality in 35 sub-Saharan Africa countries: analysis of data from demographic and health surveys

Background

Sub-Saharan Africa (SSA) has the highest burden of neonatal mortality in the world. Identifying the most critical modifiable risk factors is imperative for reducing neonatal mortality rates. This study is the first to calculate population-attributable fractions (PAFs) for modifiable risk factors of neonatal mortality in SSA.

Methods

We analysed the most recent Demographic and Health Surveys data sets from 35 SSA countries conducted between 2010 and 2022. Generalized linear latent and mixed models were used to estimate odds ratios (ORs) along with 95% confidence intervals (CIs). PAFs adjusted for communality were calculated using ORs and prevalence estimates for key modifiable risk factors. Subregional analyses were conducted to examine variations in modifiable risk factors for neonatal mortality across Central, Eastern, Southern, and Western SSA regions.

Findings

In this study, we included 255,891 live births in the five years before the survey. The highest PAFs of neonatal mortality among singleton children were attributed to delayed initiation of breastfeeding (>1 h after birth: PAF = 23.88%; 95% CI: 15.91, 24.86), uncleaned cooking fuel (PAF = 5.27%; 95% CI: 1.41, 8.73), mother's lacking formal education (PAF = 4.34%; 95% CI: 1.15, 6.31), mother's lacking tetanus vaccination (PAF = 3.54%; 95% CI: 1.55, 4.92), and infrequent antenatal care (ANC) visits (PAF = 2.45; 95% CI: 0.76, 3.63). Together, these five modifiable risk factors were associated with 39.49% (95% CI: 21.13, 48.44) of neonatal deaths among singleton children in SSA. Our subregional analyses revealed some variations in modifiable risk factors for neonatal mortality. Notably, delayed initiation of breastfeeding consistently contributed to the highest PAFs of neonatal mortality across all four regions of SSA: Central, Eastern, Southern, and Western SSA.

Interpretation

The PAF estimates in the present study indicate that a considerable proportion of neonatal deaths in SSA are preventable. We identified five modifiable risk factors that accounted for approximately 40% of neonatal deaths in SSA. The findings have policy implications.

Funding

None.

Exploring Strategies to Mitigate the Adverse Health Impacts of Air Pollution on Children in India: A Qualitative Study

BACKGROUND

Air pollution poses a significant threat to global public health, contributing to high rates of mortality and morbidity. India, home to the world's largest population of children, is particularly affected. This study aims to identify effective strategies to mitigate the adverse health impacts of air pollution on this vulnerable group.

MATERIAL AND METHODS

The study utilized directed content analysis using a deductive approach and purposeful sampling to carry out in-depth interviews with researchers, academicians, paediatricians, public health experts, and climate change experts from different organizations in India. In total, 17 interviews were conducted over two months in March and April 2024 until data saturation was reached.

RESULTS

 A total of 29 subcategories were extracted. The main sub-categories include strategies for reducing indoor emissions and multisectoral emission reduction, strategies to reduce exposure at home, schools and transit, strategies for public awareness, effective communication, health sector communication and awareness, and raising awareness by frontline workers and educational institutions, strategies for capacity building of health sector and frontline stakeholders, strategies for building research and knowledge translation, strategies for vertical and horizontal collaboration, strategies for child-centric policies, school closure policies, fiscal policies, comprehensive policymaking, sectoral policymaking, advocacy in policymaking, strategies for monitoring, and strategies for mother and child health.

CONCLUSIONS

The results of this study indicate that mitigating the adverse health impacts of pollution for children would entail a multi-pronged approach encompassing effective communication and education strategies and awareness raising of important stakeholders such as health professionals, community, grassroots-level workers, parents, teachers and children. Such strategies could be useful to trigger the desired change in behaviour of all concerned. Also, there is a need for collaboration and partnership between various stakeholders and ministries as policy-making bodies. There is a need to build on the research and strengthen the monitoring and surveillance.

Factors Associated With Low Birth Weight Among the Tribal Population in India: A Narrative Review

Low birth weight (LBW) is defined by the WHO as a birth weighing less than 2500 g (5.5 lb). The highest burden of any nation is LBW infants. In countries where the frequency of neonate babies is high, short gestation is a major cause. LBW babies have an 11-13 times greater risk of delayed developmental milestones and other medical diagnoses. Greater than the global incidence, LBW prevalence is a severe public health problem in India. A comprehensive literature search was conducted using internet sources like PubMed, Web of Science, Cochrane Library, and Google Scholar. The words "birth weight," "abnormal birth weight," "LBWs," "neonates," "premature birth," "risks factors," "causes," "factors," "prevalence," and "frequency" were searched. In this review, we examine the causes of LBW, implementation of pre-birth prevention strategies, and post-birth multifaceted health promotion interventions. The mother's knowledge, dietary requirements, and prenatal services need to be addressed to decrease the prevalence of LBWs among tribal districts of India.

Association between Long-Term Ambient PM2.5 Exposure and under-5 Mortality: A Scoping Review

Studies have established a link between exposure to fine particles (PM2.5) and mortality in infants and children. However, few studies have explored the association between post-birth exposure to PM2.5 and under-5 mortality. We conducted a scoping review to identify relevant epidemiological evidence on the association between post-birth ambient PM2.5 exposure and under-5 mortality. We searched PubMed and Web of Science for articles published between 1970 and the end of January 2022 that explicitly linked ambient PM2.5 and under-5 mortality by considering the study area, study design, exposure window, and child age. Information was extracted on the study characteristics, exposure assessment and duration, outcomes, and effect estimates/findings. Ultimately, 13 studies on infant and child mortality were selected. Only four studies measured the effect of post-birth exposure to PM2.5 on under-5 mortality. Only one cohort study mentioned a positive association between post-birth ambient PM2.5 exposure and under-5 mortality. The results of this scoping review highlight the need for extensive research in this field, given that long-term exposure to ambient PM2.5 is a major global health risk and child mortality remains high in some countries.

Acinetobacter schindleri SR-5-1 decipher morpho-physio-biochemical and nutritional improvements to Pisum sativum L. and Linum usitatissimum L. maintained under wastewater/cadmium stress

Metal retention in wastewater fertigated crops poses a potential hazard to food chain. Current work demonstrates the bioremediation and growth-promoting potential of Acinetobacter schindleri SR-5-1 by using nitrogen-fixing (pea) and non-nitrogen fixing (linseed) plants under cadmium (Cd) and wastewater irrigation regimes. Both plants were grown at 250 or 500 CdCl2 and 75 or 100% wastewater, each separately with and without A. schindleri SR-5-1 inoculation. The results revealed that Cd and wastewater significantly decreased growth, biomass, antioxidants, and nutrient acquisition through increased malondialdehyde, H2O2, and Cd accumulation. However, application of A. schindleri SR-5-1 significantly promoted morpho-physio-biochemical attributes while diminishing MDA and H2O2 under applied Cd and wastewater stress levels in both pea and linseed. Further, PGPR inoculation positively influenced pea and linseed seedlings through a substantial decline in Cd accumulation in roots/shoots and retained the optimal level of essential nutrients. It was inferred that both pea and linseed, with A. schindleri SR-5-1 application, exhibited higher growth and metabolism under Cd and wastewater stress but substantial tolerance was acquired under wastewater stress. Studied plants exhibited tolerance in order of 75% WW ≥ 250 µM Cd ≥ 100%WW ≥ 500 µM Cd treatment under A. schindleri inoculation. Current findings revealed the potential of A. schindleri to be exploited both for bioremediation and bio-fertilization under Cd, and wastewater-polluted regimes to reduce metal contamination of edible plants. It was suggested that with inoculation of A. schindleri SR-5-1, 75% WW dilution can be applied for irrigation of both nitrogen-fixing and non-nitrogen-fixing crops.

Association between household air pollution and all-cause and cause-specific mortality: a systematic review and meta-analysis

Recently, a growing number of epidemiological studies have examined the relationship between household air pollution (HAP) and all-cause and cause-specific mortality. While the results were not entirely consistent, the current study followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) protocol to conduct a comprehensive review and meta-analysis. Data sources were PubMed, Web of Science, Embase, and Cochrane Library for studies published up to 12 May 2022. The pooled relative risks (RRs) with 95% confidence intervals (CI) were used to estimate the effect of household air pollution on all-cause and cause-special mortality. Then I square value (I²) was used to assess heterogeneity, and random-effects model was used as the pooling method. Seventeen studies were included in the quantitative analysis. Our results showed a significant association between household air pollution and increased risks of all-cause mortality (RR = 1.12, 95% CI = 1.06-1.19) and cardiovascular disease mortality (RR = 1.13, 95% CI = 1.04-1.24). Similarly, the associations between household air pollution and mortality from other specific causes (respiratory, ischemic heart disease, stroke, and total cancer) were positive, although they were not statistically significant. The study suggests that exposure to household air pollution increases the risk of all-cause mortality and cardiovascular disease mortality. In addition, our results found a trend of increased mortality from the respiratory system, ischemic heart disease, stroke, and total cancer, with household air pollution.

Spatial epidemiology of acute respiratory infections in children under 5 years and associated risk factors in India: District-level analysis of health, household, and environmental datasets

Background

In India, acute respiratory infections (ARIs) are a leading cause of mortality in children under 5 years. Mapping the hotspots of ARIs and the associated risk factors can help understand their association at the district level across India.

Methods

Data on ARIs in children under 5 years and household variables (unclean fuel, improved sanitation, mean maternal BMI, mean household size, mean number of children, median months of breastfeeding the children, percentage of poor households, diarrhea in children, low birth weight, tobacco use, and immunization status of children) were obtained from the National Family Health Survey-4. Surface and ground-monitored PM_2.5 and PM₁₀ datasets were collected from the Global Estimates and National Ambient Air Quality Monitoring Programme. Population density and illiteracy data were extracted from the Census of India. The geographic information system was used for mapping, and ARI hotspots were identified using the Getis-Ord Gi^* spatial statistic. The quasi-Poisson regression model was used to estimate the association between ARI and household, children, maternal, environmental, and demographic factors.

Results

Acute respiratory infections hotspots were predominantly seen in the north Indian states/UTs of Uttar Pradesh, Bihar, Delhi, Haryana, Punjab, and Chandigarh, and also in the border districts of Uttarakhand, Himachal Pradesh, and Jammu and Kashmir. There is a substantial overlap among PM_2.5, PM₁₀, population density, tobacco smoking, and unclean fuel use with hotspots of ARI. The quasi-Poisson regression analysis showed that PM_2.5, illiteracy levels, diarrhea in children, and maternal body mass index were associated with ARI.

Conclusion

To decrease ARI in children, urgent interventions are required to reduce the levels of PM_2.5 and PM₁₀ (major environmental pollutants) in the hotspot districts. Furthermore, improving sanitation, literacy levels, using clean cooking fuel, and curbing indoor smoking may minimize the risk of ARI in children.

Environmental variable importance for under-five mortality in Malaysia: A random forest approach

BACKGROUND

Environmental factors have been associated with adverse health effects in epidemiological studies. The main exposure variable is usually determined via prior knowledge or statistical methods. It may be challenging when evidence is scarce to support prior knowledge, or to address collinearity issues using statistical methods. This study aimed to investigate the importance level of environmental variables for the under-five mortality in Malaysia via random forest approach.

METHOD

We applied a conditional permutation importance via a random forest (CPI-RF) approach to evaluate the relative importance of the weather- and air pollution-related environmental factors on daily under-five mortality in Malaysia. This study spanned from January 1, 2014 to December 31, 2016. In data preparation, deviation mortality counts were derived through a generalized additive model, adjusting for long-term trend and seasonality. Analyses were conducted considering mortality causes (all-cause, natural-cause, or external-cause) and data structures (continuous, categorical, or all types [i.e., include all variables of continuous type and all variables of categorical type]). The main analysis comprised of two stages. In Stage 1, Boruta selection was applied for preliminary screening to remove highly unimportant variables. In Stage 2, the retained variables from Boruta were used in the CPI-RF analysis. The final importance value was obtained as an average value from a 10-fold cross-validation.

RESULT

Some heat-related variables (maximum temperature, heat wave), temperature variability, and haze-related variables (PM10, PM10-derived haze index, PM10- and fire-derived haze index, fire hotspot) were among the prominent variables associated with under-five mortality in Malaysia. The important variables were consistent for all- and natural-cause mortality and sensitivity analyses. However, different most important variables were observed between natural- and external-cause under-five mortality.

CONCLUSION

Heat-related variables, temperature variability, and haze-related variables were consistently prominent for all- and natural-cause under-five mortalities, but not for external-cause.

Attributable risk of household solid fuel use and second-hand smoke associated with under-5 mortality in 46 low- and lower-middle-income countries, 2010-2020

BACKGROUND

Household solid fuel use (including indoor and outdoor) and second-hand smoke (SHS) are considered to be major contributors of under-5 mortality (U5M) in low- and lower-middle-income countries (LMICs). This study provides a comprehensive assessment of their odds ratios and attributable mortality in LMICs.

METHODS

We used the Demographic Health Surveys data for under-5 children in 46 LMICs (n = 778,532) from 2010 to 2020. Mixed effect multilevel logistic regressions were conducted to estimate the pooled adjusted odds ratio (aOR) for U5M due to solid fuel use, SHS and their combination compared to no exposure to them in 46 LMICs. The attributable mortality of solid fuel use, SHS, and their combination were assessed for each LMIC.

FINDINGS

The pooled aOR of solid fuel use and SHS for U5M was estimated to be 1.27 (95% Confidence Interval (CI): 1.19-1.36) and 1.13 (95%CI: 1.06-1.25), respectively, whereas those of their combination was 1.40 (95%CI: 1.31-1.50). U5M attributable to indoor and outdoor solid fuel use was the highest in Myanmar (18.0%) and the Gambia (16.5%), respectively, while those attributable to SHS was the highest in Indonesia (9.8%). U5M attributable to the combination of solid fuel use and SHS was the highest in Timor-Leste (22.7%).

INTERPRETATION

The combined effect of exposure to solid fuel and SHS had a higher risk of U5M than the individual risk. The use of clean fuel and tobacco control measures should be integrated with other child health promotion policies.

FUNDING

This research was partially supported by a research grant from the Ministry of Education, Culture, Sports, Science and Technology of Japan (21H03203).

Decomposition of factors associated with housing material inequality in under-five deaths in low and middle-income countries

Background

Low-and Medium-Income Countries (LMIC) continue to record a high burden of under-five deaths (U5D). There is a gap in knowledge of the factors contributing to housing materials inequalities in U5D. This study examined the contributions of the individual- and neighbourhood-level factors to housing materials inequalities in influencing U5D in LMIC.

Methods

We pooled data from the most recent Demographic and Health Surveys for 56 LMIC conducted between 2010 and 2018. In all, we analysed the data of 798,796 children living in 59,791 neighbourhoods. The outcome variable was U5D among live births within 0 to 59 months of birth. The main determinate variable was housing material types, categorised as unimproved housing materials (UHM) and improved housing materials (IHM) while the individual-level and neighbourhood-level factors are the independent variables. Data were analysed using the Fairlie decomposition analysis at α = 0.05.

Results

The overall U5D rate was 53 per 1000 children, 61 among children from houses built with UHM, and 41 among children from houses built with IHM (p < 0.001). This rate was higher among children from houses that were built with UHM in all countries except Malawi, Zambia, Lesotho, Gambia, Liberia, Sierra Leone, Indonesia, Maldives, Jordan, and Albania. None of these countries had significant pro-IHM inequality. The factors explaining housing inequalities in U5D include household wealth status, residence location, source of drinking water, media access, paternal employment, birth interval, and toilet type.

Conclusions

There are variations in individual- and neighbourhood-level factors driving housing materials inequalities as it influences U5D in LMIC. Interventions focusing on reducing the burden of U5D in households built with UHM are urgently needed.

Investigation of association between smoke haze and under-five mortality in Malaysia, accounting for time lag, duration and intensity

BACKGROUND

Studies on the association between smoke haze (hereafter 'haze') and adverse health effects have increased in recent years due to extreme weather conditions and the increased occurrence of vegetation fires. The possible adverse health effects on under-five children (U5Y) is especially worrying due to their vulnerable condition. Despite continuous repetition of serious haze occurrence in Southeast Asia, epidemiological studies in this region remained scarce. Furthermore, no study had examined the association accounting for three important aspects (time lag, duration and intensity) concurrently.

OBJECTIVE

This study aimed to examine the association between haze and U5Y mortality in Malaysia, considering time lag, duration and intensity of exposure.

METHODS

We performed a time-stratified case-crossover study using a generalized additive model to examine the U5Y mortality related to haze in 12 districts in Malaysia, spanning from 2014 to 2016. A 'haze day' was characterized by intensity [based on concentrations of particulate matter (PM)] and duration (continuity of haze occurrence, up to 3 days).

RESULTS

We observed the highest but non-significant odds ratios (ORs) of U5Y mortality at lag 4 of Intensity-3. Lag patterns revealed the possibility of higher acuteness at prolonged and intensified haze. Stratifying the districts by the 95th-percentile of PM distribution, the 'low' category demonstrated marginal positive association at Intensity-2 Duration-3 [OR: 1.210 (95% confidence interval: 1.000, 1.464)].

CONCLUSIONS

We found a null association between haze and U5Y mortality. The different lag patterns of the association observed over different duration and intensity suggest consideration of these aspects in future studies.

Long-term exposure to indoor air pollution and risk of tuberculosis

Indoor air pollution (IAP) is a recognized risk factor for various diseases. This paper examines the role of indoor solid fuel exposure in the risk of mycobacterium tuberculosis (TB) in Delhi Metropolitan, India. Using a cross-sectional design, subjects were screened for a history of active TB and lifelong exposure to IAP sources, such as solid fuel burning and kerosene. The TB prevalence rate in the study area was 1117 per 100 000 population. Every year, increase in solid fuel exposure was associated with a three percent higher likelihood of a history of active TB. Subjects exposed to solid fuel and kerosene use for both heating home and cooking showed significant associations with TB. Age, household expenditure (a proxy of income), lung function, and smoking also showed significant associations with TB. Smokers and solid fuel-exposed subjects were four times more likely to have a history of active TB than non-smoker and unexposed subjects. These finding calls strategies to mitigate solid fuel exposure, such as use of clean cookstove and ventilation, to mitigate the risk of TB which aligns with the United Nations' goal of "End TB by 2030."

A Systematic Review and Appraisal of Epidemiological Studies on Household Fuel Use and Its Health Effects Using Demographic and Health Surveys

The domestic combustion of polluting fuels is associated with an estimated 3 million premature deaths each year and contributes to climate change. In many low- and middle-income countries (LMICs), valid and representative estimates of people exposed to household air pollution (HAP) are scarce. The Demographic and Health Survey (DHS) is an important and consistent source of data on household fuel use for cooking and has facilitated studies of health effects. However, the body of research based on DHS data has not been systematically identified, nor its strengths and limitations critically assessed as a whole. We aimed to systematically review epidemiological studies using DHS data that considered cooking fuel type as the main exposure, including the assessment of the extent and key drivers of bias. Following PRISMA guidelines, we searched PubMed, Web of Science, Scopus and the DHS publication portal. We assessed the quality and risk of bias (RoB) of studies using a novel tool. Of 2748 records remaining after removing duplicates, 63 were read in full. A total of 45 out of 63 studies were included in our review, spanning 11 different health outcomes and representing 50 unique analyses. In total, 41 of 45 (91%) studies analysed health outcomes in children <5 years of age, including respiratory infections (n = 17), death (all-cause) (n = 14), low birthweight (n = 5), stunting and anaemia (n = 5). Inconsistencies were observed between studies in how cooking fuels were classified into relatively high- and low-polluting. Overall, 36/50 (80%) studies reported statistically significant adverse associations between polluting fuels and health outcomes. In total, 18/50 (36%) of the analyses were scored as having moderate RoB, while 16/50 (32%) analyses were scored as having serious or critical RoB. Although HAP exposure assessment is not the main focus of the DHS, it is the main, often only, source of information in many LMICs. An appreciable proportion of studies using it to analyse the association between cooking fuel use and health have potential for high RoB, mostly related to confounder control, exposure assessment and misclassification, and outcome ascertainment. Based on our findings, we provide some suggestions for ways in which revising the information collected by the DHS could make it even more amenable to studies of household fuel use and health, and reduce the RoB, without being onerous to collect and analyse.

Cooking, smoking, and stunting: Effects of household air pollution sources on childhood growth in India

This paper investigates the effects of household air pollution (HAP) on child stunting in India using a sample of 206, 898 under-five children from the latest National Family Health Survey (2015-16). Descriptive statistics and multivariate analysis were used to understand the association of stunting by type of cooking fuel, separate kitchen, and indoor smoking in the household. Using clean cooking fuels (CCFs), having a separate kitchen, and being unexposed to smoking can reduce the prevalence of stunting by 4%, 1%, and 1%, respectively, from the current prevalence of stunting (38%). The probability of childhood stunting among children living in households using unclean cooking fuel (UCF) was significantly higher (OR-1.16; 95% CI: 1.13-1.19) than those living in households using CCF. Findings were similar results in the absence of separate kitchen (OR-1.08; 95% CI: 1.05-1.10) and exposure to environmental tobacco smoke (OR-1.06; 95% CI: 1.04-1.08). Households using UCF had a 16% higher likelihood of stunting, while there was a strong gradient of HAP with stunting after controlling socioeconomic and demographic factors. Therefore, the LPG programs, such as the Pradhan Mantri Ujjwala Yojana, may be crucial to reduce HAP and its adverse impact on stunting, and successively to achieve sustainable development goals.

Household air pollution and under-five mortality in sub-Saharan Africa: an analysis of 14 demographic and health surveys

BACKGROUND

Globally, over four million deaths are attributed to exposure to household air pollution (HAP) annually. Evidence of the association between exposure to HAP and under-five mortality in sub-Saharan Africa (SSA) is insufficient. We assessed the association between exposure to HAP and under-five mortality risk in 14 SSA countries.

METHODS

We pooled Demographic and Health Survey (DHS) data from 14 SSA countries (N = 164376) collected between 2015 and 2018. We defined exposure to HAP as the use of biomass fuel for cooking in the household. Under-five mortality was defined as deaths before age five. Data were analyzed using mixed effects logistic regression models.

RESULTS

Of the study population, 73% were exposed to HAP and under-five mortality was observed in 5%. HAP exposure was associated with under-five mortality, adjusted odds ratio (OR) 1.33 (95% confidence interval (CI) [1.03-1.71]). Children from households who cooked inside the home had higher risk of under-five mortality compared to households that cooked in separate buildings [0.85 (0.73-0.98)] or outside [0.75 (0.64-0.87)]. Lower risk of under-five mortality was also observed in breastfed children [0.09 (0.05-0.18)] compared to non-breastfed children.

CONCLUSIONS

HAP exposure may be associated with an increased risk of under-five mortality in sub-Saharan Africa. More carefully designed longitudinal studies are required to contribute to these findings. In addition, awareness campaigns on the effects of HAP exposure and interventions to reduce the use of biomass fuels are required in SSA.

Subjective Environmental Experiences and Women's Breastfeeding Journeys: A Survival Analysis Using an Online Survey of UK Mothers

Local physical and social environmental factors are important drivers of human health and behaviour. Environmental perception has been linked with both reproduction and parenting, but links between subjective environmental experiences and breastfeeding remain unclear. Using retrospective data from an online survey of UK mothers of children aged 0-24 months, Cox-Aalen survival models test whether negative subjective environmental experiences negatively correlated with any and exclusive breastfeeding (max n = 473). Matching predictions, hazards of stopping any breastfeeding were increased, albeit non-significantly, across the five environmental measures (HR: 1.05-1.26) Hazards for stopping exclusive breastfeeding were however (non-significantly) reduced (HR: 0.65-0.87). Score processes found no significant time-varying effects. However, estimated cumulative coefficient graphs showed that the first few weeks postpartum were most susceptible to environmental influences and that contrary to our predictions, mothers with worse subjective environmental experiences were less likely to stop breastfeeding at this time. In addition, the hazard of stopping exclusive breastfeeding declined over time for mothers who thought that littering was a problem. The predicted increased hazards of stopping breastfeeding were only evident in the later stages of any breastfeeding and only for mothers who reported littering as a problem or that people tended not to know each other. Perceived harsher physical and social environmental conditions are assumed to deter women from breastfeeding, but this may not always be the case. Women's hazards of stopping breastfeeding change over time and there may be particular timepoints in their breastfeeding journeys where subjective environmental experiences play a role.

Impacts of discriminated PM2.5 on global under-five and maternal mortality

Globally, it was estimated that maternal and under-five deaths were high in low-income countries than that of high-income countries. Most studies, however, have focused only on the clinical causes of maternal and under-five deaths, and yet there could be other factors such as ambient particulate matter (PM). The current global estimates indicate that exposure to ambient PM_2.5 (with ≤ 2.5 microns aerodynamic diameter) has caused about 7 million deaths and over 100 million disability-adjusted life-years. There are also several health risks that have been linked PM_2.5, including mortality, both regionally and globally; however, PM_2.5 is a mixture of many compounds from various sources. Globally, there is little evidence of the health effects of various types of PM_2.5, which may uniquely contribute to the global burden of disease. Currently, only two studies had estimated the effects of discriminated ambient PM_2.5, that is, anthropogenic, biomass and dust, on under-five and maternal mortality using satellite measurements, and this study found a positive association in Africa and Asia. However, the study area was conducted in only one region and may not reflect the spatial variations throughout the world. Therefore, in this study, we discriminated different ambient PM_2.5 and estimated the effects on a global scale. Using the generalized linear mixed-effects model (GLMM) with a random-effects model, we found that biomass PM_2.5 was associated with an 8.9% (95% confidence interval [CI] 4.1-13.9%) increased risk of under-five deaths, while dust PM_2.5 was marginally associated with 9.5% of under-five deaths. Nevertheless, our study found no association between PM_2.5 type and global maternal deaths. This result may be because the majority of maternal deaths could be associated with preventable deaths that would require clinical interventions. Identification of the mortality-related types of ambient PM_2.5 can enable the development of a focused intervention strategy of placing appropriate preventive measures for reducing the generation of source-specific PM_2.5 and subsequently diminishing PM_2.5-related mortality.

Solid fuel use and early child development disparities in Ghana: analyses by gender and urbanicity

In Ghana, more than 77% of the population depends on biomass fuels for cooking. Previous studies show that solid fuel use (SFU) has adverse effects on pregnancy and child health outcomes. Yet, no previous study considered potential effects on early child development indicators (ECDI), nor how SFU effects may vary by gender, and rural and urban areas. We investigated the associations of SFU with ECDI measures, and whether these associations exhibited sex and urban/rural differences. We used the 2011-2012 Ghana's Multiple Indicator Cluster Surveys-UNICEF (N = 3326 children; 3-4 years). We derived a binary ECDI measure reflecting whether the child is developmentally on track or not from a caregiver-report of ten yes/no/do not know questions designed specifically to assess four domains of early child development: learning-cognition, literacy-numeracy, socio-emotional, and physical. We used multilevel Poisson regressions adjusting for neighborhood, household, mother, and child's characteristics to estimate covariate-adjusted prevalence ratios (PRs) of the associations between SFU and ECDI and its four dimensions. We run stratified analyses and used z-score tests of differences to evaluate effect modification by sex and urbanicity. Overall, 85% of children were exposed to SFU and 28% of children were not developmentally on track. After adjustment for confounders, children exposed to SFU were more likely to be not developmentally on track in comparison with nonexposed children (PR = 1.16; 95% confidence interval, [95% CI]: 1.10,1.22). These associations were stronger in girls (PR = 1.36; 95% CI: 1.03,1.79) in comparison with boys (PR = 0.87; 95% CI: 0.73,1.04). No difference in associations was observed between urban and rural children. Overall, these associations were mainly driven by the literacy-numeracy dimension. In this study, we show that SFU was associated with developmental delays in Ghanaian girls. Policy efforts which tackle SFU should be mindful of gender disparities in susceptibility to indoor pollution.

Does use of solid fuels for cooking contribute to childhood stunting? A longitudinal data analysis from low- and middle-income countries

Using longitudinal data from the first and second waves of the Young Lives Study (YLS) in Ethiopia, India (Andhra Pradesh), Peru and Vietnam, conducted in 2002 and 2006–07, and a repeated measures mixed model, this study examined the effect of the use of solid fuels for cooking on childhood stunting among children aged 5–76 months. The analysis showed that in all four populations, the average height-for-age z-score (HAZ score) was much lower among children living in households using solid fuels than among children in households using cleaner fuels for cooking. The average HAZ score was lower among children living in households that used solid fuels in both waves of the YLS compared with those whose households used solid fuels in only one of the two waves. A significant reduction was noted in the average HAZ score between the two waves in all countries except Ethiopia. The results of the repeated measures mixed model suggest that household use of solid fuels was significantly associated with lower HAZ scores in all populations, except Ethiopia. The findings also indicate that the reduction in the HAZ scores between waves 1 and 2 was not statistically significant by the type of cooking fuel after controlling for potential confounding factors. The study provides further evidence of a strong association between household use of solid fuels and childhood stunting in low- and middle-income countries using longitudinal data. The findings highlight the need to reduce exposure to smoke from the combustion of solid fuels, by shifting households to cleaner cooking fuels, where feasible, by providing cooking stoves with improved combustion of solid fuels and improved venting, and by designing and implementing public information campaigns to inform people about the health risks of exposure to cooking smoke.

Association of biomass fuel smoke with respiratory symptoms among children under 5 years of age in urban areas: results from Bangladesh Urban Health Survey, 2013

BACKGROUND

Little is known regarding the effect of exposure to biomass fuel smoke inhalation on respiratory symptoms in the Bangladeshi population which is a major health hazard in most of the developing countries. This study aims to explore the association between respiratory symptoms and biomass fuel smoke exposure among children under 5 years of age.

METHODS

Data were extracted from the Bangladesh Urban Health Survey conducted in 2013. A total of 10,575 mothers with at least one surviving children were selected. Respiratory symptoms among children under 5 years of age were considered as the primary outcome. Sequential multiple logistic regression models were used to observe the association between respiratory symptoms and biomass fuel smoke exposure adjusting the effect of residential factors and mother and child characteristics.

RESULTS

Around 40% of the mothers exclusively used biomass fuel irrespective of the kitchen location and 54% of them were habituated in indoor cooking. The prevalence of respiratory symptoms of under-five children among in-house and outdoor biomass fuel users was 23.0% and 21.9%, respectively. Results of fitted multiple logistic regression models showed that the odds of having respiratory symptoms among children under 5 years of age were increased due to in-house biomass fuel use [OR = 1.18; 95% CI, 1.04-1.36] compared with the non-biomass user. An increased risk of respiratory symptoms was also significantly associated with mother's birth complication [OR = 1.51; 95% CI, 1.36-1.67], non-government organization (NGO) membership of mothers [OR = 1.32; 95% CI, 1.16-1.51], age of the child (6-23m) [OR = 1.29; 95% CI, 1.10-1.52], and nutritional status (stunting) [OR = 1.18; 95% CI, 1.06-1.31].

CONCLUSION

This study found the use of in-house biomass fuel as a significant risk factor associated with respiratory symptoms of children under 5 years of age. More longitudinal studies should be designed to establish a causal relationship between HAP (household air pollution) and respiratory symptoms among children with more direct measures of HAP and clinical procedure.

Are mothers less likely to breastfeed in harsh environments? Physical environmental quality and breastfeeding in the Born in Bradford study

We use the United Kingdom's Born in Bradford study to investigate whether women in lower quality environments are less likely to breastfeed. We use measures of physical environmental quality (water disinfectant by-products [DBPs], air pollution, passive cigarette smoke, and household condition) alongside socio-economic indicators, to explore in detail how different exposures influence breastfeeding. Drawing on evolutionary life history theory, we predict that lower environmental quality will be associated with lower odds of initiating, and higher hazards of stopping, breastfeeding. As low physical environmental quality may increase the risk of adverse birth outcomes, which may in turn affect breastfeeding chances, we also test for mediation by gestational age, birthweight, head circumference, and abdominal circumference. Our sample is composed of mothers who gave birth at the Bradford Royal Infirmary in West Yorkshire between March 2007 and December 2010 for whom breastfeeding initiation data was available. Analyses were stratified by the two largest ethnic groups: White British (n = 3,951) and Pakistani-origin (n = 4,411) mothers. After controlling for socio-economic position, Pakistani-origin mothers had lower chances of initiating and higher chances of stopping breastfeeding with increased water DBP exposure (e.g., OR for 0.03-0.61 vs. <0.02 μg/day dibromochloromethane exposure 0.70 [0.58-0.83], HR 1.16 [0.99-1.36]), greater air pollution exposure predicted lower chances of initiation for both ethnic groups (e.g., OR for 10 μg/m³ increase in nitrogen dioxide 0.81 [0.66-0.99] for White British mothers and 0.79 [0.67-0.94] for Pakistani-origin mothers) but also a reduced hazard of stopping breastfeeding for White British mothers (HR 0.65 [0.52-0.80]), and exposure to household damp/mould predicted higher chances of breastfeeding initiation amongst White British mothers (OR 1.66 [1.11-2.47]). We found no evidence that physical environmental quality effects on breastfeeding were mediated through birth outcomes amongst Pakistani-origin mothers and only weak evidence (p < 0.10) amongst White British mothers (exposure to passive cigarette smoke was associated with having lower birthweight infants who were in turn less likely to be breastfed whereas greater air pollution exposure was associated with longer gestations and in turn reduced hazards of stopping breastfeeding). Overall, our findings suggest that there is differential susceptibility to environmental exposures according to ethnicity. Although the water DBP results for Pakistani-origin mothers and air pollution-initiation results for both ethnic groups support our hypothesis that mothers exhibit reduced breastfeeding in poorer quality environments, several physical environmental quality indicators showed null or positive associations with breastfeeding outcomes. We consider physiological explanations for our findings and their implications for life history theory and public health policy.

Does ambient ozone air pollution trigger suicide attempts? A case cross-over analysis in Taipei

Epidemiologic studies indicated that exposure to ambient air pollutants was associated with increased mortality rates attributed to suicide. The objective of this study was to investigate the potential relationship between ambient ozone (O₃) levels and daily number of hospital admissions for suicide attempts in Taipei for the period 2008-2012 using a time-stratified case-crossover analysis. In the single-pollutant model (without adjustment for other pollutants), the risk of committing a suicide attempt increased by 9% on warm days and 27% on cool days for each interquartile range (IQR) rise in O₃ levels, respectively. The concentration of O₃ was thus significantly associated with daily number of suicide attempts both on warm and cool days. In the two-pollutant models, O₃ levels remained significant after the inclusion of other air pollutants (particulate matter (PM₁₀), PM_2.5, sulfur dioxide (SO₂), nitrogen dioxide (NO₂), and carbon monoxide (CO)) on cool days. However, on warm days, no significant correlation was found between O₃ levels and reported daily number of suicide attempts. The relationship between O₃ and suicide attempts appeared to be dependent upon temperature; however, the basis for these observations requires further investigation.

Relationship between ozone air pollution and daily suicide mortality: a time-stratified case-crossover study in Taipei

Several studies suggested short-term exposure to air pollution might be associated with suicide mortality, although results have been inconsistent and vary depending upon the type of air contaminants. While seasonal variation associated with suicide was reported to occur and that in the spring and early summer there are peaks in ozone (O₃) distribution, the relationship between these two parameters is not known. The aim of this study was to examine the potential association between O₃ levels and daily mortality rate related to suicide in Taipei for the period 2004-2008 using a time-stratified case-crossover analysis. In our single pollutant model without adjustment for other pollutants, the risk of suicide increased by 11% on warm days and 15% on cool days for each interquartile range (IQR) rise in O₃ concentration, respectively. The relationship was positive but did not reach significance. In our two-pollutant models, O₃ remained non-significant on warm days after inclusion of one of any other ambient air contaminants into the model. However, on cool days, a significant association was found between O₃ levels and enhanced risk of mortality due to suicide after nitrogen dioxide (NO₂) or carbon monoxide (CO) were included. The overall positive but not significant findings of elevated risk of mortality frequently attributed to suicide on days with higher O₃ levels suggest that outdoor exposures to this gaseous contaminant may contribute to increases in daily mortality rate related to suicide.

Geographic and socio-economic variation in markers of indoor air pollution in Nepal: evidence from nationally-representative data

Background

In low-income countries such as Nepal, indoor air pollution (IAP), generated by the indoor burning of biomass fuels, is the top-fourth risk factor driving overall morbidity and mortality. We present the first assessment of geographic and socio-economic determinants of the markers of IAP (specifically fuel types, cooking practices, and indoor smoking) in a nationally-representative sample of Nepalese households.

Methods

Household level data on 11,040 households, obtained from the 2016 Nepal Demographic and Health Survey, were analyzed. Binary logistic regression analyses were conducted to assess the use of fuel types, indoor cooking practices, indoor smoking and IAP with respect to socio-economic indicators and geographic location of the household.

Results

More than 80% of the households had at least one marker of IAP: 66% of the household used unclean fuel, 45% did not have a separate kitchen to cook in, and 43% had indoor smoking. In adjusted binary logistic regression, female and educational attainment of household’s head favored cleaner indoor environment, i.e., using clean fuel, cooking in a separate kitchen, not smoking indoors, and subsequently no indoor pollution. In contrast, households belonging to lower wealth quintile and rural areas did not favor a cleaner indoor environment. Households in Province 2, compared to Province 1, were particularly prone to indoor pollution due to unclean fuel use, no separate kitchen to cook in, and smoking indoors. Most of the districts had a high burden of IAP and its markers.

Conclusions

Fuel choice and clean indoor practices are dependent on household socio-economic status. The geographical disparity in the distribution of markers of IAP calls for public health interventions targeting households that are poor and located in rural areas.

Electronic supplementary material

The online version of this article (10.1186/s12889-019-6512-z) contains supplementary material, which is available to authorized users.

Causes of death and predictors of childhood mortality in Rwanda: a matched case-control study using verbal social autopsy

Background

Rwanda has dramatically reduced child mortality, but the causes and sociodemographic drivers for mortality are poorly understood.

Methods

We conducted a matched case-control study of all children who died before 5 years of age in eastern Rwanda between 1st March 2013 and 28th February 2014 to identify causes and risk factors for death. We identified deaths at the facility level and via a community health worker reporting system. We used verbal social autopsy to interview caregivers of deceased children and controls matched by area and age. We used InterVA4 to determine probable causes of death and cause-specific mortality fractions, and utilized conditional logistic regression to identify clinical, family, and household risk factors for death.

Results

We identified 618 deaths including 174 (28.2%) in neonates and 444 (71.8%) in non-neonates. The most commonly identified causes of death were pneumonia, birth asphyxia, and meningitis among neonates and malaria, acute respiratory infections, and HIV/AIDS-related death among non-neonates. Among neonates, 54 (31.0%) deaths occurred at home and for non-neonates 242 (54.5%) deaths occurred at home. Factors associated with neonatal death included home birth (aOR: 2.0; 95% CI: 1.4–2.8), multiple gestation (aOR: 2.1; 95% CI: 1.3–3.5), both parents deceased (aOR: 4.7; 95% CI: 1.5–15.3), mothers non-use of family planning (aOR: 0.8; 95% CI: 0.6–1.0), lack of accompanying person (aOR: 1.6; 95% CI: 1.1–2.1), and a caregiver who assessed the medical services they received as moderate to poor (aOR: 1.5; 95% CI: 1.2–1.9). Factors associated with non-neonatal deaths included multiple gestation (aOR: 2.8; 95% CI: 1.7–4.8), lack of adequate vaccinations (aOR: 1.7; 95% CI: 1.2–2.3), household size (aOR: 1.2; 95% CI: 1.0–1.4), maternal education levels (aOR: 1.9; 95% CI: 1.2–3.1), mothers non-use of family planning (aOR: 1.6; 95% CI: 1.4–1.8), and lack of household electricity (aOR: 1.4; 95% CI: 1.0–1.8).

Conclusion

In the context of rapidly declining childhood mortality in Rwanda and increased access to health care, we found a large proportion of remaining deaths occur at home, with home deliveries still representing a significant risk factor for neonatal death. The major causes of death at a population level remain largely avoidable communicable diseases. Household characteristics associated with death included well-established socioeconomic and care-seeking risk factors.

Determinants of neonatal, infant and under-five mortality in a war-affected country: analysis of the 2010 Household Health Survey in South Sudan

BACKGROUND

Under-five children born in a fragile and war-affected setting of South Sudan are faced with a high risk of death as reflecting in high under-five mortality. In South Sudan health inequities and inequitable condition of daily living play a significant role in childhood mortality. This study examines factors associated with under-five mortality in South Sudan.

METHODS

The study population includes 8125 singleton, live birth, under-five children born in South Sudan within 5 years prior to the 2010 South Sudan Household Survey. Factors associated with neonatal, infant and under-five deaths were examined using generalised linear latent and mixed models with the logit link and binomial family that adjusted for cluster and survey weights.

RESULTS

The multivariate analysis showed that mothers who reported a previous death of a child reported significantly higher risk of neonatal (adjusted OR (AOR)=3.74, 95% confidence interval (CI 2.88 to 4.87), P<0.001), infant (AOR=3.19, 95% CI (2.62 to 3.88), P<0.001) and under-five deaths (AOR=3.07, 95% CI (2.58 to 3.64), P<0.001). Other associated factors included urban dwellers (AOR=1.37, 95% CI (1.01 to 1.87), P=0.045) for neonatal, (AOR=1.35, 95% CI (1.08 to 1.69), P=0.009) for infants and (AOR=1.39, 95% CI (1.13 to 1.71), P=0.002) for under-five death. Unimproved sources of drinking water were significantly associated with neonatal mortality (AOR=1.91, 95% CI (1.11 to 3.31), P=0.02).

CONCLUSIONS

This study suggested that the condition and circumstances in which the child is born into, and lives with, play a role in under-five mortality, such as higher mortality among children born to teenage mothers. Ensuring equitable healthcare service delivery to all disadvantaged populations of children in both urban and rural areas is essential but remains a challenge, while violence continues in South Sudan.

Attributable risk and potential impact of interventions to reduce household air pollution associated with under-five mortality in South Asia

BACKGROUND

Solid fuel use is the major source of household air pollution (HAP) and accounts for a substantial burden of morbidity and mortality in low and middle income countries. To evaluate and compare childhood mortality attributable to HAP in four South Asian countries.

METHODS

A series of Demographic and Health Survey (DHS) datasets for Bangladesh, India, Nepal and Pakistan were used for analysis. Estimates of relative risk and exposure prevalence relating to use of cooking fuel and under-five mortality were used to calculate population attributable fractions (PAFs) for each country. Potential impact fractions (PIFs) were also calculated assessing theoretical scenarios based on published interventions aiming to reduce exposure prevalence.

RESULTS

There are an increased risk of under-five mortality in those exposed to cooking fuel compared to those not exposed in the four South Asian countries (OR = 1.30, 95% CI = 1.07-1.57, P = 0.007). Combined PAF estimates for South Asia found that 66% (95% CI: 43.1-81.5%) of the 13,290 estimated cases of under-five mortality was attributable to HAP. Joint PIF estimates (assuming achievable reductions in HAP reported in intervention studies conducted in South Asia) indicates 47% of neonatal and 43% of under-five mortality cases associated with HAP could be avoidable in the four South Asian countries studied.

CONCLUSIONS

Elimination of exposure to use of cooking fuel in the household targeting valuable intervention strategies (such as cooking in separate kitchen, improved cook stoves) could reduce substantially under-five mortality in South Asian countries.

The association between cooking oil fume exposure during pregnancy and birth weight: A prospective mother-child cohort study

Effects of indoor air pollution on neonatal birth weight has been studied for many years. In China, cooking oil fumes are important parts of indoor air pollution. However, whether cooking oil fume exposure during pregnancy affects birth weight in China remains poorly understood. The objective of this study was to examine the association between pregnancy exposure to cooking oil fumes and birth weight in a newly established prospective mother-child cohort in China. We finally included 1420 pregnant women from 2013 to 2015 and follow up for one year until the offspring was born. According to self-reported exposure status, we categorized mothers into non-exposure group and exposed group or three exposure time subgroups, including 0h/day, 0-1h/day and >1h/day respectively. By using multinomial logistics regression models, we found that pregnancy exposure to cooking oil fumes significantly increased the risk of large for gestational age (LGA, OR=1.58, 95% CI=1.15-2.18, P=4.88×10-3). Additionally, compared to pregnant women who were in non-exposure group, 0-1h/day exposure elevated the risk of LGA (OR=1.69, 95% CI=1.22-2.33, P=1.63×10-3), while >1h/day exposure elevated the risk of small for gestational age, but were not significant (SGA, OR=2.15, 95% CI=0.61-7.66, P=0.24). In the stratification analysis, women aged 25-29years and ≥30years were predisposed to the influence of cooking oil fumes and have LGA newborns (OR=1.73, 95% CI=1.09-2.75, P=0.02; OR=1.72, 95% CI=1.07-2.77, P=0.02, respectively). In conclusion, the present study suggests inverse U-shape dose response association between maternal exposure to cooking oil fumes during pregnancy and birth weight, and further studies are needed to verify the effect of cooking oil fumes on the birth weight.

Potential Impacts of Modifiable Behavioral and Environmental Exposures on Reducing Burden of Under-five Mortality Associated with Household Air Pollution in Nepal

Objectives Household air pollution (HAP) is one of the leading causes of respiratory illness and deaths among young children in low and lower-middle income countries. This study examines for the first time trends in the association between HAP from cooking fuel and under-five mortality and measures the potential impact of interventions to reduce HAP using Nepal Demographic and Health Survey datasets (2001-2011). Methods A total of 17,780 living children across four age-groups (neonatal 0-28 days, post-neonatal 1-11 months, child 12-59 months and under-five 0-59 months) were included and multi-level logistic regression models were used for analyses. Population attributable fractions of key risk factors and potential impact fractions assessing the impact of previous interventions to reduce exposure prevalence were also calculated. Results Use of cooking fuel was associated with total under-five mortality (OR 2.19, 95% CI 1.37-3.51, P = 0.001) in Nepal, with stronger associations evident for sub-group analyses of neonatal mortality (OR 2.67, 95% CI 1.47-4.82, P = 0.001). Higher association was found in rural areas and for households without a separate kitchen using polluting fuel for cooking, and in women who had never breastfed for all age-groups of children. PIF estimates, assuming a 63% of reduction of HAP based on previously published interventions in Nepal, suggested that a burden of 40% of neonatal and 33% of under-five mortality cases associated with an indoor kitchen using polluting fuel could be avoidable. Conclusion Improved infrastructure and behavioral interventions could help reduce the pollution from cooking fuel in the household resulting in further reduction in under-five mortality in Nepal.

Nurs CZ, Mofizul Islam M, Islam MR, Rahman MM. Household air pollution from cooking and risk of adverse health and birth outcomes in Bangladesh: a nationwide population-based study

BACKGROUND

Household air pollution (HAP) from cooking with solid fuels has become a leading cause of death and disability in many developing countries including Bangladesh. We assess the association between HAP and risk of selected adverse birth and maternal health outcomes.

METHODS

Data for this study were extracted from Bangladesh Demographic and Health Survey conducted during 2007-2014. Selected adverse birth outcomes were acute respiratory infection (ARI) among children, stillbirth, low birth weight (LBW), under-five mortality, neonatal mortality and infant mortality. Maternal pregnancy complications and cesarean delivery were considered as the adverse maternal health outcomes. Place of cooking, use of solid fuel within the house boundary and in living room were the exposure variables. To examine the association between exposure and outcome variables, we used a series of multiple logistic regression models accounted for complex survey design.

RESULTS

Around 90% of the respondents used solid fuel within the house boundary, 11% of them used solid fuel within the living room. Results of multiple regression indicated that cooking inside the house increased the risk of neonatal mortality (aOR,1.25; 95% CI, 1.02-1.52), infant mortality (aOR, 1.18; 95% CI, 1.00-1.40), ARI (aOR, 1.18; 95% CI, 1.08-1.33), LBW (aOR, 1.25; 95% CI, 1.10-1.43), and cesarean delivery (aOR,1.18; 95% CI, 1.01-1.29). Use of solid fuel, irrespective of cooking places, increased the risk of pregnancy complications (aOR, 1.36; 95% CI, 1.19-1.55). Compared to participants who reported cooking outside the house, the risk of ARI, LBW were significantly high among those who performed cooking within the house, irrespective of type of cooking fuel.

CONCLUSION

Indoor cooking and use of solid fuel in household increase the risk of ARI, LBW, cesarean delivery, and pregnancy complication. These relationships need further investigation using more direct measures of smoke exposure and clinical measures of health outcomes. The use of clean fuels and structural improvement in household design such as provision of stove ventilation should be encouraged to reduce such adverse health consequences.

TRAIL REGISTRATION

Data related to health were collected by following the guidelines of ICF international and Bangladesh Medical Research Council. The registration number of data collection was 132,989.0.000, and the data-request was registered on March 11, 2015.

Cooking fuel and risk of under-five mortality in 23 Sub-Saharan African countries: a population-based study

Relationship between cooking fuel and under-five mortality has not been adequately established in Sub-Saharan Africa (SSA). We therefore investigated the association between cooking fuel and risk of under-five mortality in SSA, and further investigated its interaction with smoking. Using the most recent Demographic Health Survey data of 23 SSA countries (n = 783,691), Cox proportional hazard was employed to determine the association between cooking fuel and risk of under-five deaths. The adjusted hazard ratios were 1.21 (95 % CI, 1.10-1.34) and 1.20 (95 % CI, 1.08-1.32) for charcoal and biomass cooking fuel, respectively, compared to clean fuels. There was no positive interaction between biomass cooking fuel and smoking. Use of charcoal and biomass were associated with the risk of under-five mortality in SSA. Disseminating public health information on health risks of cooking fuel and development of relevant public health policies are likely to have a positive impact on a child's survival.