Cooking and season as risk factors for acute lower respiratory infections in African children: a cross-sectional multi-country analysis

Burden of headaches, eye irritation and respiratory symptoms among females stacking LPG with polluting cooking fuels: Modelling from peri-urban Cameroon, Ghana & Kenya

Introduction

Liquefied petroleum gas (LPG) is a clean cooking fuel that emits less household air pollution (HAP) than polluting cooking fuels (e.g. charcoal, wood). While switching from polluting fuels to LPG can reduce HAP and improve health, the impact of 'stacking' (concurrent use of polluting fuels and LPG) on adverse health symptoms (e.g. headaches, eye irritation, cough) among female cooks is uncertain.

Methods

Survey data from the CLEAN-Air(Africa) study was collected on cooking patterns and health symptoms over the last 12 months (cough, wheezing, chest tightness, shortness of breath, eye irritation, headaches) from approximately 400 female primary cooks in each of three peri‑urban communities in sub-Saharan Africa: Mbalmayo, Cameroon; Obuasi, Ghana; and Eldoret, Kenya. Random effects Poisson regression, adjusted for socioeconomic and health-related covariates, assessed the relationship between primary and secondary cooking fuel type and self-reported health symptoms.

Results

Among 1,147 participants, 10 % (n = 118) exclusively cooked with LPG, 45 % (n = 509) stacked LPG and polluting fuels and 45 % (n = 520) exclusively cooked with polluting fuels. Female cooks stacking LPG and polluting fuels had significantly higher odds of shortness of breath (OR 2.16, 95 %CI:1.04-4.48) compared with those exclusively using LPG. In two communities, headache prevalence was 30 % higher among women stacking LPG with polluting fuels (Mbalmayo:82 %; Eldoret:65 %) compared with those exclusively using LPG (Mbalmayo:53 %; Eldoret:33 %). Women stacking LPG and polluting fuels (OR 2.45, 95 %CI:1.29-4.67) had significantly higher odds of eye irritation than women cooking exclusively with LPG. Second-hand smoke exposure was significantly associated with higher odds of chest tightness (OR 1.92, 95 % CI:1.19-3.11), wheezing (OR 1.76, 95 % CI:1.06-2.91) and cough (OR 1.78, 95 %CI:1.13-2.80).

Conclusions

In peri‑urban sub-Saharan Africa, women exclusively cooking with LPG had lower odds of several health symptoms than those stacking LPG and polluting fuels. Promoting a complete transition to LPG in these communities may likely generate short-term health benefits for primary cooks.

Multidimensional energy poverty and acute respiratory infection in children under 5 years of age: evidence from 22 low-income and middle-income countries

BACKGROUND

In low-income and middle-income countries (LMICs), energy poverty has predominantly been studied from the unidimensional perspective of indoor air pollution. Acute respiratory infection (ARI) in children under 5 years of age is the most important disease associated with indoor air pollution attributable to solid fuel use in LMICs. This study aimed to extend the existing knowledge on the association between energy poverty and ARI among children under 5 years of age in LMICs, by adopting a multidimensional perspective.

METHODS

Using Demographic and Health Surveys from 22 LMICs, data from 483 088 children were analysed (mean age 2.00 years (SD 1.41); 51.3% male). Energy poverty was measured using the Multidimensional Energy Poverty Index (MEPI) (range 0-1), which comprises five dimensions of essential energy services. Binary logistic regression models were conducted to study the association between MEPI and ARI, adjusting for child, maternal, household and environmental characteristics.

RESULTS

A 0.1 increase in MEPI score was associated with greater odds of ARI (aOR 1.05; 95% CI 1.04 to 1.07). Likewise, MEPI indicators using biomass for cooking (aOR 1.15; 95% CI 1.07 to 1.23) and lack of access to electricity (aOR 1.17; 95% CI 1.10 to 1.26), entertainment/education appliances (aOR 1.07; 95% CI 1.02 to 1.13) and household appliances (aOR 1.12; 95% CI 1.04 to 1.21) were associated with greater odds of ARI.

CONCLUSION

Multidimensional energy poverty was associated with greater odds of ARI in children under 5 years of age living in 22 LMICs. Hence, our findings justify the design and implementation of interventions that address energy poverty from a multidimensional perspective, integrating energy affordability and accessibility.

Assessing the combined effect of household cooking fuel and urbanicity on acute respiratory symptoms among under-five years in sub-Saharan Africa

Background

This study sought to investigate the association between urbanicity (rural-urban residency), the use of solid biomass cooking fuels and the risk of Acute Respiratory Infections (ARIs) among children under the age of 5 in sub-Saharan Africa (SSA).

Methods

Cross-sectional data from the most recent surveys of the Demographic and Health Survey Program conducted in 31 sub-Saharan African countries were pooled for the analysis. The outcome variables, cough and rapid short breath were derived from questions that asked mothers if their children under the age of 5 suffered from cough and short rapid breath in the past two weeks preceding the survey. To examine the associations, multivariable negative log-log regression models were fitted for each outcome variable.

Results

Higher odds ratios of cough occurred among children in urban households that use unclean cooking fuel (aOR = 1.05 95% CI = 1.01, 1.08). However, lower odds ratios were observed for rural children in homes that use clean cooking fuel (aOR = 0.93 95% CI = 0.87, 0.99) relative to children in urban homes using clean cooking fuel. We also found higher odds ratios of short rapid breaths among children in rural households that use unclean cooking fuel compared with urban residents using clean cooking fuel (aOR = 1.12 95% CI = 1.08, 1.17).

Conclusion

Urbanicity and the use of solid biomass fuel for cooking were associated with an increased risk of symptoms of ARIs among children under five years in SSA. Thus, policymakers and stakeholders need to design and implement strategies that minimize children's exposure to pollutants from solid biomass cooking fuel. Such interventions could reduce the burden of respiratory illnesses in SSA and contribute to the realization of Sustainable Development Goal 3.9, which aims at reducing the number of diseases and deaths attributable to hazardous chemicals and pollution of air, water and soil.

Associations Between Indoor Air Pollutants and Risk Factors for Acute Respiratory Infection Symptoms in Children Under 5: An Analysis of Data From the Indonesia Demographic Health Survey

OBJECTIVES

The study investigated the association between indoor air pollution (IAP) and risk factors for acute respiratory infection (ARI) symptoms in children under 5 years of age.

METHODS

A cross-sectional study was conducted using data derived from Indonesia Demographic and Health Survey in 2017. Binary logistic regression modeling was employed to examine each predictor variable associated with ARI among children under 5 years of age in Indonesia.

RESULTS

The study included a total of 4936 households with children. Among children under 5 years old, 7.2% reported ARI symptoms. The presence of ARI symptoms was significantly associated with the type of residence, wealth index, and father's smoking frequency, which were considered the sample's socio-demographic characteristics. In the final model, living in rural areas, having a high wealth index, the father's smoking frequency, and a low education level were all linked to ARI symptoms.

CONCLUSIONS

The results revealed that households in rural areas had a substantially higher level of reported ARI symptoms among children under 5 years old. Furthermore, the father's smoking frequency and low education level were associated with ARI symptoms.

Trends and determinants of acute respiratory infection symptoms among under-five children in Cambodia: Analysis of 2000 to 2014 Cambodia demographic and health surveys

Acute Respiratory Infections (ARIs) are the leading cause of mortality and morbidity among children under 5 years old and about 1.3 million annually worldwide. Account for 33% of deaths among children under 5 years that occurred in developing countries. In Cambodia, ARIs prevalence in children under 5 years old was 20% in 2000, and 6% in 2014. Hence, the aimed to describe the trends of ARI symptoms among children aged 0-59 months over time using the 2000, 2005, 2010, and 2014 Cambodia Demographic and Health Survey (CDHS) and determined the relationships between socio-demographic, behavioral, and environmental factors with ARI symptoms. We analyzed existing children's data from 2000, 2005, 2010 and 2014 of Cambodia Demographic and Health Survey (CDHS) that used a two-stage stratified cluster sampling design. We limited our analysis to children born in the last five years prior to the surveys, alive and living in households during interview time. Data were pooled across the four survey years for 29,171 children aged 0-59 months. All statistics were carried out using STATA V16, and survey weights were taken into account for the survey design of the CDHS. We used multiple logistic regression to determine the main predictors of ARI symptoms among children under 5 years. ARI symptoms in the previous two weeks in children aged 0-59 months in Cambodia were 19.9% in 2000 to 8.6% in 2005 to 6.4% in 2010, and 5.5% in 2014. Factors independently associated with increased odds of ARI symptoms were children ages 6-11 months with adjusted odds ratio [AOR = 1.91; 95% CI: 1.53-2.38], 12-23 months [AOR = 1.79; 95% CI: 1.46-2.20], and 24-35 months [AOR = 1.41; 95% CI: 1.13-1.76], smoking mother [AOR = 1.61; 95% CI: 1.27-2.05], and using non-improved toilets in households [AOR = 1.20; 95% CI: 0.99-1.46]. However, the following factors were found to be associated with decreased odds of having ARI symptoms: Mothers with higher education [AOR = 0.45; 95% CI: 0.21-0.94], breastfeeding children [AOR = 0.87; 95% CI: 0.77-0.98], and children born into richest wealth quantile [AOR = 0.73; 95% CI: 0.56-0.95], respectively. Survey 2005 [AOR = 0.36; 95% CI: 0.31-0.42], 2010 [AOR = 0.27; 95% CI: 0.22-0.33], 2014 [AOR = 0.24; 95% CI: 0.19-0.30]. The trends of ARI symptoms among children under five in Cambodia significantly decreased from 2000-2014. Smoking mothers, young children ages (0-35 months), and using non-improved toilet in household are factors that independently increased the likelihood that children would develop ARI symptoms. Inversely, factors were found to be associated with decreased odds of having ARI symptoms: Mothers with higher education, breastfeeding children, and children born into the richest wealth quantile and Survey years. Therefore, government and child family programs must promote maternal education, particularly infant breastfeeding. The government ought to support maternal education and infant breastfeeding in the interest of early childhood care.

Household Factors of Foodborne Diarrhea in Children under Five in Two Districts of Maputo, Mozambique

Household factors involved in the disease of diarrhea are multifaceted. This study aimed to explore and describe the household factors affecting foodborne diarrhea in children younger than 5 years old using structured questionnaire data based on quantitative tools. The sample size was calculated based on a binomial distribution. A total of 300 children, together with their caregivers, participated, and the data were descriptively and mathematically analyzed using Epi Info modelling. The caregivers were mostly female and included 93.3% rural and 84% urban dwellers of ages between 18 and 38, who were single but living with someone. Of the children who were under six months of age, 23.3% in rural areas and 16.6% in urban areas had diarrhea, while of the children between 12 and 23 months of age, 36.6% in urban areas and 30% in rural areas had diarrhea. The relatives had similar symptoms before the child became ill, with 12.6% of relatives in rural areas and 13.3% in urban areas reporting this. Before receiving medical assistance, 51.3% of children in rural areas and 16% of children in urban areas were treated with traditional medication. Water was not treated before drinking in 48% of rural cases and 45.3% of urban cases. A total of 24.6% of infants in urban areas and 12.6% of infants in rural areas used a bottle for feeding. The factors affecting foodborne diarrhea were the use of traditional medication in rural areas, bottle feeding in urban areas and untreated water used for drinking in both areas.

Analysis of risk factors associated with acute respiratory infections among under-five children in Uganda

Background

Globally, infectious diseases are the major cause of death in children under the age of 5 years. Sub-Saharan Africa and South Asia account for 95% of global child mortalities every year, where acute respiratory infections (ARI) remain the leading cause of child morbidity and mortality. The aim of this study is to analyze the risk factors of ARI disease symptoms among children under the age of 5 years in Uganda.

Methods

A cross-sectional design was used to analyze 2016 Uganda Demographic and Health Survey (UDHS) data collected on 13,493 children under the age of 5 years in Uganda. Various methods, such as logistic regression, elastic net logistic regression, decision tree, and random forest, were compared and used to predict 75% of the symptom outcomes of ARI disease. Well-performing methods were used to determine potential risk factors for ARI disease symptoms among children under the age of 5 years.

Results

In Uganda, about 40.3% of children were reported to have ARI disease symptoms in the 2 weeks preceding the survey. Children under the age of 24 months were found to have a high prevalence of ARI disease symptoms. By considering 75% of the sample, the random forest was found to be a well-performing method (accuracy = 88.7%; AUC = 0.951) compared to the logistic regression method (accuracy = 62.0%; AUC = 0.638) and other methods in predicting childhood ARI symptoms. In addition, one-year old children (OR: 1.27; 95% CI: 1.12–1.44), children whose mothers were teenagers (OR: 1.28; 95% CI: 1.06–1.53), and farm workers (1.25; 95% CI: 1.11–1.42) were most likely to have ARI disease symptoms than other categories. Furthermore, children aged 48–59 months (OR: 0.69; 95% CI: 0.60–0.80), breastfed children (OR: 0.83; 95% CI: 0.76–0.92), usage of charcoal in cooking (OR: 0.77; 95% CI: 0.69–0.87), and the rainy season effect (OR: 0.66; 95% CI: 0.61–0.72) showed a low risk of developing ARI disease symptoms among children under the age of 5 years in Uganda.

Conclusion

Policy-makers and health stakeholders should initiate target-oriented approaches to address the problem regarding poor children’s healthcare, improper environmental conditions, and childcare facilities. For the sake of early child care, the government should promote child breastfeeding and maternal education.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-022-13532-y.

Indoor air pollution from solid fuel on children pneumonia in low- and middle-income countries: a systematic review and meta-analysis

An updated systematic review was conducted to assessing on the association between indoor air pollution caused by household energy consumption and childhood pneumonia in low- and middle-income countries. We performed a meta-analysis from the electronic databases of PubMed, Cochrane library, Web of Science, EMBASE. Studies were selected when they reported childhood pneumonia or ALRI in relation to indoor air pollution resulted from solid fuel. Studies must provide results on exposure prevalence of children aged below 5 years from Asia or Africa. We devoted ourselves to identifying randomized controlled experiments and observational epidemiological researches, which revealed the relation between household usage of solid fuel and childhood pneumonia. Among 1954 articles, 276 were reviewed thoroughly and 16 conduced to such a meta-analysis. It was found that there is a significant relationship between the solid fuel combustion and increasing risk of childhood pneumonia (OR = 1.66, 95%CI 1.36-2.02). The summary odds ratios from biomass use and mixed fuel use were, respectively, 1.86 (95%CI 1.15-3.02) and 1.58 (95%CI 1.38-1.81), with substantial between study heterogeneity (I² = 87.2% and 29.2%, respectively). According to the subgroup analysis along with the meta-regression analysis, the risk of using solid fuel in Asian regions is higher than that in African regions. Studies based on non-hospital participates (I² = 49.5%) may also a source of heterogeneity. We found that indoor air pollution generated by the usage of solid fuel might be a significant risk factor for pneumonia in children and suggested improving the indoor air quality by promoting cleaner fuel will be important in undeveloped countries.

Comparison of Respiratory Health Impacts Associated with Wood and Charcoal Biomass Fuels: A Population-Based Analysis of 475,000 Children from 30 Low- and Middle-Income Countries

BACKGROUND

The World Health Organisation reported that 45% of global acute respiratory infection (ARI) deaths in children under five years are attributable to household air pollution, which has been recognised to be strongly associated with solid biomass fuel usage in domestic settings. The introduction of legislative restrictions for charcoal production or purchase can result in unintended consequences, such as reversion to more polluting biomass fuels such as wood; which may increase health and environmental harms. However, there remains a paucity of evidence concerning the relative health risks between wood and charcoal. This study compares the risk of respiratory symptoms, ARI, and severe ARI among children aged under five years living in wood and charcoal fuel households across 30 low- and middle-income countries.

METHODS

Data from children (N = 475,089) residing in wood or charcoal cooking households were extracted from multiple population-based Demographic and Health Survey databases (DHS) (N = 30 countries). Outcome measures were obtained from a maternal report of respiratory symptoms (cough, shortness of breath and fever) occurring in the two weeks prior to the survey date, generating a composite measure of ARI (cough and shortness of breath) and severe ARI (cough, shortness of breath and fever). Multivariable logistic regression analyses were implemented, with adjustment at individual, household, regional and country level for relevant demographic, social, and health-related confounding factors.

RESULTS

Increased odds ratios of fever (AOR: 1.07; 95% CI: 1.02-1.12) were observed among children living in wood cooking households compared to the use of charcoal. However, no association was observed with shortness of breath (AOR: 1.03; 95% CI: 0.96-1.10), cough (AOR: 0.99; 95% CI: 0.95-1.04), ARI (AOR: 1.03; 95% CI: 0.96-1.11) or severe ARI (AOR: 1.07; 95% CI: 0.99-1.17). Within rural areas, only shortness of breath was observed to be associated with wood cooking (AOR: 1.08; 95% CI: 1.01-1.15). However, an increased odds ratio of ARI was observed in Asian (AOR: 1.25; 95% CI: 1.04-1.51) and East African countries (AOR: 1.11; 95% CI: 1.01-1.22) only.

CONCLUSION

Our population-based observational data indicates that in Asia and East Africa there is a greater risk of ARI among children aged under 5 years living in wood compared to charcoal cooking households. These findings have major implications for understanding the existing health impacts of wood-based biomass fuel usage and may be of relevance to settings where charcoal fuel restrictions are under consideration.

A Cross-Sectional Analysis of the Association between Domestic Cooking Energy Source Type and Respiratory Infections among Children Aged under Five Years: Evidence from Demographic and Household Surveys in 37 Low-Middle Income Countries

BACKGROUND

In low- and middle-income countries (LMICs), household air pollution as a result of using solid biomass for cooking, lighting and heating (HAP) is associated with respiratory infections, accounting for approximately 4 million early deaths each year worldwide. The majority of deaths are among children under five years. This population-based cross-sectional study investigates the association between solid biomass usage and risk of acute respiratory infections (ARI) and acute lower respiratory infections (ALRI) in 37 LMICs within Africa, Americas, Southeast Asia, European, Eastern Mediterranean and Western Pacific regions.

MATERIALS AND METHODS

Using population-based data obtained from Demographic and Health surveys (2010-2018), domestic cooking energy sources were classified solid biomass (wood, charcoal/dung, agricultural crop) and cleaner energy sources (e.g., Liquid Petroleum Gas (LPG), electricity, biogas and natural gas). Composite measures of ARI (shortness of breath, cough) and ALRI (shortness of breath, cough and fever) were composed using maternally reported respiratory symptoms over the two-week period prior to the interview. Multivariable logistic regression was used to identify the association between biomass fuel usage with ARI and ALRI, accounting for relevant individual, household and situational confounders, including stratification by context (urban/rural).

RESULTS

After adjustment, in the pooled analysis, children residing in solid biomass cooking households had an observed increased adjusted odds ratio of ARI (AOR: 1.17; 95% CI: 1.09-1.25) and ALRI (AOR: 1.16; 95% CI 1.07-1.25) compared to cleaner energy sources. In stratified analyses, a comparable association was observed in urban areas (ARI: 1.16 [1.06-1.28]; ALRI: 1.14 [1.02-1.27]), but only significant for ARI among those living in rural areas (ARI: 1.14 [1.03-1.26]).

CONCLUSION

Switching domestic cooking energy sources from solid biomass to cleaner alternatives would achieve a respiratory health benefit in children under five years worldwide. High quality mixed-methods research is required to improve acceptability and sustained uptake of clean cooking energy source interventions in LMIC settings.

Use of directed acyclic graphs (DAGs) to identify confounders in applied health research: review and recommendations

Background

Directed acyclic graphs (DAGs) are an increasingly popular approach for identifying confounding variables that require conditioning when estimating causal effects. This review examined the use of DAGs in applied health research to inform recommendations for improving their transparency and utility in future research.

Methods

Original health research articles published during 1999–2017 mentioning ‘directed acyclic graphs’ (or similar) or citing DAGitty were identified from Scopus, Web of Science, Medline and Embase. Data were extracted on the reporting of: estimands, DAGs and adjustment sets, alongside the characteristics of each article’s largest DAG.

Results

A total of 234 articles were identified that reported using DAGs. A fifth (n = 48, 21%) reported their target estimand(s) and half (n = 115, 48%) reported the adjustment set(s) implied by their DAG(s). Two-thirds of the articles (n = 144, 62%) made at least one DAG available. DAGs varied in size but averaged 12 nodes [interquartile range (IQR): 9–16, range: 3–28] and 29 arcs (IQR: 19–42, range: 3–99). The median saturation (i.e. percentage of total possible arcs) was 46% (IQR: 31–67, range: 12–100). 37% (n = 53) of the DAGs included unobserved variables, 17% (n = 25) included ‘super-nodes’ (i.e. nodes containing more than one variable) and 34% (n = 49) were visually arranged so that the constituent arcs flowed in the same direction (e.g. top-to-bottom).

Conclusion

There is substantial variation in the use and reporting of DAGs in applied health research. Although this partly reflects their flexibility, it also highlights some potential areas for improvement. This review hence offers several recommendations to improve the reporting and use of DAGs in future research.

Biomass fuel use and acute respiratory infection among children younger than 5 years in Ethiopia: a systematic review and meta-analysis

OBJECTIVES

The objective of this study was to estimate the magnitude of acute respiratory infection (ARI) among children younger than 5 years (under-five children) and its association with biomass fuel use for domestic purposes and other behavioural and housing characteristics in Ethiopia.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

PubMed, Google Scholar, MEDLINE and the Cochrane Library were systematically searched (using the Preferred Items for Systematic Review and Meta-analysis guideline) for studies that reported an association between biomass fuel use for domestic purposes and ARI. Grey literature and other sources of unpublished information, which were subjected to the same extraction methods and quality appraisal as published studies, were also identified. A meta-analysis was performed to combine the quantitative measures from eligible individual studies into a summary estimate. Quality assessment was conducted using the modified Newcastle-Ottawa Scale quality assessment tool for cross-sectional and case-control studies. Funnel and Doi plots were used to detect potential publication bias. Statistical analyses were performed using Comprehensive Meta-Analysis and MetaXL, version 5.3, software.

RESULTS

A total of 21 (18 cross-sectional and 3 case-control) eligible studies with their combined 30,013 participants were reviewed. The overall pooled prevalence of ARI among under-five children in households where biomass fuel was the main source of energy was estimated to be 22% (95% confidence interval [CI]: 17-29). In the subgroup analysis by area of residence, the highest prevalence was found in urban regions 26% (95% CI: 24-28). Based on the preceding 2 weeks before the interview, a significant association was found between biomass fuel use and ARI (odds ratio [OR] = 2.6, 95% CI: 2.05-3.30). In addition to biomass fuel use, being female (OR = 1.57, 95% CI: 1.06-2.33), absence of a window in the kitchen (OR = 2.89, 95% CI: 2.11-3.96), being carried on the back or in lap during cooking (OR = 2.76, 95% CI: 1.96-3.89) and non-separated kitchen from the main house (OR = 1.99, 95% CI: 1.49-2.68) were associated with ARI.

CONCLUSIONS

Based on the results of this review, ARI among under-five children remains high. The present study also revealed that ARI is associated with biomass fuel use, child's gender, absence of a window in the kitchen, non-separated kitchen and carrying the child while cooking. Improved solid fuel stoves, advanced combustion designs, windows or chimneys, separating the kitchen from the main house are all measures required to reduce ARI in under-five children.

SYSTEMATIC REVIEW REGISTRATION

The review has been registered with PROSPERO (registration number CRD42020181372).

Household Smoke-Exposure Risks Associated with Cooking Fuels and Cooking Places in Tanzania: A Cross-Sectional Analysis of Demographic and Health Survey Data

Household smoke-exposure risk (SER) can be defined through the assessment of cooking fuels (smoke and no smoke-producing) and cooking places (indoor and outdoor) related information, which represent different levels of household air pollution. This study aimed to explore the prevalence and geographical variations in smoke-exposure risks (SERs) associated with indoor and outdoor cooking practices and use of smoke-producing and non-smoke-producing cooking fuels in Tanzania. We further investigated the social and spatial features associated with household SERs. We defined an indicator variable, the household SER, using country-level, cross-sectional data on cooking fuels and cooking places obtained from the 2015–2016 Tanzania Demographic and Health Survey and then estimated zone-level average SERs. We used an ordered logistic regression model to assess the social and spatial characteristics associated with household SER. We identified 76.4% of the 12,425 households that practiced indoor cooking using smoke-producing fuels as having a high SER. High-level SER was more prevalent in the Central, Southern highland, and Southwest highland zones. Overall, wealthier households, female-headed households, and households with higher education attainments were more likely to be categorized as households with very low SER. Meanwhile, households headed by older individuals and with larger family sizes were less likely to be in the very low SER category. The prevalence of high SER is a major public health concern in Tanzania. Improved cooking stoves and cleaner fuels should be adopted simultaneously to minimize the adverse effects associated with household SER.

Fuel type use and risk of respiratory symptoms: A cohort study of infants in the Northern region of Ghana

Little evidence exists about the association between fuel type use and risk of respiratory symptoms among infants; we aimed to evaluate this hypothesis through a cohort study in the Northern Region of Ghana. The study was carried out from April 2018 to May 2019. We recruited 28 weeks old pregnant women at selected hospitals and prospectively followed them at birth in the hospital ward to register their newborns and at homes when the baby had attained 3 to 7 months to collect data on respiratory symptoms of infants. A logistic regression model was used to investigate the odds of respiratory symptoms in infants. Exactly 1270 infants completed the study; the average age of women was 27.1 years and standard deviation of 5.1. The study found that infants of mothers who cooked with charcoal and those with firewood had increased odds of having cough with cold 4.10 (95% CI, 2.21-7.61) and 3.95 (95% CI, 2.06-7.58), increased odds of congestion, phlegm with cold by 3.89 (95% CI, 1.73-8.79) and 3.45 (95% CI, 1.44-8.26), increased odds of wheezing 4-14 days or nights by 1.68 (95% CI, 0.72-3.91) and 3.37 (95% CI, 1.41-8.04) and increased odds of seeking medical treatments in a health facility for chest illness by 3.97 (95% CI, 1.31-12.02) and 6.67 (95% CI, 2.14-20.77) in comparison with liquid petroleum gas respectively. Some significant predictors of respiratory infections were maternal malaria, hospitalisations of an infant after birth, residence, cooking location, composite breastfeeding, sharing of a bedroom with infant and air-conditioner or fan in the living room. Our findings indicate increased odds of infant respiratory symptoms in households using solid fuel in Ghana. Although our observational design precludes ascribing any causal relationships, our results are consistent with other studies suggesting clean fuel use during pregnancy and infancy may benefit this vulnerable age group.

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.

Recommendations for building out mosquito-transmitted diseases in sub-Saharan Africa: the DELIVER mnemonic

In sub-Saharan Africa, most transmission of mosquito-transmitted diseases, such as malaria or dengue, occurs within or around houses. Preventing mosquito house entry and reducing mosquito production around the home would help reduce the transmission of these diseases. Based on recent research, we make key recommendations for reducing the threat of mosquito-transmitted diseases through changes to the built environment. The mnemonic, DELIVER, recommends the following best practices: (i) Doors should be screened, self-closing and without surrounding gaps; (ii) Eaves, the space between the wall and roof, should be closed or screened; (iii) houses should be Lifted above the ground; (iv) Insecticide-treated nets should be used when sleeping in houses at night; (v) houses should be Ventilated, with at least two large-screened windows to facilitate airflow; (vi) Environmental management should be conducted regularly inside and around the home; and (vii) Roofs should be solid, rather than thatch. DELIVER is a package of interventions to be used in combination for maximum impact. Simple changes to the built environment will reduce exposure to mosquito-transmitted diseases and help keep regions free from these diseases after elimination. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.

Place of food cooking is associated with acute respiratory infection among under-five children in Ethiopia: multilevel analysis of 2005-2016 Ethiopian Demographic Health Survey data

Background

Globally, acute respiratory infections are among the leading causes of under-five child mortality, especially in lower-income countries; it is associated with indoor exposure to toxic pollutants from solid biomass fuel. In Ethiopia, 90% of the population utilizes solid biomass fuel; respiratory illness is a leading health problem. However, there is a paucity of nationally representative data on the association of household cooking place and respiratory infections. Besides, evidence on the variability in the infection based on the data collected at different times is limited. Therefore, this study is intended to assess the association of food cooking place with acute respiratory infections and the variability in households and surveys.

Methods

The current analysis is based on the Ethiopian Demographic and Health Survey data collected in 2005, 2011, and 2016 and obtained via online registration. The association of food cooking place with acute respiratory infection was assessed using multilevel modeling after categorizing all factors into child level and survey level, controlling them in a full model. The analyses accounted for a complex survey design using a Stata command “svy.”

Result

A total of 30,895 under-five children were included in this study, of which 3677 (11.9%) children had an acute respiratory infection, with 12.7% in 2005, 11.9% in 2011, and 11.1% in 2016. The risk of having an infection in under-five children in households that cooked food outdoors was 44% lower (AOR = 0.56, 95% CI = 0.40, 0.75) compared to those households that cooked the food inside the house. There was a statistically significant difference among the children among surveys to have an acute respiratory infection.

Conclusion

The risk of having children with acute respiratory infection is lower in the households of cooking food outdoor compared to indoor. The infection difference in different surveys suggests progress in the practices in either food cooking places or the fuel types used that minimize food cooking places location or the fuel types used that minimizes the risk. But, the infection is still high; therefore, measures promoting indoor cooking in a well-ventilated environment with alternative energy sources should take place.

Trends and factors associated with acute respiratory infection among under five children in Zambia: evidence from Zambia's demographic and health surveys (1996-2014)

Introduction

acute respiratory infection (ARI) is one of the leading causes of morbidity and mortality among children under the age of five years globally accounting for 16% of deaths. In Zambia, ARI accounts for 30-40% of children's outpatient attendance and 20-30% of hospital admissions. We assessed trends and factors associated with ARI among under-five children in Zambia from 1996 to 2014.

Methods

we analysed the Zambia demographic and health survey data for 1996, 2002, 2007 and 2014 of under five children and their mothers. We extracted data using a data extraction tool from the women's file. We analysed trends using chi square for trends. We conducted a complex survey multivariable logistic regression analysis, reported adjusted odds ratios (AOR) 95% confidence intervals (CI) and p-values.

Results

we included a total of 6,854 and 2,389 (8%) had symptoms consistent with ARI. A 2% upward trend was noted between the 1996 and 2002 surveys but a sharp decline of 10% occurred in 2007. The chi2 trend test was significant p < 0.001. Children whose mothers had secondary or higher education were less likely to have ARI (AOR 0.30 95% CI 0.15-0.58) compared to those with no education. Underweight children had 1.50 times increased odds of having ARI (AOR 1.50 95% CI 1.25 - 1.68) compared with children who were not. Use of biomass fuels such as charcoal (AOR 2.67 95% CI 2.09 - 3.42) and wood (2.79 95% CI 2.45 -3.19) were associated with high odds for ARI compared to electricity.

Conclusion

the prevalence of ARI has declined in Zambia from 1996 to 2014. Factors associated with occurrence of ARI included being a child under one year, underweight, use of biomass fuel such as charcoal and wood. Interventions to reduce the burden of ARI should be targeted at scaling up nutrition programs, as well as promoting use of cleaner fuels.

Investigating the Association between Wood and Charcoal Domestic Cooking, Respiratory Symptoms and Acute Respiratory Infections among Children Aged Under 5 Years in Uganda: A Cross-Sectional Analysis of the 2016 Demographic and Health Survey

Background: Household air pollution associated with biomass (wood, dung, charcoal, and crop residue) burning for cooking is estimated to contribute to approximately 4 million deaths each year worldwide, with the greatest burden seen in low and middle-income countries. We investigated the relationship between solid fuel type and respiratory symptoms in Uganda, where 96% of households use biomass as the primary domestic fuel. Materials and Methods: Cross-sectional study of 15,405 pre-school aged children living in charcoal or wood-burning households in Uganda, using data from the 2016 Demographic and Health Survey. Multivariable logistic regression analysis was used to identify the associations between occurrence of a cough, shortness of breath, fever, acute respiratory infection (ARI) and severe ARI with cooking fuel type (wood, charcoal); with additional sub-analyses by contextual status (urban, rural). Results: After adjustment for household and individual level confounding factors, wood fuel use was associated with increased risk of shortness of breath (AOR: 1.33 [1.10-1.60]), fever (AOR: 1.26 [1.08-1.48]), cough (AOR: 1.15 [1.00-1.33]), ARI (AOR: 1.36 [1.11-1.66] and severe ARI (AOR: 1.41 [1.09-1.85]), compared to charcoal fuel. In urban areas, Shortness of breath (AOR: 1.84 [1.20-2.83]), ARI (AOR: 1.77 [1.10-2.79]) and in rural areas ARI (AOR: 1.23 [1.03-1.47]) and risk of fever (AOR: 1.23 [1.03-1.47]) were associated with wood fuel usage. Conclusions: Risk of respiratory symptoms was higher among children living in wood compared to charcoal fuel-burning households, with policy implications for mitigation of associated harmful health impacts.

Personal strategies to minimise effects of air pollution on respiratory health: advice for providers, patients and the public

As global awareness of air pollution rises, so does the imperative to provide evidence-based recommendations for strategies to mitigate its impact. While public policy has a central role in reducing air pollution, exposure can also be reduced by personal choices. Qualified evidence supports limiting physical exertion outdoors on high air pollution days and near air pollution sources, reducing near-roadway exposure while commuting, utilising air quality alert systems to plan activities, and wearing facemasks in prescribed circumstances. Other strategies include avoiding cooking with solid fuels, ventilating and isolating cooking areas, and using portable air cleaners fitted with high-efficiency particulate air filters. We detail recommendations to assist providers and public health officials when advising patients and the public regarding personal-level strategies to mitigate risk imposed by air pollution, while recognising that well-designed prospective studies are urgently needed to better establish and validate interventions that benefit respiratory health in this context.

Household air pollution profiles associated with persistent childhood cough in urban Uganda

BACKGROUND

Most household air pollution (HAP) interventions in developing countries of sub-Saharan Africa have focused on a single source, such as replacing polluting cooking sources with cleaner burning cooking stoves. Such interventions, however, have resulted in insufficient reductions in HAP levels and respiratory health risks in children. In this study we determined how multiple HAP combustion sources and exposure-mitigation factors in the home environment influence child respiratory health alone and in combination.

METHODS

We carried out a case-control study to determine associations between multiple indicators of HAP and persistent cough among children (<15 years of age) seeking care at three primary-care clinics in Kampala, Uganda. HAP indicators included self-report of combustion sources inside the home (e.g., stove type, fuel type, and smoking); housing characteristics and cooking practices that mitigate HAP exposure (e.g., use of windows, location of cooking, location of children during cooking) and perceptions of neighborhood air quality. To explore joint associations between indicators of HAP, we applied a Bayesian clustering technique (Bayesian profile regression) to identify HAP indicator profiles most strongly associated with persistent cough in children.

RESULTS

Most HAP indicators demonstrated significant positive bivariate associations with persistent cough among children, including fuel-type (kerosene), the number of hours burning solid fuels, use of polluting fuels (kerosene or candles) for lighting the home, tobacco smoking indoors, cooking indoors, cooking with children indoors, lack of windows in the cooking area, and not opening windows while cooking. Bayesian cluster analysis revealed 11 clusters of HAP indicator profiles. Compared to a reference cluster that was representative of the underlying study population cough prevalence, three clusters with profiles characterized by highly adverse HAP indicators resulted in ORs of 1.72 (95% credible interval: 1.15, 2.60), 4.74 (2.88, 8.0), and 8.6 (3.9, 23.9). Conversely, at least two clusters of HAP indicator-profiles were protective compared to the reference cluster, despite the fact that these protective HAP indicator profiles used solid fuels for cooking in combination with an unimproved stove (cooking was performed predominantly outdoors in these protective clusters).

CONCLUSIONS

In addition to cooking fuel and type of cook stove, multiple HAP indicators were strongly associated with persistent cough in children. Bayesian profile regression revealed that the combination of HAP sources and HAP exposure-mitigating factors was driving risk of adverse cough associations in children, rather than any single HAP source at the home.

Antibiotic Prescription Patterns among Children Younger than 5 Years in Nouna District, Burkina Faso

Understanding antibiotic use may help predict emergence of antimicrobial resistance. We evaluated antibiotic prescription trends in rural Burkina Faso, where little is known about antibiotic consumption. Antibiotic prescription data for 20 communities were extracted through record review in six primary health-care facilities serving the communities. The number of antibiotic prescriptions per child-year was calculated using population-based census data from the communities. A total of 1,444 antibiotic prescriptions were made from March to June 2017 among 3,401 children in the communities. The frequency of antibiotic prescription was 1.70 prescriptions per child-year (95% CI: 1.61-1.79). Penicillins were the most common (1.04 prescriptions per child-year, 95% CI: 1.01-1.06), followed by sulfonamides (0.69 prescriptions per child-year, 95% CI: 0.67-0.71) and macrolides (0.38 prescriptions per child-year, 95% CI: 0.37-0.40). Continued monitoring of antibiotic consumption in diverse settings will be important to understand the potential for emergence of antibiotic resistance.

Environmental Health Research in Africa: Important Progress and Promising Opportunities

The World Health Organization in 2016 estimated that over 20% of the global disease burden and deaths were attributed to modifiable environmental factors. However, data clearly characterizing the impact of environmental exposures and health endpoints in African populations is limited. To describe recent progress and identify important research gaps, we reviewed literature on environmental health research in African populations over the last decade, as well as research incorporating both genomic and environmental factors. We queried PubMed for peer-reviewed research articles, reviews, or books examining environmental exposures and health outcomes in human populations in Africa. Searches utilized medical subheading (MeSH) terms for environmental exposure categories listed in the March 2018 US National Report on Human Exposure to Environmental Chemicals, which includes chemicals with worldwide distributions. Our search strategy retrieved 540 relevant publications, with studies evaluating health impacts of ambient air pollution (n=105), indoor air pollution (n = 166), heavy metals (n = 130), pesticides (n = 95), dietary mold (n = 61), indoor mold (n = 9), per- and polyfluoroalkyl substances (PFASs, n = 0), electronic waste (n = 9), environmental phenols (n = 4), flame retardants (n = 8), and phthalates (n = 3), where publications could belong to more than one exposure category. Only 23 publications characterized both environmental and genomic risk factors. Cardiovascular and respiratory health endpoints impacted by air pollution were comparable to observations in other countries. Air pollution exposures unique to Africa and some other resource limited settings were dust and specific occupational exposures. Literature describing harmful health effects of metals, pesticides, and dietary mold represented a context unique to Africa. Studies of exposures to phthalates, PFASs, phenols, and flame retardants were very limited. These results underscore the need for further focus on current and emerging environmental and chemical health risks as well as better integration of genomic and environmental factors in African research studies. Environmental exposures with distinct routes of exposure, unique co-exposures and co-morbidities, combined with the extensive genomic diversity in Africa may lead to the identification of novel mechanisms underlying complex disease and promising potential for translation to global public health.

Do fuel type and place of cooking matter for acute respiratory infection among Afghan children? Evidence from the Afghanistan DHS 2015

In Afghanistan, acute respiratory infection (ARI) is a leading cause of under-five mortality. Previous studies on the effects of cooking fuel on ARI have only looked at the types of cooking fuel, and not the effects of the location of the cooking place. The present study aimed to assess the effects of fuel type and place of cooking on the prevalence of ARI among under-five children in Afghanistan. Descriptive statistics and multilevel logistic regression analysis were performed for 31,063 children using data from the first round of the Afghanistan Demographic and Health Survey conducted in 2015. Overall, 13% of the children suffered from ARI symptoms in the 2 weeks before the survey, but this varied widely across the country. The multilevel analysis showed that, compared with households using clean cooking fuel in a separate building or outside, households using clean cooking fuel within the house and without a separate kitchen had a 32% lower risk [95% confidence interval (CI)=0.51-0.91] of having under-five children with ARI, and those using clean fuel in a separate kitchen in the house had a 17% lower risk (95% CI=0.67-1.03). On the other hand, households using polluting cooking fuel in the house without a kitchen had a 14% (95% CI=0.91-1.44) higher risk of having under-five children with ARI, and those using polluting cooking fuel in the house with a separate kitchen had a 5% (95% CI=0.85-1.30) higher risk, after adjusting for other covariates. The findings indicate that type of cooking fuel is not the only issue affecting ARI in children. Place of cooking (in a house with or without a separate kitchen versus outside) also affects the risk of ARI among under-five children. The study also found that mother's education and occupational status, community poverty and ethnicity are other important factors affecting the prevalence of ARI in under-five children in Afghanistan.

Effects of a large-scale distribution of water filters and natural draft rocket-style cookstoves on diarrhea and acute respiratory infection: A cluster-randomized controlled trial in Western Province, Rwanda

BACKGROUND

Unsafe drinking water and household air pollution (HAP) are major causes of morbidity and mortality among children under 5 in low and middle-income countries. Household water filters and higher-efficiency biomass-burning cookstoves have been widely promoted to improve water quality and reduce fuel use, but there is limited evidence of their health effects when delivered programmatically at scale.

METHODS AND FINDINGS

In a large-scale program in Western Province, Rwanda, water filters and portable biomass-burning natural draft rocket-style cookstoves were distributed between September and December 2014 and promoted to over 101,000 households in the poorest economic quartile in 72 (of 96) randomly selected sectors in Western Province. To assess the effects of the intervention, between August and December, 2014, we enrolled 1,582 households that included a child under 4 years from 174 randomly selected village-sized clusters, half from intervention sectors and half from nonintervention sectors. At baseline, 76% of households relied primarily on an improved source for drinking water (piped, borehole, protected spring/well, or rainwater) and over 99% cooked primarily on traditional biomass-burning stoves. We conducted follow-up at 3 time-points between February 2015 and March 2016 to assess reported diarrhea and acute respiratory infections (ARIs) among children <5 years in the preceding 7 days (primary outcomes) and patterns of intervention use, drinking water quality, and air quality. The intervention reduced the prevalence of reported child diarrhea by 29% (prevalence ratio [PR] 0.71, 95% confidence interval [CI] 0.59-0.87, p = 0.001) and reported child ARI by 25% (PR 0.75, 95% CI 0.60-0.93, p = 0.009). Overall, more than 62% of households were observed to have water in their filters at follow-up, while 65% reported using the intervention stove every day, and 55% reported using it primarily outdoors. Use of both the intervention filter and intervention stove decreased throughout follow-up, while reported traditional stove use increased. The intervention reduced the prevalence of households with detectable fecal contamination in drinking water samples by 38% (PR 0.62, 95% CI 0.57-0.68, p < 0.0001) but had no significant impact on 48-hour personal exposure to log-transformed fine particulate matter (PM2.5) concentrations among cooks (β = -0.089, p = 0.486) or children (β = -0.228, p = 0.127). The main limitations of this trial include the unblinded nature of the intervention, limited PM2.5 exposure measurement, and a reliance on reported intervention use and reported health outcomes.

CONCLUSIONS

Our findings indicate that the intervention improved household drinking water quality and reduced caregiver-reported diarrhea among children <5 years. It also reduced caregiver-reported ARI despite no evidence of improved air quality. Further research is necessary to ascertain longer-term intervention use and benefits and to explore the potential synergistic effects between diarrhea and ARI.

TRIAL REGISTRATION

Clinical Trials.gov NCT02239250.

Primary Cooking Fuel Choice and Respiratory Health Outcomes among Women in Charge of Household Cooking in Ouagadougou, Burkina Faso: Cross-Sectional Study

Background: Approximately 3 billion people, worldwide, rely primarily on biomass for cooking. This study aimed to investigate the association between respiratory symptoms among women in charge of household cooking and the type of fuel used for cooking. Methods: A community-based cross-sectional survey was conducted. A total of 1705 women that were randomly selected, completed the survey. We also performed a bivariate and a multivariate analysis to verify the possible associations between respiratory symptoms in women in charge of household cooking and the type of cooking fuel used. Results: Dry cough, breathing difficulties, and throat irritation frequencies were statistically high in biomass fuel users when compared to liquefied petroleum gas (LPG) users. It was also the case for some chronic respiratory symptoms, such as sputum production, shortness of breath, wheezing, wheezing with dyspnea, wheezing without a cold, waking up with shortness of breath, waking up with coughing attacks, and waking up with breathing difficulty. After adjustment for the respondents’ and households’ characteristics; dry cough, breathing difficulties, sneezing, nose tingling, throat irritation, chronic sputum production, wheezing, wheezing with dyspnea, wheezing without a cold, waking up with shortness of breath, waking up with coughing attacks, and waking up with breathing difficulty were symptoms that remained associated to biomass fuel compared to LPG. Women who used charcoal reported the highest proportion of all the chronic respiratory symptoms compared to the firewood users. However, this difference was not statistically significant except for the wheezing, waking up with coughing attacks, and waking up with breath difficulty, after adjustment. Conclusion: Exposure to biomass smoke is responsible for respiratory health problems in women. Charcoal, which is often considered as a clean fuel compared to other biomass fuels and often recommended as an alternative to firewood, also presents health risks, including increased respiratory morbidity in women. Effective and efficient energy policies are needed to accelerate the transition to clean and sustainable energies.

Acute respiratory infection related to air pollution in Bamenda, North West Region of Cameroon

Introduction

Air pollution is a global health problem. It's responsible for over 4 million deaths each year and constitutes a risk factor for acute respiratory infections (ARI). The aims of this study was to assess knowledge about air pollution, and to determine environmental risk factors associated with ARIs occurence in the city of Bamenda, Cameroon.

Methods

We conducted a cross sectional study and performed a rectrospective analysis of ARI consultation within the period March 2016 to July 2016 in the Bamenda Health District. We interviewd 201 patients and recorded 1849 cases from hospital registers of patients diagnosed ARI from January 2013 to April 2016. Epi-info 7.2 was used for data entry and analysis. Logistic regression analysis was conducted to determine the importance of the different environmental risk factors.

Results

Over 70% of the participants used at least a form of solid fuel for cooking. The Odds of developing an ARI was 3.62 greater among those exposed to indoor cooking compared to the unexposed (OR 3.62, CI 1.45-4.90). Participants exposed to open fire burning were 1.91 times more like to develop ARI compared to unexposed (OR: 1.91, CI 1.03-3.55: p : 0.03). Particulate Matter (PM 2.5) levels was 13.2 times higher than the World Health Organization (WHO) recommended levels. Dry and dusty weathers increased the risk of ARIs (OR 3.24; CI 1.47-7.13). The prevalence of ARIs in the Bamenda Health District was 6% of all consultations.

Conclusion

Using solid fuels in poorly ventilated homes increase the total air particle suspension indoor. Inhalling this poor air irritates the repiratory tract, eyes while longterm exposure increases the odds of cancers. Ventilating homes with indoor cooking space reduces exposure while using clean fuels like electricity reduces the odds of ARI associated with pollution.

Understanding the effect of indoor air pollution on pneumonia in children under 5 in low- and middle-income countries: a systematic review of evidence

Exposure to indoor air pollution increases the risk of pneumonia in children, accounting for about a million deaths globally. This study investigates the individual effect of solid fuel, carbon monoxide (CO), black carbon (BC) and particulate matter (PM)2.5 on pneumonia in children under 5 in low- and middle-income countries. A systematic review was conducted to identify peer-reviewed and grey full-text documents without restrictions to study design, language or year of publication using nine databases (Embase, PubMed, EBSCO/CINAHL, Scopus, Web of Knowledge, WHO Library Database (WHOLIS), Integrated Regional Information Networks (IRIN), the World Meteorological Organization (WMO)-WHO and Intergovernmental Panel on Climate Change (IPCC). Exposure to solid fuel use showed a significant association to childhood pneumonia. Exposure to CO showed no association to childhood pneumonia. PM2.5 did not show any association when physically measured, whilst eight studies that used solid fuel as a proxy for PM2.5 all reported significant associations. This review highlights the need to standardise measurement of exposure and outcome variables when investigating the effect of air pollution on pneumonia in children under 5. Future studies should account for BC, PM1 and the interaction between indoor and outdoor pollution and its cumulative impact on childhood pneumonia.

Kitchen PM2.5 concentrations and child acute lower respiratory infection in Bhaktapur, Nepal: The importance of fuel type

BACKGROUND

Globally, solid fuels are used by about 3 billion people for cooking and a smaller number use kerosene. These fuels have been associated with acute lower respiratory infection (ALRI) in children. Previous work in Bhaktapur, Nepal, showed comparable relationships of biomass and kerosene cooking fuels with ALRI in young children, compared to those using electricity for cooking. We examine the relationship of kitchen PM_2.5 concentrations to ALRI in those households.

METHODS

ALRI cases and age-matched controls were enrolled from a cohort of children 2-35 months old. 24-h PM_2.5 was measured once in each participant's kitchen. The main analysis was carried out with conditional logistic regression, with PM_2.5 measures specified both continuously and as quartiles.

RESULTS

In the kitchens of 393 cases and 431 controls, quartiles of increasing PM_2.5 concentration were associated with a monotonic increase in odds ratios (OR): 1.51 (95% CI: 1.00, 2.27), 2.22 (1.47, 3.34), 2.48 (1.63, 3.77), for the 3 highest exposure quartiles. The general kitchen concentration-response shape across all stoves was supralinear. There was evidence for increased risk with biomass stoves, but the slope for kerosene stoves was steeper, the highest quartile OR being 5.36 (1.35, 21.3). Evidence for increased risk was also found for gas stoves.

CONCLUSION

Results support previous reports that biomass and kerosene cooking fuels are both ALRI risk factors, but suggests that PM_2.5 from kerosene is more potent on a unit mass basis. Further studies with larger sample sizes and preferably using electricity as the baseline fuel are needed.

Firewood, smoke and respiratory diseases in developing countries-The neglected role of outdoor cooking

Smoke from cooking in the kitchen is one of the world’s leading causes of premature child death, claiming the lives of 500,000 children under five annually. This study analyses the role of outdoor cooking and the prevalence of respiratory diseases among children under five years by means of probit regressions using information from 41 surveys conducted in 30 developing countries from Asia, Africa and Latin America. I find that outdoor cooking reduces respiratory diseases among young children aged 0-4 by around 9 percent, an effect that reaches 13 percent among children aged 0-1. The results suggest that simple behavioral interventions, such as promoting outdoor cooking, can have a substantial impact on health hazards.

Maternal biomass smoke exposure and birth weight in Malawi: Analysis of data from the 2010 Malawi Demographic and Health Survey

BACKGROUND

Use of biomass fuels has been shown to contribute to ill health and complications in pregnancy outcomes such as low birthweight, neonatal deaths and mortality in developing countries. However, there is insufficient evidence of this association in the Sub-Saharan Africa and the Malawian population. We, therefore, investigated effects of exposure to biomass fuels on reduced birth weight in the Malawian population.

METHODS

We conducted a cross-sectional analysis using secondary data from the 2010 Malawi Demographic Health Survey with a total of 9124 respondents. Information on exposure to biomass fuels, birthweight, and size of child at birth as well as other relevant information on risk factors was obtained through a questionnaire. We used linear regression models for continuous birth weight outcome and logistic regression for the binary outcome. Models were systematically adjusted for relevant confounding factors.

RESULTS

Use of high pollution fuels resulted in a 92 g (95% CI: -320.4; 136.4) reduction in mean birth weight compared to low pollution fuel use after adjustment for child, maternal as well as household characteristics. Full adjusted OR (95% CI) for risk of having size below average at birth was 1.29 (0.34; 4.48). Gender and birth order of child were the significant confounders factors in our adjusted models.

CONCLUSIONS

We observed reduced birth weight in children whose mothers used high pollution fuels suggesting a negative effect of maternal exposure to biomass fuels on birth weight of the child. However, this reduction was not statistically significant. More carefully designed studies need to be carried out to explore effects of biomass fuels on pregnancy outcomes and health outcomes in general.