Indoor air pollution: a poverty-related cause of mortality among the children of the world

Application of an Ultra-Low-Cost Passive Sampler for Light-Absorbing Carbon in Mongolia

Low-cost, long-term measures of air pollution concentrations are often needed for epidemiological studies and policy analyses of household air pollution. The Washington passive sampler (WPS), an ultra-low-cost method for measuring the long-term average levels of light-absorbing carbon (LAC) air pollution, uses digital images to measure the changes in the reflectance of a passively exposed paper filter. A prior publication on WPS reported high precision and reproducibility. Here, we deployed three methods to each of 10 households in Ulaanbaatar, Mongolia: one PurpleAir for PM2.5; two ultrasonic personal aerosol samplers (UPAS) with quartz filters for the thermal-optical analysis of elemental carbon (EC); and two WPS for LAC. We compared multiple rounds of 4-week-average measurements. The analyses calibrating the LAC to the elemental carbon measurement suggest that 1 µg of EC/m3 corresponds to 62 PI/month (R2 = 0.83). The EC-LAC calibration curve indicates an accuracy (root-mean-square error) of 3.1 µg of EC/m3, or ~21% of the average elemental carbon concentration. The RMSE values observed here for the WPS are comparable to the reported accuracy levels for other methods, including reference methods. Based on the precision and accuracy results shown here, as well as the increased simplicity of deployment, the WPS may merit further consideration for studying air quality in homes that use solid fuels.

Indoor air pollutants and respiratory symptoms among residents of an informal urban settlement in Uganda: A cross-sectional study

BACKGROUND

Indoor air pollutants (IAP) and household conditions such as dampness, crowding and chemical exposures have been associated with acute and chronic respiratory infections. In Uganda, literature on the effects of IAP on respiratory outcomes in informal settlements is limited.

METHODS

We describe the baseline household characteristics of 284 adults and their children in an informal settlement in Uganda from April to May 2022. We monitored same-day indoor concentrations of particulate matter PM2.5, PM10, Carbon monoxide (CO), relative humidity %, and temperature from 9 am to 2 pm and interviewed caregivers/mothers about their respiratory symptoms and those of their children in the previous 30 days. We employed robust Poisson regressions to evaluate the associations between indoor air indicators and respiratory health symptoms.

RESULTS

Approximately 94.7% of households primarily used biomass fuels and 32.7% cooked from inside their dwelling rooms. The median PM2.5, PM10 and CO levels were 49.5 (Interquartile range (IQR) = 31.1,86.2) μg/m3, 73.6 (IQR = 47.3,130.5) μg/m3 and 7.70 (IQR = 4.1,12.5) ppm respectively. Among adults, a 10 unit increase in PM2.5 was associated with cough (Prevalence Ratio (PR) = 3.75, 95%CI 1.15-1.55). Dwelling unit dampness was associated with phlegm (PR = 2.53, 95%CI = 1.39-4.61) and shortness of breath (PR = 1.78, 95% CI 1.23-2.54) while cooking from outside the house was protective against shortness of breath (PR = 0.62, 95% CI = 0.44-0.87). In children, dampness was associated with phlegm (PR = 13.87, 95% CI 3.16-60.91) and cough (PR = 1.62, 95% CI 1.12-2.34) while indoor residual spraying was associated with phlegm (PR = 3.36, 95%CI 1.71-6.61).

CONCLUSION

Poor indoor air conditions were associated with respiratory symptoms in adults and children. Efforts to address indoor air pollution should be made to protect adults and children from adverse health effects.

Poluição do ar

Introdução: As mortes atribuíveis à poluição do ar em longo prazo chegam a 9 milhões ao ano, concentrando-se principalmente em países de baixa e média renda como o Brasil. Classifica-se a poluição do ar em: domiciliar (indoor) ou ambiente (outdoor). A inalação de poluentes está relacionada com o aumento da incidência e desenvolvimento de condições clínicas, como doenças cardiovasculares, respiratórias e outras, que fazem parte da prática da medicina de família e comunidade. Objetivo: Verificar as evidências clínicas para a abordagem da poluição do ar relacionada à saúde humana no contexto da prática na Atenção Primária à Saúde. Métodos: Revisão de escopo do papel clínico da medicina de família e comunidade em relação à poluição do ar e saúde, voltada para questões clínicas associadas com a poluição do ar. Incluíram-se 35 artigos nesta revisão. Recomendações clínicas: Em nível individual, destacam-se a redução do uso de fogões a lenha, o uso de estratégias de proteção de fontes poluidoras (como queimadas, vias de trânsito e indústria), a filtragem do ar, o estímulo ao transporte ativo, a cessação do tabagismo. Essas recomendações devem ser complementares às políticas governamentais relacionadas à poluição do ar. Propõem-se perguntas para a entrevista clínica. Exploram-se recomendações específicas sobre uso de máscaras, atividade física e COVID-19. Sugerem-se temas de pesquisa que podem ser realizadas na Atenção Primária à Saúde e o papel da medicina de família e comunidade nesse contexto. Considerações: A inclusão na classificação internacional de atenção primária e no Código internacional de Doenças poderia melhorar a notificação e os estudos epidemiológicos sobre o assunto.

Ambient air pollution and non-communicable respiratory illness in sub-Saharan Africa: a systematic review of the literature

INTRODUCTION

Aerosol pollutants are known to raise the risk of development of non-communicable respiratory diseases (NCRDs) such as asthma, chronic bronchitis, chronic obstructive pulmonary disease, and allergic rhinitis. Sub-Saharan Africa's rapid pace of urbanization, economic expansion, and population growth raise concerns of increasing incidence of NCRDs. This research characterizes the state of research on pollution and NCRDs in the 46 countries of Sub-Saharan Africa (SSA). This research systematically reviewed the literature on studies of asthma; chronic bronchitis; allergic rhinitis; and air pollutants such as particulate matter, ozone, NOx, and sulfuric oxide.

METHODS

We searched three major databases (PubMed, Web of Science, and Scopus) using the key words "asthma", "chronic bronchitis", "allergic rhinitis", and "COPD" with "carbon monoxide (CO)", "sulfuric oxide (SO)", "ozone (O3)", "nitrogen dioxide (NO2)", and "particulate matter (PM)", restricting the search to the 46 countries that comprise SSA. Only papers published in scholarly journals with a defined health outcome in individuals and which tested associations with explicitly measured or modelled air exposures were considered for inclusion. All candidate papers were entered into a database for review.

RESULTS

We found a total of 362 unique research papers in the initial search of the three databases. Among these, 14 met the inclusion criteria. These papers comprised studies from just five countries. Nine papers were from South Africa; two from Malawi; and one each from Ghana, Namibia, and Nigeria. Most studies were cross-sectional. Exposures to ambient air pollutants were measured using spectrometry and chromatography. Some studies created composite measures of air pollution using a range of data layers. NCRD outcomes were measured by self-reported health status and measures of lung function (spirometry). Populations of interest were primarily schoolchildren, though a few studies focused on secondary school students and adults.

CONCLUSIONS

The paucity of research on NCRDs and ambient air pollutant exposures is pronounced within the African continent. While capacity to measure air quality in SSA is high, studies targeting NCRDs should work to draw attention to questions of outdoor air pollution and health. As the climate changes and SSA economies expand and countries urbanize, these questions will become increasingly important.

Long-Term PM2.5 Exposure Is Associated with Symptoms of Acute Respiratory Infections among Children under Five Years of Age in Kenya, 2014

Introduction: Short-term exposures to air pollutants such as particulate matter (PM) have been associated with increased risk for symptoms of acute respiratory infections (ARIs). Less well understood is how long-term exposures to fine PM (PM2.5) might increase risk of ARIs and their symptoms. This research uses georeferenced Demographic Health Survey (DHS) data from Kenya (2014) along with a remote sensing based raster of PM2.5 concentrations to test associations between PM2.5 exposure and ARI symptoms in children for up to 12 monthly lags. Methods: Predicted PM2.5 concentrations were extracted from raster of monthly averages for latitude/longitude locations of survey clusters. These data and other environmental and demographic data were used in a logistic regression model of ARI symptoms within a distributed lag nonlinear modeling framework (DLNM) to test lag associations of PM2.5 exposure with binary presence/absence of ARI symptoms in the previous two weeks. Results: Out of 7036 children under five for whom data were available, 46.8% reported ARI symptoms in the previous two weeks. Exposure to PM2.5 within the same month and as an average for the previous 12 months was 18.31 and 22.1 µg/m3, respectively, far in excess of guidelines set by the World Health Organization. One-year average PM2.5 exposure was higher for children who experienced ARI symptoms compared with children who did not (22.4 vs. 21.8 µg/m3, p < 0.0001.) Logistic regression models using the DLNM framework indicated that while PM exposure was not significantly associated with ARI symptoms for early lags, exposure to high concentrations of PM2.5 (90th percentile) was associated with elevated odds for ARI symptoms along a gradient of lag exposure time even when controlling for age, sex, types of cooking fuels, and precipitation. Conclusions: Long-term exposure to high concentrations of PM2.5 may increase risk for acute respiratory problems in small children. However, more work should be carried out to increase capacity to accurately measure air pollutants in emerging economies such as Kenya.

Health service underutilization and its associated factors for chronic diseases patients in poverty-stricken areas in China: a multilevel analysis

Background

Underutilization of health services among chronic non-communicable disease sufferers, especially for hypertension (HBP) and diabetes mellitus (DM), was considered as a significant contributing factor to substantial cases in terms of both avoidable morbidity and mortality. However, evidence on health services underutilization and its associated factors in poverty-stricken areas remain scarce based on previous literature. This study aims to describe health services underutilization for people diagnosed with chronic diseases in impoverished regions and to identify its associated factors, which are expected to provide practical implications for the implementations of interventions tailored to the specific needs of disadvantaged residents in rural China to achieve effective utilization of health services in a timely manner.

Methods

Data were collected from a cross-sectional survey conducted through face-to-face interviews among 2413 patients from six counties in rural central China in 2019. The Anderson behavioral model was adopted to explore the associated factors. A two-level logistic model was employed to investigate the association strengths reflected by adjusted odds ratios (AOR) and 95% confidence intervals in forest plots.

Results

On average, 17.58% of the respondents with HBP and 14.87% with DM had experienced health services underutilization during 1 month before the survey. Multilevel logistic regression indicated that predisposing factors (age), enabling factors (income and a regular source of care), and need factors (self-reported health score) were the common predictors of health service underutilization both for hypertensive and diabetic patients in impoverished areas, among which obtaining a regular source of care was found to be relatively determinant as a protective factor for health services underutilization after controlling for other covariates.

Conclusions

Our results suggested that the implementation of a series of comprehensive strategies should be addressed throughout policy-making procedures to improve the provision of regular source of care as a significant determinant for reducing health services underutilization, thus ultimately achieving equal utilization of health services in impoverished regions, especially among chronic disease patients. Our findings are expected to provide practical implications for other developing countries confronted with similar challenges resulting from underdeveloped healthcare systems and aging population structures.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12913-021-06725-5.

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.

Risk factors of acute respiratory infections among under five children attending public hospitals in southern Tigray, Ethiopia, 2016/2017

Background

Acute Respiratory infection accounts for 94,037000 disability adjusted life years and 1.9 million deaths worldwide. Acute respiratory infections is the most common causes of under-five illness and mortality. The under five children gets three to six episodes of acute respiratory infections annually regardless of where they live. Disease burden due to acute respiratory infection is 10–50 times higher in developing countries when compared to developed countries. The aim of this study was to assess risk factors of acute respiratory infection among under-five children attending Public hospitals in Southern Tigray, Ethiopia 2016/2017.

Methods

Institution based case control study was conducted from Nov 2016 to June 2017. Interviewer administered structured questionnaire was used to collect data from a sample of 288 (96 cases and 192 controls) children under 5 years of age. Systematic random sampling was used to recruit study subjects and SPSS version 20 was used to analyze the data. Bivariate and multivariate analysis were employed to examine statistical association between the outcome variable and selected independent variables at 95% confidence level. Level of statistical Significance was declared at p < 0.05. Tables, figures and texts were used to present data.

Result

One hundred sixty (55.6%) and 128 (44.4%) of the participants were males and females respectively. Malnutrition (AOR = 2.89; 95%CI: 1.584–8.951; p = 0.039), cow dung use (AOR =2.21; 95%CI: 1.121–9.373; p = 0.014), presence of smoker in the family (AOR = 0.638; 95% CI: 0.046–0.980; p = 0.042) and maternal literacy (AOR = 3.098; 95%CI: 1.387–18.729; p = 0.021) were found to be significant predictors of acute respiratory infection among under five children.

Conclusion

According to this study maternal literacy, smoking, cow dung use and nutritional status were strongly associated with increased risk of childhood acute respiratory infection. Health care providers should work jointly with the general public, so that scientific knowledge and guidelines for adopting particular preventive measures for acute respiratory infection are disseminated.

Air pollution dispersion from biomass stoves to neighboring homes in Mirpur, Dhaka, Bangladesh

BACKGROUND

Indoor air pollution, including fine particulate matter (PM2.5) and carbon monoxide (CO), is a major risk factor for pneumonia and other respiratory diseases. Biomass-burning cookstoves are major contributors to PM2.5 and CO concentrations. However, high concentrations of PM2.5 (> 1000 μg/m3) have been observed in homes in Dhaka, Bangladesh that do not burn biomass. We described dispersion of PM2.5 and CO from biomass burning into nearby homes in a low-income urban area of Dhaka, Bangladesh.

METHODS

We recruited 10 clusters of homes, each with one biomass-burning (index) home, and 3-4 neighboring homes that used cleaner fuels with no other major sources of PM2.5 or CO. We administered a questionnaire and recorded physical features of all homes. Over 24 h, we recorded PM2.5 and CO concentrations inside each home, near each stove, and outside one neighbor home per cluster. During 8 of these 24 h, we conducted observations for pollutant-generating activities such as cooking. For each monitor, we calculated geometric mean PM2.5 concentrations at 5-6 am (baseline), during biomass burning times, during non-cooking times, and over 24 h. We used linear regressions to describe associations between monitor location and PM2.5 and CO concentrations.

RESULTS

We recruited a total of 44 homes across the 10 clusters. Geometric mean PM2.5 and CO concentrations for all monitors were lowest at baseline and highest during biomass burning. During biomass burning, linear regression showed a decreasing trend of geometric mean PM2.5 and CO concentrations from the biomass stove (326.3 μg/m3, 12.3 ppm), to index home (322.7 μg/m3, 11.2 ppm), neighbor homes sharing a wall with the index home (278.4 μg/m3, 3.6 ppm), outdoors (154.2 μg/m3, 0.7 ppm), then neighbor homes that do not share a wall with the index home (83.1 μg/m3,0.2 ppm) (p = 0.03 for PM2.5, p = 0.006 for CO).

CONCLUSION

Biomass burning in one home can be a source of indoor air pollution for several homes. The impact of biomass burning on PM2.5 or CO is greatest in homes that share a wall with the biomass-burning home. Eliminating biomass burning in one home may improve air quality for several households in a community.

Pregnancy outcomes and ethanol cook stove intervention: A randomized-controlled trial in Ibadan, Nigeria

BACKGROUND

Household air pollution (HAP) exposure has been linked to adverse pregnancy outcomes.

OBJECTIVES

A randomized controlled trial was undertaken in Ibadan, Nigeria to determine the impact of cooking with ethanol on pregnancy outcomes.

METHODS

Three-hundred-twenty-four pregnant women were randomized to either the control (continued cooking using kerosene/firewood stove, n=162) or intervention group (received ethanol stove, n=162). Primary outcome variables were birthweight, preterm delivery, intrauterine growth restriction (IUGR), and occurrence of miscarriage/stillbirth.

RESULTS

Mean birthweights for ethanol and controls were 3076 and 2988g, respectively; the difference, 88g, (95% confidence interval: -18g to 194g), was not statistically significant (p=0.10). After adjusting for covariates, the difference reached significance (p=0.020). Rates of preterm delivery were 6.7% (ethanol) and 11.0% (control), (p=0.22). Number of miscarriages was 1(ethanol) vs. 4 (control) and stillbirths was 3 (ethanol) vs. 7 (control) (both non-significant). Average gestational age at delivery was significantly (p=0.015) higher in ethanol-users (39.2weeks) compared to controls (38.2weeks). Perinatal mortality (stillbirths and neonatal deaths) was twice as high in controls compared to ethanol-users (7.9% vs. 3.9%; p=0.045, after adjustment for covariates). We did not detect significant differences in exposure levels between the two treatment arms, perhaps due to large seasonal effects and high ambient air pollution levels.

CONCLUSIONS

Transition from traditional biomass/kerosene fuel to ethanol reduced adverse pregnancy outcomes. However, the difference in birthweight was statistically significant only after covariate adjustment and the other significant differences were in tertiary endpoints. Our results are suggestive of a beneficial effect of ethanol use. Larger trials are required to validate these findings.

Pilot Intervention Study of Household Ventilation and Fine Particulate Matter Concentrations in a Low-Income Urban Area, Dhaka, Bangladesh

Fine particulate matter (PM_2.5) is a risk factor for pneumonia; ventilation may be protective. We tested behavioral and structural ventilation interventions on indoor PM_2.5 in Dhaka, Bangladesh. We recruited 59 good ventilation (window or door in ≥ 3 walls) and 29 poor ventilation (no window, one door) homes. We monitored baseline indoor and outdoor PM_2.5 for 48 hours. We asked all participants to increase ventilation behavior, including opening windows and doors, and operating fans. Where permitted, we installed windows in nine poor ventilation homes, then repeated PM_2.5 monitoring. We estimated effects using linear mixed-effects models and conducted qualitative interviews regarding motivators and barriers to ventilation. Compared with poor ventilation homes, good ventilation homes were larger, their residents wealthier and less likely to use biomass fuel. In multivariable linear mixed-effects models, ventilation structures and opening a door or window were inversely associated with the number of hours PM_2.5 concentrations exceeded 100 and 250 μg/m³. Outdoor air pollution was positively associated with the number of hours PM_2.5 concentrations exceeded 100 and 250 μg/m³. Few homes accepted window installation, due to landlord refusal and fear of theft. Motivators for ventilation behavior included cooling of the home and sunlight; barriers included rain, outdoor odors or noise, theft risk, mosquito entry, and, for fan use, perceptions of wasting electricity or unavailability of electricity. We concluded that ventilation may reduce indoor PM_2.5 concentrations but, there are barriers to increasing ventilation and, in areas with high ambient PM_2.5 concentrations, indoor concentrations may remain above recommended levels.

Household-level risk factors for secondary influenza-like illness in a rural area of Bangladesh

Objective

To describe household‐level risk factors for secondary influenza‐like illness (ILI), an important public health concern in the low‐income population of Bangladesh.

Methods

Secondary analysis of control participants in a randomised controlled trial evaluating the effect of handwashing to prevent household ILI transmission. We recruited index‐case patients with ILI – fever (<5 years); fever, cough or sore throat (≥5 years) – from health facilities, collected information on household factors and conducted syndromic surveillance among household contacts for 10 days after resolution of index‐case patients’ symptoms. We evaluated the associations between household factors at baseline and secondary ILI among household contacts using negative binomial regression, accounting for clustering by household.

Results

Our sample was 1491 household contacts of 184 index‐case patients. Seventy‐one percentage reported that smoking occurred in their home, 27% shared a latrine with one other household and 36% shared a latrine with >1 other household. A total of 114 household contacts (7.6%) had symptoms of ILI during follow‐up. Smoking in the home (RR_adj 1.9, 95% CI: 1.2, 3.0) and sharing a latrine with one household (RR_adj 2.1, 95% CI: 1.2, 3.6) or >1 household (RR_adj 3.1, 95% CI: 1.8–5.2) were independently associated with increased risk of secondary ILI.

Conclusion

Tobacco use in homes could increase respiratory illness in Bangladesh. The mechanism between use of shared latrines and household ILI transmission is not clear. It is possible that respiratory pathogens could be transmitted through faecal contact or contaminated fomites in shared latrines.

Antibiotics for preventing suppurative complications from undifferentiated acute respiratory infections in children under five years of age

BACKGROUND

Undifferentiated acute respiratory infections (ARIs) are a large and heterogeneous group of infections not clearly restricted to one specific part of the upper respiratory tract, which last for up to seven days. They are more common in pre-school children in low-income countries and are responsible for 75% of the total amount of prescribed antibiotics in high-income countries. One possible rationale for prescribing antibiotics is the wish to prevent bacterial complications.

OBJECTIVES

To assess the effectiveness and safety of antibiotics in preventing bacterial complications in children aged two months to 59 months with undifferentiated ARIs.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL 2015, Issue 7), which contains the Cochrane Acute Respiratory Infections Group's Specialised Register, MEDLINE (1950 to August week 1, 2015) and EMBASE (1974 to August 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or quasi-RCTs comparing antibiotic prescriptions with placebo or no treatment in children aged two months to 59 months with an undifferentiated ARI for up to seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted and analysed data using the standard Cochrane methodological procedures.

MAIN RESULTS

We identified four trials involving 1314 children. Three trials investigated the use of amoxicillin/clavulanic acid to prevent otitis and one investigated ampicillin to prevent pneumonia.The use of amoxicillin/clavulanic acid compared to placebo to prevent otitis showed a risk ratio (RR) of 0.70 (95% confidence interval (CI) 0.45 to 1.11, three trials, 414 selected children, moderate-quality evidence). Methods of random sequence generation and allocation concealment were not clearly stated in two trials. Performance, detection and reporting bias could not be ruled out in three trials.Ampicillin compared to supportive care (continuation of breastfeeding, clearing of the nose and paracetamol for fever control) to prevent pneumonia showed a RR of 1.05 (95% CI 0.74 to 1.49, one trial, 889 selected children, moderate-quality evidence). The trial was non-blinded. Random sequence generation and allocation concealment methods were not clearly stated, so the possibility of reporting bias could not be ruled out.Harm outcomes could not be analysed as they were expressed only in percentages.We found no studies assessing mastoiditis, quinsy, abscess, meningitis, hospital admission or death.

AUTHORS' CONCLUSIONS

There is insufficient evidence for antibiotic use as a means of reducing the risk of otitis or pneumonia in children up to five years of age with undifferentiated ARIs. Further high-quality research is needed to provide more definitive evidence of the effectiveness of antibiotics in this population.

Impact of biogas digesters on cookhouse volatile organic compound exposure for rural Kenyan farmwomen

Women living on rural Kenyan smallholder dairy farms burn wood as biofuel in family cookhouses. Unventilated biofuel combustion produces harmful levels of respirable particles and volatile organic compound (VOC) emissions in indoor environments. Biogas digesters, which can generate high methane-content biogas from livestock manure composting were recently installed on 31 farms. The study objectives were to compare VOC exposure profiles for women cooking on farms with and without biogas digesters, and to compare seasonal variations in VOC exposures for those women cooking with biogas. Participants (n=31 biogas farms, n=31 referent farms) wore passive thermal desorption VOC sampling tubes and recorded cookhouse fuel use on time activity sheets for 7 days. Women using biogas spent significantly less time (mean=509 min/week) exposed to cookhouse wood smoke compared with the referent group (mean=1122 min/week) (P<0.01). Total VOC exposure did not differ between farm groups (P=0.14), though concentrations of trans-1,3-dichloropropene, bromoform, and 1,4-dichlorobenzene in biogas cookhouses were significantly lower than in referent cookhouses, even after Bonferroni correction. The composition of VOC species was also significantly different, reflecting the different fuel sources. Biogas digester technologies have great potential for reducing exposure to wood smoke VOCs in low-income countries.

Lung disease in a global context. A call for public health action

As described in a recently released report of the Forum of International Respiratory Societies, four of the leading causes of death in the world are chronic obstructive pulmonary disease, acute respiratory tract infections, lung cancer, and tuberculosis. A fifth, asthma, causes enormous global morbidity. Not enough progress has been made in introducing new therapies and reducing disease burden for these illnesses in the last few decades, despite generous investments and some notable progress in biomedical research. Four external and modifiable drivers are responsible for a substantial percentage of the disease burden represented by the major lung diseases: tobacco, outdoor air pollution, household air pollution, and occupational exposures to lung toxins. Especially in low- and middle-income countries, but in highly developed economies as well, pressures for economic development and lax regulation are contributing to the continued proliferation of these drivers. Public health approaches to the most common lung diseases could have enormous effects on reducing morbidity and mortality. There must be increased advocacy from and mobilization of civil society to bring attention to the drivers of lung diseases in the world. The World Health Organization should negotiate accords similar to the Framework Convention on Tobacco Control to address air pollution and occupational exposures. Large increases in funding by government agencies and nongovernmental organizations around the world are needed to identify technologies that will reduce health risks while allowing populations to enjoy the benefits of economic development. This paradigm, focused more on public health than on individual medical treatment, has the best chance of substantial reduction in the burden of lung disease around the world in the next several years.

Asthma and asthma related symptoms in 23,326 Chinese children in relation to indoor and outdoor environmental factors: the Seven Northeastern Cities (SNEC) Study

BACKGROUND

Both the levels and patterns of outdoor and indoor air pollutants have changed dramatically during the last decade in China. However, few studies have evaluated the effects of the present air pollution on the health of Chinese children. This study examines the association between outdoor and indoor air pollution and respiratory diseases among children living in Liaoning, a heavy industrial province of China.

METHODS

A cross-sectional study of 23,326 Chinese children aged 6 to 13 years was conducted in 25 districts of 7 cities in Northeast China during 2009. Three-year (2006-2008) average concentrations of particles with an aerodynamic diameter of ≤10 μm (PM10), sulfur dioxide (SO2), nitrogen dioxides (NO2), and ozone (O3) were calculated from monitoring stations in each of the 25 districts. We used two-level logistic regression models to examine the effects of yearly variations in exposure to each pollutant, controlling for important covariates.

RESULTS

The prevalence of respiratory symptoms was higher for those dwelling close to a busy road, those living near smokestacks or factories, those living with smokers, those living in one-story houses typically with small yards, and those with home renovation, bedroom carpet or pets. Ventilation device use was associated with decreased odds of asthma in children. The adjusted odds ratio for diagnosed-asthma was 1.34 (95% confidence interval [CI], 1.24-1.45) per 31 μg/m(3) increase in PM10, 1.23 (95%CI, 1.14-1.32) per 21 μg/m(3) increase in SO2, 1.25 (95%CI, 1.16-1.36) per 10 μg/m(3) increase in NO2, and 1.31 (95%CI, 1.21-1.41) per 23 μg/m(3) increase in O3, respectively.

CONCLUSION

Outdoor and indoor air pollution was associated with an increased likelihood of respiratory morbidity among Chinese children.

Household air quality risk factors associated with childhood pneumonia in urban Dhaka, Bangladesh

To inform interventions to reduce the high burden of pneumonia in urban settings such as Kamalapur, Bangladesh, we evaluated household air quality risk factors for radiographically confirmed pneumonia in children. In 2009-2010, we recruited children < 5 years of age with pneumonia and controls from a population-based surveillance for respiratory and febrile illnesses. Piped natural gas was used by 85% of 331 case and 91% of 663 control households. Crowding, a tin roof in the living space, low socioeconomic status, and male sex of the child were risk factors for pneumonia. The living space in case households was 28% less likely than in control households to be cross-ventilated. Particulate matter concentrations were not significantly associated with pneumonia. With increasing urbanization and supply of improved cooking fuels to urban areas, the high burden of respiratory illnesses in urban populations such as Kamalapur may be reduced by decreasing crowding and improving ventilation in living spaces.

Antibiotics for preventing suppurative complications from undifferentiated acute respiratory infections in children under five years of age

BACKGROUND

Undifferentiated acute respiratory infections (ARIs) are a large and heterogeneous group of infections not clearly restricted to one specific part of the upper respiratory tract, which last for up to seven days. They are more common in pre-school children in low-income countries and are responsible for 75% of the total amount of prescribed antibiotics in high-income countries. One possible rationale for prescribing antibiotics is the wish to prevent bacterial complications.

OBJECTIVES

To assess the effectiveness and safety of antibiotics in preventing complications in children aged two to 59 months with undifferentiated ARIs.

SEARCH METHODS

We searched CENTRAL 2013, Issue 4, MEDLINE (1950 to May week 2, 2013) and EMBASE (1974 to May 2013).

SELECTION CRITERIA

Randomised controlled trials (RCT) or quasi-RCTs comparing antibiotic prescriptions with placebo or non-treatment in children up to 59 months with an undifferentiated ARI for up to seven days.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted and analysed data using the standard Cochrane methodological procedures.

MAIN RESULTS

We identified four trials involving 1314 children. Three trials investigated the use of amoxicillin/clavulanic acid to prevent otitis and one investigated ampicillin to prevent pneumonia.The use of amoxicillin/clavulanic acid compared to placebo to prevent otitis showed a risk ratio (RR) of 0.70 (95% confidence interval (CI) 0.45 to 1.11, three trials, 414 selected children, moderate-quality evidence). Methods of random sequence generation and allocation concealment were not clearly stated in two trials. Performance, detection and reporting bias could not be ruled out in three trials.Ampicillin compared to supportive care (continuation of breastfeeding, clearing of the nose and paracetamol for fever control) to prevent pneumonia showed a RR of 1.05 (95% CI 0.74 to 1.49, one trial, 889 selected children, moderate-quality evidence). The trial was non-blinded. Random sequence generation and allocation concealment methods were not clearly stated so the possibility of reporting bias could not be ruled out.Harm outcomes could not be analysed as they were expressed only in percentages.No studies were found assessing mastoiditis, quinsy, abscess, meningitis, hospital admission or death.

AUTHORS' CONCLUSIONS

The quality of evidence currently available does not provide strong support for antibiotic use as a means of reducing the risk of otitis or pneumonia in children up to five years of age with undifferentiated ARIs. Further high-quality research is needed to provide more definitive evidence of the effectiveness of antibiotics in this population.

Perception and Barriers to Indoor Air Quality and Perceived Impact on Respiratory Health: An Assessment in Rural Honduras

Objective. The aim of this study was to identify household-specific factors associated with respiratory symptoms and to study the perceived impact of indoor air pollution (IAP) as a health issue.Methods. An IRB-approved, voluntary, anonymous 23-item survey was conducted in Spanish at a medical outreach clinic in June 2012 and at the homes of survey respondentsN=79. Comparative analyses were performed to investigate relationships between specific house characteristics and respiratory complaints.Results. Seventy-nine surveys were completed. Respiratory symptoms were frequently reported by survey respondents: 42% stated that smoke in their household caused them to have watery eyes, 42% reported household members with coughs within the past two weeks, and 25% stated that there were currently household members experiencing difficulty in breathing. Stove location and kitchen roof construction material were significantly associated with frequency of respiratory symptoms. The vast majority used firewood as their major fuel type. Most respondents indicated that neither indoor air quality was a problem nor did it affect their daily life.Conclusions. Respiratory complaints are common in Yoro, Honduras. Stove location and kitchen roof construction material were significantly associated with frequency of respiratory symptoms; this may have implications for efforts to improve respiratory health in the region.

Biomass fuel use and the risk of asthma in Nigerian children

BACKGROUND

Biomass fuel smoke exposure contributes to respiratory infections in childhood, but its association with asthma has not been established. We studied the relationship of biomass fuel use with asthma symptoms and lung function in Nigerian children.

METHODS

A cross-sectional study was performed in 299 village children aged 5-11 years in North Central Nigeria. Data were collected regarding the cooking fuels used and duration of daily smoke exposure in the cooking area. Asthma symptoms were assessed with a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire, and lung function was assessed with spirometry.

RESULTS

The prevalence of a lifetime history of wheeze was 9.4% (95% CI: 6.3%-13.2%). Fourteen children (4.7%) had airway obstruction (FEV1/FEV6 <85%). Female subjects had lower FEV1 and FEV6 (110 % and 120% percent predicted, respectively) than males (121% and 130%, respectively, P <0.001 for both differences). Advancing age was associated with a relative decline in the predicted value of FEV1 of 7.8 % per year (r = -0.61; P < 0.001). Children in families that used firewood daily did not have a significantly increased likelihood of asthma-related symptoms (OR = 2.36, 95% CI: 0.66-8.44). Similarly, airway obstruction did not differ significantly between children in households that did and did not use firewood daily (mean FEV1/FEV6 of 0.95 and 0.97, respectively; P = 0.41).

CONCLUSION

Reported smoke exposure was not associated with an increased risk of asthma symptoms or airway obstruction. However, lifetime smoke exposure may explain the reduction in spirometric values in female subjects and with advancing age.

Indoor air pollution and respiratory health of children in the developing world

Indoor air pollution (IAP) is a key contributor to the global burden of disease mainly in developing countries. The use of solid fuel for cooking and heating is the main source of IAP in developing countries, accounting for an estimated 3.5 million deaths and 4.5% of Disability-Adjusted Life Years in 2010. Other sources of IAP include indoor smoking, infiltration of pollutants from outdoor sources and substances emitted from an array of human utilities and biological materials. Children are among the most vulnerable groups for adverse effects of IAP. The respiratory system is a primary target of air pollutants resulting in a wide range of acute and chronic effects. The spectrum of respiratory adverse effects ranges from mild subclinical changes and mild symptoms to life threatening conditions and even death. However, IAP is a modifiable risk factor having potential mitigating interventions. Possible interventions range from simple behavior change to structural changes and from shifting of unclean cooking fuel to clean cooking fuel. Shifting from use of solid fuel to clean fuel invariably reduces household air pollution in developing countries, but such a change is challenging. This review aims to summarize the available information on IAP exposure during childhood and its effects on respiratory health in developing countries. It specifically discusses the common sources of IAP, susceptibility of children to air pollution, mechanisms of action, common respiratory conditions, preventive and mitigating strategies.

Relationship between household air pollution from biomass smoke exposure, and pulmonary dysfunction, oxidant-antioxidant imbalance and systemic inflammation in rural women and children in Nigeria

Background:

Exposure to particulate matter from burning biomass fuels is believed to affect oxidant-antioxidant balance and to induce oxidative stress.

Methods:

Fifty-nine mother-child pairs from 59 households that used firewood exclusively for cooking in three rural communities in southwest Nigeria underwent blood test for albumin, pre-albumin, retinol-binding protein (RBP), superoxide dismutase (SOD), vitamins C, vitamin E, malondialdehyde (MDA) and C-reactive protein (CRP). Spirometry was performed and indoor levels of PM_2.5 were determined.

Results:

Mean age (± SD; years) of mothers and children was 43.0±11.7 and 13.6±3.2, respectively. The median indoor PM_2.5 level was 1575.1 µg/m³ (IQR 943.6–2847.0, p<0.001), which is substantially higher than the World Health Organization (WHO) standard of 25 µg/m³. The mean levels of pre-albumin (0.21±0.14 g/dL) and RBP (0.03±0.03 g/dL) in women were significantly lower than their respective normal ranges (1-3 g/dL and 0.2-0.6 g/dL, respectively, p<0.05). Similarly, the mean levels of pre-albumin (0.19±0.13 g/dL) and RBP (0.01±0.01 g/dL) in children were significantly lower than the respective normal ranges (1-3 g/dL and 0.2-0.6 g/dL, respectively, p<0.05). Mean serum concentrations of MDA in children (5.44±1.88 µmol/L) was positively correlated to serum concentrations of CRP (r=0.3, p=0.04) and negatively correlated to lung function (FEV₁/FVC) in both mothers and children (both r=-0.3, p<0.05). Also, regression analysis indicates that CRP and SOD are associated with lung function impairment in mothers (-2.55±1.08, p<0.05) and children (-5.96±3.05, p=0.05) respectively.

Conclusion:

Exposure to HAP from biomass fuel is associated with pulmonary dysfunction, reduced antioxidant defense and inflammation of the airways. Further studies are needed to better define causal relationships and the mechanisms involved.

Pilot study on the impact of biogas as a fuel source on respiratory health of women on rural Kenyan smallholder dairy farms

Biomass burning in indoor environments has been highlighted as a major cause of respiratory morbidity for women and children in low-income countries. Inexpensive technological innovations which reduce such exposures are needed. This study evaluated the impact of low tech compost digesters, which generate biogas for cooking, versus traditional fuel sources on the respiratory health of nonsmoking Kenyan farmwomen. Women from 31 farms with biogas digesters were compared to age-matched women from 31 biomass-reliant farms, in June 2010. Only 43% of the biogas group reported any breathing problems, compared to 71% in the referent group (P = 0.03). Referent women self-reported higher rates of shortness of breath (52% versus 30%), difficulty breathing (42% versus 23%), and chest pain while breathing (35% versus 17%) during the last 6 months (P = 0.09 to 0.12) compared to biogas women. Biogas women demonstrated slightly better spirometry results but differences were not statistically significant, likely due to limited latency between biogas digester installation and spirometry testing. Most biogas women reported improved personal respiratory health (87%) and improved children's health (72%) since biogas digester installation. These findings suggest that using biogas in cookhouses improves respiratory symptoms but long-term impacts on lung function are unclear.

Association of indoor air pollution with acute lower respiratory tract infections in children under 5 years of age

BACKGROUND

Indoor air pollution is an important risk factor for acute lower respiratory tract infections (ALRTI) in developing countries.

AIM

To determine the relationship of indoor air pollution with ALRTI in children under 5 years of age.

METHODS

A prospective, case-control study of risk factors, particularly indoor air pollution, for developing ALRTI in children under 5 years of age was conducted in Udupi District Hospital. The WHO definition of ALRTI was used. Healthy children attending immunisation services were enrolled as controls. Data pertaining to important factors causing indoor air pollution such as cooking fuel other than liquid petroleum gas (LPG) and passive smoking were collected along with potential socio-demographic factors and nutrition in both groups and analysed.

RESULTS

A total of 202 children including 101 cases and 101 controls were studied. The proportions of infants (1-12 months) among cases and controls were 62.4% and 71.3%, respectively. Of those with ALRTI, 24.8% had pneumonia, 45.5% had severe pneumonia and 29.7% had very severe disease. Exposure to passive smoking was not associated with ALRTI. Cooking fuel other than LPG was significantly associated with ALRTI (OR 26.3, 95% CI 10.5-65.7). On logistic regression analysis of multiple risk factors, cooking fuel other than LPG emerged as a significant risk factor for developing ALRTI (adjusted OR 4.73, 95% CI 1.67-13.45) along with poor socio-economic status (adjusted OR 3.38, 95% CI 1.63-7.03). Other than LPG, the main fuels used were wood (95%), kerosene and dung and crop residues.

CONCLUSION

Indoor air pollution caused by using cooking fuel other than LPG and socio-economic factors are significantly associated with ALRTI.

A strategy to increase adoption of locally-produced, ceramic cookstoves in rural Kenyan households

Background

Exposure to household air pollutants released during cooking has been linked to numerous adverse health outcomes among residents of rural areas in low-income countries. Improved cookstoves are one of few available interventions, but achieving equity in cookstove access has been challenging. Therefore, innovative approaches are needed. To evaluate a project designed to motivate adoption of locally-produced, ceramic cookstoves (upesi jiko) in an impoverished, rural African population, we assessed the perceived benefits of the cookstoves (in monetary and time-savings terms), the rate of cookstove adoption, and the equity of adoption.

Methods

The project was conducted in 60 rural Kenyan villages in 2008 and 2009. Baseline (n = 1250) and follow-up (n = 293) surveys and a stove-tracking database were analyzed.

Results

At baseline, nearly all respondents used wood (95%) and firepits (99%) for cooking; 98% desired smoke reductions. Households with upesi jiko subsequently spent <100 Kenyan Shillings/week on firewood more often (40%) than households without upesi jiko (20%) (p = 0.0002). There were no significant differences in the presence of children <2 years of age in households using upesi jiko (48%) or three-stone stoves (49%) (p = 0.88); children 2–5 years of age were less common in households using upesi jiko versus three-stone stoves (46% and 69%, respectively) (p = 0.0001). Vendors installed 1,124 upesi jiko in 757 multi-family households in 18 months; 68% of these transactions involved incentives for vendors and purchasers. Relatively few (<10%) upesi jiko were installed in households of women in the youngest age quartile (<22 years) or among households in the poorest quintile.

Conclusions

Our strategy of training of local vendors, appropriate incentives, and product integration effectively accelerated cookstove adoption into a large number of households. The strategy also created opportunities to reinforce health messages and promote cookstoves sales and installation. However, the project’s overall success was diminished by inequitable and incomplete adoption by households with the lowest socioeconomic status and young children present. Additional evaluations of similar strategies will be needed to determine whether our strategy can be applied equitably elsewhere, and whether reductions in fuel use, household air pollution, and the incidence of respiratory diseases will follow adoption of improved cookstoves.

Quantification and analysis of airborne bacterial characteristics in a nursing care institution

Indoor air quality has become a critical issue because people spend most of their time in the indoor environment. The factors that influence indoor air quality are very important to environmental sanitation and air quality improvement. This study focuses on monitoring air quality, colony counts, and bacteria species of the indoor air of a nursing care institution. The regular colony counts in two different wards range from 55 to 600 cfu m(-3) Regression analysis results indicate that the bacterial colony counts have close correlation with relative humidity or carbon dioxide (CO2) but not with carbon monoxide (CO) or ozone (O3). Real-time PCR was used to quantify the bacterial pathogens of nosocomial infection, including Acinetobacter baumannii, Citrobacter freundii, Escherichia coli, Klebsiella pneumoniae, and methicillin-sensitive Staphylococcus aureus. The most abundant bacteria species in the air of the nursing care institution is E. coli.

Physical-chemical and microbiological characterization, and mutagenic activity of airborne PM sampled in a biomass-fueled electrical production facility

Biomass combustion is used in heating and electric power generation in many areas of the world. Airborne particulate matter (PM) is released when biomass is brought to a facility, stored, and combusted. Occupational exposure to airborne PM within biomass-fueled facilities may lead to health problems. In March and August of 2006, airborne PM was collected from a biomass-fueled facility located in Denmark. In addition, source-specific PM was generated from straw and wood pellets using a rotating drum. The PM was analyzed for polycyclic aromatic hydrocarbons (PAHs), metals, microbial components, mutagenic activity, and ability to generate highly reactive oxygen species (hROS) in cell-free aqueous suspensions. PM collected from the boiler room and the biomass storage hall had higher levels of mutagenic activity, PAHs and metals, and a higher hROS generating potential than the source specific PM. The mutagenic activity was generally more potent without S9 activation, and on the metabolically enhanced strain YG1041, relative to TA98. Significant correlations were found between mutagenicity on YG1041 (without S9) and PAH concentration and mutagenicity on YG1041 (with S9) and hROS generating ability. PM collected in March was more toxic than PM collected in August. Overall, airborne PM collected from the facility, especially that from the boiler room, were more toxic than PM generated from straw and wood chips. The results suggest that exposure to combustion PM in a biomass-fueled facility, which likely includes PM from biomass combustion as well as internal combustion vehicles, may contribute to an elevated risk of adverse health effects.

Raising the priority of preventing chronic diseases: a political process

Chronic diseases, especially cardiovascular diseases, diabetes, cancer, and chronic obstructive respiratory diseases,are neglected globally despite growing awareness of the serious burden that they cause. Global and national policies have failed to stop, and in many cases have contributed to, the chronic disease pandemic. Low-cost and highly effective solutions for the prevention of chronic diseases are readily available; the failure to respond is now a political, rather than a technical issue. We seek to understand this failure and to position chronic disease centrally on the global health and development agendas. To identify strategies for generation of increased political priority for chronic diseases and to further the involvement of development agencies, we use an adapted political process model. This model has previously been used to assess the success and failure of social movements. On the basis of this analysis,we recommend three strategies: reframe the debate to emphasise the societal determinants of disease and the interrelation between chronic disease, poverty, and development; mobilise resources through a cooperative and inclusive approach to development and by equitably distributing resources on the basis of avoidable mortality; and build one merging strategic and political opportunities, such as the World Health Assembly 2008–13 Action Plan and the high level meeting of the UN General Assembly in 2011 on chronic disease. Until the full set of threats—which include chronic disease—that trap poor households in cycles of debt and illness are addressed, progress towards equitable human development will remain inadequate.

Bayesian modelling of household solid fuel use: insights towards designing effective interventions to promote fuel switching in Africa

Indoor air pollution from solid fuel use is a significant risk factor for acute lower respiratory infections among children in sub-Saharan Africa. Interventions that promote a switch to modern fuels hold a large health promise, but their effective design and implementation require an understanding of the web of upstream and proximal determinants of household fuel use. Using Demographic and Health Survey data for Benin, Kenya and Ethiopia together with Bayesian hierarchical and spatial modelling, this paper quantifies the impact of household-level factors on cooking fuel choice, assesses variation between communities and districts and discusses the likely nature of contextual effects. Household- and area-level characteristics appear to interact as determinants of cooking fuel choice. In all three countries, wealth and the educational attainment of women and men emerge as important; the nature of area-level factors varies between countries. In Benin, a two-level model with spatial community random effects best explains the data, pointing to an environmental explanation. In Ethiopia and Kenya, a three-level model with unstructured community and district random effects is selected, implying relatively autonomous economic and social areas. Area-level heterogeneity, indicated by large median odds ratios, appears to be responsible for a greater share of variation in the data than household-level factors. This may be an indication that fuel choice is to a considerable extent supply-driven rather than demand-driven. Consequently, interventions to promote fuel switching will carefully need to assess supply-side limitations and devise appropriate policy and programmatic approaches to overcome them. To our knowledge, this paper represents the first attempt to model the determinants of solid fuel use, highlighting socio-economic differences between households and, notably, the dramatic influence of contextual effects. It illustrates the potential that multilevel and spatial modelling approaches hold for understanding determinants of major public health problems in the developing world.

Child mortality from solid-fuel use in India: a nationally-representative case-control study

Background

Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India.

Methods

We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias.

Results

Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio (PR) boys: 1.30, 95%CI 1.08-1.56; girls: 1.33, 95%CI 1.12-1.58). More girls than boys died from exposure to solid fuels. Solid fuel use was also associated with non-fatal pneumonia (boys: PR 1.54 95%CI 1.01-2.35; girls: PR 1.94 95%CI 1.13-3.33).

Conclusions

Child mortality risks, from all causes, due to solid fuel exposure were lower than previously, but as exposure was common solid, fuel caused 6% of all deaths at ages 0-4, 20% of deaths at ages 1-4 or 128 000 child deaths in India in 2004. Solid fuel use has declined only modestly in the last decade. Aside from reducing exposure, complementary strategies such as immunization and treatment could also reduce child mortality from acute respiratory infections.

Cooking fuels and the push for cleaner alternatives: a case study from Burkina Faso

Introduction

More than 95% of the population in Burkina Faso uses some form of solid biomass fuel. When these fuels are burned in traditional, inefficient stoves, pollutant levels within and outside the home can be very high. This can have important consequences for both health and climate change. Thus, the push to switch to cleaner burning fuels is advantageous. However, there are several considerations that need to be taken into account when considering the use and promotion of different fuel types.

Objective

In the setting of the semi-urban area of Nouna, Burkina Faso, we examine the common fuel types used (wood, charcoal and liquid petroleum gas (LPG)) in terms of consumption, energy, availability, air pollution and climate change.

Results and conclusion

Although biomass solid fuel does offer some advantages over LPG, the disadvantages make this option much less desirable. Lower energy efficiencies, higher pollutant emission levels, the associated health consequences and climate change effects favour the choice of LPG over solid biomass fuel use. Further studies specific to Burkina Faso, which are lacking in this region, should also be undertaken in this area to better inform policy decisions.

Bibliography. Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 November 2007 and 31 October 2008 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.

Magnitude of indoor NO2 from biomass fuels in rural settings of Ethiopia

Half of the world's population and about 80% of households in Sub-Saharan Africa depend on biomass fuels. Indoor air pollution due to biomass fuel combustion may constitute a major public health threat affecting children and women. The purpose of this study was to measure levels of indoor NO(2) concentration in homes with under-five children in rural Ethiopia. The study was undertaken in the Butajira area in Ethiopia from March 2000 to April 2002. 24-h samples were taken regularly at about three month intervals in approximately 3300 homes. Indoor air sampling was done using a modified Willems badge. For each sample taken, an interview with the mother of the child was performed. A Saltzman colorimetric method using a spectrometer calibrated at 540 nm was employed to analyze the mass of NO(2) in field samples. Wood, crop residues and animal dung were the main household fuels. The mean (s.d.) 24-h concentration of NO(2) was 97 microg/m(3) (91.4). This is more than double the currently proposed annual mean of WHO air quality guideline. Highland households had significantly higher indoor NO(2) concentration. This study demonstrates high levels of indoor NO(2) in rural homes of Ethiopia.

PRACTICAL IMPLICATIONS

Respiratory infection is a major cause of morbidity and mortality, globally. Acute respiratory symptoms are also related to high levels of air pollution. Interventions aimed at reducing exposure to indoor air pollution should focus on cooking and heating practices in developing countries. This study is not undermining the role of other biomass smoke constituents in determining respiratory infections.