Respiratory Symptoms and Lung Function among Ethiopian Women in Relation to Household Fuel Use

The effect of chimney fitted improved stove on kitchen fine particulate matter (PM2.5) concentrations in rural Ethiopia: Evidence from a randomized controlled trial

BACKGROUND

Millions of Ethiopian people cook with biomass fuels using traditional stoves, releasing harmful pollutants and contributing to a significant public health crisis. Improved stoves offer a potential escape route, but their effectiveness needs close scrutiny. This study delves into the impact of chimney-fitted stoves on kitchen PM2.5 concentrations in rural Ethiopian households.

METHOD

We conducted a randomized controlled trial with 86 households equally divided (1:1 ratio) between intervention and control groups. The 24-h average kitchen PM2.5 concentrations was measured using Particle and Temperature Sensor (PATS+) at baseline and after intervention. All relevant sociodemographic and cooking related characteristics were collected at baseline and dynamic characteristics were updated during air monitoring visits. Three distinct statistical models, including independent sample t-tests, paired sample t-tests and one-way analysis of variance were used to analyze the data using Statistical Package for the Social Sciences (SPSS) software for Windows (v 24.0).

RESULT

At baseline, the average 24-h kitchen PM2.5 concentrations were 482 μg/m3 (95% CI: 408, 557) for the control and 405 μg/m3 (95% CI: 318, 492) for the intervention groups. Despite remaining elevated at 449 μg/m3 (95% CI: 401, 496) in the control group, PM2.5 concentrations reduced to 104 μg/m3 (95% CI: 90,118) in the intervention group, indicating a statistically significant difference (t = 6.97, p < 0.001). All three statistical analyses delivered remarkably consistent results, estimating a PM2.5 reductions of 74% with the before-and-after approach, 76% when comparing groups, and 74% for difference in difference analysis. Beyond the overall reduction, homes with primary school completed women, larger kitchens, smaller family size, and those specifically baking Injera (the traditional energy-intensive staple food), witnessed even greater drops in PM2.5 levels.

CONCLUSION

Pregnant women in our study encountered dangerously high PM2.5 exposures in their kitchens. While the intervention achieved a significant PM2.5 reductions, unfortunately remained above the WHO's safe limit, highlighting the need for further interventions.

Methods in Public Health Environmental Justice Research: a Scoping Review from 2018 to 2021

PURPOSE OF REVIEW

The volume of public health environmental justice (EJ) research produced by academic institutions increased through 2022. However, the methods used for evaluating EJ in exposure science and epidemiologic studies have not been catalogued. Here, we completed a scoping review of EJ studies published in 19 environmental science and epidemiologic journals from 2018 to 2021 to summarize research types, frameworks, and methods.

RECENT FINDINGS

We identified 402 articles that included populations with health disparities as a part of EJ research question and met other inclusion criteria. Most studies (60%) evaluated EJ questions related to socioeconomic status (SES) or race/ethnicity. EJ studies took place in 69 countries, led by the US (n = 246 [61%]). Only 50% of studies explicitly described a theoretical EJ framework in the background, methods, or discussion and just 10% explicitly stated a framework in all three sections. Among exposure studies, the most common area-level exposure was air pollution (40%), whereas chemicals predominated personal exposure studies (35%). Overall, the most common method used for exposure-only EJ analyses was main effect regression modeling (50%); for epidemiologic studies the most common method was effect modification (58%), where an analysis evaluated a health disparity variable as an effect modifier. Based on the results of this scoping review, current methods in public health EJ studies could be bolstered by integrating expertise from other fields (e.g., sociology), conducting community-based participatory research and intervention studies, and using more rigorous, theory-based, and solution-oriented statistical research methods.

Health risk perceptions of household air pollution and perceived benefits of improved stoves among pregnant women in rural Ethiopia: a mixed method study

OBJECTIVE

Since community perceptions of the risk of biomass smoke and the benefits of improved stoves play a critical role in behaviour change to the uptake and sustainable utilisation of improved stoves, we aimed to assess the level of health risk perception on kitchen smoke and benefits of using improved stoves among pregnant women.

DESIGN

A community-based cross-sectional mixed method study.

SETTING

In six kebeles of a low-income rural community of South Gondar Zone, Northwestern Ethiopia.

PARTICIPANTS

All 455 households with pregnant women aged 18-38 years, in their first-trimester or second-trimester gestation, exclusively use traditional biomass-fuelled or locally modified mud stoves, and the primary cook in her household were included. But completed data were obtained only from 422 households.

RESULT

From 422 completed data, more than half, 63% (95% CI 58% to 68%) had high-level health risk perception of household air pollution, and nearly three-fourths, 74% (95% CI 70% to 79%) of the respondents perceived that using improved stove had benefits for their families. Participants in the 32-38 years age group, rich in asset index, presence of under-five children, being a member of any women group and large family size were positively associated with high-level health risk perception. Whereas respondents in the 18-24 years age group, presence of under-five children, husbands of primary or higher education, high health risk perception and not happy with the current stove were positively associated with perceived benefits of using an improved stove.

CONCLUSION

The observed level of health risk perception of biomass smoke and the benefits of using improved stoves may help to adopt effective intervention measures. This study also suggests that for successful intervention, clean cooking programmes and policies must consider many local factors influencing health risk perception and benefits of using improved stoves.

TRIAL REGISTRATION NUMBER

ACTR202111534227089.

Health risk assessment of indoor air quality, sociodemographic and kitchen characteristics on respiratory health among women responsible for cooking in urban settings of Oromia region, Ethiopia: a community-based cross-sectional study

OBJECTIVES

In Ethiopia, where biomass fuel is used by the majority of the population, women who are primarily responsible for cooking are at a higher risk of having respiratory symptoms. However, there is limited information on the respiratory symptoms of exposed women. This study assessed the magnitude of respiratory disease symptoms and associated factors among women responsible for cooking in Mattu and Bedele towns, south-west Ethiopia.

METHODS

A community-based cross-sectional study was conducted among 420 randomly selected women in urban settings in south-west Ethiopia. Data were collected through face-to-face interviews using a modified version of the American Thoracic Society Respiratory Questionnaire. The data were cleaned, coded and entered into EpiData V.3.1 and exported into SPSS V.22 for analysis. Bivariable and multivariable logistic regression analyses were used to identify factors associated with respiratory symptoms at a value of p<0.05.

RESULTS

It is found that 34.9% of the study participants have respiratory symptoms (95% CI 30.6% to 39.4%). Unimproved floor (adjusted OR (AOR)=2.4 at 95% CI 1.42 to 4.15), presence of thick black soot in the ceiling (AOR=2.1 at 95% CI 1.2 to 3.6), using fuel wood (AOR=2.3 at 95% CI 1.1 to 4.7), using a traditional stove (AOR=3.37 at 95% CI 1.85 to 6.16), long duration of cooking (AOR=2.52 at 95% CI 1.4 to 4.5) and cooking room without a window (AOR=2.4 at 95% CI 1.5 to 3.9) were significantly associated with women's respiratory symptoms.

CONCLUSION

More than two in six women who cook had respiratory symptoms. Floor, fuel and stove type, soot deposits in the ceiling, duration of cooking and cooking in a room without a window were the identified factors. Appropriate ventilation, improved floor and stove design and the switch to high-efficiency, low-emission fuels could help to lessen the effects of wood smoke on women's respiratory health.

Prevalence of obstructive lung patterns and actual spirometric result at different workplaces in Ethiopia: A systematic review and meta-analysis

Background and Aims

Burdens of occupational exposure like insoluble dust particles and chemicals in the respiratory tract leads to impaired clearance. This study aims to assess the prevalence of obstructive lung patterns and actual spirometric result in Ethiopia at different workplaces.

Methods

Five electronic databases such as: PubMed, HINARI, Science Direct, Google Scholar, and African Journals Online were searched in studies conducted from 2010 to 2021. In this study, we used STATA 14 software for data analysis and the quality of included studies were appraised using the New Castle Ottawa quality assessment tool. The pooled prevalence of obstructive lung patterns and actual spirometric results were estimated using effect size and standardized mean differences (SMD).

Results

A total representative of 3511 participants was included in this study. The pooled prevalence of obstructive lung patterns in occupational exposure at different workplaces was found 13.04% (95% CI: 7.96, 18.12, I ² = 89.2%). On the other hand, the pooled prevalence of obstructive lung patterns in controls was 4.10% (95% CI: 1.86, 6.34, I ² = 76.8%). SMD of spirometric results was significantly decreased in cases as compared to the controls. The SMD of FVC in a litter (L) at 95% of CI: -0.50 (-0.70, -0.30, I ² = 87.7%), SMD of FEV₁ in (L) at 95% CI: -0.54 (-0.72, -0.36, I ² = 84.9%), SMD of FEF₂₅%-₅₀% in litter per second (L/s) at 95% of CI: -0.42 (-0.67, -0.17, I ² = 81.9%) and SMD of PEFR in L/s at 95% CI: -0.45 (-0.68, -0.21, I ² = 78.4%) were significantly decreased in cases as compared to the controls.

Conclusion

The pooled prevalence of obstructive lung pattern was higher in people who are working at different workplace that generating dusts and chemicals. The SMD of actual spirometric results were reduced in cases than controls. Therefore, to alleviate this problem appropriate preventive measure would be warranted for those people who are working in different dust and chemical generating environments.

Household fuel use and its association with potential respiratory pathogens among healthy mothers and children in Ethiopia

Background

Over 90% of Ethiopians still rely on solid fuels for cooking food. The pollution from the burning process causes adverse respiratory outcomes including respiratory infections. This study aimed to assess the association of the pollution with nasopharyngeal occurrence of potential pathogens.

Methods

We conducted a comparative cross-sectional study in urban and rural settings in Ethiopia in 2016. Questionnaire-based data were collected from 168 mothers and 175 children aged below two years. Multiplex real-time PCR assays were performed on nasopharyngeal secretions for detection of bacteria and viruses and for the identification of pneumococcal serotypes/groups.

Results

High rates of bacteria and viruses in the nasopharynx were detected by PCR among both the children and the mothers. Among the detected viruses, enterovirus was more commonly detected among rural children than among children from urban areas. Streptococcus pneumoniae and Haemophilus influenzae were both more prevalent among children and mothers from rural areas compared with urban groups and among those using solid fuels compared with cleaner fuel users. Children from rural households using solid fuels and children whose mothers had educational status below high school had four times higher odds for detection of S. pneumoniae compared with those households using cleaner energy or those children having mothers with a higher educational status, respectively. One or more serotype/serogroup was identified in about 40% of the samples that were positive for pneumococci. Out of all identified serotypes/serogroups, 43% in the children and 45% in the mothers belonged to PCV13, indicating the larger majority of detected pneumococci being non-PCV13 serotypes.

Conclusion

This study presented a high carriage rate of S. pneumoniae and H. influenzae among both children and their mothers, especially in rural areas and among solid fuel users. Thus, interventions should target cleaner energy sources to the public and promote maternal education.

Characterization of fine particulate matter from indoor cooking with solid biomass fuels

Household burning of solid biomass fuels emits pollution particles that are a huge health risk factor, especially in low-income countries (LICs) such as those in Sub-Saharan Africa. In epidemiological studies, indoor exposure is often more challenging to assess than outdoor exposure. Laboratory studies of solid biomass fuels, performed under real-life conditions, are an important path toward improved exposure assessments. Using on- and offline measurement techniques, particulate matter (PM) from the most commonly used solid biomass fuels (charcoal, wood, dung, and crops residue) was characterized in laboratory settings using a way of burning the fuels and an air exchange rate that is representative of real-world settings in low-income countries. All the fuels generated emissions that resulted in concentrations which by far exceed both the annual and the 24-hour-average WHO guidelines for healthy air. Fuels with lower energy density, such as dung, emitted orders of magnitude more than, for example, charcoal. The vast majority of the emitted particles were smaller than 300 nm, indicating high deposition in the alveoli tract. The chemical composition of the indoor pollution changes over time, with organic particle emissions often peaking early in the stove operation. The chemical composition of the emitted PM is different for different biomass fuels, which is important to consider both in toxicological studies and in source apportionment efforts. For example, dung and wood yield higher organic aerosol emissions, and for dung, nitrogen content in the organic PM fraction is higher than for the other fuels. We show that aerosol mass spectrometry can be used to differentiate stove-related emissions from fuel, accelerant, and incense. We argue that further emission studies, targeting, for example, vehicles relevant for LICs and trash burning, coupled with field observations of chemical composition, would advance our understanding of air pollution in LIC. We believe this to be a necessary step for improved air quality policy.

High Levels of Fine Particulate Matter (PM2.5) Concentrations from Burning Solid Fuels in Rural Households of Butajira, Ethiopia

The use of solid fuel, known to emit pollutants which cause damage to human health, is the primary energy option in Ethiopia. Thus, the aim of this study was to measure the level of household air pollution by using the 24-h mean concentration of fine particulate matter (PM_2.5) in 150 randomly recruited households in rural Butajira, Ethiopia. Data relating to household and cooking practices were obtained by conducting face-to-face interviews with the mothers. The 24-h mean (standard deviation) and median PM_2.5 concentrations were 410 (220) and 340 µg/m³, respectively. Households using only traditional stoves and those who did not open the door or a window during cooking had a significantly higher mean concentration compared with their counterparts. There is a statistically significant correlation between the mean concentration of PM_2.5 and the self-reported cooking duration. The pollution level was up to 16 times higher than the WHO 24-h guideline limit of 25 μg/m^3, thus leaving the mothers and children who spend the most time at the domestic hearth at risk of the adverse health effects from solid fuel use in Ethiopia. Thus, effective short- and long-term interventions are urgently needed.

Evaporation rates and pollutants emission from heated cooking oils and influencing factors

The heating of edible oils during cooking activities promotes the emissions of pollutants that have adverse impacts on the health of humans. This study investigated the evaporative emissions of fifteen (15) commonly used cooking oils. Split-plot experimental design under the response surface methodology framework was used to study singular and interaction effects of influencing parameters (temperature, volume of cooking oil and time) on cooking oil evaporation rate and pollutants emissions (i.e. Particulate matter of aerodynamic diameter ≤1 μm (PM_1.0); ≤2.5 μm (PM_2.5); ≤10 μm (PM₁₀); Total Suspended Particulate (TSP); Total Volatile Organic Compounds -TVOCs, and Carbon Monoxide- CO) on a groundnut oil sample that served as a case study. Obtained values of density, viscosity, kinematic viscosity, smoke, flash and fire points were; 873-917 kg/m³; 1.12-9.7 kg/ms; 2.4-3.4 m²/s; 96 -100 °C; 124-179 °C and 142-186 °C, respectively. The role of temperature as the most significant parameter influencing the rate of evaporative emissions was established. Evaporation rate and pollutants emission from unrefined samples were the highest. The restricted maximum likelihood (REML) analysis results suggested a strong relationship between the actual values and the predicted values as R-squared values obtained were greater than 0.8 for all the responses. These results suggest that minimal rates of evaporation and pollutants emission from heating cooking oils can be achieved with a high volume of the cooking oil at moderate temperature levels.

Solid fuel users' perceptions of household solid fuel use in low- and middle-income countries: A scoping review

Almost half of the global population is exposed to household air pollution (HAP) from the burning of biomass fuels primarily for cooking, and this has been linked with considerable mortality and morbidity. While alternative cooking technologies exist, sustained adoption of these is piecemeal, indicating that there is insufficient knowledge of understandings of HAP within target communities. To identify potential gaps in the literature, a scoping review was conducted focused on solid fuel users' perceptions of HAP and solid fuel use in low- and middle-income countries. From the initial 14,877 search returns, 56 were included for final analysis. An international multi-disciplinary workshop was convened to develop the research question; six key domains: health; family and community life; home, space, place and roles; cooking and cultural practices, environment; and policy and practice development, were also identified using a Social Ecological Model framework. The review showed a series of disconnects across the domains which highlighted the limited research on perceptions of HAP in the literature. Reviewed studies showed that participants emphasized short-term health impacts of HAP as opposed to longer-term health benefits of interventions and prioritized household security over improved ventilation. There was also a socio-demographic gendered disconnect as although women and children generally have most exposure to HAP, their decision-making power about use of solid fuels is often limited. In the domain of policy and practice, the review identified the importance of community norms and cultural traditions (including taste). Research in this domain, and within the environment domain is however limited and merits further attention. We suggest that interventions need to be locally situated and community-led and a deeper understanding of perceptions of HAP could be obtained using participatory and innovative research methods. Bridging the disconnects and gaps identified in this review is essential if the global disease burden associated with HAP is to be reduced.

Acute respiratory symptoms and its associated factors among mothers who have under five-years-old children in northwest, Ethiopia

Background

Poor air quality of the household is likely to be the largest public health concern in resource-constrained countries. Exposure to household air pollution, poor working environment, and fuel type used at household level have been associated with respiratory symptoms. This study aimed to assess acute respiratory symptoms and its associated factors among mothers who have under five-years-old children in Gondar city, northwest Ethiopia.

Method

A cross-sectional study was carried out from February 15, 2019 to June 20, 2019. Study participants were selected using simple random sampling, and data were collected via face-to-face interviews. Binary logistic regression analysis was used to test the association of explanatory and outcome variables. Variables with p < 0.05 were considered as significantly associated with the outcome variable.

Results

The prevalence of respiratory symptoms among mothers of under-five years-old children in this study was 46.1%. Education (vocational training compared to cannot read and write) (adjusted odd ratio (AOR) = 0.26 at 95% confidence interval (CI): 0.08–0.82), working in dusty environment (AOR = 2.90 at 95% CI: 1.39–6.08), wood fire use (AOR = 0.37 at 95% CI: 0.16–0.85), living in mud- and wood-walled houses (AOR = 0.53 at CI: 0.32–0.89), recent house painting (AOR = 1.95 at 95% CI: 1.03–3.69), new carpet (AOR = 2.02 at 95% CI: 1.08–3.77), pesticide use (AOR = 1.71 at 95% CI: 1.03–2.84), damp stain (AOR = 2.45 at 95% CI: 1.04–5.75), spending longer time in house for 6 to 11 h (AOR = 2.59 at 95% CI: 1.53–4.37) and 11 to 15 h (AOR = 3.47 at 95% CI: 1.87–6.43), and living less than 100 m from unpaved roads/streets (AOR = 4.35 at 95% CI: 2.64–7.18) were significantly associated with respiratory symptoms among mothers of under-five years-old children.

Conclusion

Respiratory symptoms were common among mothers who have under five-years-old children. Air quality improvement, fuel selection, and residential planning will help to reduce respiratory symptoms.