Respiratory effects of biomass fuel combustion on rural fish smokers in a Nigerian fishing settlement: a case control study

Exposure to Wood Smoke and Associated Health Effects in Sub-Saharan Africa: A Systematic Review

Background

Observational studies suggest that exposure to wood smoke is associated with a variety of adverse health effects in humans.

Objective

We aimed to summarise evidence from sub-Saharan Africa on levels of exposure to pollutants in wood smoke and the association between such exposures and adverse health outcomes.

Methods

PubMed and Google scholar databases were searched for original articles reporting personal exposure levels to pollutants or health outcomes associated with wood smoke exposure in Sub-Saharan African population.

Results

Mean personal PM_2.5 and carbon monoxide levels in the studies ranged from 26.3 ± 1.48 μg/m³ to 1574 ± 287μg/m³ and from 0.64 ± 2.12 ppm to 22 ± 2.4 ppm, respectively. All the reported personal PM_2.5 exposure levels were higher than the World Health Organization's Air Quality Guideline (AQG) for 24-hour mean exposure. Use of wood fuels in domestic cooking is the major source of wood smoke exposure in this population. Occupational exposure to wood smoke included the use of wood fuels in bakery, fish drying, cassava processing and charcoal production. Females were exposed to higher levels of these pollutants than males of the same age range. Major determinants for higher exposure to wood smoke in SSA included use of unprocessed firewood, female gender and occupational exposure. We recorded strong and consistent associations between exposure to wood smoke and respiratory diseases including acute respiratory illness and impaired lung function. Positive associations were reported for increased blood pressure, low birth weight, oesophageal cancer, sick building syndrome, non-syndromic cleft lip and/or cleft palate and under-five mortality.

Conclusion

There is high level of exposure to wood smoke in SSA and this exposure is associated with a number of adverse health effects. There is urgent need for aggressive programs to reduce wood smoke exposure in this population.

Association between choice of cooking fuel and peak expiratory flow rate among rural women in the Niger Delta, Nigeria

Background: Long-term exposure to indoor air pollution from biomass fuel combustion is a risk factor for respiratory disease, which is an increasingly prevalent contributor to morbidity and mortality in low- and middle-income countries. This study evaluated the association between household fuel use and the peak expiratory flow rate (PEFR) of rural-dwelling women in selected communities of the Niger Delta. Methods: This was a cross-sectional study including 321 non-smoking women aged 18 years and older. Questionnaires were used to obtain data on predominant fuel used and a brief medical history. Women with current respiratory symptoms were excluded. Fuel use was classified into three categories: biomass fuels (BMF), such as wood, animal dung and coal, kerosene and liquefied petroleum gas (LPG). The PEFR was measured with an Omron peak flow meter using standard protocols and was abnormal if it was less than 80% of predicted value based on age and height. Results: The mean age of the 321 women was 38.5±14.2 years. The biomass fuel users had significantly lower PEFR (353.9±104.4) compared to kerosene users (376.2±70.1) and LPG users (393.6± 93.3) (p=0.030). The overall prevalence of abnormal PEFR was 22.4%. The PEFR was abnormal in more BMF users (28%) than kerosene users (13.4%) and LPG users (9.4%) (p=0.005). The PEFR of women who used LPG was 20.8 l/min higher than BMF users (p=0.012). The users of BMF were 5.8 times more likely to have abnormal PEFR than LPG users (OR 5.8, 95% CI 1.62, 20.52, p=0.007). Conclusion: In this population, the use of biomass fuel was significantly associated with abnormal PEFR. This needs to be further explored in this population with a larger study using more objective measures, such as spirometry testing, to guide policies for the implementation of preventive strategies to protect vulnerable women from chronic obstructive airway disease.

Knowledge, attitudes and beliefs about the health hazards of biomass smoke exposure amongst commercial food vendors in Nigeria

BACKGROUND

Exposure to biomass smoke is a major cause of morbidity and mortality in Africa. Commercial food vendors in Nigeria and elsewhere in Africa are commonly exposed to biomass smoke from open fire cooking both at work and home. Little is known about the knowledge, attitudes and beliefs of food vendors about the health hazards of biomass smoke exposure in Nigeria.

METHODS

We did a descriptive cross sectional survey of the knowledge, attitudes and beliefs of commercial food vendors in the cities of Benin and Calabar in Nigeria. We recruited respondents using a multi-stage approach. Structured interviewer-administered questionnaires were used for data collection.

RESULTS

We recruited 308 participants (164, 53.2% female). The majority 185(60.2%) were married and had post-primary education 206(67.4%). The average monthly income was <30,000 Naira (US$150). Most 198(64.4%) were not aware that biomass smoke exposure is harmful to human health. About three-quarters (221; 71.8%) were unconcerned as to the effect of exposure to fumes from biomass fuels on their health. Less than half of respondents (110, 41.6%) believed biomass smoke was harmful to health. Male gender, being single, having post-primary education and preferring electricity or gas fuels were associated with good knowledge of the adverse health effects of biomass smoke exposure whilst female gender and having good knowledge of the adverse health effects of biomass smoke were associated with positive attitudes towards preventing exposure.

CONCLUSION

Commercial food vendors in our study had limited knowledge about the adverse health effects of biomass smoke exposure and negative attitudes towards preventing these adverse health effects. We suggest an educational intervention is needed to improve this knowledge.