Respiratory risks from household air pollution in low and middle income countries

Abstract

A third of the world’s population uses solid fuel derived from plant material (biomass) or coal for cooking, heating, or lighting. These fuels are smoky, often used in an open fire or simple stove with incomplete combustion, and result in a large amount of household air pollution when smoke is poorly vented. Air pollution is the biggest environmental cause of death worldwide, with household air pollution accounting for about 3·5–4 million deaths every year. Women and children living in severe poverty have the greatest exposures to household air pollution. In this Commission, we review evidence for the association between household air pollution and respiratory infections, respiratory tract cancers, and chronic lung diseases. Respiratory infections (comprising both upper and lower respiratory tract infections with viruses, bacteria, and mycobacteria) have all been associated with exposure to household air pollution. Respiratory tract cancers, including both nasopharyngeal cancer and lung cancer, are strongly associated with pollution from coal burning and further data are needed about other solid fuels. Chronic lung diseases, including chronic obstructive pulmonary disease and bronchiectasis in women, are associated with solid fuel use for cooking, and the damaging effects of exposure to household air pollution in early life on lung development are yet to be fully described. We also review appropriate ways to measure exposure to household air pollution, as well as study design issues and potential effective interventions to prevent these disease burdens. Measurement of household air pollution needs individual, rather than fixed in place, monitoring because exposure varies by age, gender, location, and household role. Women and children are particularly susceptible to the toxic effects of pollution and are exposed to the highest concentrations. Interventions should target these high-risk groups and be of sufficient quality to make the air clean. To make clean energy available to all people is the long-term goal, with an intermediate solution being to make available energy that is clean enough to have a health impact.

Noncommunicable Lung Disease in Sub-Saharan Africa. A Community-based Cross-Sectional Study of Adults in Urban Malawi

“…The absence of a relationship between biomass exposure and airway obstruction may be explained by limited study power related to the low prevalence of moderate to severe obstruction (3.6%), or misclassification of self-reported rather than objectively quantified biomass exposure, but it is consistent with findings of a recent population-based study in Nigeria (31,32). In the case of tobacco, it may also reflect a low intensity of exposure in this setting, which was insufficient to produce significant levels of clinically important COPD; smoking prevalence was limited and pack-year exposure was low.…”

The association between environmental tobacco smoke exposure and childhood respiratory disease: a review

“…The use of alternate fuel sources for cooking and heating is an important contributor to IAP particularly in LMIC [95]. The multiplicative effects of air pollution, from both indoor and outdoor sources and ETS exposures are important particularly as these countries carry the highest burden of child respiratory diseases [96].…”

“…ETS combined with other IAP, particularly antenatal exposure, affects lung growth that persists through adulthood [97]. There are numerous by-products of combustion; particulate matter (PM), carbon dioxide (CO 2 ), sulfur dioxide (SO 2 ), nitrogen dioxide (NO 2 ), and volatile organic compounds (VOC) are the most commonly assessed by-products of ETS and other combustions [95,98]. Recently it has been shown that sub- and nano-micron particles contribute to adverse effect of PM on the lung health of children [99].…”

Barriers to Understanding the Epidemiology of Noncommunicable Lung Disease in Sub-Saharan Africa

“…This is largely driven by recent data documenting the rise of several putative risk factors for NCLD in sSA, including uptake of tobacco and related products (2), exposure to worsening outdoor air pollution from vehicle and industrial emissions (3), and sustained indoor air pollution from the use of biomass fuels for cooking and heating (4). However, empirical evidence of the burden of NCLD, especially spirometry-based general population data, is lacking ( Figure 1) (5,6).…”

“…Large-scale genetic studies have identified MUC5B and telomerase mutations as important predictors of disease susceptibility (3). Other studies have attempted to identify biomarkers in peripheral blood that might predict disease progression or behavior (4,5).…”