Lung function in woodsmoke-exposed Guatemalan children following a chimney stove intervention

Abstract

Rationale Household air pollution (HAP) from solid fuel combustion is a major contributor to the global burden of disease, with considerable impact from respiratory infections in children. The impact of HAP on lung function is unknown. Objectives The Childhood Exposure to Respirable Particulate Matter (CRECER) prospective cohort study followed Guatemalan children who participated in the Randomised Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) trial of a chimney stove intervention to determine the effect of early childhood HAP exposure on growth of lung function. Methods RESPIRE households with pregnant women or infant children were randomised to receive a chimney stove at the beginning or at the end of the 18-month trial. During CRECER, a subset of these children, as well as children from households with newly installed stoves, were followed with spirometry beginning at age 5. Biomass smoke exposure was measured using personal carbon monoxide tubes. Two-stage regression models were employed to analyse associations with lung function growth. Measurements and main results Longitudinal peak expiratory flow (PEF) and FEV 1 data were available for 443 and 437 children, respectively, aged 5-8 (mean follow-up 1.3 years). Decreases in PEF growth of 173 mL/min/year (95% CI −341 to −7) and FEV 1 of 44 mL/year (95% CI −91 to 4) were observed with stove installation at 18 months compared with stove installation at birth in analyses adjusted for multiple covariates. No statistically significant associations were observed between personal HAP exposure and lung function. Conclusions A significant decrease in PEF growth and a large non-significant decrease in FEV 1 growth were observed with later stove installation. Additional studies including longer follow-up and cleaner stoves or fuels are needed.

Airflow Obstruction and Use of Solid Fuels for Cooking or Heating. BOLD (Burden of Obstructive Lung Disease) Results

“…An earlier report from the Burden of Obstructive Lung Disease (BOLD), mostly undertaken in high income countries, also failed to show an association between airflow obstruction and use of solid fuel (14). Results from trials of solid fuel use reduction are so far inconclusive in relation to the effects on lung function (15,16). Overall, the evidence supporting an association of COPD (or airflow obstruction) with use of solid fuels for cooking or heating is conflicting and inconsistent.…”

Associations between household air pollution and reduced lung function in women and children in rural southern India

“…Other studies have focused on establishing the influence of HAP on lung diseases, such as chronic obstructive pulmonary disease and asthma, by evaluating exposure levels of cookstove emissions and their influence on lung function (Clark et al, 2009;da Silva et al, 2012;Diaz et al, 2007;Heinzerling et al, 2016;Kulshreshtha, Khare, & Seetharaman, 2008;Pope et al, 2015). Some studies have directly attributed the observed decrease in lung function of exposed individuals to cookstove emissions (da Silva et al, 2012); but inconsistent results have also been reported.…”

Small Airway Disease in COPD Associated to Biomass Exposure

“…The age of onset of biomass and tobacco exposures is different. Biomass exposure begins much earlier in life (in utero and from the neonatal period) than does active smoking (usually in the teenage years), thereby increasing the risk for COPD in relative terms 25,26 . In addition, young children and infants, who are typically carried on the back or placed near their mother to sleep, are also exposed to biomass smoke 14 .…”

“…Children exposed to biomass smoke have a larger number of acute respiratory infections, including pneumonia, and asthma compared to unexposed children 28,29 . The consequence is a lower growth in lung function, leading to COPD 25 .…”