Use of cleaner-burning biomass stoves and airway macrophage black carbon in Malawian women

Abigail L Whitehouse,Lisa Miyashita,Norrice M Liu,Maia Lesosky,Graham Flitz,Chifundo Ndamala,John R Balmes,Stephen B Gordon,Kevin Mortimer,Jonathan Grigg

doi:10.1016/j.scitotenv.2018.04.125

Abstract

Exposure to particulate matter (PM) from burning of biomass for cooking is associated with adverse health effects. It is unknown whether or not cleaner burning biomass-fuelled cookstoves reduce the amount of PM inhaled by women compared with traditional open fires.We sought to assess whether airway macrophage black carbon (AMBC) - a marker of inhaled dose of carbonaceous PM from biomass and fossil fuel combustion - is lower in Malawian women using a cleaner burning biomass-fuelled cookstove compared with those using open fires for cooking. AMBC was assessed in induced sputum samples using image analysis and personal exposure to carbon monoxide (CO) and PM were measured using Aprovecho Indoor Air Pollution meters. A fossil-fuel exposed group of UK women was also studied.Induced sputum samples were obtained from 57 women from which AMBC was determined in 31. Median AMBC was 6.87μm2 (IQR 4.47–18.5) and 4.37μm2 (IQR 2.57–7.38) in the open fire (n=11) and cleaner burning cookstove groups (n=20), respectively (p=0.028). There was no difference in personal exposure to CO and PM between the two groups. UK women (n=5) had lower AMBC (median 0.89μm2, IQR 0.56–1.13) compared with both Malawi women using traditional cookstoves (p<0.001) and those using cleaner cookstoves (p=0.022).We conclude that use of a cleaner burning biomass-fuelled cookstove reduces inhaled PM dose in a way that is not necessarily reflected by personal exposure monitoring.

Highlights

Exposure to carbonaceous particulate matter (PM) from the burning of biomass fuels is associated with a range of adverse health effects, including chronic obstructive pulmonary disease (COPD) in adults (Kelly and Fussell, 2011), and increased risk of pneumonia in infants and young children (Goldizen et al, 2015)
This is the first study of the effect of a cleaner burning biomassfuelled cookstove on inhaled dose of carbonaceous PM
We found that Malawian women using the cleaner cookstove had 36% lower airway macrophage black carbon (AMBC) compared with those who used an open fire for cooking

Summary

Introduction

Exposure to carbonaceous particulate matter (PM) from the burning of biomass fuels is associated with a range of adverse health effects, including chronic obstructive pulmonary disease (COPD) in adults (Kelly and Fussell, 2011), and increased risk of pneumonia in infants and young children (Goldizen et al, 2015). In an recent open cluster randomised study in Malawi (Children and Pneumonia Study, CAPS), we found no difference in rates of pneumonia in young children from households in community clusters assigned to cleaner burning biomass-fuelled cookstoves (Philips HD4012LS; Philips South Africa, Johannesburg, South Africa) compared with continuation of open fire cooking (Mortimer et al, 2017). We sought to compare AMBC in women using the cleaner cookstove with those using a traditional open fire We recruited these two groups from women nearing end of the CAPS trial (i.e. after 20–24 months) who were recruited into the Malawi Adult Lung Health Study (ALHS). In order to give comparison with a non-biomass exposed population a small group of British women were recruited

Methods

Results

Conclusion