Cookstove Smoke Impact on Ambient Air Quality and Probable Consequences for Human Health in Rural Locations of Southern Nepal.

Sagar Adhikari,Siva Praveen Puppala,Parth Sarathi Mahapatra,Chiranjibi Prasad Pokheral

doi:10.3390/ijerph17020550

Abstract

Residential emission from traditional biomass cookstoves is a major source of indoor and outdoor air pollution in developing countries. However, exact quantification of the contribution of biomass cookstove emissions to outdoor air is still lacking. In order to address this gap, we designed a field study to estimate the emission factors of PM2.5 (particulate matter of less than 2.5 µ diameter) and BC (black carbon) indoors, from cookstove smoke using biomass fuel and with smoke escaping outdoors from the roof of the house. The field study was conducted in four randomly selected households in two rural locations of southern Nepal during April 2017. In addition, real-time measurement of ambient PM2.5 was performed for 20 days during the campaign in those two rural sites and one background location to quantify the contribution of cooking-related emissions to the ambient PM2.5. Emission factor estimates indicate that 66% of PM2.5 and 80% of BC emissions from biomass cookstoves directly escape into ambient air. During the cooking period, ambient PM2.5 concentrations in the rural sites were observed to be 37% higher than in the nearby background location. Based on the World Health Organization (WHO)’s AirQ+ model simulation, this 37% rise in ambient PM2.5 during cooking hours can lead to approximately 82 cases of annual premature deaths among the rural population of Chitwan district.

Highlights

Exposure to polluted air has become a major concern in most of the low- and middle-income countries (LMIC) [1,2,3]
Variable carbon monoxide (CO)/black carbon (BC) and CO/PM2.5 ratios indicate that a certain portion of PM2.5 and BC was lost during transportation from near the cookstove to ambient conditions
Most of the PM2.5 may consist of semi-volatile aerosols such as organic carbon, which are converted from gas to particle phase and may be in liquid form

Summary

Introduction

Exposure to polluted air has become a major concern in most of the low- and middle-income countries (LMIC) [1,2,3]. In most of the LMIC, biomass fuel based cooking and heating is considered to be a significant source of household as well as ambient air pollution [2,3,4,5,6,7]. The avergae village level and background level PM2.5 concentration during cooking hours was found to be 116.94 ± 38.97 μg/m3 and 84.94 ± 18.96 μg/m3 respectively. The PM2.5 concentration during non-cooking hours for village and background were 67.64 ± 10.48 μg/m3 and 66.85 ± 8.58 μg/m3 respectively. We constructed a scatter plot between cooking and non-cooking hours PM2.5 concentration of the rural and background locations. The cooking period showed an enhancement of ~37% at the village site compared to the background site; while non-cooking hours had a similar PM2.5 level, indicating a well-mixed atmosphere and similar sources of emissions impacting all three sites during that period

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Conclusion