Patterns of domestic exposure to carbon monoxide and particulate matter in households using biomass fuel in Janakpur, Nepal

J.G. Ayres,J. Gulliver,N.M. Saville,D. Devakumar,S.E. Bartington,D. Osrin,A.L. Hansell,O.P. Kurmi,I. Bakolis,A. Costello,G. Chaube,D.S. Manandhar

doi:10.1016/j.envpol.2016.08.074

Abstract

Household Air Pollution (HAP) from biomass cooking fuels is a major cause of morbidity and mortality in low-income settings worldwide. In Nepal the use of open stoves with solid biomass fuels is the primary method of domestic cooking. To assess patterns of domestic air pollution we performed continuous measurement of carbon monoxide (CO) and particulate Matter (PM2.5) in 12 biomass fuel households in Janakpur, Nepal. We measured kitchen PM2.5 and CO concentrations at one-minute intervals for an approximately 48-h period using the TSI DustTrak II 8530/SidePak AM510 (TSI Inc, St. Paul MN, USA) or EL-USB-CO data logger (Lascar Electronics, Erie PA, USA) respectively. We also obtained information regarding fuel, stove and kitchen characteristics and cooking activity patterns. Household cooking was performed in two daily sessions (median total duration 4 h) with diurnal variability in pollutant concentrations reflecting morning and evening cooking sessions and peak concentrations associated with fire-lighting. We observed a strong linear relationship between PM2.5 measurements obtained by co-located photometric and gravimetric monitoring devices, providing local calibration factors of 4.9 (DustTrak) and 2.7 (SidePak). Overall 48-h average CO and PM2.5 concentrations were 5.4 (SD 4.3) ppm (12 households) and 417.6 (SD 686.4) μg/m3 (8 households), respectively, with higher average concentrations associated with cooking and heating activities. Overall average PM2.5 concentrations and peak 1-h CO concentrations exceeded WHO Indoor Air Quality Guidelines. Average hourly PM2.5 and CO concentrations were moderately correlated (r = 0.52), suggesting that CO has limited utility as a proxy measure for PM2.5 exposure assessment in this setting. Domestic indoor air quality levels associated with biomass fuel combustion in this region exceed WHO Indoor Air Quality standards and are in the hazardous range for human health.

Highlights

Household Air Pollution (HAP) is a major global cause of morbidity and mortality, estimated to be responsible for 3.5 million premature deaths each year (Lim et al, 2012)
Overall diurnal pollutant patterns were similar in pattern but lower in magnitude than those reported from the Sarlahi District of Nepal, where average 24-h pollutant concentrations of carbon monoxide (CO)
Our findings indicate that domestic CO and PM2.5 levels in biomass fuel households in this area of Nepal frequently exceed World Health Organization (WHO) Air Quality Standards and are likely to contribute to increased morbidity, mortality and adverse birth outcomes

Summary

Introduction

Household Air Pollution (HAP) is a major global cause of morbidity and mortality, estimated to be responsible for 3.5 million premature deaths each year (Lim et al, 2012). The greatest disease burden is in low-income countries, due to reliance upon coal and biomass fuels including wood, crop residues and animal dung as the principal energy source for domestic cooking, heating and lighting (Bruce et al, 2000; Rehfuess et al, 2006). Solid fuel combustion results in emission of harmful airborne pollutants including particulate matter (PM), carbon monoxide (CO), and other toxic organic compounds (Fullerton et al, 2008; Smith, 2002). In Nepal it is estimated that approximately 80% of households use biomass as the principal source of domestic energy (Central Bureau of Statistics, 2011), with cooking typically performed on traditional open stoves with limited household ventilation. There remains limited information regarding the characteristics and determinants of daily exposure patterns (Gurung and Bell, 2013)

Methods

Results

Discussion

Conclusion