title: Patterns of domestic exposure to carbon monoxide and particulate matter in households using biomass fuel in Janakpur, Nepal.
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 PM2.5and 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 PM2.5measurements 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 PM2.5concentrations 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 PM2.5concentrations and peak 1-h CO concentrations exceeded WHO Indoor Air Quality Guidelines. Average hourly PM2.5and CO concentrations were moderately correlated (r = 0.52), suggesting that CO has limited utility as a proxy measure for PM2.5exposure 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.
authors.affiliation: Institute of Applied Health Research, University of Birmingham, Birmingham, B15 2TT, UK. Electronic address: s.bartington@birmingham.ac.uk.
authors.forename: S E
authors.initials: SE
authors.lastname: Bartington
authors.affiliation: UK Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London W2 1PG, UK; Department of Biostatistics, Institute of Psychiatry, Psychology and Neuroscience, De Crespigny Park, London SE5 8AF, UK; Department of Health Services and Population Research, Institute of Psychiatry, Psychology and Neuroscience, De Crespigny Park, London SE5 8AF, UK.
authors.forename: I
authors.initials: I
authors.lastname: Bakolis
authors.affiliation: UCL Institute for Global Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
authors.forename: D
authors.initials: D
authors.lastname: Devakumar
authors.affiliation: Clinical Trial Service Unit and Epidemiological Studies Unit (CTSU), Nuffield Department of Population Health, Old Road Campus, Oxford OX3 7LF, UK.
authors.forename: O P
authors.initials: OP
authors.lastname: Kurmi
authors.affiliation: UK Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London W2 1PG, UK.
authors.forename: J
authors.initials: J
authors.lastname: Gulliver
authors.affiliation: Mother and Infant Research Activities (MIRA), Kathmandu 44600, Nepal.
authors.forename: G
authors.initials: G
authors.lastname: Chaube
authors.affiliation: Mother and Infant Research Activities (MIRA), Kathmandu 44600, Nepal.
authors.forename: D S
authors.initials: DS
authors.lastname: Manandhar
authors.affiliation: UCL Institute for Global Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
authors.forename: N M
authors.initials: NM
authors.lastname: Saville
authors.affiliation: UCL Institute for Global Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
authors.forename: A
authors.initials: A
authors.lastname: Costello
authors.affiliation: UCL Institute for Global Health, University College London, 30 Guilford Street, London WC1N 1EH, UK.
authors.forename: D
authors.initials: D
authors.lastname: Osrin
authors.affiliation: UK Small Area Health Statistics Unit, MRC-PHE Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College, London W2 1PG, UK; Imperial College Healthcare NHS Trust, London, UK.
authors.forename: A L
authors.initials: AL
authors.lastname: Hansell
authors.affiliation: Institute of Occupational and Environmental Medicine, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK.
authors.forename: J G
authors.initials: JG
authors.lastname: Ayres
mesh_terms: D000397:Air Pollution; D016902:Air Pollution, Indoor / Q000032:analysis / Q000706:statistics & numerical data*; D018533:Biomass; D002248:Carbon Monoxide / Q000032:analysis*; D003296:Cooking / Q000379:methods* / Q000706:statistics & numerical data; D005191:Family Characteristics; D005390:Fires; D006361:Heating; D006801:Humans; D019570:Inhalation Exposure / Q000706:statistics & numerical data*; D009390:Nepal; D052638:Particulate Matter / Q000032:analysis*; D011203:Poverty
chemical_list: D052638:Particulate Matter; D002248:Carbon Monoxide
keywords: Biomass; Carbon monoxide; Exposure assessment; Household air pollution; Nepal; Particulate matter