title: Low correlation between household carbon monoxide and particulate matter concentrations from biomass-related pollution in three resource-poor settings.
abstract: Household air pollution from the burning of biomass fuels is recognized as the third greatest contributor to the global burden of disease. Incomplete combustion of biomass fuels releases a complex mixture of carbon monoxide (CO), particulate matter (PM) and other toxins into the household environment. Some investigators have used indoor CO concentrations as a reliable surrogate of indoor PM concentrations; however, the assumption that indoor CO concentration is a reasonable proxy of indoor PM concentration has been a subject of controversy. We sought to describe the relationship between indoor PM2.5 and CO concentrations in 128 households across three resource-poor settings in Peru, Nepal, and Kenya. We simultaneously collected minute-to-minute PM2.5 and CO concentrations within a meter of the open-fire stove for approximately 24h using the EasyLog-USB-CO data logger (Lascar Electronics, Erie, PA) and the personal DataRAM-1000AN (Thermo Fisher Scientific Inc., Waltham, MA), respectively. We also collected information regarding household construction characteristics, and cooking practices of the primary cook. Average 24h indoor PM2.5 and CO concentrations ranged between 615 and 1440 μg/m(3), and between 9.1 and 35.1 ppm, respectively. Minute-to-minute indoor PM2.5 concentrations were in a safe range (<25 μg/m(3)) between 17% and 65% of the time, and exceeded 1000 μg/m(3) between 8% and 21% of the time, whereas indoor CO concentrations were in a safe range (<7 ppm) between 46% and 79% of the time and exceeded 50 ppm between 4%, and 20% of the time. Overall correlations between indoor PM2.5 and CO concentrations were low to moderate (Spearman ρ between 0.59 and 0.83). There was also poor agreement and evidence of proportional bias between observed indoor PM2.5 concentrations vs. those estimated based on indoor CO concentrations, with greater discordance at lower concentrations. Our analysis does not support the notion that indoor CO concentration is a surrogate marker for indoor PM2.5 concentration across all settings. Both are important markers of household air pollution with different health and environmental implications and should therefore be independently measured.
authors.affiliation: Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, USA.
authors.forename: Elizabeth M
authors.initials: EM
authors.lastname: Klasen
authors.affiliation: Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, USA.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Wills
authors.affiliation: Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, USA; Nepal Nutrition Intervention Project Sarlahi, Kathmandu, Nepal.
authors.forename: Neha
authors.initials: N
authors.lastname: Naithani
authors.affiliation: Program in Global Disease Epidemiology and Control, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Gilman
authors.affiliation: Department of Global Health, School of Public Health and Health Services, George Washington University, Washington DC, USA.
authors.forename: James M
authors.initials: JM
authors.lastname: Tielsch
authors.affiliation: Biomedical Research Unit, A.B. PRISMA, Lima, Peru.
authors.forename: Marilu
authors.initials: M
authors.lastname: Chiang
authors.affiliation: Nepal Nutrition Intervention Project Sarlahi, Kathmandu, Nepal.
authors.forename: Subarna
authors.initials: S
authors.lastname: Khatry
authors.affiliation: Department of Environmental Health Sciences, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA.
authors.forename: Patrick N
authors.initials: PN
authors.lastname: Breysse
authors.affiliation: School of Public Health, Moi University, Eldoret, Kenya; AMPATH (Academic Model Providing Access to Healthcare), Eldoret, Kenya.
authors.forename: Diana
authors.initials: D
authors.lastname: Menya
authors.affiliation: AMPATH (Academic Model Providing Access to Healthcare), Eldoret, Kenya.
authors.forename: Cosmas
authors.initials: C
authors.lastname: Apaka
authors.affiliation: AMPATH (Academic Model Providing Access to Healthcare), Eldoret, Kenya; Division of Pulmonary Medicine, The Warren Alpert School of Medicine, Brown University, Providence, USA.
authors.forename: E Jane
authors.initials: EJ
authors.lastname: Carter
authors.affiliation: AMPATH (Academic Model Providing Access to Healthcare), Eldoret, Kenya; Division of Pulmonary Medicine, The Warren Alpert School of Medicine, Brown University, Providence, USA.
authors.forename: Charles B
authors.initials: CB
authors.lastname: Sherman
authors.affiliation: CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: J Jaime
authors.initials: JJ
authors.lastname: Miranda
authors.affiliation: Division of Pulmonary and Critical Care, School of Medicine, Johns Hopkins University, Baltimore, USA; Program in Global Disease Epidemiology and Control, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, USA; CRONICAS Center of Excellence in Chronic Diseases, Universidad Peruana Cayetano Heredia, Lima, Peru. Electronic address: wcheckl1@jhmi.edu.
authors.forename: William
authors.initials: W
authors.lastname: Checkley
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis*; D018533:Biomass; D002248:Carbon Monoxide / Q000032:analysis*; D003296:Cooking; D004736:Energy-Generating Resources; D006798:Housing / Q000592:standards / Q000706:statistics & numerical data; D007630:Kenya; D009390:Nepal; D052638:Particulate Matter / Q000032:analysis*; D010568:Peru; D011203:Poverty; D012424:Rural Population / Q000706:statistics & numerical data
chemical_list: D052638:Particulate Matter; D002248:Carbon Monoxide
keywords: Biomass fuel smoke; Carbon monoxide; Particulate matter; Rndomized field trial