title: Indoor carbon monoxide and PM2.5 concentrations by cooking  fuels in Pakistan.
abstract: In developing countries biomass combustion is a frequently used source of domestic energy and may cause indoor air pollution. Carbon monoxide (CO)and particulate matter with an aerodynamic diameter of 2.5 lm or less (PM2.5)were measured in kitchens using wood or natural gas (NG) in a semi-rural community in Pakistan. Daytime CO and PM2.5 levels were measured for eight continuous hours in 51 wood and 44 NG users from December 2005 to April 2006. The laser photometer PM2.5 (Dustrak, TSI) was calibrated for field conditions and PM2.5 measurements were reduced by a factor of 2.77. CO was measured by an electrochemical monitor (Model T15v, Langan). The arithmetic mean for daytime CO concentration was 29.4 ppm in wood users; significantly higher than 7.5 ppm in NG users (P < 0.001). The arithmetic mean for daytime PM2.5 concentrations was 2.74 mg/m3 in wood users; significantly higher than 0.38 mg/m3 in NG users (P < 0.001). Higher peak levels of CO and PM2.5 were also observed in wood users. Time spent in the kitchen during fuel burning was significantly related to increasing CO and PM2.5 concentrations in wood users.These findings suggest that cooking with wood fuel may lead to hazardous concentrations of CO and PM2.5.
  
  
  CONCLUSIONS
  Biomass combustion is frequently used in developing countries for cooking. This study showed very high level of air pollution in kitchens using wood as the cooking fuel. Many people, especially women and children, are vulnerable to exposure to very high levels of air pollutants as they spend time in the kitchen during cooking hours.
authors.affiliation: Department of Public Health Sciences, University of California at Davis, CA, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Siddiqui
authors.forename: K
authors.initials: K
authors.lastname: Lee
authors.forename: D
authors.initials: D
authors.lastname: Bennett
authors.forename: X
authors.initials: X
authors.lastname: Yang
authors.forename: K H
authors.initials: KH
authors.lastname: Brown
authors.forename: Z A
authors.initials: ZA
authors.lastname: Bhutta
authors.forename: E B
authors.initials: EB
authors.lastname: Gold
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000032:analysis*; D016902:Air Pollution, Indoor / Q000032:analysis*; D002248:Carbon Monoxide / Q000032:analysis*; D003296:Cooking; D005260:Female; D005579:Fossil Fuels / Q000009:adverse effects*; D006798:Housing; D006801:Humans; D016014:Linear Models; D010154:Pakistan; D052638:Particulate Matter / Q000032:analysis*; D014934:Wood; D055815:Young Adult
chemical_list: D000393:Air Pollutants; D005579:Fossil Fuels; D052638:Particulate Matter; D002248:Carbon Monoxide