title: Maternal exposure to biomass smoke and carbon monoxide in relation to adverse pregnancy outcome in two high altitude cities of Peru.
abstract: BACKGROUND
  Exposure to pollution from biomass fuel has been associated with low birthweight in some studies. Few studies have included exposure-response analyses.
  
  
  METHODS
  We conducted a case-control study of biomass fuel use and reproductive outcome at high altitude in Peru. Cases (n=101) were full term births who were SGA (birth weight <10th percentile for gestational age). Controls (n=101) had a birthweight ≥10th percentile, and were matched to cases on birth week and residence. Biomass fuel use during pregnancy was determined by questionnaire. Carbon monoxide (CO) in the kitchen was measured in a subgroup (n=72). Logistic regression was used to estimate the effects of biofuel and CO on the risk of SGA, controlling for maternal education and parity.
  
  
  RESULTS
  Among cases, 30%, 27% and 44% used gas, gas+biomass, and biomass, respectively, while the figures for controls were 39%, 33%, and 29%. The adjusted odds ratio (OR) for biomass fuel alone compared with gas alone was 4.5 (95% CI: 1.3, 15.5, p=0.02), while the OR for biomass+gas vs. gas alone was 2.1 (0.80-5.5) (p=0.13). Among the subgroup with measured CO, the mean 48-h kitchen CO levels were 4.8, 2.2 and 0.4ppm for biofuel only, biofuel+gas, and gas respectively. ORs by increasing tertile of CO level were 1.0, 1.16, and 3.53 (test for trend, p=0.02). The exposure-response trend corresponds well with one other study with analogous data.
  
  
  CONCLUSIONS
  Despite limited sample size, our data suggest that maternal exposure to biomass smoke and CO, at high altitude, is associated with SGA among term births.
authors.affiliation: Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: S
authors.initials: S
authors.lastname: Yucra
authors.affiliation: Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: V
authors.initials: V
authors.lastname: Tapia
authors.affiliation: Rollins School of Public Health, Emory University, Atlanta, 1518 Clifton Rd., GA 30322, United States. Electronic address: nsteenl@emory.edu.
authors.forename: K
authors.initials: K
authors.lastname: Steenland
authors.affiliation: University of Georgia, Athens, GA, United States.
authors.forename: L P
authors.initials: LP
authors.lastname: Naeher
authors.affiliation: Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: G F
authors.initials: GF
authors.lastname: Gonzales
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D018533:Biomass; D002248:Carbon Monoxide / Q000633:toxicity*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007236:Infant, Small for Gestational Age; D016015:Logistic Models; D018811:Maternal Exposure / Q000009:adverse effects*; D010568:Peru; D011247:Pregnancy; D011256:Pregnancy Outcome; D012424:Rural Population; D012906:Smoke; D011795:Surveys and Questionnaires; D014505:Urban Population
chemical_list: D000393:Air Pollutants; D012906:Smoke; D002248:Carbon Monoxide
keywords: Altitude; Biomass; Carbon monoxide; Peru; Small for gestational age