title: A cross-sectional analytical study of geophagia practices and blood metal concentrations in pregnant women in Johannesburg, South Africa.
abstract: BACKGROUND
  Geophagia, a form of pica, has been shown to be widely practised in sub-Saharan Africa, especially among pregnant women.
  
  
  OBJECTIVE
  To assess the prevalence of geophagia and examine exposure to selected metals and associated risk factors in women attending an antenatal clinic at Rahima Moosa Mother and Child Hospital, Johannesburg, South Africa, during June and July 2010.
  
  
  METHODS
  We conducted a cross-sectional study on a convenience sample of 307 pregnant women, ranging in age from 18 to 46 years. Structured interviews were conducted to understand geophagia practices. Blood samples were collected to determine haemoglobin values and concentrations of arsenic, cadmium, mercury and lead. Statistical analyses using the χ2 test, Wilcoxon's rank-sum test and logistic regression analyses were performed as appropriate.
  
  
  RESULTS
  Mean parity was 1.4 and the mean (standard deviation) gestational age 30.3 (6.0) weeks. Geophagia was reported by 60 women (19.5%), and the majority purchased soil from street vendors (83.3%). The prevalence of anaemia in the study sample was 16.9% (95% confidence interval 13.1 - 21.6%). Geophagic women had significantly higher blood lead levels than non-geophagic women (2.1 v. 1.4 µg/dl; p<0.001). Anaemia, the use of African traditional medicines and craving of non-nutritive substances in a previous pregnancy were associated with geophagia.
  
  
  CONCLUSIONS
  Geophagia is practised by a considerable proportion of pregnant women in Johannesburg, especially migrant women. Greater vigilance in respect of pica, especially geophagia, may be needed as part of antenatal care programmes to avoid potentially detrimental health effects of the practice.
authors.affiliation: Environment and Health Research Unit, South African Medical Research Council, Johannesburg, South Africa; School of Public Health, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg; Faculty of Health Sciences, University of Johannesburg, South Africa. angela.mathee@mrc.ac.za.
authors.forename: Angela
authors.initials: A
authors.lastname: Mathee
authors.forename: Nisha
authors.initials: N
authors.lastname: Naicker
authors.forename: Tahira
authors.initials: T
authors.lastname: Kootbodien
authors.forename: Tshepo
authors.initials: T
authors.lastname: Mahuma
authors.forename: Palesa
authors.initials: P
authors.lastname: Nkomo
authors.forename: Inakshi
authors.initials: I
authors.lastname: Naik
authors.forename: Thea
authors.initials: T
authors.lastname: de Wet
mesh_terms: D000293:Adolescent; D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D016015:Logistic Models; D008670:Metals / Q000097:blood*; D008875:Middle Aged; D010842:Pica / Q000097:blood / Q000453:epidemiology*; D011247:Pregnancy; D011248:Pregnancy Complications / Q000097:blood / Q000453:epidemiology*; D015995:Prevalence; D013019:South Africa / Q000453:epidemiology
chemical_list: D008670:Metals