title: Environmental pathways of exposure to DDT for children living in a malarious area of Chiapas, Mexico.
abstract: Considering that DDT was used for control of malaria vectors in Mexico, and taking into account that the information regarding children in areas exposed to DDT is scarce, we started a research program for the assessment of health effects in children living in DDT sprayed areas. In this first report, we present information about pathways of exposure in two communities with a different history of exposure to DDT. Environmental pathways such as outdoor soils, indoor soils and household dust were assessed comparing a community highly exposed to DDT (HEC) and a community less exposed to DDT (LEC). Also in these communities, a cross-sectional study of 60 children (30 in each community) aged 6--12 years was conducted. Tests included a questionnaire and the measurement of whole blood DDT and DDE. Results show that in children living in the HEC, DDT and DDE mean blood levels were higher (15.9+/-8.2 and 58.2+/-29.2 microg/L) than in the LEC (1.9+/-3.6 and 9.2+/-5.7 microg/L) (P<0.01). Concentrations of DDT, DDE and DDD in indoor soil were higher in the HEC (10.3+/-10; 4.9+/-5.8; and 4.4+/-9.1mg/kg) than in the LEC (0.3+/-0.3; 0.04+/-0.06; and 0.03+/-0.04 mg/kg) (P<0.001). Similar results were obtained for outdoor soils; in the HEC, levels for DDT, DDE and DDD were 3.1+/-3.0; 1.0+/-0.8; and 0.3+/-0.2mg/kg; whereas levels in the LEC were 0.16+/-0.2; 0.02+/-0.03; and 0.02+/-0.03 mg/kg (P<0.001). High concentrations of DDT, DDE, and DDD were obtained in samples of indoor dust collected from the walls in the HEC (17.5+/-10.0; 5.5+/-6.2; and 9.8+/-16.8 mg/kg); levels in the LEC were lower (0.6+/-0.9; 0.07+/-0.1; and 0.05+/-0.07 mg/kg) (P<0.001). We did not find any correlation between blood levels of DDE and total DDT with environmental concentrations but there levels increased in LEC and HEC as the frequency of fish consumption increased (P<0.01).
authors.affiliation: Universidad Autónoma de Chiapas, Facultad de Ciencias Químicas, Laboratorio de Toxicología Ambiental, Km. 2 Carretera a Puerto Madero, CP 30700, Tapachula, Chiapas, México. cportugal@prodigy.net.mx
authors.forename: Crispín
authors.initials: C
authors.lastname: Herrera-Portugal
authors.forename: Héctor
authors.initials: H
authors.lastname: Ochoa
authors.forename: Guadalupe
authors.initials: G
authors.lastname: Franco-Sánchez
authors.forename: Leticia
authors.initials: L
authors.lastname: Yáñez
authors.forename: Fernando
authors.initials: F
authors.lastname: Díaz-Barriga
mesh_terms: D016902:Air Pollution, Indoor / Q000032:analysis; D002648:Child; D003634:DDT / Q000097:blood*; D003633:Dichlorodiphenyl Dichloroethylene / Q000097:blood*; D003632:Dichlorodiphenyldichloroethane / Q000097:blood*; D004391:Dust / Q000032:analysis; D004784:Environmental Monitoring; D005260:Female; D005506:Food Contamination; D006798:Housing; D006801:Humans; D007306:Insecticides / Q000097:blood; D008297:Male; D008800:Mexico; D010573:Pesticide Residues / Q000097:blood*; D017747:Seafood; D012989:Soil Pollutants / Q000032:analysis
chemical_list: D004391:Dust; D007306:Insecticides; D010573:Pesticide Residues; D012989:Soil Pollutants; D003633:Dichlorodiphenyl Dichloroethylene; D003634:DDT; D003632:Dichlorodiphenyldichloroethane