title: Spatial clustering of toxic trace elements in adolescents around the Torreón, Mexico lead-zinc smelter.
abstract: High blood lead (BPb) levels in children and elevated soil and dust arsenic, cadmium, and lead were previously found in Torreón, northern Mexico, host to the world's fourth largest lead-zinc metal smelter. The objectives of this study were to determine spatial distributions of adolescents with higher BPb and creatinine-corrected urine total arsenic, cadmium, molybdenum, thallium, and uranium around the smelter. Cross-sectional study of 512 male and female subjects 12-15 years of age was conducted. We measured BPb by graphite furnace atomic absorption spectrometry and urine trace elements by inductively coupled plasma-mass spectrometry, with dynamic reaction cell mode for arsenic. We constructed multiple regression models including sociodemographic variables and adjusted for subject residence spatial correlation with spatial lag or error terms. We applied local indicators of spatial association statistics to model residuals to identify hot spots of significant spatial clusters of subjects with higher trace elements. We found spatial clusters of subjects with elevated BPb (range 3.6-14.7 μg/dl) and urine cadmium (0.18-1.14 μg/g creatinine) adjacent to and downwind of the smelter and elevated urine thallium (0.28-0.93 μg/g creatinine) and uranium (0.07-0.13 μg/g creatinine) near ore transport routes, former waste, and industrial discharge sites. The conclusion derived from this study was that spatial clustering of adolescents with high BPb and urine cadmium adjacent to and downwind of the smelter and residual waste pile, areas identified over a decade ago with high lead and cadmium in soil and dust, suggests that past and/or present plant operations continue to present health risks to children in those neighborhoods.
authors.affiliation: 1] Facultad de Medicina, Universidad Juárez del Estado de Durango, Gómez Palacio Durango, México [2] Secretaría de Salud del Estado de Coahuila, Coahuila, México.
authors.forename: Gonzalo G
authors.initials: GG
authors.lastname: Garcia-Vargas
authors.affiliation: Centro de Investigación en Salud Poblacional, Instituto Nacional de Salud Pública, Cuernavaca, Morelos, México.
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Rothenberg
authors.affiliation: 1] Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [2] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Ellen K
authors.initials: EK
authors.lastname: Silbergeld
authors.affiliation: 1] Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [2] Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [3] Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
authors.forename: Virginia
authors.initials: V
authors.lastname: Weaver
authors.affiliation: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Rachel
authors.initials: R
authors.lastname: Zamoiski
authors.affiliation: Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Carol
authors.initials: C
authors.lastname: Resnick
authors.affiliation: Facultad de Medicina, Universidad Juárez del Estado de Durango, Gómez Palacio Durango, México.
authors.forename: Marisela
authors.initials: M
authors.lastname: Rubio-Andrade
authors.affiliation: 1] Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, New York, USA [2] Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, New York, USA.
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Parsons
authors.affiliation: 1] Laboratory of Inorganic and Nuclear Chemistry, Wadsworth Center, New York State Department of Health, Albany, New York, USA [2] Department of Environmental Health Sciences, School of Public Health, University at Albany, Albany, New York, USA.
authors.forename: Amy J
authors.initials: AJ
authors.lastname: Steuerwald
authors.affiliation: 1] Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [2] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [3] Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Ana
authors.initials: A
authors.lastname: Navas-Acién
authors.affiliation: 1] Department of Environmental Health Sciences, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [2] Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA [3] Welch Center for Prevention, Epidemiology, and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA.
authors.forename: Eliseo
authors.initials: E
authors.lastname: Guallar
mesh_terms: D000293:Adolescent; D001151:Arsenic / Q000652:urine; D002648:Child; D016000:Cluster Analysis; D003404:Creatinine / Q000652:urine*; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000009:adverse effects*; D004785:Environmental Pollutants / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007854:Lead; D008297:Male; D008669:Metallurgy; D019216:Metals, Heavy / Q000097:blood* / Q000652:urine*; D008800:Mexico; D012044:Regression Analysis; D062206:Spatial Analysis; D013054:Spectrophotometry, Atomic; D011795:Surveys and Questionnaires; D014131:Trace Elements / Q000097:blood / Q000652:urine; D015032:Zinc
chemical_list: D004785:Environmental Pollutants; D019216:Metals, Heavy; D014131:Trace Elements; D007854:Lead; D003404:Creatinine; D015032:Zinc; D001151:Arsenic