HR: 0800h
AN: H51A-03    [Abstracts]
TI: Lead isotope fingerprints of childhood lead poisoning in Torreón, México
AU: * SOTO-JIMENEZ, M
EM: martin@ola.icmyl.unam.mx
AF: Universidad Nacional Autonoma de Mexico, Av. Joel Montes Camarena, Mazatlan, SIN 82040, Mexico
AU: Flegal, R
EM: flegal@etox.ucsc.edu
AF: University of California Santa Cruz, Department of Environmental Toxicology 430 Physical Sciences Building University of California, Santa Cruz, CAL 95064, United States
AB: A comparison of high-precision lead isotopic ratios in blood and environmental samples was conducted to identify sources of lead contamination in thirty-four (34) children living near a silver-zinc-lead smelter plant at Torreón, Mexico. Sixty-five (65) samples of street and ceiling dust and six of atmospheric deposition to collect smelter emissions from a four (4) km2 grid covering the smelter surrounding residential areas were analyzed for lead concentrations and stable isotopic compositions. Lead concentrations in the study area ranged from 400 to 15,400 g/g and 400 to 14,500 g/g in street and ceiling dust, respectively. These indicated orders of magnitude contamination, based on regional background concentrations ranging from 15 to 35 g/g. Concentrations were greatest closest to smelter and decreased with distance from the smelter, with the highest levels southeast of the smelter corresponding with prevailing the wind direction; and atmospheric lead depositions varied between 130- 1350 g/m2d, again with highest rates within the 1 km perimeter of the smelter. Blood lead (PbB) levels in the children (ages ranges 2-17 years) ranged from 6.9 to 37.7 μg/dL with a mean of 16.3 μg/dl (sd = 8.2 μg/dL). Based on interviews, most of those children have been exposed to lead emissions from the smelter since they were in utero. In all cases, lead isotopic ratios (206Pb/207Pb: 208Pb/207Pb) on dust urban (1.200±0.009: 2.467±0.003), deposited particles (1.200±0.002: 2.466±0.002), and PbB (1.199±0.001: 2.468±0.002) were consistent with those of domestic lead ores processed at the smelter (1.199±0.007: 2.473±0.007). Consequently, both exceptionally elevated PbB concentrations of children living near the smelter and the distinctive isotopic composition of that PbB attest to pollution from the lead smelter in Torreón, México.
DE: 1041 Stable isotope geochemistry (0454, 4870)
DE: 4870 Stable isotopes (0454, 1041)
SC: Hydrology [H]
MN: 2007 Joint Assembly