title: The urban environment and children's health: soils as an integrator of lead, zinc, and cadmium in New Orleans, louisiana, U.S.A.
abstract: Soils are evaluated as a diagnostic tool of environmental conditions that influence health. The samples for this study are urban topsoil (0-2.5 cm depth) samples (n=4026) analyzed for Pb, Zn, and Cd by inductively coupled plasma-atomic emission spectrometry (ICP-AES). The parent materials for New Orleans soils are derived from the Mississippi River, and alluvium from the Bonnet Carré Spillway (n=31) serve as control samples for this study. The urban samples were stratified by census tract (n=286). Blood Pb (BL) levels of children </=6 years were also stratified by census tract and paired with soil Pb (SL) (n=175). A significant association (P=1.2x10(-23)) was found between median BL and median SL. The association was modeled by BL=3.06+0.33 (SL)(0.5) (correlation coefficient=0.69 between the modeled BL and the observed BL and P=3.5x10(-22)). A median SL threshold (>/=310 microgram g(-1) and <310 microgram g(-1)) for higher metal census tracts (HMCTs) and lower metal census tracts (LMCTs), respectively, represents median BL exposures above and below 9 microgram dL(-1). HMCTs and LMCTs were characterized by demographic and socioeconomic data. HMCTs are more likely (P=4. 5x10(-6)) inhabited by Blacks than by Whites. Of 13,803 children </=6 years in HMCTs, 75% are Black and 22% are White, with other making up the remaining 3%. In LMCTs, the Black to White children ratio is 50:50. In HMCTs, socioeconomic indicators for Blacks are depressed compared to Whites. Zn and Cd are potentially phytotoxic in HMCTs. Children exhibit a steep rise in BL at SL <100 microgram g(-1), and empirically, a safe SL for most children is around 80 microgram++ g(-1). SL is a useful diagnostic tool, and curtailing SL may complement primary Pb prevention for children.
authors.affiliation: College of Pharmacy, Xavier University, New Orleans, Louisiana, 70125, USA.
authors.forename: H W
authors.initials: HW
authors.lastname: Mielke
authors.forename: C R
authors.initials: CR
authors.lastname: Gonzales
authors.forename: M K
authors.initials: MK
authors.lastname: Smith
authors.forename: P W
authors.initials: PW
authors.lastname: Mielke
mesh_terms: D002104:Cadmium / Q000032:analysis* / Q000633:toxicity; D002648:Child; D005260:Female; D006801:Humans; D007854:Lead / Q000032:analysis* / Q000097:blood; D007855:Lead Poisoning / Q000209:etiology*; D008297:Male; D012959:Socioeconomic Factors; D012989:Soil Pollutants / Q000032:analysis* / Q000633:toxicity; D015032:Zinc / Q000032:analysis* / Q000633:toxicity
chemical_list: D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead; D015032:Zinc