HR: 08:45h
AN: B31A-02    [Abstracts]
TI: Bioavailability Of Arsenic In Arsenical Pesticide-Amended Soils: Preliminary Greenhouse Study
AU: * Quazi, S
EM: squazi@utsa.edu
AF: University Of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249 United States
AU: Sarkar, D
EM: dsarkar@utsa.edu
AF: University Of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249 United States
AU: Khairom, A
EM: akhairom@utsa.edu
AF: University Of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249 United States
AU: Datta, R
EM: rdatta@utsa.edu
AF: University Of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249 United States
AU: Sharma, S
EM: ssharma@utsa.edu
AF: University Of Texas at San Antonio, 6900 North Loop 1604 West, San Antonio, TX 78249 United States
AB: Long-term application of arsenical pesticides in agricultural lands has resulted in high levels of arsenic (As). Conversion of former agricultural lands to residential areas has resulted in increased human contact with soil As. Soil ingestion from incidental hand-to-mouth activity by children is now a very important issue in assessing human health risk associated with exposure to arsenical pesticide-applied former agricultural soils. Human health risk from direct exposure to soil As via hand to mouth action is restricted only to those fractions of As in the soil that are available to the human gastrointestinal system. Thus this study aimed at addressing the issue of soil variability on As bioavailability as a function of soil physiochemical properties in a dynamic interaction between soils, water and plants and pesticides. In the current greenhouse study two soils with drastically different chemical characteristics w.r.t As reactivity (Immokalee-low As retention potential and Millhopper-high As retention potential) and one pesticide (sodium arsenate) were used. Soils were amended with sodium arsenate at two rates representing the high and low ends of As contamination, generally representative of Superfunds site conditions: 675 and 1500 mg/kg As. Rice (Oryza sativa) was used as the test crop. Sequential digestion to estimate in-vitro As in the stomach phase and the intestinal phase was employed on soils sampled at 4 times: 0-time, after 3 mo, 6 mo and 9 mo of soil-pesticide equilibration. In-vitro bioavailability experiments were also performed with the same soils in order to obtain an estimate of the amount of As that would be absorbed to the intestinal linings in simulated systems. Following the greenhouse study, selective in-vivo bioavailability studies using As-contaminated soils will be conducted on male and female mice to correlate in-vitro results with the in-vivo data. Treatments will consist of a soil group (As in soil), a positive control group (only As) and a negative control group (no soil, no As). Results from the in-vitro and in-vivo studies will help understand the effects of soil properties on As bioavailability. Keywords: Bioavailability, pesticide, soil, arsenic, greenhouse.
DE: 0400 Biogeosciences
DE: 1803 Anthropogenic effects
DE: 4825 Geochemistry
DE: 4857 Pollution
DE: 4875 Trace elements
SC: Biogeosciences [B]
MN: 2005 Joint Assembly