R6 AM Plant Uptake of Organic Pollutants - Processes and Modeling
Thursday, 17 November 2005: 8:00 AM - 11:40 AM in 324-326

(BUR-1117-833900) Modeling the Uptake of Organic Contaminants from Soil into Plant Foliage.

Burris, J. ¹, Sample, B.², Hoff, D. ³, Ells, S. ⁴, ¹ Syracuse Research Corporation, Denver, CO, USA² USEPA, Washington, DC, USA³ USEPA Region 8, Denver, CO⁴

ABSTRACT- As part of EPAs effort to establish ecological soil screening values (Eco–SSLs), models were developed to estimate the uptake of non–ionic organic contaminants from soil into plant tissue. A limited literature search was completed and data were compiled from this as well as citations used in the Travis and Arms (1988) model. All data were extracted from published literature and studies were deemed acceptable if they presented measured analyte concentrations in soil and tissues of plants grown in that soil (paired data) and provided details concerning expsoure duration, sample collection and handling and analytical methods. Studies based on uptake from solution or by excised plants parts were excluded as were bioaccumulation data summarized in review papers. Rinsed and unrinsed data were segregated. Estimation of chemical concentrations in plant foliage was accomplished by either chemical–specific linear regressions relating the concentration in soil to the concentration in plant or by estimation using a predictive model based on the log Kow. For DDT and metabolites, ten separate polynuclear aromatic hydrocarbons (PAHs) and for PAHs as a group, chemical specific regression equations were identified. For other non-ionic organic contaminants, a regression model was developed relating the Kow of the chemical to the bioaccumulation factor (BAF). These models were added to the Eco–SSL guidance in March of 2005. Data will also be presented concerning uptake of non-ionic organics into roots and seeds.

Key words: Plant uptake, Non-ionic organic contaminants, Soil screening level, Bioaccumulation factor model