PARENT SESSION
PS9 - Plant Toxicology
Sunday, 17 November 2002
8:00 AM to 6:30 PM
Exhibit Hall
(P111) Soil Phytotoxicity Resulting fromToxic Chemicals and their Combustion Byproducts after Train Derailment.
Black, Clanton*,1, Counce, Paul2, Ruppert, D.3, Irvin, Thomas3, 1 The University of Georgia, Athens, Georgia, USA2 The University of Arkansas Rice Research and Extension Center, Stuttgart, Arkansas, USA3 Registry Consultants, Atlanta, Georgia, USA
ABSTRACT- We have characterized, in qualitative and quantitative terms, the in vitro and in vivo phytoxicity of soils collected from farming lands adjacent to site of a train derailment which released toxic chemicals near Eunice, LA in May, 2000. Airborne toxic chemicals contained on the train and released into the adjacent environment included phenol, dichloropropane, toluene di-isocyanate, methyl chloride, acrylic acid, and hexanes; these toxicants also ignited and burned for up to five days after the derailment. Literature data on the individual agents reported a wide spectra of biological effects including phytotoxicity. Air-dispersion models of each toxicant report airborne concentrations reached biologically-active levels more than 20 kilometers from the derailment site; in addition, a five mile radius area was temporarily embargoed from crop harvesting. To evaluate the phytotoxicity of these toxicants and their combustion byproducts, four rice fields were selected from areas bounded by the air dispersion models and known to have been exposed to biologically-active concentrations of train-derived toxicants. Rice growth in selected impacted fields was found to be significantly inhibited as compared to control areas. Soils were also collected from impacted areas as well as control areas and evaluated in a radish (Paphanus sativus) and rice (Orysz sativa) germination, growth and development study. Results from the in vitro germination study correlated with results from in vivo field study. Radish germination studies showed decreased germination for selected impacted sites; rice studies also indicated germination was inhibited. These results document the soil phytoxicity created by the airborne complex mixture of train toxicants and combustion byproducts. These results also provide a model system with which to document plant and ecosystem damage from toxic chemical releases in which acute as well as chronic ecosystem effects are of concern.
Key words: soil toxicology, train derailment , airborne toxicants , plant toxicity