PARENT SESSION
IP10 - Vapor Phase Phytotoxicity Testing
Chair: Kapustka, Lawrence1, 1 5010 SW Hout Street, Corvallis, OR, USA
Co-chair: Gorsuch, Joseph2, Bradlee, Christopher3, 2 1100 Ridgeway Avenue, Rochester, NY, USA3 1609 Biddle Avenue, Wayandotte, MI
8:00 AM to 12:00 PM - Wednesday, 20 November 2002
Room Room 150 G
(IP80) Screening of plant species sensitivity to chronic exposures of atmospheric DBP.
Dueck, Tom*,1, Van Dijk, Chris1, David, Frank2, Vanwalleghem, Freddy2, Scholz, Norbert3, 1 Plant Research International, Wageningen, Netherlands2 Research Institute for Chromatography, Kortrijk, Belgium3 Oxeno, Marl, Germany
ABSTRACT- Experimental data on the effects of atmospheric di-n-butyl phthalate (DBP) on terrestrial plants is extremely scarce, thus a fumigation experiment was performed to assess its toxicity to a number of plant species. Pressurised air was bubbled through warmed liquid DBP to bring it into the gas phase and then injected into the air-stream of the plant fumigation chambers, maintaining constant concentrations for a period of 76 days. A number of the technical problems encountered and overcome in this procedure are described. The realized mean concentrations were 0.14, 0.81, 1.37, 3.07 and 13.67 
g m-3 DBP. Visual injury was observed on all species, varying from chlorosis and necrosis (Brassica campestris, Trifolium repens and Holcus lanatus), leaf crinkling (Plantago major) to a loss of color in the leaves and needles (Phaseolus vulgaris, Picea abies). Species sensitivity to atmospheric DBP was quantified on the basis of whole plant biomass to derive no-observable-effect-concentrations (NOECs). Significant dose-response relationships were derived using non-linear regression. These results indicate that it is not B. campestris, but T. repens which appears to be the most sensitive species to DBP. A significant reduction in growth was also observed for Holcus lanatus, but due to the variation at lower levels of DBP exposure, no NOEC could be derived. No significant effect on the growth of Piciea abies was observed. Differences in the biomass produced by shoots and roots exposed to DBP were observed. The above-ground biomass produced by B. campestris and T. repens, the two most sensitive species, was shown to be significantly more affected than their roots, while for P. major and P. vulgaris, the opposite was observed. The amount of reproductive biomass in the form of bean pods was also significantly reduced by DBP for P. vulgaris.
Key words: di-n-butyl-phthalate, atmospheric, fumigation system, plants