Phytotoxicity of hexachlorocyclohexane: Effect on germination and early growth of different plant species.

The aim of the present study was to select candidate plant species for phytoremediation of soils contaminated with hexachlorocyclohexane (HCH). For this purpose, an experiment was carried out under controlled conditions of germination and growth, with nine plant species of economic and/or agricultural interest, in a soil contaminated with a heterogeneous mixture (at eight different levels of contamination) of the main HCH isomers (alpha-, beta-, gamma- and delta-HCH). The results revealed differences in the plant responses to the control soil and the soils containing HCH. Germination was not as strongly affected as other parameters such as the rate of germination and seedling vigour. In general, all of the species displayed signs of stress in response to the presence of HCH, although to different degrees. Some of the species used in the experiment (Hordeum vulgare L., Brassica sp., Phaseoulus vulgaris L.) were capable of mitigating the negative effects of HCH, and displayed a certain degree of resistance, as their biomass production was not greatly affected by the contaminant. These (tolerant) plants therefore appear to be ideal for phytoremediation purposes.