Distribution pathways of hexachlorocyclohexane isomers in a soil-plant-air system. A case study with Cynara scolymus L. and Erica sp. plants grown in a contaminated site.
This study focuses on the main routes of distribution and accumulation of different hexachlorocyclohexane (HCH) isomers (mainly alpha-, beta-, gamma- and delta-HCH) in a soil-plant-air system. A field assay was carried out with two plant species, Cynara scolymus L. and Erica sp., which were planted either: (i) directly in the HCH-contaminated soil; or (ii) in pots filled with uncontaminated soil, which were placed in the HCH-contaminated soil. Both plant species accumulated HCH in their tissues, with relatively higher accumulation in above-ground biomass than in roots. The beta-HCH isomer was the main isomer in all plant tissues. Adsorption of HCH by the roots from contaminated soil (soil-->root pathway) and adsorption through the aerial biomass from either the surrounding air, following volatilization of the contaminant (soil-->air-->shoot pathway), and/or contact with air-suspended particles contaminated with HCH (soil particles-->shoot pathway) were the main mechanisms of accumulation. These results may have important implications for the use of plants for reducing the transfer of contaminants via the atmosphere.
D000327:Adsorption; D000393:Air Pollutants / Q000032:analysis / Q000378:metabolism; D001673:Biodegradation, Environmental; D002849:Chromatography, Gas; D031943:Cynara scolymus / Q000378:metabolism; D004463:Ecology / Q000295:instrumentation / Q000379:methods; D004785:Environmental Pollutants / Q000032:analysis* / Q000378:metabolism; D029791:Ericaceae / Q000378:metabolism; D001556:Hexachlorocyclohexane / Q000032:analysis* / Q000378:metabolism; D007536:Isomerism; D018515:Plant Leaves / Q000737:chemistry / Q000378:metabolism; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D010944:Plants / Q000378:metabolism*; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism; D014835:Volatilization
D000393:Air Pollutants; D004785:Environmental Pollutants; D012987:Soil; D012989:Soil Pollutants; C040534:alpha-hexachlorocyclohexane; C086916:delta-hexachlorocyclohexane; D001556:Hexachlorocyclohexane; C023888:beta-hexachlorocyclohexane