title: Phytotoxicity and bioaccumulation of copper and chromium using barley (Hordeum vulgare L.) in spiked artificial and natural forest soils.
abstract: The toxicities of two heavy metals, copper (Cu2+) and chromium (Cr6+), to barley (Hordeum vulgare L.) were evaluated using two types of substrates: artificial and natural forest soils. Phytotoxicity was assessed using a standardized toxicity test. Endpoints included plant emergence and shoot and root growth. Shoot and root concentrations of Cu and Cr were also measured. Data indicated that the root biomass was the most sensitive endpoint. The results showed that toxicity of Cr to root growth (IC50=6.6 microg/g in artificial soil; IC50=61.8 microg/g in forest soil) was higher than that of Cu (IC50=13.7 microg/g in artificial soil; IC50>322 microg/g in forest soil). Data also indicated that the toxicity of Cu and Cr was significantly decreased in the spiked forest soil, suggesting lower metal bioavailability to barley in the natural soil. Analysis of tissue concentrations in barley showed that Cu and Cr were mainly accumulated in the roots. Toxicity was correlated with Cr residues in shoots (< or =11.2 microg Cr/g and < or =5.3 microg Cr/g for artificial and natural soils, respectively) and roots (< or =161 microg Cr/g and < or =51.7 microg Cr/g for artificial and natural soils, respectively) and Cu residues in roots (< or =61.8 microg Cu/g and < or =91.3 microg Cu/g for artificial and natural soils, respectively). Cu concentration in shoot tissues was < or =61.8 microg Cu/g. Since it may overestimate toxicity, effect and risk assessment using spiked soils, particularly in artificial soil, must be used with diligence.
authors.affiliation: Applied Ecotoxicology Group, Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montreal, QC, Canada H4P 2R2.
authors.forename: Nadia Ait
authors.initials: NA
authors.lastname: Ali
authors.forename: Mohammed
authors.initials: M
authors.lastname: Ater
authors.forename: Geoffrey I
authors.initials: GI
authors.lastname: Sunahara
authors.forename: Pierre Yves
authors.initials: PY
authors.lastname: Robidoux
mesh_terms: D018533:Biomass; D002857:Chromium / Q000493:pharmacokinetics* / Q000633:toxicity*; D003300:Copper / Q000493:pharmacokinetics* / Q000633:toxicity*; D001467:Hordeum / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D018517:Plant Roots / Q000254:growth & development; D018570:Risk Assessment; D012989:Soil Pollutants / Q000493:pharmacokinetics* / Q000633:toxicity*; D014018:Tissue Distribution; D014197:Trees
chemical_list: D012989:Soil Pollutants; D002857:Chromium; D003300:Copper