title: Genotoxicity of 2,4- and 2,6-dinitrotoluene as measured by the Tradescantia micronucleus (Trad-MCN) bioassay.
abstract: The phytogenotoxicity of 2,4-dinitrotoluene (2,4-DNT) and 2,6-dinitrotoluene (2,6-DNT) was assessed using the Tradescantia micronucleus (Trad-MCN) bioassay. Tradescantia cuttings bearing young inflorescences were exposed for 6h to 2,4- or 2,6-DNT amended water solutions up to their respective solubilities. The nominal concentrations were 0, 1.9, 3.8, 7.5, 15, 30, 60, 100, 150, 200mg/l of 2,4-DNT, and 0, 7.5, 15, 30, 60, 90, 120, 180mg/l of 2,6-DNT. Each treatment was repeated three or four times. Chemical concentrations in test solutions were analyzed prior to and after the exposure. Cadmium chloride (0-20mM) was used as the positive control. Micronuclei (MCN) were scored in the tetrad-stage pollen mother cells. The MCN frequency (%), i.e. the number of micronuclei scored in 100 tetrads, was the measurement endpoint. Results indicated that both 2,4-DNT and 2,6-DNT were genotoxic with the minimum effective dose (MED) of 30 and 135mg/l, respectively. Longer exposure (30h) without recovery time at 150mg/l of 2,4-DNT and 180mg/l of 2,6-DNT did not induce significantly higher MCN frequencies.
authors.affiliation: Biotechnology Research Institute, National Research Council of Canada, Montreal, Que., Canada.
authors.forename: Ping
authors.initials: P
authors.lastname: Gong
authors.forename: Roman G
authors.initials: RG
authors.lastname: Kuperman
authors.forename: Geoffrey I
authors.initials: GI
authors.lastname: Sunahara
mesh_terms: D000395:Air Pollutants, Occupational / Q000633:toxicity*; D004136:Dinitrobenzenes / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D015162:Micronucleus Tests; D009153:Mutagens / Q000633:toxicity*; D034823:Tradescantia / Q000235:genetics*
chemical_list: D000395:Air Pollutants, Occupational; D004136:Dinitrobenzenes; D009153:Mutagens; C016403:2,4-dinitrotoluene; C023514:2,6-dinitrotoluene