title: Mutagenic Effects of Potassium Dichromate as Evaluated by Means of Animal and Plant Bioindicators.
abstract: BACKGROUND
  Chromium typically occurs in two oxidation states in the natural environment, Cr(3+) [Cr(III)] and Cr(6+) [Cr(VI)]. Out of the two chromium species, Cr(VI) is the most mobile, labile and toxic. Hexavalent chromium [Cr(VI)] compounds are classified by the International Agency for Research on Cancer (IARC) as carcinogenic agents to humans. The main source of release of chromium in aquatic ecosystems is related to the industrial application of this metal in metallurgies, tanneries, and in the manufacturing of paints and dyes. The ecotoxicology of Cr(VI) is linked to its environmental persistence and the ability to induce adverse effects in biological systems. In the present study, we evaluated mutagenic effects of Cr(VI) in animal and plant bioindicators.
  
  
  METHODS
  We evaluated primary DNA damage and frequencies of micronuclei (MN) and morphological nuclear abnormalities (NA) in erythrocytes in peripheral blood of the fish Oreochromis niloticus exposed to potassium dichromate at 12 mg l(-1). The genotoxicity and cytotoxicity of Cr(VI) in the onion (Allium cepa) test were also assessed.
  
  
  RESULTS
  The comet assay showed a significant increase of tailed nucleoids in the erythrocytes of fish treated with K2Cr2O7; MN frequency was also increased in the treatments; cytotoxicity of a low concentration of potassium dichromate, however, was not confirmed.
  
  
  CONCLUSIONS
  The combination of both systems - animal and plant - is adequate and advantageous for mutagenicity evaluation. The findings indicate that at the concentration tested, the chromium compound is a clastogenic as well as an aneugenic.
authors.affiliation: Federal Institute of Education, Science and Technology of Pará, Belém, Pará, Brazil carlos.rocha@ifpa.edu.br.
authors.forename: Carlos
authors.initials: C
authors.lastname: Rocha
authors.affiliation: Human Cytogenetics Laboratory, Biological Science Institute, Federal University of Pará, Belém, Pará, Brazil.
authors.forename: Plínio
authors.initials: P
authors.lastname: Cardoso
authors.affiliation: Human Cytogenetics Laboratory, Biological Science Institute, Federal University of Pará, Belém, Pará, Brazil.
authors.forename: Lorena
authors.initials: L
authors.lastname: Cunha
authors.affiliation: Federal Institute of Education, Science and Technology of Pará, Belém, Pará, Brazil.
authors.forename: Cláudia
authors.initials: C
authors.lastname: Gomes
authors.affiliation: Federal Institute of Education, Science and Technology of Pará, Belém, Pará, Brazil.
authors.forename: Rubens Ribeiro
authors.initials: RR
authors.lastname: Júnior
authors.affiliation: Institute of Socio-Environmental and Water Resources, Amazon Federal Rural University, Belém, Pará, Brazil.
authors.forename: Raul Henrique
authors.initials: RH
authors.lastname: Pinheiro
authors.affiliation: Federal Institute of Education, Science and Technology of Pará, Belém, Pará, Brazil Human Cytogenetics Laboratory, Biological Science Institute, Federal University of Pará, Belém, Pará, Brazil.
authors.forename: Mary Helen
authors.initials: MH
authors.lastname: Costa
authors.affiliation: Human Cytogenetics Laboratory, Biological Science Institute, Federal University of Pará, Belém, Pará, Brazil.
authors.forename: Rommel
authors.initials: R
authors.lastname: Burbano
mesh_terms: D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D023681:Cichlids / Q000235:genetics; D020552:Comet Assay; D004249:DNA Damage / Q000187:drug effects; D004912:Erythrocytes / Q000187:drug effects; D006801:Humans; D009153:Mutagens / Q000633:toxicity*; D009369:Neoplasms / Q000139:chemically induced / Q000235:genetics* / Q000473:pathology; D019697:Onions / Q000187:drug effects / Q000235:genetics; D011192:Potassium Dichromate / Q000633:toxicity*
chemical_list: D002273:Carcinogens; D009153:Mutagens; D011192:Potassium Dichromate
keywords: Allium cepa test; Cytotoxicity; Oreochromis niloticus; chromium; genotoxicity