In vivo genotoxicity evaluation of a treated urban sewage sludge sample.
Tons of sludge is produced daily in sewage treatment plants of large cities, causing an enormous disposal problem. Because recycling has been proposed to mitigate the situation, the potential adverse health effects of the sludge should be verified before that policy is undertaken. The present study is a part of an assessment of oral toxicity in rats fed with sewer-treated sludge and aimed to contribute to its genotoxicity characterization. After a 2-week acclimatization period, male and female Wistar rats were fed ad libitum for 90 days a pelleted commercial diet containing 0, 5000, 10,000 and 50,000 ppm of a treated sludge sample. The potential mutagenic or genotoxic effect was detected in recent animal cells by the bone marrow micronucleus test and the comet assay, respectively. For the comet assay peripheral blood samples were obtained immediately before the sacrifice from the periorbital plexus. Following sacrifices, polychromatic erythrocytes (PCEs) were analyzed in femoral bone marrow smears and the frequencies of micronucleated polychromatic erythrocytes (MNPCEs) were registered. Results of both assays indicated that exposure to any of the sludge concentrations tested did not increase the frequency of MNPCEs or the levels of DNA damage when compared to non-exposed concurrent control rats.
de Lourdes Marzo Solano
Marize
M
Center for the Evaluation of the Environmental Impact of Human Health (TOXICAM), Department of Pathology, Botucatu Medical School, UNESP-São Paulo State University, São Paulo, Brazil. marizesolano@fmb.unesp.br
de Lima
Patrícia Lepage Alves
PL
Luvizutto
João Francisco Lozano
JF
Silva
Paula Regina Pereira
PR
de Aragão Umbuzeiro
Gisela
G
de Camargo
João Lauro Viana
JL
D000818:Animals; D016587:Antimutagenic Agents / Q000494:pharmacology; D001853:Bone Marrow / Q000528:radiation effects; D004249:DNA Damage / Q000187:drug effects* / Q000235:genetics; D004913:Erythrocytes, Abnormal; D005260:Female; D005720:Gamma Rays; D007220:Industrial Waste / Q000009:adverse effects*; D008297:Male; D048629:Micronuclei, Chromosome-Defective / Q000139:chemically induced* / Q000706:statistics & numerical data; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D012037:Refuse Disposal; D012722:Sewage / Q000737:chemistry*
D016587:Antimutagenic Agents; D007220:Industrial Waste; D009153:Mutagens; D012722:Sewage