title: Tire debris organic extract affects Xenopus development.
abstract: Tire debris (TD) and its organic components were identified as a main source of PM10 atmospheric and water pollution. Because few data are available on the embryotoxic effects of TD organic components, the lethal and teratogenic potential of tire debris organic extract (TDOE) was evaluated using the frog embryo teratogenesis assay-Xenopus (FETAX), coupled with a histopathological screening of the survived larvae. From stage 8 to stage 47, Xenopus laevis embryos were exposed to TDOE at concentrations of 50, 80, 100, 120 and 140 mg/L. The results showed 50 mg/L TDOE to be the non-observable effect concentration (NOEC). TDOE mortality at 80 mg/L was significantly higher than the control, but did not increase further with higher concentrations. A good concentration-response was observed for percentages of malformed larva and from 80 mg/L on these percentages were significantly higher than the control. Therefore, probit analysis gave a 144.6 mg/L TC50. At 120 and 140 mg/L, many larvae were plurimalformed. The most frequent alterations observed were abnormal gut coiling, microphthalmia, monolateral anophthalmia, and narrowing eyes. The histological screening mainly revealed ocular malformations such as double retina, retina nervous cell layer coiling, and altered lens. Moreover severe vacuolisation and necrosis were scored in liver and axial musculature. These results strongly support the assumption that TDOE is a powerful teratogen for X. laevis.
authors.affiliation: Department of Environmental Science, University of Milano-Bicocca, 1 piazza della Scienza, 20126 Milan, Italy.
authors.forename: Paride
authors.initials: P
authors.lastname: Mantecca
authors.forename: Maurizio
authors.initials: M
authors.lastname: Gualtieri
authors.forename: Manuela
authors.initials: M
authors.lastname: Andrioletti
authors.forename: Renato
authors.initials: R
authors.lastname: Bacchetta
authors.forename: Claudio
authors.initials: C
authors.lastname: Vismara
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vailati
authors.forename: Marina
authors.initials: M
authors.lastname: Camatini
mesh_terms: D000818:Animals; D002070:Butadienes; D004625:Embryo, Nonmammalian / Q000002:abnormalities / Q000187:drug effects / Q000473:pathology; D004785:Environmental Pollutants / Q000633:toxicity*; D005124:Eye Abnormalities / Q000139:chemically induced; D005260:Female; D045782:Hemiterpenes; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008297:Male; D052638:Particulate Matter / Q000633:toxicity*; D010420:Pentanes; D011108:Polymers; D013623:Tail / Q000187:drug effects / Q000473:pathology; D013723:Teratogens / Q000633:toxicity*; D014982:Xenopus laevis / Q000002:abnormalities*
chemical_list: D002070:Butadienes; D004785:Environmental Pollutants; D045782:Hemiterpenes; D052638:Particulate Matter; D010420:Pentanes; D011108:Polymers; D013723:Teratogens; C005059:isoprene