title: Developmental abnormalities in chicken embryos exposed to N-nitrosoatrazine.
abstract: Nitrate and atrazine (ATR) occur in combination in some drinking-water supplies and might react to form N-nitrosoatrazine (NNAT), which is reportedly more toxic than nitrate, nitrite, or ATR. Current evidence from population-based studies indicates that exposure to nitrate, nitrite, and nitrosatable compounds increases the risk of congenital defects and/or rate of embryo lethality. To test the hypothesis that NNAT induces malformations during embryogenesis, chicken embryos were examined for lethality and developmental abnormalities after treating fertilized eggs with 0.06-3.63 μg NNAT. After 5 d of incubation (Hamburger and Hamilton stage 27), 90% of embryos in NNAT-treated eggs were alive, of which 23% were malformed. Malformations included heart and neural-tube defects, caudal regression, gastroschisis, microphthalmia, anophthalmia, and craniofacial hypoplasia. The findings from this investigation suggest further studies are needed to determine the mechanisms underlying NNAT-induced embryotoxicity.
authors.affiliation: a Department of Environmental , Agricultural and Occupational Health, College of Public Health, University of Nebraska Medical Center , Omaha , Nebraska , USA.
authors.forename: Nikita
authors.initials: N
authors.lastname: Joshi
authors.forename: Martha G
authors.initials: MG
authors.lastname: Rhoades
authors.forename: Gregory D
authors.initials: GD
authors.lastname: Bennett
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Wells
authors.forename: Sidney S
authors.initials: SS
authors.lastname: Mirvish
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Breitbach
authors.forename: Patrick J
authors.initials: PJ
authors.lastname: Shea
mesh_terms: D000014:Abnormalities, Drug-Induced / Q000209:etiology*; D000818:Animals; D001280:Atrazine / Q000031:analogs & derivatives* / Q000633:toxicity; D002642:Chick Embryo / Q000187:drug effects / Q000254:growth & development; D019465:Craniofacial Abnormalities / Q000139:chemically induced; D008850:Microphthalmos / Q000139:chemically induced; D009436:Neural Tube Defects / Q000139:chemically induced; D009602:Nitrosamines / Q000633:toxicity*
chemical_list: D009602:Nitrosamines; C015394:N-nitrosoatrazine; D001280:Atrazine