title: Study of the toxicity of 1-Bromo-3-chloro-5,5-dimethylhydantoin to zebrafish.
abstract: OBJECTIVE
  1-Bromo-3-chloro-5,5-dimethylhydantoin (BCDMH) is a solid oxidizing biocide for water disinfection. The objective of this study was to investigate the toxic effect of BCDMH on zebrafish.
  
  
  METHODS
  The developmental toxicity of BCDMH on zebrafish embryos and the dose-effect relationship was determined. The effect of BCDMH exposure on histopathology and tissue antioxidant activity of adult zebrafish were observed over time.
  
  
  RESULTS
  Exposure to 4 mg/L BCDMH post-fertilization was sufficient to induce a number of developmental malformations, such as edema, axial malformations, and reductions in heart rate and hatching rate. The no observable effects concentration of BCDMH on zebrafish embryo was 0.5 mg/L. After 96 h exposure, the 50% lethal concentration (95% confidence interval (CI)) of BCDMH on zebrafish embryo was 8.10 mg/L (6.15-11.16 mg/L). The 50% inhibitory concentration (95% CI) of BCDMH on hatching rate was 7.37 mg/L (6.33-8.35 mg/L). Histopathology showed two types of responses induced by BCDMH, defensive and compensatory. The extreme responses were marked hyperplasia of the gill epithelium with lamellar fusion and epidermal peeling. The histopathologic changes in the gills after 10 days exposure were accompanied by significantly higher catalase activity and lipid peroxidation.
  
  
  CONCLUSIONS
  These results have important implications for studies on the toxicity and use of BCDMH and its analogs.
authors: Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing, China.
authors: WanFang
authors: W
authors: Li
authors: JinFeng
authors: J
authors: Wei
authors: HongTao
authors: H
authors: Jin
authors: MingFang
authors: M
authors: Huang
authors: JingXuan
authors: J
authors: Zhang
authors: ChengHe
authors: C
authors: Li
authors: ChaoJie
authors: C
authors: Chen
authors: Chang
authors: C
authors: Liu
authors: AiPing
authors: A
authors: Wang
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D004202:Disinfectants / Q000633:toxicity*; D004305:Dose-Response Relationship, Drug; D004625:Embryo, Nonmammalian / Q000187:drug effects; D006827:Hydantoins / Q000633:toxicity*; D013997:Time Factors; D014867:Water / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000633:toxicity; D015027:Zebrafish
chemical_list: D000975:Antioxidants; D004202:Disinfectants; D006827:Hydantoins; D014874:Water Pollutants, Chemical; D014867:Water; C039283:di-halo