Melnick Ronald L, Nyska Abraham, Foster Paul M, Roycroft Joseph H, Kissling Grace E
Environmental Toxicology Program, National Institute of Environmental Health Sciences, P.O. Box 12233, Research Triangle Park, NC 27709, USA.
Toxicology. 2007 Feb 12;230(2-3):126-36. doi: 10.1016/j.tox.2006.11.006. Epub 2006 Dec 8.
Dibromoacetic acid (DBA) is a water disinfection byproduct formed by the reaction of chlorine oxidizing compounds with natural organic matter in water containing bromide. Male and female F344/N rats and B6C3F(1) mice were exposed to DBA in drinking water for 2 weeks (N=5), 3 months (N=10), or 2 years (N=50). Concentrations of DBA in drinking water were 0, 125, 250, 500, 1000, and 2000mg/L in the 2-week and 3-month studies, and 0, 50, 500, and 1000mg/L in the 2-year studies. Toxic effects of DBA in the prechronic studies were detected in the liver (hepatocellular cytoplasmic vacuolization in rats and mice) and testes (delayed spermiation and atypical residual bodies in male rats and mice, and atrophy of the germinal epithelium in rats). In the 2-year studies, neoplasms were induced at multiple sites in rats and mice exposed to DBA; these included mononuclear cell leukemia and abdominal cavity mesothliomas in rats, and neoplasms of the liver (hepatocellular adenoma or carcinoma and hepatoblastoma) and lung (alveolar adenoma or carcinoma) in mice. The increase in incidence of hepatocellular neoplasms in male mice was significant even at the lowest exposure concentration of 50mg/L, which is equivalent to an average daily dose of approximately 4mg/kg. These studies provide critical information for future re-evaluations of health-based drinking water standards for haloacetic acids.
二溴乙酸（DBA）是一种水消毒副产物，由含溴水中的氯氧化化合物与天然有机物反应形成。将雄性和雌性F344/N大鼠以及B6C3F(1)小鼠暴露于饮用水中的DBA中，为期2周（N = 5）、3个月（N = 10）或2年（N = 50）。在为期2周和3个月的研究中，饮用水中DBA的浓度分别为0、125、250、500、1000和2000mg/L；在为期2年的研究中，浓度分别为0、50、500和1000mg/L。在前期慢性研究中，DBA对肝脏（大鼠和小鼠肝细胞胞质空泡化）和睾丸（雄性大鼠和小鼠精子发生延迟和非典型残留体，以及大鼠生精上皮萎缩）产生了毒性作用。在为期2年的研究中，暴露于DBA的大鼠和小鼠多个部位诱发了肿瘤；这些肿瘤包括大鼠的单核细胞白血病和腹腔间皮瘤，以及小鼠的肝脏肿瘤（肝细胞腺瘤或癌和肝母细胞瘤）和肺部肿瘤（肺泡腺瘤或癌）。即使在最低暴露浓度50mg/L（相当于平均每日剂量约4mg/kg）时，雄性小鼠肝细胞肿瘤的发生率增加也很显著。这些研究为未来重新评估基于健康的卤乙酸饮用水标准提供了关键信息。
