(1992a) incorporated microencapsulated BDCM into the diet of Wistar rats for 1 month, and a LOAEL of 66 mg/kg of body weight per day and a NOAEL of 21 mg/kg of body weight per day were determined based on histopathological findings of hepatocellular vacuolization.
Microencapsulated BDCM was fed in the diet to Wistar rats for 24 months, resulting in average daily doses of 6, 26 or 138 mg/kg of body weight for males and 8, 32 or 168 mg/kg of body weight for females (Aida et al., 1992b).
However, the LD50 for 1,3-DCPN was stated to be 25 mg/kg of body weight, indicating that the liver was probably not the critical target organ for this compound, at least with acute treatment.
However, there appeared to be a substantial increase in skin tumour yield at an oral dose of 300 mg of 2-bromopropenal per kg of body weight (19 tumours in 38 mice [50%] vs.
The response to the 10 mg/kg of body weight dose led to statistically elevated levels of tumours between 48 and 92 weeks, but the results are based on the appearance of three adenomas and three carcinomas among eight animals.
Longer-term exposures (e.g., months) lead to some enlargement of the liver, if humans are as sensitive as mice in this regard, but the doses remain considerably above the fraction of a µg/kg of body weight that would be expected from most chlorinated drinking-waters.
If it is assumed that rats drink about 10% of their body weight per day, the level of 1200 mg/litre corresponds to approximately 120 mg/kg of body weight per day, or about 8 g for a 70-kg human, close to the estimated doses in the study by van Heijst et al.
Significant depletion of non-protein sulfhydryl content (primarily GSH) was observed with single acute oral doses of 62.5 mg/kg of body weight and above in male Alderley Park Wistar-derived rats.
If an average weight of 300 g is assumed for rats for the duration of the experiment (i.e., study was started with weanling rats), the doses can be estimated to be roughly 300 mg/kg of body weight per day for DCA and 250 mg/kg of body weight per day for 2-CP.
DCAN and TCAN at doses of 55 mg/kg of body weight administered in tricaprylin by gavage from day 7 to day 21 of gestation significantly reduced the percentage of females delivering viable litters, increased resorption rates and reduced maternal weight gain.
Spermiation also appeared to be mildly affected, with step 19 spermatids being retained beyond stage VIII in animals dosed with as little as 10 mg/kg of body weight per day.
Administration of single doses of BDCA, BCA and DBA by gavage in water as the vehicle induced increases in thiobarbituric acid reactive substances (TBARS) and increased the 8-OH-dG content of nuclear DNA in the liver of male B6C3F1 mice at doses as low as 30 mg/kg of body weight (Austin et al., 1996).
However, there is considerable doubt about whether these effects would be induced by the doses of less than 1 µg/kg of body weight experienced by humans consuming chlorinated drinking-water.
In this case, DCAN dissolved in tricaprylin was administered to Long-Evans rats at doses of 0, 5, 15, 25 or 45 mg/kg of body weight per day from day 6 to day 18 of gestation.
18.104.22.168 Developmental effects Treatment of pregnant rats with TCA at 0, 330, 800, 1200 or 1800 mg/kg of body weight per day by gavage in a water vehicle on gestation days 6-15 produced dose-dependent reductions in body weight and length of rat pups from dams administered doses of 800 mg/kg of body weight per day and above.