{"content":[{"text":"7.","bbox":{"left":0.108403,"top":0.083631,"width":0.013866000000000003,"height":0.017428}},{"text":"Conflicting results have been produced in the mutagenicity tests conducted with chlorine dioxide, \n sodium chlorite, and sodium chlorate. Sodium chlorite was positive in two separate Ames tests, \n an in vitro chromosomal aberration test, and an in vivo mouse micronucleus test after \n intraperitoneal dosing. In contrast, it was non-mutagenic in a mouse micronucleus test when \n administered orally, and also negative in a test to assess sperm-head abnormalities induced in \n mice after oral treatment. \n Chlorine dioxide was reported to be positive in an Ames test in only one strain out of 6 \n (TA100), but negative in an in vitro chromosome aberration test in Chinese hamster fibroblasts. \n In vivo, two mouse micronucleus studies were conducted, resulting in one positive and one \n negative result. Chlorine dioxide also did not induce sperm head abnormalities in mice. \n Sodium chlorate was positive in two separate Ames tests with metabolic activation, and in a \n Drosophila recessive lethal mutation test. It was negative in two mouse micronucleus tests and in \n a bone marrow chromosomal aberration assay. \n However, these conflicting mutagenicity results were considered of limited relevance since \n consumer exposure to residues in milk is extremely low compared to exposure via drinking \n water. \n Classical carcinogenicity studies have not been conducted with sodium chlorite, however chronic \n studies have been performed where sodium chlorite was administered via drinking water at doses \n up to 0.05% in mice for 80 weeks and 0.06% in rats for 85 weeks. The survival rate and \n incidence of tumours were not significantly different between treated and control groups. \n Conventional carcinogenicity studies have not been conducted with chlorine dioxide or sodium \n chlorate, however, the data that are available do not suggest a significant carcinogenic hazard. \n Data are available from a clinical trial in humans exposed to 500 ml of 5 mg/kg sodium chlorite \n (equivalent to 0.036 mg/kg bw) daily for 12 weeks, and also a prospective epidemiological study \n where 198 individuals were exposed for three months to chlorinated water with a mean chlorite \n concentration of 5 mg/l, and compared with 112 non-exposed individuals. In both studies there \n was no evidence of any overt toxicity as indicated by an extensive battery of biochemical and \n haematological tests and physical examination. \n Chlorine dioxide, sodium chlorite and sodium chlorate are all present in drinking water which has \n been disinfected by chlorination processes. \n A considerable amount of data has been reviewed by various authorities regulating water quality, \n including WHO and U.S EPA, and regulatory limits have been proposed of 0.21 to 0.5 mg/l for \n chlorine dioxide and 0.024 to 0.5 mg/l for chlorite and chlorate in drinking water. \n No specific pharmacokinetics studies have been performed in the target species, although dermal \n absorption in rats and absorption via the teat canal in cattle have both been shown to be \n negligible. \n Milk collected in the normal way from treated cattle (even without udder washing), and also \n directly by catheterisation of the teat canal, has been shown not to possess antimicrobial \n activity when tested with Bacillus stearothermophilus (limit of detection 3 mg/l, although no \n validation data were provided for this method). \n Residues of chlorite and chlorate in milk from cows treated with the formulated product tended \n to be below the limit of detection of 0.1 mg/l for the HPLC analytical method. \n Transfer studies using chromium (III) oxide (Cr2O3) as an analytical marker have indicated that \n less than 0.025% of the applied formulated product is transferred to milk. On this basis, the \n maximum level of chlorite present in the milk (based on 0.32 % NaClO2 present in the product, \n and assuming no degradation) would be 8 g (total dip used) x 0.025 % (degree of transfer) x \n 0.32%/14.4 kg (of milk), or 0.00044 ppm (0.44 µg/l). \n When these residues data are compared with the regulatory limits set for water quality of 0.21 - \n 0.5 mg/l for chlorine dioxide and 0.024-0.5 mg/l for chlorite and chlorate, it can be seen that the","bbox":{"left":0.143697,"top":0.083631,"width":0.7519060000000001,"height":0.815527}},{"text":"8.","bbox":{"left":0.108403,"top":0.343726,"width":0.013866000000000003,"height":0.017428}},{"text":"9.","bbox":{"left":0.108403,"top":0.439925,"width":0.013866000000000003,"height":0.017428}},{"text":"10.","bbox":{"left":0.108403,"top":0.536125,"width":0.024511000000000005,"height":0.017428}},{"text":"11.","bbox":{"left":0.108403,"top":0.625198,"width":0.024511000000000005,"height":0.017428}},{"text":"12.","bbox":{"left":0.108403,"top":0.678643,"width":0.024511000000000005,"height":0.017428}},{"text":"13.","bbox":{"left":0.108403,"top":0.746338,"width":0.024511000000000005,"height":0.017428}},{"text":"14.","bbox":{"left":0.108403,"top":0.785531,"width":0.024511000000000005,"height":0.017428}},{"text":"15.","bbox":{"left":0.108403,"top":0.867479,"width":0.024511000000000005,"height":0.017428}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}