TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 1072. HEALTH EFFECTSto potassium chromate via drinking water at 1–20 ppm for 48 hours or to bolus doses up to 4 µg/kg for2 days (Mirsalis et al. 1996). Similarly in rats, no unscheduled DNA synthesis in hepatocytes was found.However, an increase in DNA-protein crosslinking was found in the livers of rats exposed to potassiumchromate in the drinking water at $6 mg chromium(VI)/kg/day for 3 or 6 weeks (Coogan et al. 1991a).The clastogenic effects of male Swiss albino mice fed chromium(VI) trioxide (20 mg/kg body weight) bygavage were studied; after 24 hours, bone marrow cells were isolated and 500 metaphase plates werescored for chromosomal aberrations (Sarkar et al. 1993). The treated cells showed a significant increasein aberrations per cell over controls by 4.4-fold. When animals were treated simultaneously withchlorophyllin (1.5 mg/kg), a sodium-copper derivative of chlorophyll and an antioxidant, numbers ofaberrations were reduced to nearly background levels.Other genotoxicity studies are discussed in Section 2.5.2.2.2.8 CancerA retrospective mortality study conducted on a population who resided in a polluted area near an alloyplant that smelted chromium in the People's Republic of China found increased incidences of lung andstomach cancer. The alloy plant began smelting chromium in 1961 and began regular production in 1965,at which time sewage containing chromium(VI) dramatically increased. The population was followedfrom 1970 to 1978. The size of the population was not reported. The adjusted mortality rates of theexposed population ranged from 71.89 to 92.66 per 100,000, compared with 65.4 per 100,000 in thegeneral population of the district. The adjusted mortality rates for lung cancer ranged from 13.17 to 21.39per 100,000 compared with 11.21 per 100,000 in the general population. The adjusted mortality rates forstomach cancer ranged from 27.67 to 55.17 per 100,000, which were reported to be higher than theaverage rate for the whole district (control rates not reported). The higher cancer rates were found forthose who lived closer to the dump site (Zhang and Li 1987). No other information was provided, and itwas not possible to estimate exposure levels based on the description of the pollution process. Theexposed population was probably exposed by all environmentally relevant routes (i.e., air drinking water,food, soil).A follow-up study reevaluated this cohort; the adjusted total cancer death rates for the six areas analyzedwere 68.8, 68.4, 64.7, 54.3, 57.5, and 45.9 (Zhang and Li 1997). These rates were comparable to theoverall provincial rate of 66.1 in which the six exposed regions were located. When total cancer mortality