TOXICOLOGICAL PROFILE FOR CHROMIUM - Davidborowski.com

CHROMIUM 2442. HEALTH EFFECTSThe respiratory tract and the immune system are targets in animals exposed to chromium(VI) andchromium(III) via inhalation for intermediate durations (Adachi 1987; Adachi et al. 1986; Glaser et al.1985, 1990; Johansson et al. 1986a, 1986b). Pharmacokinetic studies indicate that chromium isdistributed to the spleen of rats exposed to chromium(VI) via inhalation, oral, or dermal routes (Baetjer etal. 1959a; Wahlberg and Skog 1965; Witmer et al. 1989, 1991), but chromium(III) and chromium(VI) arenot readily absorbed from the gut (Anderson 1986; Anderson et al. 1983; Donaldson and Barreras 1966;Sullivan et al. 1984; Witmer et al. 1987, 1991). LOAEL values have been identified for respiratory andimmune effects after inhalation (Glaser et al. 1985, 1990). A MRL of 0.001 mg chromium(VI)/m 3 hasbeen determined for lower respiratory effects in humans after intermediate-duration inhalation exposureto chromium(VI) as particulate hexavalent compounds based on the study in rats by Glaser et al. (1990).An oral study of intermediate duration in rats reported no effects of chromium(III) in any system(Ivankovic and Preussmann 1975). One oral study in rats, however, found proteinuria and decreasedmotor activity at relatively high drinking water concentrations of chromium(VI) (Diaz-Mayans et al.1986). In addition, intermediate-duration oral exposure of rats resulted in biochemical and histochemicalchanges in the liver and kidney (Kumar and Rana 1982, 1984; Kumar et al. 1985). In addition,developmental and reproductive studies identify chromium(VI) as a reproductive and developmentaltoxicant in mice and rats after oral exposure (Al-Hamood et al. 1998; Bateineh et al. 1997; Chowdhuryand Mitra 1995; Junaid et al. 1996b; Kanojia et al. 1996, 1998; Trivedi et al. 1989; Zahid et al. 1990). Nooral MRL has been derived for chromium(VI) or chromium(III) because a NOAEL for reproductiveeffects has not been adequately characterized. Additional studies are needed to identify a threshold fortoxicity and establish dose-response relationships. However, any MRL derived for the oral route wouldhave to take into consideration the essentiality of chromium. No dermal studies of intermediate durationin animals were located. The toxicity of intermediate-duration exposure to chromium compounds isrelatively well characterized for the oral and inhalation routes. Dermal studies would be useful todetermine possible target organs other than the skin. There are populations surrounding hazardous wastesites that might be exposed to the substance for similar durations.Chronic-Duration Exposure and Cancer. The respiratory system (Bovet et al. 1977; Cohen et al.1974; Davies et al. 1991; Keskinen et al. 1980; Kleinfeld and Rosso 1965; Kuo et al. 1997a; Letterer1939; Lucas and Kramkowski 1975; Mancuso 1951; Meyers 1950; Novey et al. 1983; Olaguibel andBasomba 1989; Pastides et al. 1991; Sassi 1956; Sluis-Cremer and du Toit 1968; Sorahan et al. 1987;Taylor 1966) and the skin (Gomes 1972; Hanslian et al. 1967; Lee and Goh 1988; Leiberman 1941; PHS1953; Royle 1985b) are the primary target organs for occupational exposure to chromium and itscompounds. There are more data regarding the effects of chronic inhalation exposure in humans and