NYC-WTC_000195068

NYC 9/11 Public Portal Document

ASBESTOS MEDUEXT ® - Medical Management Page 2 of 3

2. Minor oral exposure occurs from ingestion of contaminated drinking water or after mucociliary clearance from the lungs, but the role, if any, of ingested asbestos as an etiologic agent is not known (ATSDR, 1990). 3. The US EPA proposed maximum contaminant level for asbestos in drinking water is 7 million fibers (larger than 10 microns in length) per liter (ATSDR, 1990). 4. Gastrointestinal tumors potentially caused by asbestos have only been statistically significantly increased in persons with occupational exposure (Anon, 1978). A possible synergistic effect of smoking and asbestos for cancers of the stomach, colon-rectum, and kidney has not been confirmed (ATSDR, 1990).

7.6 LD50/LC50

A. References: Lewis, 1996; RTECS, 1999

TCLo - (INHL) HUMTUJ: 1.2 fb/cc for 19Y-C -- pulmonary effects TDLo - (IMPLANT) RAT: 750 mg/kg -- equivocal tumorigenic agent

7.8 OTHER

A. GENERAL 1. ASBESTOS - The cancer-causing ability of asbestos seems to be related to fiber length, type, size, geometry, and insolubility in aqueous solutions (ACGIH, 1986; Brown et al, 1990; Churg et al, 1989; Gibbs, 1990; ILO, 1983; Lippman, 1988; McDonald et al, 1989; Mossman & Gee, 1989; Sebastien et al, 1989; Spumy et al, 1983). In order of toxicity, these fibers are crocidolite, amosite, and chrysotile. B. SPECIFIC SUBSTANCE 1. CHRYSOTILE- a. Chrysotile and other amphiboles are not stable in acids, hydroxides, and living tissue (Spumy et al, 1983). Chrysotile is by far the most sensitive to these effects. 1. Leaching of minerals from chrysotile will change various biological effects (Spuraey et al, 1983). Leaching occurs naturally but slowly in human tissue. For example - the less magnesium, the less propensity to absorb albumin; when 50 percent of magnesium is removed, the hemolytic activity decreases; when 90 percent of magnesium is removed, the incidence of mesothelial tumors decreases substantially. When magnesium is leached from chrysotile by either acids or organic acids, both the cytotoxicity and hemolytic activity is decreased. 2. With amosite or crocidolite, cytotoxicity and hemolytic activity are slightly enhanced rather than decreased by leaching. C. OTHER TDLo/TCLo 1. AMOSITE- a. TCLo (INHL) RAT - 11 mg/m(3)/2 years-intermittent CARCINOGENIC (Lewis, 1992) b. TDLo (INTRAPLEURAL) RAT - 80 mg/kg CARCINOGENIC (Lewis, 1992) c. TDLo (SC) MOUSE - 2400 mg/kg/13 weeks-intermittent CARCINOGENIC (Lewis, 1992) 2. ANTHOPHYLTTE- a. TCLo (INHL) RAT - 11 mg/m(3)/l year-intermittent CARCINOGENIC (Lewis,

http://www.tomescps.conn/DATA/TM/TM356-7.htm 1/4/2002

CITY_21MC100_011105074

NYC-WTC_000195092