home edit2 whole TSD November 2002 PDF format - OEHHA

ARSENIC (INORGANIC)
CAS No: 7440-38-2
I. PHYSICAL AND CHEMICAL PROPERTIES (From HSDB, 1998)
Molecular weight 74.92
Boiling point
613 °C (sublimes)
Melting point
817 °C @ 28 atm
Vapor pressure 1 mm Hg at 372 °C
Air concentration conversion 1 ppm = 2.21 mg/m 3
II.
HEALTH ASSESSMENT VALUES
Unit Risk Factor: 3.3 E-3 (µg/m 3 ) -1
Slope Factor: 1.2 E+1 (mg/kg-day) -1
[Human occupational exposure lung tumor incidence (Enterline et al., 1987a);.
relative risk model, adjusted for interaction with tobacco smoking (CDHS, 1990).]
Oral slope factor: 1.5 E+0 (mg/kg-day) -1
[Human skin cancer incidence (Tseng et al., 1968, 1977), time- and dose-related formulation
of the multistage procedure (U.S. EPA, 1988).]
III.
CARCINOGENIC EFFECTS
Human Studies
Inhalation
Cancer mortality has been studied among workers employed in three major smelters in the U.S., in (1)
Tacoma, Washington, (2) Anaconda, Montana, and (3) Garfield, Utah. Smelter workers in Sweden
(Ronnskarverken) and in Japan (Sagnoseki-Machi) and cohorts of both miners and smelter workers in
China have also been studied.
Enterline and Marsh (1982) and Enterline et al. (1987a) examined the longest follow-up period for the
Tacoma, Washington cohort. The 1982 report used cumulative doses based on urinary arsenic
measurements. Standardized mortality ratios (SMRs) for respiratory cancer ranged from 170 for those
receiving the lowest intensity and shortest duration of exposure, to 578 for those with the highest
intensity and with 20-29 years duration of exposure. A strong dose-response relationship was evident
only when the analysis was limited to the 582 retired workers in the cohort. In the 1987 reanalysis,
Enterline and colleagues incorporated newly available historical air sampling data (Enterline et al.,
1987a); in this study, the dose-response relationship appears more clearly.
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