Reference Dose for Oral Exposure (RfD) (PDF) (29 pp, 186 K)
last updated: 09/01/1991
|System||RfD (mg/kg-day)||Basis||PoD||Composite UF||Confidence|
|Cardiovascular, Dermal||3 x 10-4||Hyperpigmentation, keratosis and possible vascular complications||
: 8 x 10-4
Reference Concentration for Inhalation Exposure (RfC) (PDF) (29 pp, 186 K)
Not assessed under the IRIS Program.
Weight of Evidence for Cancer (PDF) (29 pp, 186 K)
last updated: 06/01/1995
|WOE Characterization||Framework for WOE Characterization|
|A (Human carcinogen)||Guidelines for Carcinogen Risk Assessment (U.S. EPA, 1986)|
- Based on sufficient evidence from human data. An increased lung cancer mortality was observed in multiple human populations exposed primarily through inhalation. Also, increased mortality from multiple internal organ cancers (liver, kidney, lung, and bladder) and an increased incidence of skin cancer were observed in populations consuming drinking water high in inorganic arsenic.
- This may be a synopsis of the full weight-of-evidence narrative.
Oral Slope Factor:
1.5 per mg/kg-day
Drinking Water Unit Risk: 5 x 10 -5 per µg/L
Extrapolation Method: Time- and dose-related formulation of the multistage model
Tumor site(s): Dermal
Tumor type(s): Skin cancer (Tseng, 1977; Tseng et al., 1968; U.S. EPA, 1988)
Inhalation Unit Risk:
4.3 x 10 -3 per µg/m3
Extrapolation Method: Absolute-risk linear model
Tumor site(s): Respiratory
Tumor type(s): Lung cancer (Brown and Chu, 1983a,b,c; Lee-Feldstein, 1983; Higgins, 1982; Enterline and Marsh, 1982)
Arsenic, inorganic is being reassessed.
|Step||Assessment Materials Released to the Public||Release Date||Public Meeting Date|
|1||Problem Formulation Materials||11/2012||01/2013|
|1||Preliminary Assessment Materials||04/2014||06/2014|
|4||Public Comment Draft||TBD||TBD|
|4||Peer Review Draft||TBD||TBD|
|7||Post Final Assessment||TBD|
Please note: Any future dates displayed under Release Date are estimates and subject to change.
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