HUMAN HEALTH COMMITTEE

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HUMAN HEALTH COMMITTEE

SUMMARY SHEET

INORGANICS

Line Code II-6

I. DEFINITION

Inorganic chemicals not covered as items on the Environmental Stressors List are addressed in this Topic Area.

II. HUMAN HEALTH RISK ASSESSMENT RESULTS FOR INDICATOR CHEMICALS
A. Summary Table: Cancer Risks

Indicator Chemical	Weight of Evidence	Average Individual Risk	Size of Exposed Population	Estimated Annual Cancer Cases	Risk Distrib. # > 10-4	Comments
Arsenic Groundwater	A	> 10-2 > 10-3 > 10-4	30,000 - 200,000? 100,000-1 million? 1 - 10 million?	200 - 2000?	1 - 10 million	Exposure to contaminated groundwater widespread but poorly characterized
Cadmium Ambient air	B1	5 x 10-6	30 million	2	a	See write-up for Topic Area I-10
Chromium (hexavalent) Ambient air	A	4 x 10-5	30 million	18	a	See write-up for Topic Area I-10

a Emitting facilities have been identified where theoretical lifetime risks estimated for the maximally exposed individual exceed 1 x 10-4/life for hexavalent chromium. There was insufficient information for extrapolating estimates to other facilities in California, or for determining whether risks to some populations near cadmium emitting facilities exceed 10-4/life.

B. Summary Table: Non-cancer Risks

Indicator Chemical	Health Effect	Hazard Index	Size of Population at Risk	Cases per year or Exposures above Acceptable Level	Comments
Arsenic	hyperpigmentation, keratosis and possible vascular complications	> 1	> 50,000	Extent of exposure to those on private systems or wells unknown.	Only some of the more highly exposed populations accounted for here.

III. ESTIMATED PERCENT OF TOPIC AREA ANALYZED

High

Medium

Low

IV. LEVEL OF CONFIDENCE

X

High

Medium

Low

V. POPULATIONS OF CONCERN

Highly Exposed Subpopulations

Those living in living in areas with high arsenic levels in tap water (primarily due to geochemical contamination of groundwater).

VI. COMPARATIVE RANK

X

High

Medium

Low