The risk implications of the distribution of chromium forms in environmental media

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:495390

Mahoney, L A; Petroff, D M; Batey, J C ^[1]

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1. Eckenfelder Inc., Nashville, TN (United States)

Chromium exhibits multiple oxidation (valence) states, ranging from ({minus}2) to (+6). Under natural conditions, however, chromium typically exists in the Cr(III) (trivalent) and/or Cr(VI) (hexavalent) form, with the hexavalent form exhibiting higher solubility and much greater toxicity than the trivalent form. Due to the large differences in toxicity, the distribution of chromium oxidation states (Cr(III) and Cr(VI)) in site media is potentially of great importance to the calculation of site risk levels, and thus ultimately to cleanup activities. Despite its importance, chromium oxidation states are often not available for media samples collected at waste sites. Typical assumptions regarding the chromium distribution in site media are presented. Actual chromium distribution data from media from baseline investigations of several waste sites are also presented for groundwater, surface water, and soil and compared in terms of background chromium levels and the nature of site wastes. The differences in toxicity of Cr(III) and Cr(VI) are briefly discussed. Risk estimates and risk-based cleanup levels generated using different assumptions for the distribution of chromium in site media for a selected example site are then given. These risk-based cleanup levels are compared to various state regulatory limits, MCLs, and Practical Quantitation Limits (PQLs) for chromium.

• OSTI ID: 495390
• Report Number(s): CONF-9504216--
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
56 BIOLOGY AND MEDICINE
APPLIED STUDIES
CHROMIUM
ENVIRONMENTAL IMPACTS
GROUND WATER
REMEDIAL ACTION
RISK ASSESSMENT
SITE CHARACTERIZATION
SOILS
SURFACE WATERS
TOXICITY