14    APPLICATION OF MAMMALIAN CELL CULTURE SYSTEMS
FOR THE RISK-BASED ASSESSMENT AND
REMEDIATION OF HAZARDOUS WASTES
T. Rick Irvin, Associate Professor
Institute for Environmental Studies
Louisiana State University
Baton Rouge, Louisiana 70803
INTRODUCTION: PERSPECTIVES ON THE ISSUE
Previous manufacturing activities at thousands of sites in the US have resulted in the on-site storage
and discharge of hazardous organic and inorganic chemical mixtures.1"5 These toxicants often contaminate surface and subsurface soils as well as water supplies at very low (parts-per-million to parts-
per-billion) concentrations. Traditional site remediation methods involve:
1. Sample collection at numerous sites;
2. off-site chemical analysis of collected samples;
3. remediation of large volumes of environmental material to very low, EPA-specified
levels; and
4. extensive post-closure sample collection and monitoring.
In the case of areas contaminated by very low toxic chemical concentrations or localized high
concentrations of toxic wastes, this approach can pose several problems:5,8,11
1. Most samples collected contain no waste constituents;
2. long time periods and significant funds are required for chemical analysis;
3. no information is provided regarding the cumulative hazards of waste chemical mixtures;
4. scarce remediation funds are often expended to remove chemicals to levels below the
threshold for toxic effects; and
5. risks involved in active site remediation versus no on-site action cannot be evaluated.
Environmental assessment methods, which may be deployed on-site, are thus needed to:
1. Determine rapidly, accurately, and efficiently, the human and environmental risk of
chemical mixtures populating waste-contaminated sites;
2. identify the level of site-associated subsurface chemical contamination and migration;
3. establish site-specific and intrasite-specific targets validating EPA environmental standards for chemical pollutant levels;
4. evaluate candidate remediation and management technologies for different classes of
site-specific waste chemicals;
5. monitor onsite management activities to achieve risk-defined remediation goals; and
6. monitor post-closure status of remediated sites.
A viable adjunct technology complementary to chemical analysis of sites contaminated by hazardous wastes is the direct assessment of toxic effects associated with contaminated samples.3 Prioritization of waste sites, according to human and environmental risks from site-specific toxic chemical
mixtures, would direct scarce human technical resources to those sites of greatest public health risk.
Sites containing small quantities of toxic chemicals or large quantities of relatively nontoxic agents
would be given a lower priority than sites with high quantities of toxic agents or critical mixtures of
chemicals which interact (synergize) to potentiate toxic effects of individual chemical species.
Historically, laboratory animal exposure to single chemical agents of interest is the method
employed to evaluate human risk from toxic chemical exposure. Whole animal experiments to characterize the toxic effects of hazardous waste samples, however, prove too costly and lengthy to be of
49th Purdue Industrial Waste Conference Proceedings, 1994 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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