[CPEO-MEF] TCE in LA

[Lenny Siegel <lsiegel@cpeo.org>]

THE TRICHLOROETHYLENE LEGACY IN THE LOS ANGELES AREA

by Lenny Siegel
with the assistance of Jane Horton


June, 2006

Prepared for Physicians for Social Responsibility-Los Angeles

The Los Angeles Metropolitan Area is a checkerboard of underground 
plumes of trichloroethylene (TCE), a cancer-causing industrial solvent, 
largely a legacy of military activities, military contracting, and 
support industries during the Cold War. At the request of Physicians for 
Social Responsibility-Los Angeles, the Center for Public Environmental 
Oversight has identified at least 114 major TCE sites in the Los Angeles 
area. Though state and federal environmental agencies have taken action 
to ensure that many of the sites are slowly being cleaned up, no one has 
taken a comprehensive look at the risks that TCE and similar compounds 
pose today to the metropolitan area's population, in drinking water, 
indoor air, and outdoor air. In fact, there is not even a complete map 
of known TCE contamination in the region.

Primarily from government databases, CPEO identified 114 TCE sites, 
ranging from small, contaminated properties to regional groundwater 
plumes with hundreds of "responsible parties"-companies and others 
believed to have contributed to the pollution. Large military bases on 
the list contain multiple plumes. Forty of those sites, including most 
of the largest areas of contamination, were directly the result of 
contaminant releases by military/aerospace companies or federal agencies 
themselves. Many of the rest were caused by metalworking, chemical 
handling, and waste disposal businesses that served the military and its 
contractors.

Though government agencies have been collecting this data for decades, 
there is no centralized list of TCE contamination sites. Instead, the 
information-along with oversight-is divided among agencies and between 
programs within agencies. The principal sources used by CPEO were 
California's Department of Toxic Substances Control's (DTSC) new 
Envirostor database, U.S. Environmental Protection Agency's "Superfund" 
National Priorities List, and U.S. EPA's Environmental Indicators 
database, associated with Corrective Action activities under the 
Resource Conservation and Recovery Act. The State Water Resources 
Control Board's Geotracker data base also contains a great deal of 
information, but thus far is has been difficult to search and the 
records are brief or incomplete. CPEO believes that a full search of 
Geotracker records would add a large number of relatively minor TCE 
releases to the list.

Furthermore, based upon data that is readily available in government 
databases, further testing is necessary at other large industrial 
facilities that operated during the Cold War. Since most enterprises 
engaged in the same chemical and waste-handling practices, it's likely 
that those companies that don't show up on the lists are omitted because 
no one has looked, not because they are clean.

Trichloroethylene or TCE (C2HCl3) is a colorless, sweet-smelling liquid 
used widely in the decades since World War as a solvent for metal parts, 
electronics, and other materials. Most agencies believe TCE exposure, 
even at low levels, causes cancer. In addition, reports the federal 
Agency for Toxic Substances and Disease Registry:

     "Breathing small amounts may cause headaches, lung irritation, 
dizziness, poor coordination, and difficulty concentrating.

     "Breathing large amounts of trichloroethylene may cause impaired 
heart function, unconsciousness, and death. Breathing it for long 
periods may cause nerve, kidney, and liver damage.

     "Drinking large amounts of trichloroethylene may cause nausea, 
liver damage, unconsciousness, impaired heart function, or death.

     "Drinking small amounts of trichloroethylene for long periods may 
cause liver and kidney damage, impaired immune system function, and 
impaired fetal development in pregnant women, although the extent of 
some of these effects is not yet clear.

     "Skin contact with trichloroethylene for short periods may cause 
skin rashes."

Government agencies and water suppliers pay close watch to ensure that 
the public is not drinking water containing more than 5 parts per 
billion (ppb) of TCE, the current drinking water standard. But that 
standard is in dispute. A 2001 draft Human Health Risk Assessment for 
TCE found that TCE was 5 to 65 times as toxic as previously believed, 
particularly to young children and other susceptible populations. Under 
pressure from the White House and polluting federal agencies-the 
Department of Defense, the Department of Energy, and NASA-U.S. EPA has 
withdrawn that study and sought advice from the National Academy of 
Sciences. While scientists debate the severity of TCE's toxicity, an 
unknown number of people in the LA area are being continuously exposed 
to the chemical at arguably unsafe levels.

Hundreds of million of dollars have been spent containing and removing 
TCE and other contaminants from the LA-area's largest contamination 
sites. Conventional treatment systems, such as soil vapor extraction and 
pump-and-treat systems, are in place throughout the region. But many 
plumes continue to spread, and at some of the large Superfund sites the 
TCE standard is met only by blending water imported from the Colorado 
River. That water contains another contaminant that targets young 
children, perchlorate. However, EPA's original, more stringent findings 
on perchlorate toxicity were also thrown out, so the blended water is 
legally "safe" for both TCE and perchlorate.

Ingestion is not the only risk posed by the huge reservoirs of 
contaminated groundwater in the greater Los Angeles area. For the past 
few years, it has been widely recognized that volatile compounds such as 
TCE tend to migrate from shallow groundwater into overlying structures. 
The mechanism, known as the vapor intrusion pathway, exposes residents, 
workers, students, etc. to continuous, low-but potentially 
health-threatening-levels of TCE in the air that they breathe. At some 
TCE sites in the LA area, ventilation systems have been installed to 
reduce exposures to legally safe levels. At others, mathematical models 
have been used to find exposures safe-at least, according to the less 
protective historical standard. But at most sites neither air sampling 
nor mathematical modeling has been conducted yet.

CPEO's study shows that government agencies or others have identified a 
potential for vapor intrusion at nearly 40 of the TCE sites. In fact, 
there many be many more. Most of the descriptive records in government 
databases don't even have place to note the possibility of vapor 
intrusion. On the other hand, some of those identified might not have an 
unacceptable level of toxic vapor indoors. CPEO believes that any site 
where TCE or similar compounds are found, above the drinking water 
standard in shallow groundwater, should be evaluated and perhaps sampled 
to determine if the building occupants are likely to be exposed to 
unsafe levels.

Furthermore, much of the outdoor air in urban Los Angeles contains a 
continuous, possibly hazardous level of TCE vapors. According to the 
California Air Resources Board, monitoring stations in Azusa, Burbank, 
and Los Angeles detected an average concentration of .3 micrograms of 
TCE in each cubic meter (µg/m3) of air. Though this is below levels 
detected a decade or more ago, it's not far below the 1 (µg/m3) 
currently used to require mitigation of indoor air. And it's 
substantially more than the .017 (µg/m3) that EPA scientists said in 
2003-using the draft 2001 Health Risk Assessment-corresponded to a 
one-in-a-million excess lifetime cancer risk. That is, southern 
Californians are breathing TCE, at levels that many scientists believe 
unsafe, "24-7."

TCE, unlike other controversial toxic compounds-such as lead, arsenic, 
and perchlorate-never occurs naturally. Furthermore, it has a half -life 
or three to eight days in air. That is, TCE breaks down due to 
photo-oxidation. Therefore, any continuing levels of TCE in air must 
come from one of three sources.

1. Household products. TCE is still used a solvents and glues, but there 
is no evidence that large volumes are sold or released in the Los 
Angeles area.

2. Industrial use. In recent years, the major users of TCE have phased 
it out. In 2004, only one enterprise in a five-county area reported to 
the government's Toxics Release Inventory that it had emitted TCE-and 
only 15 pounds. It's possible, however, that some industries are still 
using and releasing TCE without reporting it to the government, either 
because there are still loopholes in the law, or because they are simply 
ignoring their legal responsibilities.

3. Releases from "legacy" contaminated in soil and groundwater. Based 
upon the evidence available, CPEO believes that the subsurface 
contamination throughout the LA region, most of which was deposited 
during the military buildup of the latter half of the 20th Century, is 
releasing a small but steady level of TCE and other volatile compounds 
into the atmosphere, enough to replenish the ambient air pollution 
despite a constant breakdown process. These releases both come from 
clean-up treatment systems and are directly vented from the subsurface. 
The levels seem low, but the safety level may be even lower, and 
everyone in much of the LA basin is breathing the contamination around 
the clock.

How risky is the ongoing low-level exposure that southern Californians 
have to TCE?

CPEO believes that exposure to TCE in water, indoor air, and outdoor air 
must be better evaluated and probably more aggressively addressed. Its 
review of TCE sites in the Los Angeles area found that other toxic 
compounds are usually found at the same locations. TCE's risk must be 
considered in light of ongoing exposures to a multitude of pollutants 
through all pathways. That is, the widespread emission of other air 
contaminants from both mobile and stationary sources doesn't make the 
continuing presence of TCE less of a problem. Since exposures are often 
additive, cumulative, or synergistic, TCE is likely to be more of a 
problem than if it were a single, isolated pollutant.


CPEO RECOMMENDS

Environmental and health agencies must improve and consolidate their 
data on the presence of TCE and other volatile compounds in soil, 
groundwater, and air in the Los Angeles area. Cold War-ERA legacy 
contamination, no matter which program or agency regulates it, should be 
mapped in a single, accessible, user-friendly database, and the 
appropriate agencies should identify and close any legal loopholes that 
allow current use and related releases to go unreported.

Environmental regulation has greatly reduced the use and release of 
these chemicals, but exposures may continue for decades unless a 
comprehensive picture is painted of all sources and pathways. Based on 
that, agencies should work with the public-as well as polluters and 
other responsible parties-to accelerate cleanup and protect the public.



Three major data bases provided the bulk of information in the 
accompanying table:

Envirostor, California Department of Toxic Substances Control
http://www.envirostor.dtsc.ca.gov/public/

Corrective Action Environmental Indicators, U.S. EPA Region 9
http://yosemite.epa.gov/r9/r9coract.nsf/facilities?readform&GeographicArea=Southern+Ca

National Priorities List Sites in California, U.S. EPA
http://www.epa.gov/superfund/sites/npl/ca.htm



For a formatted version of this report, go to
http://www.cpeo.org/pubs/TCE-LA.doc.

For the supporting table, go to http://www.cpeo.org/pubs/TCE-LA.xls.

For notes explaining the table, go to 
http://www.cpeo.org/pubs/TCE-LAnotes.doc.

--


Lenny Siegel
Director, Center for Public Environmental Oversight
c/o PSC, 278-A Hope St., Mountain View, CA 94041
Voice: 650/961-8918 or 650/969-1545
Fax: 650/961-8918
<lsiegel@cpeo.org>
http://www.cpeo.org


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