loREiSUL S
SCIENCE lies at the heart of the mission of the U.S. Environmental Protection Agency (EPA). The Agency must rely on cutting edge research, accurate
measurements and effective technology to implement its programs to protect the environment and human health. Without sound science and credible data,
EPA con not wisely set environmental and health standards, clean up contaminated sites, measure ambient air and water quality conditions, or identify the new
technologies or practices that will reduce releases to the environment. These fact sheets shore with you some of"our EPA New England's laboratory capabilities
and exemplify some of the very best science we do to meet our agency mission.
GOAL:
In order to support risk assessments and clean-up decisions at hazardous waste sites, EPA's New England
Regional Laboratory conducts studies to determine levels of indoor air contamination in buildings adjacent to
these sites. Regional scientists are continuing to refine and improve vapor intrusion study methods and have
expanded the use of these studies in New England in response to increased concerns about vapor intrusion and
health risks to building occupants.
KEY CONTACTS:
PETER KAHN
Environmental Engineer
(617) 918-8392
kahn.peter@epa.gov
KATRINA KIPP
Chief, Ecosystem /Assessment
(617) 918-8309
kipp.katrina@epa.gov
M ICHAEL KEN YON
Director, EPA New England
Regional Laboratory
(617) 918-8317
kenyon.michael@epa.gov
GENERAL INFO:
EPA NEW ENGLAND
REGIONAL LABORATORY
I I Technology Dr.
North Chelmsford, MA 01863
(617) 918-8300
www.epa.gov/ne/lab
TOLL-FREE
CUSTOMER SERVICE
1-800-EPA-7341
PROGRESS:
Vapor intrusion is the movement of volatile organic chemi-
cals (VOCs) from contaminated groundwater and/or
soils through the ground into the air contained in overly-
ing buildings. EPA New England scientists conduct vapor
intrusion studies to investigate the extent and severity
of contamination associated with Superfund hazardous
waste sites. Frequently, the contamination is associated
with a dry cleaning business where tetrachloroethylene
(PCE). a solvent used in the dry cleaning industry, has con-
taminated the groundwater. These chemicals are trans-
ported in the groundwater, released as vapors, travel
through the soil and may migrate into buildings where
they can adversely impact the health of occupants.
Indoor air sampling results can be misleading because it is
difficult to eliminate or adequately account for contribu-
tions from "background" sources, including items stored
or used by the homeowner, such as household solvents,
gasoline, and cleaning products. Therefore, a combina-
tion of soil gas, indoor air and outdoor air sampling is
necessary to make an appropriate evaluation of expo-
sure and potential health risk to building occupants. The
laboratory's scientists work with the Superfund proj-
ect manager to review existing data on contaminated
groundwater plumes, soils data, past indoor air testing
data, if available, and any other relevant information to
select properties for evaluation. The scientists then col-
lect and analyze outdoor and indoor air samples, soil gas
samples, and vapor samples from below the basement
floor or slab (by drilling holes through the floor). EPA's
mobile laboratory conducts on-site analyses of soil gas
and air grab samples, which help refine the sampling
program as it progresses and help ensure the scientists
will not need to return to the site for more samples at
a later date. Samples are also returned to the regional
laboratory where indoor air, ambient air and soil gas
canister samples are analyzed to confirm field results.
Based on the findings of the laboratory's vapor intru-
sion studies, EPA takes mitigation actions to reduce
potential health risks. Typically, the chemical concen-
tration levels are low, and the main concern is whether
the chemicals may pose an unacceptable health risk
to occupants due to long-term exposure. When sig-
nificant vapor intrusion is found, ventilation is likely the
most appropriate response option. Affected homes
and buildings often have soil gas mitigation systems in-
stalled to minimize exposure to vapors from actual or
suspected water contamination incidents.
BENEFITS:
By providing timely and useful data on potential human
health risks from indoor air contamination associated
with hazardous waste sites, EPA New England scien-
tists are helping protect the health of affected New
England residents.
<>EPA
United States
Environmental Protection
Agency
EPA-901-F-09-031
April 2009
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