HomeMy WebLinkAbout2014-05-14 PACKET 05.02.Environmental Health Division, Site Assessment and Consultation Unit
P.O.Box64975
St. Paul, MN 55164-0975
651-201-4897
Perfluorochemicals in Homes and Gardens Study:
Summary of Results
BackgroundMDH respondsto community concerns
Since 2004, local and state agencies have been MDH starteda study of PFC levelsin homegrown
responding to the presence of perfluorochemicals produce, garden soil, and outdoortap waterfrom
(PFCs) in drinking water supplies in several eastern the eastern Twin Cities areain 2010.
Twin Cities communities.Wells with levels of
PFCs exceeding Minnesota Department of Health MDH collected samples from 20
(MDH) health-based criteria have been identified homes in Lake Elmo, Oakdale,
and addressed through installation of granular and Cottage Grovethat have a
activated carbon (GAC) filtration systems, or historyof PFCs in the water.A
hooked upto city water. Residents now drink water total of 20 water samples, 34
with no to low levels of PFCs.soil samples, and 232 produce
samples were analyzed for seven different PFCs.
Drinking water is safe, but homeowners have
expressed concernsabouteating fruits and All samples have been analyzed by the MDH lab
vegetablesthat have been grown in soil that and results have been provided to study participants.
contains PFCs. PFCs have been released to the Data analyses of the results for dust arestill in
environment by watering lawns and gardens using process.The study report will be completed and
water sources that contain PFCs. PFCs stay in the posted on the MDH website in the summer of 2014.
environment for a long time after they have been
Study Results
released. Water sources used in gardening may still
contain PFCs ifthe outdoortapsused to wateryardsWater:PFBA was found in 85% of outdoor tap
and gardensare left unfiltered at homes with private water samplesand found at higher levelsthanother
wells. Some PFCs may also “break through” GAC PFCs.The median PFBA concentration was 0.98
filters used in private or public water systems. micrograms per liter (µg/L).No sample exceeded
the Health Risk Limit (HRL) set by MDH of7
Laboratorystudies show that PFCs ug/L. PFBA is the most widespread PFC in East
in soilor water can be taken up by Metro groundwater. It is also difficult to
edible plants. These studies completely remove PFBA withstandard water
consistently show that PFCs with treatment methods.
short fluorocarbon-chains-such as
perfluorobutanoic acid (PFBA)-are more readily Soil:PFCs were detected at low levels in most soil
taken up into plants compared to long-chain PFCs–samples. PFOS, PFOA, and PFBA were found in
such as perfluorooctane sulfonate (PFOS)or every sample and atthe highest levels.Median
perfluorooctanoic acid (PFOA).concentrations of PFOS, PFOA, and PFBA were
March 2014
Perfluorochemicals in Homes and Gardens Study: Summary of Results/English
Perfluorochemicals in Homes and Gardens Study: Summary of Results–Page 2
2.65, 0.73, and 0.99µg/kg)Findings include:
microgram per kilogram (
respectively. These levels are well below health-
The presence of PFBA in water contributes
based guidelines for PFCs in soil. Theamount of
to elevated levels of PFBA in soil and
PFBA in waterand the amount of garden watering
garden producein the East Metro.
PFBA concentrations in produce are low and
were found to significantly contribute to the soil
no health risks of concern were found for
concentration of PFBA.
infants, children or adults living in the study
area from exposure to PFBA, PFOS, and
Produce:In produce, PFBA was detected in 98%
PFOA in drinking water, soil, homegrown
of samplesand found at higherlevels than other
produceand house dust.
The results of this study are consistent with
PFCs.The median PFBA produce concentration
experimental plant studies. Although PFOS
was 0.68 µg/kg. The amount of PFBA in the water,
and PFOA were present in soil at higher or
the amount of garden watering, and the type of
similar levels to PFBA, the results
produce grownwere found to influencetheamount
demonstrate that plant uptake of PFCs is
of PFBA in produce. PFOS and PFOA were found
chain-length dependent with highest uptake
and movement of short-chain PFCs by
in very few of the produce samples.
edible plants.
Health Risk Assessment
This study was conducted at homes in the East
MDH conducted a risk assessment that evaluated
Metro with historically the highest levels of PFCs in
exposure to the three PFCsfor which safe dose
their drinking water, a long history of home
levels have been established. The three PFCs
gardening, and generallyextensive varieties of
evaluated were PFOS, PFOA, and PFBA. The safe
fruits and vegetables grown and consumed. Other
levels used in the assessment provide protection for
residents or gardeners in the area –with lower
even the most sensitive people who may be exposed
levels of PFCs or no PFCs in water used for
to PFCs. Three age categories were considered:
watering lawns and gardens -can expect to have
adults, small children, and infants. Exposure was
even less exposure to PFCs through soil and home
combined across four sources(drinking water,
garden produce.
homegrown produce, soil, and house dust).
Contact for more information:
Conclusions
James Kelly, M.S.
No health risks of concern were found for anyone
Minnesota Department of Health
living in these communitieswhen considering
Division of Environmental Health
combined risk from all exposure pathways.
651-201-4910 or email: james.kelly@state.mn.us
Therefore, MDH has determined that the health
For more information on PFCs in Minnesota:
http://www.health.state.mn.us/divs/eh/hazardous/to
benefits provided by growing and eating
pics/pfcs/index.html
homegrown produce greatly outweigh any potential
risk from low levels of PFBA or other PFCs in
produce.
March 2014
Perfluorochemicals in Homes and Gardens Study: Summary of Results/English