|
Great Lakes
Article:
DEQ Funded Aquatic Ecological Risk Assessment
Identifies Risks and Impacts to Wildlife Resulting from
Dioxin and Furan Contaminated Sediments in the Tittabawassee
River
Department of Environmental Quality
12/01/03
Dioxin and furan contaminated sediments in the Tittabawassee
River downstream of the city of Midland pose significant
reproductive, embryo, and early life-stage mortality risk
to fish-eating birds and mammals according to a recent
report commissioned by the Department of Environmental
Quality.
The 48-page Tittabawassee River Aquatic Ecological Risk
Assessment Report, prepared by Vermont-based Galbraith
Environmental Sciences, LLC, was initiated after investigations
of river sediments and flood plain soil conducted by the
DEQ found dioxin and furan contamination. The contamination
is pervasive throughout the Tittabawassee River and its
flood plain downstream of Midland and the Dow Chemical
plant.
"The report provides critical risk assessment data
that will assist the DEQ in determining the impacts and
risks to wildlife posed by dioxin and furan contamination
and the appropriate response activities needed to reduce
those risks," said DEQ Director Steven Chester.
The conclusions of this study are based on the concentrations
of dioxins and furans in sediment and fish collected from
the Tittabawassee River and from duck and chicken eggs
collected from the Tittabawassee River floodplain.
Specific conclusions reached from the aquatic risk assessment
include:
Carp, catfish, shad, and bass in the Tittabawassee River
downstream of Midland are contaminated with dioxin and
furans at levels posing serious reproductive impairment
to: 1) fish-eating birds and mammals that consume them
(even as small portions of their diet), and 2) bird species
that are normally insensitive to dioxins and furans.
Risks of reproductive impairment to fish-eating birds
and mammals resulting from dioxin contaminated sediments
also exists within the Saginaw River and inner Saginaw
Bay, based on the limited amount of sediment data that
currently exists.
Tittabawassee River ecological habitats downstream of
Midland are contaminated with dioxin and furans at levels
that could result in toxic impacts to exposed wildlife
species.
Concentrations of dioxin and furans measured in waterfowl
eggs collected from the Shiawassee National Wildlife Refuge
near the Tittabawassee River were much higher than concentrations
measured in waterfowl eggs collected from unimpacted areas.
Concentrations of dioxin and furans confirmed to be present
in fish tissue and in waterfowl eggs provide actual site-specific
information that supports the findings and conclusions
of the aquatic ecological risk assessment.
The 48-page report is now available on the DEQ webpage
www.michigan.gov/tittabawassee;
or from the DEQ Saginaw Bay District Office, 503 N. Euclid,
Bay City, Michigan; or by calling Sue Kaelber-Matlock,
DEQ Remediation and Redevelopment Division, at 989-686-8025,
ext. 8303.
|
