by Don Hopey,
Post-Gazette Staff Writer
reprinted from the Pittsburgh Post-Gazette
January 25, 1998 edition
Preservative known to have compounds that
CCA isnt the only toxic wood preservative to be the focus of
Edward Polaski, the former state employee who compiled a critical
report on CCA, also wrote a report for the state Department of
Conservation and Natural Resources that reviewed research on an older
preservative, called creosote, which is used in Pennsylvania in the
Timber Bridge Program administered by the U.S. Forest Service.
The Forest Bureau has built one such bridge in Centre County, and
has plans for 22 more in state forests. Creosote-treated wood bridges
also have been built by the state Department of Transportation and local
The Baileyville Bridge, a timber bridge just outside State College,
was built in 1991 out of glued, laminated red oak timber. Creosote drips
and seepage are visible on many of the wood beams, and creosote stains
are visible on the rocks, in and along the stream it crosses.
Similar creosote stains can be seen on the rocks and in the stream
below the red maple timber bridge in East Pennsboro, Cumberland
While Pennsylvania is just beginning to build such bridges, a 1995
report on 51 creosote-treated timber bridges in West Virginia found that
15 - 29.4 percent - showed creosote problems, including stream and stream
bank contamination. Under the Fieldcrest Bridge in Morgantown, W.Va., for
example, Polaski said he saw football-sized gobs of creosote
in the stream.
Terri Shistar, assistant professor of environmental studies at the
University of Kansas and a board member of the National Coalition Against
Misuse of Pesticides, said creosotes toxicity varied from batch to
batch, but that all batches contained known cancer-causing compounds.
Whether from pressure-treated wood or brushed on, if creosote
is oozing out of bridges and released into the environment or into
streams, its not a good thing, said Shistar.
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