(Fwd) VI on dioxin source

["Charlie Cray" <ccray@dialb.greenpeace.org>]

>From the Vinyl Institute's "EnVIronmental Briefs"
August 1998

U.S. EPA Finds New Dioxin Source in American Backyards

The U.S. Environmental Protection Agency's (EPA) long-awaited dioxin
reassessment has always contained one mystery: the agency's inventory
of dioxin sources has never balanced with its total dioxin emission
estimates, signaling the existence of a large "unknown" source of
dioxin. However, a recent EPA experiment may have located one of those
mystery sources: backyard trash burning, still a common practice in
some parts of the United States. Initial EPA data indicate that the
dioxin generated daily by four families openly burning their trash is
equivalent to that of a 200-ton-per-day-capacity municipal solid waste
incinerator. Most important to the vinyl industry is the EPA's finding
that an increased amount of vinyl in the trash barrels did not, on
average, produce higher levels of dioxin. This result is consistent
with the American Society of Mechanical Engineers' 1995 study that
showed the design and operating conditions of an incinerator - not the
vinyl content of its waste - are the determining factors in dioxin
generation and emission. The EPA is expected to release its finalized
dioxin source inventory this fall, and the full dioxin reassessment
report in early to mid 1999.

____

As people here have noticed in the past, this is just the opposite of 
what Paul Lemieux et al wrote:

"It is probable that the fraction of PVC in the refuse contributes
significantly to the total amount of PCDDs/PCDFs produced. . [O]pen
burning in barrels produced very high levels of PCDDs/PCDFs. .
[E]missions of PCDDs/PCDFs are significantly higher for the avid
recycler.  This phenomenon is likely due to several factors, including
the higher mass fraction of PVC in the avid recycler's waste, a
different temperature profile, and possibly a different mix of
metallic catalysts. "

Lemieux, Paul M., "Evaluation of Emissions from the Open Burning of
Household Waste in Barrels. Volume 1. Technical Report,"
EPA-600/R-97-134a, U.S. Environmental Protection Agency, Office of
Research and Development, Washington, D.C. , November 1997.