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GLIN==> NAS Study on Waste Incineration

The National Academies News
Date: Oct. 13, 1999
Contacts: William Kearney, Media Relations Associate
Megan O'Neill, Media Relations Assistant
(202) 334-2138; e-mail <news@nas.edu>

Publication Announcement

New Waste Incinerators Safer, But Some Emissions
and Health Concerns Need Further Study

Incineration is widely used in the United States to reduce the volume of
waste. Hundreds of incinerators -- including industrial kilns, boilers, and
furnaces -- combust municipal and hazardous waste, while many more are
used to burn medical waste. Whether waste incineration poses a health
risk to incinerator employees or to people living and working nearby has
been the subject of much debate.

When operated properly by well-trained employees, modern waste
incinerators pose little risk to public health. But older designs, human
error, and equipment failure can result in higher-than-normal, short-term
emissions that need to be studied further, says a new report by the
National Research Council of the National Academies. Three federal
agencies asked the Research Council to assess the relationship between
waste incineration and human health.

Few studies have tried to establish a link between an incinerator and
illness in the surrounding area, and most studies have been unable to
detect any adverse health effects, said the committee that wrote the
report. The studies that did identify effects on health had shortcomings
and failed to provide convincing evidence. The fact that ailments may
occur infrequently or take years to appear, and the presence of pollution
from other sources, make it difficult to determine if waste incineration can
be blamed for local health problems.

Some studies have shown, however, that workers at municipal-waste
incinerators have been exposed to high concentrations of dioxins and
toxic metals, particularly lead, cadmium, and mercury, the report says.
But follow-up studies were not performed to determine if this exposure
caused disease. Workers can be exposed to emissions directly, or --
when doing maintenance inside the combustion chamber -- to the toxic
residue resulting from incomplete combustion and chemicals trapped by
pollution-control devices.

Better epidemiological research is needed to assess the health risks of
exposure to pollutants from incinerators, including studies that evaluate
combined data from all incinerators in a particular area and that compare
findings from similar facilities located in different regions, the report says.
Biological tests should be used to monitor the exposure of workers. And
researchers need to examine health risks that may be attributable to
emissions resulting from incinerators which do not run properly, paying
particular attention to particulate matter, lead, mercury, and dioxins.

The report also calls for better data on the level of emissions that occur
during start-up and shutdown, when they are likely to be greater. Sudden
increases in emissions also can result from maintenance problems,
accidents, a change in the composition of the waste being burned, and
poor management of the incineration process. Furnaces designed for
municipal-waste incineration prior to the mid-1980s are less efficient at
combustion than newer designs. Modern plants often use auxiliary burners
to maintain an optimal temperature during start-up and shutdown, though
increased emissions can still occur. But with current technology,
  incinerators can achieve nearly complete combustion of the burnable
portion of waste under normal operating conditions, emitting low amounts
of unhealthy pollutants. In addition, using highly trained employees can
help ensure maximum combustion efficiency and proper operation of
emission-control devices.

Policy-makers should base future regulatory decisions on the actual
performance of incinerators, from start-up through shutdown, taking into
consideration accidents and other mishaps, the committee said. Since
the highest emissions may occur at these times, failure to include them in
monitoring records may misrepresent the total emission output of a
facility. To better measure actual emissions, government agencies should
encourage research into improved continuous-emission monitors, and
make real-time data available to regulators and the public, perhaps on the

Environmental monitoring studies indicate that specific waste incinerators
are not likely to add much to local concentrations of airborne pollutants,
but flaws in the methodology of these studies prevented the committee
from drawing any general conclusions about the contribution of waste
incineration to pollution levels overall. However, the committee noted that
although one incinerator might emit only a small fraction of total
  concentrations, the sum of emissions from all incinerators in a region can
be considerable.

The U.S. Environmental Protection Agency (EPA) has issued standards
that would decrease emissions of key pollutants from waste incinerators.
The EPA rules require incinerators to reduce emissions to a standard
known as "maximum achievable control technology," or MACT. The
Research Council report says compliance with MACT regulations will
diminish the exposure of local populations to emissions, but it is unclear
what effect compliance will have on a metropolitan or regional scale, since
little is known about the risks posed by collective emissions from several
incinerators. The committee noted that cumulative emissions of dioxins
and metals are of substantial concern since those pollutants are capable
of traveling long distances and persisting in the environment. It also
recommended that all medical- and municipal-waste incinerators have
uniform limits for each pollutant irrespective of plant size, age, or design,
as is currently the case for hazardous-waste incinerators.

MACT standards were not designed to address the exposure of incinerator
workers to emissions and other toxic byproducts, the report notes. It calls
on EPA and the U.S. Occupational Safety and Health Administration to
continue striving to improve coordination of their enforcement activities to
protect the health of incineration workers.

The study was funded by EPA, the U.S. Agency for Toxic Substances
and Disease Registry, and the U.S. Department of Energy. The National
Research Council is the principal operating arm of the National Academy
of Sciences and the National Academy of Engineering. It is a private,
nonprofit institution that provides independent advice on science and
technology issues under a congressional charter. A committee roster

Copies of Waste Incineration and Public Health will be available in
November from the National Academy Press for $44.95 (prepaid) plus
shipping charges of $4.50 for the first copy and $.95 for each additional
copy; tel. (202) 334-3313 or 1-800-624-6242. Reporters may obtain a copy
from the Office of News and Public Information (contacts listed above).

Commission on Life Sciences
Board on Environmental Studies and Toxicology

Committee on Health Effects of Waste Incineration

Donald R. Mattison, M.D. (chair)
Medical Director
March of Dimes Defects Foundation
White Plains, N.Y.

Regina Austin, J.D.
Professor of Law
University of Pennsylvania Law School

Paul C. Chrostowski, Ph.D.
CPF Associates Inc.
Takoma Park, Md.

Marjorie J. Clarke, Ph.D.
Department of Geography
Rutgers University, and
Environmental Consultant
New York City

Edmund A. Crouch, Ph.D.
Senior Scientist
Cambridge Environmental Services Inc.
Cambridge, Mass.

Mary R. English, Ph.D.
Associate Director
Energy, Environment, and Resources Center
University of Tennessee

Dominic Golding, Ph.D.
Research Assistant Professor
Center for Technology, Environment, and Development
The George Perkins Marsh Institute
   Clark University
Worcester, Mass.

  Ian A. Greaves, M.D.
Associate Professor
Department of Environmental and Occupational Health
University of Minnesota

S. Katharine Hammond, Ph.D.
Associate Professor of Public Health
Environmental Health Sciences Division
School of Public Health
University of California Berkeley

Allen Hershkowitz, Ph.D.
Senior Scientist
Natural Resources Defense Council
New York City

Robert J. McCormick, B.S.
Franklin Engineering Group
Franklin, Tenn.

Thomas E. McKone, Ph.D.
Adjunct Professor
School of Public Health
University of California

Adel F. Sarofim, S.M., Sc.D.
Professor of Chemical Engineering
Department of Chemical Engineering
University of Utah
Salt Lake City

  Carl M. Shy, M.D., Ph.D.
Department of Epidemiology
University of North Carolina
Chapel Hill

George D. Thurston, Ph.D.
Associate Professor
Department of Environmental Medicine
New York University School of Medicine


Raymond Wassel, M.S.
Study Director
Alex J. Sagady & Associates        Email:  ajs@sagady.com

Environmental Enforcement, Permits/Technical Review, Public Policy and
Communications on Air, Water and Waste Issues
and Community Environmental Protection

PO Box 39  East Lansing, MI  48826-0039
(517) 332-6971 (voice); (517) 332-8987 (fax)

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