Are there valid reasons for people to be worried about air pollution
from garbage incinerators?
The incineration of garbage (often called "mass burn," "resource
recovery" or "waste-to-energy") seems to produce the family of toxic
chemicals known as dioxins. The dioxins are partly released from the
smoke stack of the incinerator, and they are partly retained in the
ash, which is eventually sent to a landfill. No one seems to dispute
that burning garbage produces dioxins. People argue about the amount of
dioxins produced, and they argue about which particular components of
garbage cause the production of dioxins. But no one seems to argue that
you can burn garbage without producing dioxins.
Given that mass burn produces dioxins, whenever someone proposes a mass
burn incinerator for garbage, we need to ask ourselves whether dioxins
are really dangerous to humans. No one seems to doubt that dioxins are
harmful to animals. The only unsettled question seems to be whether
dioxins are harmful to humans.
Writing in the JOURNAL OF THE AMERICAN MEDICAL ASSOCIATION April 18,
1986 (pgs. 2031-2038) a team of doctors and scientists reported on
their study of 154 humans who had been exposed to dioxins during a two-
year period (and their study of a control group of 155 people who had
not been exposed to dioxins). The exposed group had lived for several
years in a trailer park where dioxins had been mixed with waste oil and
sprayed on roads to suppress dust.
The doctors reported no differences in the medical histories of the
exposed and non-exposed groups; physical exams show-ed no differences;
studies of blood and urine chemistry showed no differences; neurologic
tests showed no differences. Yet the doctors reported that protective
cells in the immune systems of the dioxin-exposed humans were reduced
in number or impaired, not operating at peak levels, compared to the
immune systems of the unexposed control group. The results were
expressed in terms of impaired liver function, and in terms of impaired
T-cell characteristics. It is the immune system in humans that fights
off disease, so an impaired immune system would expose a person to risk
of disease from non-dioxin-related causes.
For a free reprint of the medical article, write to Dr. Richard E.
Hoffman, MD, Division of Environmental Hazards and Health Effects,
Center for Environmental Health, Centers for Disease Control, U.S.
Department of Health and Human Services, Atlanta, GA 30333; or phone
(404) 329-3311 and ask for Dr. Hoffman. Request a copy of "Health
Effects of Long-term Exposure to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin."
* * *
The California Air Resources Board (the state agency concerned with air
pollution) in 1986 asked a Scientific Review Panel on Toxic Air
Contaminants to look at available evidence on dioxins. Dr. Emil M.
Mrak, Chancellor Emeritus of the University of California at Davis, on
May 23, 1986, submitted the findings of the Scientific Review Panel,
which he chaired. The report says, in part, "Dioxins are potent toxins
and are known carcinogens and/or promoters of carcinogenesis in
animals. Dioxins... are potential carcinogens or promoters of
carcinogenesis in humans. The current and planned waste-to-energy
facilities in California will provide a high potential for emissions of
dioxins into air in the state. An exposure level [at] which no
significant health effects will occur cannot be identified. For these
reasons, we agree that dioxins should be listed by the ARB [Air
Resources Board] as toxic air contaminants with no determined threshold
below which adverse health effects will not occur."
The report goes on to say, "Dioxins and dibenzofurans are stable,
lipophilic [fat-soluble] compounds that may be expected to accumulate
up the food chain. Thus, airborne dioxins emitted during combustion may
contribute to dioxin intake by humans not only via inhalation but by
other routes such as ingestion of food. Assessment of dioxin intake
only via inhalation may thus underestimate total intake.
"Given that tissue levels of these compounds [in humans] are
measurable, we expect measurable levels in air, and we feel that the
expense involved in obtaining baseline data [on dioxins in air] is
small compared to the potential risk. Monitoring of ambient dioxin
levels should be commenced before any waste-to-energy facilities go on
"Since there is good evidence that dioxins can enhance the action of
other carcinogens, the potential for the harmful interaction of dioxins
with other environmental toxins could be important and must not be
forgotten or underestimated when considering research reports on the
actions of dioxins alone."
The two-page report, "Findings of the Scientific Review Panel on the
Report on Chlorinated Dioxins and Dibenzofurans as Adopted at the April
16, 1986 Meeting" is available from Mr. William Lockett, California Air
Resources Board, P.O. Box 2815, Sacramento, CA 95812; phone (916) 322-
8168; or from Dr. Emil Mrak, Chancellor Emeritus, University of
California at Davis, Davis, CA 95616; phone (916) 752-2442.
NEW STUDY SHOWS HOW ONE TOWN CAN RECYCLE AND CUT LANDFILL USE 70%
The town of East Hampton, New York, hired Barry Commoner's Center for
the Biology of Natural Systems (CBNS) to devise a plan for handling the
town's garbage without using an incinerator. The town has 15,000 winter
time residents but it swells with tourists during summer. The resulting
report recommends a combination of recycling and composting that would
reduce by 70% the amount of garbage going to the landfill. Get AN
INTENSIVE TRASH SEPARATION AND RECYCLING SYSTEM FOR THE TOWN OF EAST
HAMPTON for $10 from CBNS, Queens College, Flushing, NY 11367; phone
--Peter Montague, PhD
Descriptor terms: air pollution; msw; incineration; dioxin;
landfilling; jama; immune system; cdc; hhs; cbns; ca; ca air resources
board; chlorine; studies; health; emissions; food chain; carcinogens;
emil mrak; cbns; recycling; composting; msw;