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Good morning. I am Barry Johnson, Ph.D., Assistant Administrator,
Agency for Toxic Substances and Disease Registry (ATSDR). I am
accompanied today by Maureen Lichtveld, M.D., Chief Biomedical Officer
for Public Health Practice, ATSDR. We welcome this opportunity to
present testimony on the health impacts of incineration: what we do and
do not know. Our testimony is derived from ATSDR's responsibilities and
findings under the Comprehensive Environmental Response, Compensation,
and Liability Act, as amended (CERCLA, or Superfund), and the Resource
Conservation and Recovery Act (RCRA, Section 3019).
In testimony presented by ATSDR before this Subcommittee on January 24,
1994, we responded to eight issues related to our experience with the
health impacts of incinerators. Our testimony today will elaborate on
the January testimony and respond to your request for an update on
research needed on incineration of municipal waste. As the Subcommittee
knows, there are many scientific, technology, and policy issues that
attend incineration of wastes. Our focus will be on the public health
issues.
Many communities have expressed their concerns about the potential
implications of incineration of wastes to ATSDR. Their concerns are
usually expressed as questions about the associations between
incineration of wastes and possible health effects. We are often unable
to answer those questions. Scientific information on the human health
impacts of incineration isn't often available because the relevant
studies haven't been conducted.
To achieve a true public health perspective, incineration of wastes
should be viewed in the larger context of generation and management of
wastes. Wastes become a public health concern when they are disposed of
and improperly managed. Therefore, in a public health context, the
most protective action is not to produce waste. Waste elimination or
minimization equates with prevention or reduction of the health
consequences of wastes.
When wastes are generated, the question becomes how to dispose of them
in ways that do not harm the public's health or the environment.
Incineration has been one means of disposing of wastes. The permitting
of incinerators is handled by government regulatory agencies. Analysis
of health and environmental impacts is normally conducted by assessing
the risk associated with incinerators proposed for specific
applications. These risk assessments consider the toxicologic data on
substances assumed to be emitted from the incinerator under operating
conditions.
ATSDR has had some experience in working on health issues pertaining to
incineration of wastes. Examples of our activities related to
incineration of wastes follow.
In particular, I draw your attention to a consultation requested of
ATSDR by Senator Lugar and Congressman McCloskey of Indiana concerning
incineration of PCB-contaminated wastes in Bloomington, Indiana. They
asked ATSDR to review the health implications of incinerating PCB-contaminated soil from the Bloomington
area. In response, ATSDR convened 40 national experts in the fields of
combustion engineering, toxicology, epidemiology, medicine, chemistry,
and related fields to review the scientific literature on incineration
of wastes, the health effects of PCBs, and nonincineration means of
disposing of PCB-contaminated wastes. Reports from these three panels
are in peer review, and ATSDR will be pleased to make them available to
the Subcommittee when they have been completed. A few pertinent
preliminary findings from this report are included in this testimony
under the section "The Public Health Impact of Older Municipal Solid
Waste Incinerators."
ATSDR has also investigated the effects on community health of an
incinerator in North Carolina. The Caldwell Systems incinerator
disposed of industrial solvents and hazardous wastes in the 1970s and
1980s. This incinerator appears to have been operated beyond its
operating capacity, resulting in incomplete combustion of hazardous
wastes. ATSDR was asked by a local physician and EPA Region IV to
evaluate the health problems of residents living in the vicinity of the
incinerator. ATSDR's investigation found an increased pattern of
respiratory problems in community residents. In addition, residents
complained about irritation of the airways and poor motor coordination.
A follow-up study is currently underway to evaluate better the health
problems reported by the residents; its focus is on determining the
presence of adverse health effects of the pulmonary, neurobehavioral,
and immune systems. The field work for this study has been conducted
and ATSDR is currently analyzing the data.
In Arkansas, the community living near the Vertac Superfund site
incinerator expressed to the Arkansas Department of Health (ADD)
concerns about the public health impact of the facility. To assist ADD,
ATSDR awarded two grants to conduct an exposure study and a reproductive
outcome study. Preliminary findings from the exposure study indicate an
association between elevated body burdens of certain compounds (2,4-T
and dioxin) and length of residence near the site. This constitutes
historical, pre-incineration exposure. The incinerator is currently
operating. A second round of testing was conducted in March 1994 to
assess exposures to the chemicals incinerated to date. Following
completion of the incineration of the dioxin-containing wastes, a third
round of testing will be conducted.
ATSDR is also supporting a Health and Clean Air Study conducted by the
University of North Carolina. The study will further explore the
occurrence of and risk factors for lung and respiratory diseases
potentially caused by hazardous substances. The study compares
residents of communities near a municipal solid waste incinerator, a
medical waste incinerator, and a hazardous waste incinerator with three
nearby control populations, over 3 years. Components of the study
include baseline spirometry, peak flow measurements, nasal lavage, and a
survey to collect information about respiratory symptoms and outcomes.
Data collection for this study is in its third year.
At another site, at the request of local citizens, ATSDR reviewed the
location, design, and operating plans for a temporarily sited
incinerator proposed for placement at the Brio Superfund site near
Houston, Texas. Because ATSDR was not a party to considering other
remedial options, our consultation was confined to the health issues
attending incineration. ATSDR advised EPA to move the location of the
proposed incinerator away from residential areas, to increase off-site
emissions monitoring during the incinerator's operation, to conduct
additional characterization of on-site contaminants, and to develop a
means of sharing the monitoring data with local residents. In addition,
ATSDR has undertaken a comprehensive health study in the community. The
purposes of the study are to determine a) if there is an increased
reporting of health effects by the current residents; b) if subtle
adverse health effects have occurred in some organ systems (kidney,
liver, and immune); and c) the occurrence of birth defects in children
born to mothers who lived near the Brio site. The report discussing the
first phase of the study will be available for public release within 1
month.
Earlier this year, EPA Region V, State and local health departments, and
the local community requested ATSDR's assistance in addressing health
concerns associated with a municipal waste incinerator in Columbus,
Ohio. The Columbus Municipal Waste Facility is a waste-to-energy
facility in Columbus, Ohio, where municipal trash is burned in boilers
to generate energy. It has operated since December 1983. Of particular
concern to residents is the fact that analysis of past samples has
identified dioxin compounds in the stack emissions. Currently, ATSDR is
working with other federal, state, and local agencies and the community
to develop a plan of action for evaluating the residents' health
concerns.
ATSDR is assisting EPA Region III in addressing the health concerns of
residents living in two heavily industrialized communities in southwest
Philadelphia and Chester, Pennsylvania. ATSDR was also petitioned by a
citizen living in southwest Philadelphia to address the health concerns
of the two communities. Residents are concerned that the proliferation
of industries is polluting the air and creating an inordinate threat to
their health. In addition, officials are considering establishing a new
hazardous waste incinerator in Chester.
ATSDR is concerned about the public health impact of such multiple
emission sources and the resulting exposures to hazardous substance
mixtures. These concerns are heightened when communities may be
disadvantaged and underserved. As a result, the Agency is reviewing
methods for determining which adverse health conditions may be present
at higher rates in disadvantaged, underserved, and minority communities
to assess whether exposures to hazardous substances in the environment
are impacting the public health.
The Public Health Impact of Older Municipal Solid Waste Incinerators
In your letter of invitation, you asked us to address the health impacts
on communities of an older municipal solid waste incinerator, like the
one in Greenpoint.
The public health impact of incinerators can be influenced by the age of
the equipment. Older incinerators, unless they have been upgraded in the
past few years, may not have the most recent pollution control equipment
and operating technologies; therefore, these incinerators may not be
able to achieve the same level of emission control as a new municipal
solid waste incinerator. In addition, in some instances, older
incinerators may be operating under less stringent permits than those
currently required by the EPA and State and local regulatory agencies.
ATSDR supports the efforts by EPA in recent years to impose greater
regulatory control over all forms of incineration, including municipal
solid waste incineration, and to require incinerators to upgrade to the
maximum achievable emissions control.
Some preliminary findings from the expert panels convened recently to
assist ATSDR in evaluating the public health implications associated
with incinerating PCB-contaminated waste in Bloomington, Indiana, are
applicable to incineration in general. For example, the panels stressed
the importance of evaluating information related to all aspects of the
facility operations, design, and maintenance, including stack emissions
data, when assessing the public health implications of incineration.
Moreover, the panels highly recommended the need for epidemiological
studies to measure exposures and specific adverse health outcomes. To
enhance our collective knowledge about the health impact of
incineration, a recommendation was also made to establish relevant
toxicological and environmental databases.
Health Impacts from Incinerator Emissions
Emissions of hazardous substances from incinerators are of particular
concern to communities.
However, there are very few data on the impact of incinerator emissions
on the health of nearby communities. Epidemiologic investigations have
rarely been conducted and few studies of disease and illness patterns
have been undertaken. For example, ATSDR staff recently searched the 10
most frequently used computerized environmental databases. More than 1
million entries were identified. Approximately 72,000 of the entries
dealt with incineration. Of those, only a single entry included
information about a population-based study conducted in a community
living in the vicinity of an incinerator. That study of residents
living near the Caldwell Systems incinerator in North Carolina was
conducted by ATSDR. The findings from the Caldwell study were
previously described in this testimony.
In the absence of human health data on the effects of a hazardous
substance on public health, we rely on toxicity data. The effect of any
toxic substance depends on factors such as duration of exposure,
concentration of the substance in the environment, biological uptake,
and personal susceptibility factors (e.g., age). All of these factors
have to be considered in any estimate of the public health impact of
incinerator emissions.
Much is known about the toxic effects of contaminants that may be
released from waste incinerators, lead, mercury, dioxin, and furans.
Scientific literature is available on each substance. This knowledge is
based on laboratory animal studies, occupational investigations, and
some community health studies. For example, lead exerts toxic effects
on the nervous system, kidney, immune function, and reproduction. It is
associated with hypertension in middleaged persons. Mercury or mercury
compounds are toxic to the nervous system, kidney, and immune function.
Data from epidemiologic studies and the scientific literature indicate
that human exposure to PCBs may result in cancers of the hepato-biliary
tract, as well as reproductive/developmental, dermatologic,
cardiovascular, hepatic, and endocrine/thyroid effects. Dioxins have
been extensively studied in toxicological studies. The most toxic
member of the family of compounds called dioxins is 2,3,7,8-TCDD. What
is known about human health effects has come primarily from occupational
studies of workers. TCDD has been associated with chloracne, metabolism
alterations, soft tissue sarcoma, and altered reproductive hormone
levels. EPA lists TCDD as a probable human carcinogen. EPA is
currently completing a reassessment of the human health risk of dioxin.
Furans have been associated with dermal, ocular, and neurologic effects
in humans.
Few data are documented in the scientific literature on specific
interactions of the contaminants released from waste incinerators. In
the absence of specific studies of combined contaminants, and because of
our limited understanding of the mechanisms of actions of some
substances, it is prudent to assume that the effects of exposure to
these contaminants are additive.
It is important to emphasize that almost all of our toxicologic data are
from studies in which exposure levels greatly exceeded those typical of
incinerator releases.
Adequate information does not exist to support speculation on what, if
any, human health effects might be associated with incinerator
emissions. However, our experience with public health effects related
to hazardous waste sites suggests the need to conduct two types of human
health investigations. One type of investigation would look at cancer,
birth defects, and respiratory disease rates in areas believed to be
impacted by releases from incinerators. These studies would combine
health data from many geographic areas. A second type of study would be
site specific. Community health surveys would help clarify whether any
unusual exposure or morbidity might be associated with exposure to
substances from a given incinerator.
The Sensitivity of Various Populations-Because of Age, Gender, or
Ethnic Background-to These Chemicals
Of special concern because of their risk for adverse health impacts from
exposure to hazardous substances are sensitive subpopulations.
Infants and children. Of all human populations, infants and
children are arguably most sensitive to toxic exposures. They are at
special risk because they play outdoors; they ingest or mouth foreign
objects; they are smaller (greater chemical doses per pound) than
adults; they breathe more air (greater volume and breathing rate per
pound) than adults; they are nutritionally challenged (because of
protein-calorie requirements to support rapid physical growth); and they
are undergoing developmental changes that make them especially
vulnerable to chemical exposures. Moreover, they have the longest life
expectancies, during which long-term adverse health effects may become
manifest. Certain disorders may not become evident until a child
reaches a particular developmental stage, which may be long after damage
has been done. Some of the largest environmental health programs (e.g.,
lead, asbestos) are directed primarily at children.
People of reproductive age.
All women of reproductive age must
be included in this population because the most severe effects usually
occur during the very early stages of pregnancy, often before a woman
knows she is pregnant. In addition, pregnant women, especially those
with multiple pregnancies, and the developing fetus have increased
protein-calorie requirements to support rapid physical growth.
The developing fetus is particularly sensitive to chemical exposures.
Exposure to chemicals has the greatest impact on those functions
undergoing the most active development at the time of exposure. Animal
studies and some human studies show that there are critical fetal
developmental stages during which chemical exposure can cause permanent
and devastating effects.
A small, but growing, scientific literature suggests that some toxicants
affect male reproductive processes. For example, laboratory animal
studies have shown that exposure to lead causes adverse reproductive
outcomes in male rats, leading to neurologic effects on their offspring.
Similarly, PCB exposures in fish and waterfowl have been reported to
cause feminine features in males of these species.
Elderly persons and persons with chronic illnesses.
Elderly
persons and the chronically ill tend to be more susceptible to
respiratory irritants. Long-standing public health policies, such as
immunization guidelines for influenza, support this notion.
The elderly are also often nutritionally challenged because of reduced
protein-calorie intake and the metabolic changes that occur during this
life stage. Underlying illnesses, as in the case of the chronically ill
may increase their susceptibility to particular toxicants. For example,
persons with chronic diseases of the kidney system may experience more
harmful effects from exposure to renal toxicants, such as lead and
cadmium, compared with a healthy individual.
Moreover, elderly persons and those with chronic illnesses are often
socially isolated and potentially less aware of environmental
emergencies. Because of physical challenges, they may require special
services during evacuation in the event of such an emergency.
Minorities.
Preventing adverse health effects in minority populations
exposed to hazardous substances is a priority for ATSDR. Minority
populations, particularly African Americans, Hispanics, and Native
Americans, suffer disproportionately from preventable morbidity and
mortality. Regardless of income, education, or geographic location,
these populations are often in poorer health than their white
counterparts. This disparity is often associated with inadequate access
to health care?for preventive services as well as for early diagnosis
and treatment of disorders that may be associated with exposure to
hazardous substances. Disadvantaged economic status also frequently
affects nutritional status. Occupational chemical exposures may
increase this population's susceptibility to adverse health effects
resulting from other exposures to hazardous substances. In addition,
certain pre-existing genetic disorders (G6-PD deficiency, sickle cell
anemia) may compound the impact of such exposures.
Research Gaps
As a followup to ATSDR's testimony in January, an outline of relevant
research was provided to address the lack of studies on any associations
between emissions from municipal waste incinerators and human health
effects. We continue to believe that the following areas need to be
addressed:
Cancer and birth defects and reproductive outcomes can be evaluated
using available health information and an ecologic or geographically
based cross-sectional approach. The choice and number of incinerators
studied would be based on the presence of good health outcome data
(preferably disease incidence registries) and historical air monitoring
data. As a basic study, case rates could be calculated for geopolitical
units near the incinerator sites and compared with reference rates.
Lung and respiratory diseases, for which there are no databases of
information, would be evaluated by defining a population of people with
asthma (or other chosen respiratory disease) and without asthma. Those
people would be monitored for up to 3 years to determine any adverse
health effects and to correlate air quality with respiratory disease
symptoms and pulmonary function measures. The human health studies
would be conducted by university investigators through grants from the
sponsoring Federal agency.
This page last updated on May 15, 2000
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Health Impacts of Incineration - Part II
Congressional Testimony by
Barry L. Johnson, Ph.D.
Assistant Surgeon General
Assistant Administrator
Agency for Toxic Substances and Disease Registry
Public Health Service
U. S. Department of Health and Human Services
Before the
Subcommittee on Human Resources
and Intergovernmental Relations
Committee on Government Operations
United States House of Representatives
July 8, 1994
This concludes our testimony. We will be pleased to answer
questions.
Joanne Cox / JDCox@cdc.gov
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