Availability of ATSDR's Draft Criteria for Determining the Appropriateness of a Medical Monitoring Program Under CERCLA

DEPARTMENT OF HEALTH AND HUMAN SERVICES

Agency for Toxic Substances and Disease Registry

[ATSDR-81]

Availability of ATSDR's Draft Criteria for Determining the

Appropriateness of a Medical Monitoring Program Under CERCLA

AGENCY: Agency for Toxic Substances and Disease Registry (ATSDR),

Public Health Service (PHS), HHS.

ACTION: Notice.

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SUMMARY: This notice announces the availability of draft criteria for

determining the appropriateness of site-specific medical monitoring

programs under the Comprehensive Environmental Response, Compensation,

and Liability Act (CERCLA). The public is invited to comment on these

draft criteria.

DATES: Comments must be received on or before October 24, 1994.

ADDRESSES: Submit written comments relating to the draft criteria to

Division of Health Studies, Agency for Toxic Substances and Disease

Registry, 1600 Clifton Road, NE., Mailstop E-31, Atlanta, Georgia

30333, telephone (404) 639-6200.

FOR FURTHER INFORMATION CONTACT: Dr. Wendy E. Kaye, Chief, Epidemiology

and Surveillance Branch, Division of Health Studies, ATSDR, telephone

(404) 639-6203.

SUPPLEMENTARY INFORMATION: Section 104(i)(9) of the CERCLA, as amended

[42 U.S.C. 9604(i)(9)], provides for the Administrator of ATSDR to

initiate a health surveillance program for populations at significant

increased risk of adverse health effects as a result of exposure to

hazardous substances released from a facility. A program included under

health surveillance is referred to as ``Medical Monitoring or

Screening'' by ATSDR and is defined in the legislation as ``the

periodic medical testing'' to screen people ``at significant increased

risk'' for diseases. The legislation states that a mechanism to refer

people who are screened positive for such diseases for treatment should

be included in the program. Statutory language only enables ATSDR to

provide medical care or treatment in cases of public health

emergencies. ATSDR has established criteria to determine when medical

monitoring is an appropriate health activity and the requirements for

establishing a medical monitoring program at a site.

Background

ATSDR is responsible for the public health related activities of

CERCLA. ATSDR's primary initial response at a hazardous substance

release or facility is the public health assessment, which is required

for every site on the National Priorities List (NPL). A public health

assessment can also be conducted in response to a petition from the

public. Other important components of ATSDR's initial response at sites

include health consultations and public health advisories. The public

health assessments, health consultations, and public health advisories

undergo review by ATSDR to determine if follow-up health activities are

needed at a site.

The types of follow-up health activities recommended for a site

will depend on the amount of information on the possible exposures and

their suspected pathways. In any case in which an association has not

been established between an exposure and a specific adverse health

outcome, several research and health education activities could be

considered. Those activities could include exposure assessment at the

site, epidemiologic studies, or professional education.

ATSDR's Division of Health Assessment and Consultation is

establishing a program for the investigation of exposures in

communities. That program will enable a more timely response to

questions on whether individuals in a community are being exposed. The

program will incorporate a variety of industrial hygiene techniques for

measuring chemicals in the environment, as well as selected biological

markers of exposure.

The Division of Health Education provides a wide variety of

services to educate health care professionals and communities on the

effects of exposures to hazardous substances. Activities in a community

around a hazardous substance release or facility may include conducting

grand rounds for health care providers on the effects of a specific

chemical, providing fact sheets on chemicals, conducting workshops on

clues to environmental disease, and producing case studies in

environmental medicine.

The Division of Health Studies (DHS) is responsible for conducting

epidemiologic research, including several types of studies,

surveillance programs, and exposure registries. Cluster investigations

and disease and symptom prevalence studies examine the occurrence of

disease in populations. Analytic epidemiology studies are conducted to

evaluate the causal nature of associations between exposure to

hazardous substances and disease outcomes.

DHS also has a surveillance program focusing on exposures to

substances at hazardous substance release or facility. The surveillance

program includes systems that follow populations exposed to hazardous

substances because of where they live or their occupation. It also

includes surveillance of emergency events in which hazardous substances

are released into the environment.

DHS is responsible for maintaining the National Exposure Registry,

a listing of people exposed to hazardous substances. The Registry is

composed of substance specific subregistries. The chemicals are

selected from the list designated by ATSDR as being of greatest threat

to health.

Medical monitoring is considered one of several follow-up health

activity options under the site-specific work conducted by ATSDR. A

medical monitoring program for the community exposed to hazardous

substances from a site will be considered with other health follow-up

activities when the information from ATSDR's initial response at the

site is reviewed. In cases in which there is no known association

between the exposure and specific adverse health effects (which could

include health outcomes, illnesses, or markers of effect), medical

monitoring is not an appropriate public health activity. In cases in

which there is limited information on a specific health effect's

relationship to an exposure, then options such as epidemiologic

surveillance, a disease and symptom prevalence study, or an

epidemiologic study are more appropriate. When adequate information

exists linking exposure to a hazardous substance with a specific

adverse health effect, further consideration will then be given to the

appropriateness of medical monitoring in that population.

Medical monitoring should be directed towards a target community

identified as being at ``significant increased risk for disease'' on

the basis of exposure. Significant increased risk will vary for

particular sites depending upon such factors as the underlying risk of

the outcome of concern, the risk attributable to the exposure, and the

presence of sensitive subpopulations. These factors will be considered

when evaluating the appropriateness of medical monitoring in a

community.

The CERCLA legislation also provides for a mechanism for referral

for treatment of those who are screened positive for the health

outcomes of concern; therefore, a mechanism to refer people for

diagnosis, interventions, or treatment should be in place prior to the

initiation of a medical monitoring program.

The primary purpose of a medical monitoring program is not

considered to be a research activity that further investigates the

cause-effect relationship between exposure and outcome. The primary

purpose of a medical monitoring program is case finding in order to

refer individuals for further evaluation and, as appropriate,

treatment. Within this framework, medical monitoring may include both

testing for early biological effect and an assessment of exposure using

biological specimens (for example, blood or urine), when appropriate.

This is provided as a service to individuals in communities where there

is believed to be significant increased risk of disease from exposure

to hazardous substances released into the environment.

Criteria for Considering Medical Monitoring

The criteria outlined below will be used to determine the

appropriateness of conducting medical monitoring in a community and

will be applied in a phased approach. Phase I, conducted by ATSDR,

consists of an evaluation of the exposure and outcome criteria. Phase

II consists of an evaluation of the system criteria. Phase II will be

conducted by a panel consisting of community, State and local health

officials, and ATSDR. At the end of Phase II, a detailed medical

monitoring plan for a community will be written. All of the criteria

must be met at a site in order for a medical monitoring program to be

established at that site.

Phase I

Exposure Criteria

A. There Should Be Evidence of Contaminant Levels in Environmental

Media That Would Suggest the High Likelihood of Environmental Exposure

to a Hazardous Substance and Subsequent Adverse Health Outcomes

The exposure must be to a hazardous substance as defined under

CERCLA, and the result of a release from a CERCLA covered facility. The

primary criteria for medical monitoring should be documented evidence

of exposure of a population to a hazardous substance in the

environment. An exposure will be considered to be at a sufficient level

if there is documentation of an increased opportunity for exposure to a

level that meets or exceeds some health-based comparison value or that

meets or exceeds a level reported in the peer-reviewed literature to

result in some adverse health effect. Documentation is considered

sufficient if it is from an exposure assessment, environmental exposure

modeling, or sampling from a general area (for example, water samples

from an aquifer or a town water supply). Documentation of individual

levels of exposure is not required. In cases in which exposures are

unknown or undocumented, environmental monitoring is a more appropriate

initial activity.

B. There Should Be a Well-Defined, Identifiable Target Population of

Concern in Which Exposure to a Hazardous Substance at a Sufficient

Level Has Occurred

Initially, the target population of concern will be defined

geographically on the basis of exposure. In addition, all populations

considered will be assessed for the presence of any sub-population at

increased risk of the adverse health effects associated with the

exposures. An example of a subpopulation at increased risk would be

preschool children in an area with soil lead contamination. The size of

the target population of concern is not a factor in the decision for

monitoring. In areas where biological markers of exposure have not been

collected, environmental sampling can be used to estimate exposure

levels. The target population of concern is the population in which

there is documented exposure at a sufficient level to place the

individuals in that population at significant increased risk for

developing some specific adverse health effect.

Outcome Criteria

A. There Should Be Documented Human Health Research That Demonstrates a

Scientific Basis for a Reasonable Association Between an Exposure to a

Hazardous Substance and a Specific Adverse Health Effect (Such As an

Illness or Change in a Biological Marker of Effect)

There must be previous studies on human populations which

demonstrate a reasonable association between a particular exposure and

an adverse health effect. In order to make that inference,

consideration should be given to the strength, specificity, and

consistency of the association among the identified studies. The period

of exposure (including its timing and duration) and its relationship to

the latency period for the disease or illness should also be examined

if information is available. Consideration should be given as to

whether the association has demonstrated a dose-response relationship

and whether the association is consistent with the existing body of

knowledge. This information could include a variety of occupational,

epidemiologic, or other studies involving human populations.

B. The Monitoring Should Be Directed at Detecting Adverse Health

Effects That Are Consistent With the Existing Body of Knowledge and

Amenable to Prevention or Intervention Measures

The monitoring should be established for specific adverse health

effects. The specific adverse health effect being monitored should be a

result of the possible exposure consistent with the existing body of

knowledge. An adverse health effect is consistent with the existing

body of knowledge if it has been described in the literature as caused

by that agent or by similar agents, taking into account structure-

activity relations.

In addition, the adverse health effects (disease process, illness,

or biomarkers of effect) should be such that early detection and

treatment or intervention interrupts the progress to symptomatic

disease, improves the prognosis of the disease, improves the quality of

life of the individual, or is amenable to primary prevention. If the

adverse health effects that are of concern in an individual or in a

community are not easily detectable and not medically treatable, then

medical monitoring would not be beneficial and would not be an

appropriate public health activity. An easily detectable effect is one

that can be found on clinical examination, or through the use of

simple, diagnostic tests in an outpatient setting. Also, the test

procedures must be acceptable to the patient and the community. The

diagnostic tests must be nonexperimental, relatively noninvasive (such

as the drawing of a tube of blood for laboratory tests), and simple to

administer.

Monitoring for Evidence of Continuing Exposure

In cases such as those at sites with lead exposure, the monitoring

program might include following biological markers of continuing

exposure. Those sites would be ones in which the exposure is known to

have a variety of adverse health effects, but for which no tests are

available to detect those effects at a time when intervention could

affect the course of the disease process. In those instances, the

primary intervention is to remove the individual from the exposure.

This allows the medical monitoring system to recommend referral for

intervention prior to the onset of detectable adverse health effects. A

monitoring system that includes biomarkers of continuing exposure is

similar to medical surveillance of hazardous waste workers where

changes indicative of increasing or continued exposures occur

sufficiently early that the exposure can be curtailed and the risk for

disease reduced (Gochfeld 1990).

Phase II

General Information

When ATSDR has determined that exposure from a site has met the

exposure and outcome criteria, a site panel will be formed to review

the system criteria and to develop a site-specific medical monitoring

plan.

The site panel will include representatives from the community,

State or local health departments, and local medical societies.

System Criteria

A. The General Requirements for a Medical Screening Program Should Be

Satisfied

The monitoring aspect of a health surveillance program consists of

the periodic medical testing to screen individuals who are at increased

risk of disease. Monitoring serves to identify those individuals with

an unrecognized adverse health effect. This is consistent with the

definition of screening as ``the presumptive identification of

unrecognized disease or defect by the application of tests,

examinations, or other procedures which can be applied rapidly.

Screening tests sort out apparently well persons who probably have a

disease from those who probably do not. A screening test is not

intended to be diagnostic. Persons with positive or suspicious findings

must be referred to their physicians for diagnosis and necessary

treatment.'' (Commission on Chronic Illness, 1957) In general, the

ability to predict the presence or absence of disease from test results

depends on the sensitivity and specificity of the test and the

prevalence of the disease in the population being tested. The higher

the prevalence, the more likely a positive test indicates disease

(Mausner & Kramer, 1985). In order for a screening program to be of

public health benefit, the population being screened should be at a

significantly high risk for the undiagnosed disease (i.e., the disease

should have a sufficiently high prevalence in the population).

Given that definition, there are certain requirements for screening

programs that should be considered when evaluating a possible medical

monitoring program for a site (adopted from Mausner & Kramer, 1985).

The natural history of the disease process should be

understood sufficiently for screening.

The early detection through screening should be known to

have an impact on the natural history of that disease process. For

example, the detection of breast cancer while it is localized has been

shown to increase the ten-year survival rate. For that reason, several

groups have made recommendations for the early detection of breast

cancer in asymptomatic women. Those recommendations include breast

self-examination, breast physical examination, and mammography (Mettlin

& Dodd, 1991; Kelsey & Gammon, 1991).

There should be an accepted screening test that meets the

requirements for validity, reliability, estimates of yield,

sensitivity, specificity, and acceptable cost. The purpose of ATSDR-

sponsored medical monitoring is not to develop new screening tests. The

medical monitoring program will use tests that have been recommended

and used for screening in other settings.

The screening program should be one that is feasible and

acceptable to individuals and the community. Therefore, plans for a

medical monitoring program will be presented to the community for input

prior to the initiation of any recommended program.

B. An Accepted Treatment, Intervention, or Both for the Condition

(Outcome or Marker of Exposure) Must Exist and a Referral System Should

Be in Place Prior to the Initiation of Medical Monitoring Program

There should be established criteria for determining who should

receive referral for intervention or treatment. These criteria will be

based on the selected effect being screened for and the screening test

being used. Results will be evaluated longitudinally and cross-

sectionally to identify changes in the system or screening tools that

require follow-up (Gochfeld 1990). A referral mechanism should exist so

that those who are eligible for the intervention can be referred to a

qualified health care provider for further diagnosis, treatment, or

intervention. The referral must be for treatment or intervention that

is standard practice and not experimental in nature. The medical

monitoring (screening) program is not responsible for the cost of the

referral, the intervention, or the treatment of individuals

participating in the program.

C. The Logistics of the System Must Be Resolved Before the Program Can

Be Initiated

After medical monitoring has been determinedappropriate for a site,

the specifics of the monitoring system will be detailed in a medical

monitoring plan. The site panel consisting of the community members and

appropriate health officials will develop the site- specific medical

monitoring plan. The specifics of the medical monitoring system

recommended can vary for each site. The monitoring plan is the protocol

for the specific program to be proposed in a community. The plan will

outline the target community, the types of outcomes to be screened for,

the participants in the referral system, and the program reports. The

plan will include a review of the latency period for the outcomes being

monitored and the duration of the exposure to define the period of time

that the program will operate in a specific site population. The target

population; the completeness with which the exposed population can be

identified, contacted, and followed; the screening tests; and the

selected health outcomes will all influence the specifics of the

system. Existing medical facilities and personnel will be used when

possible. The plan for a site might require review by an expert panel.

ATSDR's Division of Health Studies will work closely with the Division

of Health Education to provide for professional health education when

needed to enhance the medical monitoring program. Additionally, the

monitoring plan will be submitted for peer review prior to its

implementation at a site. The monitoring activity at each site will be

routinely evaluated for the effectiveness of the screening tests in

place and the types of effects being detected. Due to confidentiality

issues in dealing with small groups of people, the reporting from the

system will consist of annual reports noting the number of individuals

screened, the number of referrals made, and the number of conditions

diagnosed in the referral system.

The referral system will consist of the review of the screening

results and the referral to appropriate health care providers or

referral physicians. The specific mechanisms for determining who needs

referral and for selecting the health care providers in the referral

pool must be in place prior to the initiation of the medical

monitoring. Once the participant has been referred to the referral

providers, those providers will be responsible for the subsequent

diagnosis, treatment, or intervention.

Summary

Medical monitoring will be considered along with the other health

follow-up activities to be recommended for populations around specific

sites. The Division of Health Studies will make a determination on

whether a site meets the exposure and outcome criteria for medical

monitoring. If a site meets the previously discussed criteria and is

selected for further consideration of a medical monitoring program,

ATSDR will work with the community and other appropriate entities in

designing the specific monitoring and referral system for that site's

target population. ATSDR will notify, and where appropriate, will work

with the State health department to establish the program. The Division

of Health Studies will monitor the program and be responsible for

oversight on the annual reports.

References

Commission on Chronic Illness: Chronic Illness in the United

States, Vol. 1. Commonwealth Fund, Harvard University Press,

Cambridge, 1957, page 45.

Gochfeld M. Medical surveillance of hazardous waste workers. In

Principles and Problems in Occupational Medicine State of the Art

Reviews: Hazardous Waste Workers. Gochfeld M and EA Favata, editors.

Philadelphia: Hanley & Belfus, Inc., 1990;5(1):1-8.

Kelsey JL and MD Gammon. The epidemiology of breast cancer. CA-A

Cancer Journal for Clinicians 1991;41(3):146-165.

Mausner JS and S Kramer. Epidemiology--an introductory text.

Philadelphia: W.B. Saunders, 1985, pages 220-230.

Mettlin C and GD Dodd. The American Cancer Society guidelines

for the cancer-related checkup: An Update. CA-A Cancer Journal for

Clinicians 1991;41(5):279-282.

Dated: September 1, 1994.

Claire V. Broome,

Deputy Administrator, Agency for Toxic Substances and Disease Registry.

[FR Doc. 94-22228 Filed 9-8-94; 8:45 am]

BILLING CODE 4163-70-P