Surveillance is the ongoing, systematic collection, analysis, and interpretation of health data essential to the planning, implementation, and evaluation of public health practice, which is closely integrated with the timely dissemination of these data to those who need to know. To be effective, surveillance must be directly linked to preventive action. In the case of occupational health, the actions prompted by the surveillance system should be directed not only at the individual case or the affected group, but also at the responsible workplace factors. Surveillance programs (i.e., 2ry prevention) should be designed to support programs intended to control workplace hazards (i.e., 1ry prevention). In OSH, surveillance programs should: • Identify cases of occupational illness or injury; and/or • Monitor trends of occupational illness or injury.

1. Dr. Dalia El-Shafei
Assist.Prof. of Occupational Medicine

2. http://www.slideshare.net/daliaelshafei

3.  Ongoing, systematic collection, analysis, and
interpretation of health data essential to the
planning, implementation, and evaluation of
public health practice, which is closely integrated
with the timely dissemination of these data to
those who need to know.
 Surveillance programs (i.e., 2ry prevention)
should be designed to support programs intended
to control workplace hazards (i.e., 1ry
prevention).

4. Surveillanceprograms
Identifying cases
Medical screening;
Health care provider
reporting
Employer case
reporting
Monitoringtrends
Health effects
surveillance
"Occupational illness"
Occupational diseases
"OD"
Work-related diseases
"WRD"
Hazard surveillance

5. Assessment of
workplace
hazards
Identification
of target organ
toxicities for
each hazard
Selection of a
test for each
screenable
health effect
Development of
action criteria
Standardizatio
n of the testing
process
Performance of
testing
Interpretation
of test results
Test
confirmation
Determination
of work status
Notification
Diagnostic
evaluation
Evaluation and
control of
exposure
Record keeping

6. •Exposure assessments & risk assessments for target organ damage.
Steps 1, 2, 3
•Development of action criteria in response to medical test results. Guidelines by consensus
groups, such as the Biological Exposure Index (BEI) of the ACGIH, and OSHA standards are
available for selected indicators.
Step 4
•Standardization of test procedures & quality control,
•Provision of information to employees about the tests & written evidence of informed consent.
•Confidentiality of results “Record access control system”.
Step 5&6
•Interpretation of the test results should be based on several factors, including the
predetermined action level criteria, and exposure data for the individual.
•Abnormal results should be reconfirmed.
Step 7&8
•Removal of the employee from further exposure
•Legal provisions to safeguard wages and benefits in the event of job transfer due to such a
reason.
•Employees themselves should be notified of the results, in addition to statutory notifications.
•Further medical evaluations may be indicated, including referral to the appropriate specialist.
Step 9,10&11
•The work environment of the employee with an abnormal screening result has to be re-
evaluated.
•Measures should be implemented to reduce the exposure to safe levels.
•Record keeping: Medical records, records of notifications, exposure evaluations and resulting
environmental modifications.
Step 12&13

8. Physician
• Design and administration of screening programs.
• Provide all medical test results to the employee, along with an interpretation of the abnormal
tests.
• Ensure that appropriate medical follow-up of abnormal test results.
• Ensure that if worksite exposures were responsible for abnormal test findings, these exposures
are controlled to an acceptable level before the employee returns to work
• Ascertain whether or not the employee’s coworkers with similar exposures are at risk, and if
so, the appropriate action that should be taken (e.g., screening).
• Medical results should be released by management if such knowledge would prompt action to
protect the health of employees.
Employer
• Providing unrestricted access to medical screening for employees at risk
• Providing exposure information (e.g., job history and results of environmental sampling)
• Maintaining a safe and healthful workplace
Employee
• Providing accurate information (e.g., medical history)
• Cooperating with medical testing procedures
• Assume personal responsibility for changing the behavior to reduce the risk

10. Employers are required to provide employees with access to
medical screening examination when the employees are
exposed to certain hazards.
In a few instances, decision models are provided (e.g., Lead and
Cotton Dust Standards) that guide physicians in their evaluation
of results and in their recommendations for action.
In most instances, little or no guidance is provided in the
interpretation of results.
OSHA requires that records be maintained for the duration of
employment plus 30 years, and that access of the employee to
his or her personal records be provided on request.

11. A
• 2-Acetylaminofluorene
• Acrylonitrile
• 4-Aminodiphenyl
• Inorganic arsenic
• Asbestos
B
• Benzene
• Benzidine
• Bischloromethyl ether
C
• Cadmium
• Coal tar pitch volatiles
• Coke oven emissions
• Cotton dust
D
• Dibromochloropropane
• 3,3′-Dichlorobenzidine
• 4-Dimethylaminoazobenzene
E
• Ethylene oxide
• Ethylenimine
F
• Formaldehyde
H
• Hazardous waste
L
• Lead
M
• Methylchloromethyl ether
N
• Alpha-naphthylamine
• Beta-naphthylamine
• 4-Nitrobiphenyl
• Nitrosodimethylamine
• Noise
P
• Beta-propiolactone

12.  Regulations have been developed in many cities, states, and
countries that instruct healthcare providers to report suspected
cases of occupational illness or injury to an office of government.
 To develop a systematic approach to the use of reports
received from healthcare providers in the US, NIOSH developed
the Sentinel Event Notification System for Occupational Risks
(SENSOR).
 Once reports are received and confirmed by the health
department’s surveillance centers, an active response occurs.
 Three possible actions may take place:
• Management of the individual case;
• Screening of coworkers with similar job exposures; and
• Investigation of the worksite.

14.  Surveillance systems designed to monitor trends for
occupational disorders or exposure usually rely on existing
records collected for purposes other than surveillance.
 These records are coded or modified in some way to
make them suitable for analysis.
 Each data source has certain limitations and advantages
that must be considered in assessing the usefulness of the
data for surveillance purposes.

15. Pre-existing
healthcare &
vital records
Employer case
reporting
Workers’
compensation
data
Biologic
monitoring
data
National
health surveys
Exposure
surveillance
systems

16.  Death certificates (including those of fetal deaths), birth certificates, hospital
discharge records, office records of healthcare providers, and insurance claim files.
 Limitations:
• Information on the occupation of the patient is often not in the record;
• Physicians often fail to recognize disorders caused by occupational hazards;
• Misclassification or omission of conditions and occupations of interest.
 Advantages:
• Records are available at modest cost;
• Records are coded using generally accepted code schemes (e.g., ICD).
 Improve awareness among healthcare providers of the impact of work on health.

17.  In the US, employers are required by OSHA to record
occurrences of occupational illness and injury on a form maintained
at the worksite (called the OSHA log).
 The responsibility for completing this record often falls to an
individual who has had no medical training and guidance in
determining what should be recorded. Studies have shown that many
disorders, particularly occupational illness, are not reported in the
OSHA log.
 Each year, the Bureau of Labor Statistics of the US Department of
Labor collects a sample of these records from a portion of employers;
certain categories of the workforce are not included in the survey.
This sample is used to generate national estimates for selected
conditions.

22.  Limitations of workers’ compensation data for surveillance:
• In view of reporting disincentives and inherent difficulties in
recognizing occupational disorders, workers’ compensation data
consistently underestimate the true rate of occurrence of occupational
disorders. Furthermore, the rate of underestimation varies among
conditions, with greater under-reporting of diseases than for
occupational injuries.
• Workers’ compensation laws vary from state to state. Many workers’
compensation systems have requirements that claims be filed within a
brief time period (e.g., within 1 year) following the suspected exposure;
this requirement may present substantial barriers to filing claims for
occupational diseases of long latency (e.g., cancer).

23. Advantages to the use of workers’ compensation data include
the following:
• All records in the data set relate to conditions of suspected
occupational etiology.
• Information on the job and the industry for each claimant is
contained in the record.
• The circumstances of the illness or injury are frequently described
in a way that provides understanding of the cause of the condition.
• If case identification leads to improvement of workplace
conditions, prevention of further claims should occur, thus
benefiting both the employee and the employer.
• If these data are used for surveillance purposes, technical
improvements in the data management system (e.g., better coding
procedures or computer systems) could occur that would benefit the
management of the workers’ compensation insurance system itself.

24. In summary, workers’ compensation data represent an
important source of surveillance data that can be used to
monitor trends in the occurrence of selected occupational
disorders and to identify cases for follow-up action.

25.  Limitations:
• Biologic assays exist for only a few substances.
• Quality control programs for these analyses may be limited.
• Participation in biologic monitoring programs is often limited
to larger workplaces in which hazards are well controlled.
• Within workplaces that participate in a biologic monitoring
program, individual workers may choose not to be tested.
 Advantages:
• Each test (e.g., BLL) is a specific index of exposure to the
toxic substance.
• In states where commercial laboratories are required to report
results to the state agency, data can be obtained widely and at
low additional cost.

27.  Different countries maintain different health survey
systems.
 Each year in the US, the National Center for Health
Statistics (NCHS) performs surveys of statistical samples of
the population. Within each sample, a subset of employed
persons can be identified. In each survey, health status data
and occupational listing information are collected.
 The US Health Interview Survey (HIS) is a questionnaire
survey.
 The National Health and Nutrition Examination Survey
(NHANES) uses both a questionnaire and detailed medical
tests to obtain health status information.

29.  Exposure surveillance can be performed using existing
data or through the performance of worksite surveys.
 Existing environmental data are most commonly
developed as part of compliance inspections performed by
the US Department of Labor (either OSHA or the Mine
Safety and Health Administration, MSHA).
 Direct surveys have been performed by NIOSH: the
National Occupational Hazard Survey, the National
Occupational Exposure Survey, and the National Mining
Survey.