Operator Safety - Wastewater Operators - page 18

than 5-year intervals, depending on the age of the worker. If the worker
is 40 years or older, annual medical examinations should be required.
The ultimate decision on what the actual frequency of re-examination is
to be made by a physician.
The medical screening procedure used widely in preplacement and
medical surveillance testing of a worker's medical suitability to wear
respirators is the pulmonary function test or spirometry . The pulmo-
nary function test measures two important parameters: FVC (forced
vital capacity) and FEV 1 (forced expiratory volume in 1 second). FVC
measures the worker's vital capacity when air is exhaled as rapidly and
forcefully as possible. The vital capacity (lung volume) is the amount of
air that can be exhaled after a maximal inspiration. FVC decreases with
the loss of lung volume that occurs in restrictive lung diseases resulting
from exposure to various fibrogenic dusts such as asbestos and silica.
FEV 1 measures the amount of air that the worker is able to expire in the
first second. FEV 1 divided by FVC (FEV 1 /FVC) decreases in obstructive
disease due to cigarettes, asthma, or exposure to chemicals, among oth-
ers. The American National Standards Institute recommends that the
FVC should be measured as 80% or greater and FEV 1 as 70% or greater. If
the FVC is less than 80% or the FEV 1 is less than 70%, restriction from
respirator use should be considered; however, the ultimate decision on
whether or not the worker is disqualified from respirator use for medical
reasons must be made by competent medical authority. The safety prac-
titioner must keep in mind that, although the pulmonary function test
is an excellent screening tool, it is not the definitive test or statement
as to whether one is medically fit or not; again, only competent medical
authority can make this decision. Pulmonary function testing can also
provide the employer with baseline data against which an assessment
can be made regarding any physiological changes in respirator wearers
that might occur with the passage of time.
Before the organizational safety person performs pulmonary func-
tion tests on employees, two requirements are necessary. First, the safety
person must be formally trained as a National Institute for Occupational
Safety and Health (NIOSH) pulmonary function technician. This training
usually can be completed in not more than 3 days at a NIOSH-approved
training center. Moreover, serving as a pulmonary function technician
does not require a medical degree or background. The second require-
ment is equipment. Spirometers are available from various vendors and
usually can be purchased for less than $3000.
A final word on pulmonary function testing. Experience has shown
that workers generally look forward to this test. This is especially the
case for those employees who are active cigarette smokers and those
who have recently given up smoking. When workers can receive graphic
illustrations or parameters that indicate what is going on inside their
lungs, they are interested. It can be very gratifying to observe workers
who have given up cigarette smoking as a direct result of their annual
pulmonary function tests. Persuading workers to give up cigarettes not
only helps workers maintain their good health but also helps to signifi-
cantly reduce their sick leave requests.