Board Review 2018 (Occupational Medicine - Prevent, Assess, Recognize, and Control)

True/False: The LONG TERM effect of radiation which presents the greatest risk to the exposed person is cataracts.

False. Long term effects of radiation exposure include stochastic effects such as cancer, genetic effects, and life-shortening.

True/False: The reproductive effects from video display terminals have been attributed to ionizing radiation and thermal stress.

False. The main area of discussion has been the possible effects of low level pulsed magnetic fields.

True/False: The speed of rotation should be 7-10 days on each shift for shift work workers.

False. The speed of the rotation should be rapid; two to three days on each shift.

Efficiency (equation)

Efficiency (%) = (Work output/energy consumption) x 100

The 1991 committee for the Revised NIOSH Lifting Equation chose a physiological criterion that represented the capacity for ______.

The 1991 NIOSH committee reduced the baseline aerobic capacity from 10.5 kcal/min down to 9.5 kcal/min. This value assumed the mean aerobic lifting capacity of the 50th percentile 40 year old female.

True/False: In the design of work, muscular work can be maintained for several hours per day without symptoms of muscle fatigue if the force exerted does not exceed approximately 18% of the maximum voluntary force of the muscle involved.

False. Experts are of the opinion that work can be maintained for several hours per day without symptoms of fatigue if the force exerted does not exceed about 10% of the maximum force of the muscle involved.

Regarding workspaces and specifically workspace envelopes, Pheasant (1986) describes the zone of convenient reach as ______.

The space in which an object may be reached without undo exertion, i.e., within arm's reach.

How long must employee noise exposure measurement records be kept on file?

OSHA requires employee noise exposure measurement records to be kept on file for two years. Note, however, that audiometric test records must be retained for the duration of the employee's employment.

Define reactive and proactive worksite analysis.

Reactive (with respect to worksite analysis) by definition means analysis of past incidences while proactive means identification of problem jobs and tasks before injury or illness has occurred.

True/False: Design reviews are proactive actions that allow for ergonomic issues to be identified and eliminated before workers are exposed.


What is the metabolite of interest in biological monitoring for styrene exposure?

Mandelic acid is the metabolite of interest in biological monitoring for styrene exposure.

What is the action level for urine phenol in a worker who has been exposed to benzene?

If the result of the urinary phenol test is equal to or greater than 75 mg phenol/L of urine, the employer shall provide the employee with a complete blood count including an erythrocyte count, leukocyte count with differential and thrombocyte count at mo

True/False: An air-purifying respirator can be worn safely if the odor threshold is greater than the allowable level.

False. To wear an air-purifying respirator safely, the worker must be able to detect the material at a safe level.

When selecting a respirator, the length of time the respirator can be used is determined by ______.

Concentration, duration, and type of cartridge.

Assigned Protection Factor (APF) of various masks

Dusk mask = 5 to 10 APF
Half mask = 10 APF
Full facepiece = 50 APF

Assigned Protection Factor (calculation)

APF = outside concentration / inside concentration

Cannister respirator colors and use

The correct canister color for carbon monoxide is blue. Black is for organic vapors, green is for ammonia, and white is for acid gases. See for more detail.

Chemical cartridge air-purifying respirator

A respirator that uses various chemical substances to purify inhaled air which contains certain contaminant gases and vapors.

Concept of Universal Precautions

All human blood and certain human body fluids are treated as if known to be infectious for HIV, HBV, and other bloodborne pathogens.

Sound pressure level equation

For each halving of the distance you must add 6 dB.

At what frequencies is the A-weighted sound level measurement the preferred scale?

A-weighted sound level measurement is the preferred scale of measurement in the > 1000 Hz frequencies.

Why is A-weighted sound level measurement the preferred scale of measure?

Because the A-weighting most closely weights the sound to the injurious effects of the noise on the ear.

How is the prediction of combined decibel readings from two separately measured noise sources, where the two sources differ by 3 decibels, made?

The rule of thumb for combining decibels where the two sources differ from 2-5 decibels, is adding 2 to the higher decibel level.

Calculating sound level measurements with increasing distance

A rule of thumb for calculating this is each doubling of distance from the source results in -6 dB.

What instrument is used to measure vibration?

An accelerometer

For employees with a threshold shift, hearing protection attenuation must reduce exposure to what time weighted average (TWA)?

To an 8-hour TWA of 85 dB.

What is the usual unit of measurement for laser radiation?

J/cm2 or W/cm2

The total body burden (in radiation terminology) is measured in which of the following units?


True/False: Roentgen equivalent man (rem) can be measured directly by instruments.

False. The rem is not generally measured directly, while the exposure (roentgen) and absorbed dose (rad) are quantities which can be measured directly by instruments.

Sievert to rem conversion

One Sievert is equivalent to 100 rem

What control measures would be effective in controlling exposure to radon?

Pressurizing the building, increasing dilution ventilation, and natural ventilation would be methods for controlling radon gas exposure.

When a nucleus of an atom undergoes nuclear fission, the nucleus releases what?

Nuclear fission of a nucleus causes the release of 1-3 neutrons.

True/False: Positrons have the same mass as the beta particle.

True. Positrons are positively charged electrons of nuclear origin.

90 Sr 38 -> Beta electron + xx Y zz

The "XX" refers to the mass number for Yttrium. As beta decay causes no change in the mass number--it remains at 90 for Yttrium.

True/False: Gamma rays acquire their energy from nuclear disintegration.


Define roentgen.

The roentgen is a unit of measure of the ionization produced by gamma rays in air.

Define ionizing radiation.

Any particle or photon with enough energy to ionize.

What type of radiation does not fall completely within the nonionizing radiation portion of the electromagnetic spectrum?

Ultraviolet falls partially within the ionizing radiation portion and partially within the non-ionizing portion of the electromagnetic spectrum.

Which wavelengths of UV light are of greatest health concern?

The wavelengths from 280-320 (UVB) are capable of causing skin cancer, photokeratitis, and erythema.

True/False: The Ultraviolet Light threshold limit value (TLV) applies to "radiation from arcs, gas and vapor discharges, fluorescent and incandescent sources, solar radiation, and ultraviolet lasers".

False. The TLV does not apply to ultraviolet lasers.

What potential optical radiation hazards are there to laser operators other than those from the laser beam itself?

Ultraviolet radiation emitted from laser discharge tubes, pumping lamps, and plasma (from laser welding), may have sufficient UV content to cause a potential hazard.

Gray conversion to rad

1 Gray (Gy) = 100 rad. A rad, or radiation absorbed dose, is the dose of radiation absorbed by tissue.

The primary function of a Geiger counter is to measure _______.

Geiger counters can separate beta from gamma with a cover on the thin window, but the primary function is to detect gammas. Proportional counters can separate alphas from betas, and ionizing region detectors measure alpha, beta, and gamma.

Biological Exposure Indices (BEI)

Biological Exposure Indices (BEI) provide a direct estimate of body burden from a chemical or its metabolite. The measurement will account for exposures from multiple routes of entry, such as skin, inhalation, and ingestion.

True/False: If a hazard exists that requires PPE, then engineering controls should be used instead of PPE.

True. Only during emergencies, non-routine tasks, and when engineering controls are being repaired or installed, should PPE be the preferred choice for employee protection.

In what circumstances can static effort be said to be considerable?

1. A high level of effort is maintained for 10 seconds or more.
2. A moderate effort persists for 1 minute or more.
3. A slight effort (about 1/3 of maximum force) lasts for 5 minutes or more.

Identify some advantages to the Dvorak keyboard.

1. The balance between the left and right hand usage is optimized.
2. Designed for the most frequently used letters in the English language to be better placed to correspond with the stronger fingertips.

True/False: A variable geometry keyboard is one of several experimental keyboards that can split down the middle and allow the worker to adjust the angle in an attempt to keep the wrist in a neutral position.


True/False: The hand is significantly more powerful when it turns in a pronated direction.


Work condition pause

Interruptions that arise either from the operation of a machine or organization of the work.

The instrument used to measure a persons threshold of hearing (that is the minimum sound pressure level that is just audible) at selected frequencies is called an ______.


What are zeitgebers?

These may be natural phenomena such as light/dark, thermal conditions, sleeping, and diet that trigger or cue biological rhythms.

The OSHA action level for a hearing conservation program is 90 dBA.

False. The action level for a hearing conservation program is 85 dBA, while the 8 hour time-weighted-average (TWA) permissible exposure limit (PEL) is 90 dBA.

What is the maximal annual permissible dose equivalent for occupational radiation exposure?

5 rems is the maximal annual permissible dose equivalent for whole body occupational radiation exposure recommended by Federal OSHA.

True/False: For employees with a significant threshold shift, hearing protector attenuation must be sufficient to reduce exposure to a time-weighted average of 90dB.

False. For employees with a significant threshold shift, hearing protector attenuation must be sufficient to reduce exposure to a time-weighted average of 85dB.

True/False: By the age of 60, muscle strength is approximately 70% of the maximum strength attained in the late twenties.

False. By the age of 60, muscle strength is approximately 80% of the maximum strength attained in the late twenties.

What are examples of source controls in TB prevention?

Identify, isolate, and treat cases.

True/False: OSHA requires audiometric testing of employees potentially exposed at or greater than 85 decibels for 8 hours within 6 months and annually thereafter.


Haddon Matrix

The Haddon Matrix emphasizes timing of intervention and preventive strategies based on the injury-producing event.

Health risk assessment

The quantitative prediction of the probability of an adverse effect in a specific population.

Health protection

Health protection is an intervention strategy that aims to provide individuals with resistance to hazardous factors typically by modifying the environment to decrease the potential for harmful interactions with those factors. Examples include personal pro

Mean time to failure

Mean time to failure (MTF) relates to the amount of time that a system or individual performs successfully until failure or between failures. It is a measure of reliability.

Risk management

The process of dealing with the uncertainty and unpredictability of personal injury, property loss, business interruption, and liability.

True/False: In selecting appropriate personal protective equipment (PPE) for your HAZMAT team, compliance of PPE with NIOSH standards on chemical protective clothing is recommended.

False. As an aid in selecting suitable chemical protective clothing, the National Fire Protection Agency (NFPA) has developed standards on chemical protective clothing for HAZMAT work.

In biosafety nomenclature which agent is the most hazardous?

Biosafety level IV (BSL-IV)

Neutron activation product activity

The highest potential occupational radiation exposure source from nuclear power plants.

Define chronicity index

The chronicity index is defined as the 90 day LD50 divided by the one day LD50. It is a measure of the cumulative effects of a chemical.

With respect to radiation exposure, why are the dose equivalent limits for occupationally exposed persons so much higher than those set for members of the general public?

The number of radiation workers is very low compared to the population so the total risk is very small.

True/False: Arsenic has been shown to cause carcinoma of the bladder.


True/False: Biologic monitoring for benzene is best accomplished using serum metabolite levels.

False. Biologic monitoring for benzene is best accomplished using total urinary phenols for acute overexposure, and complete blood count with differential for compliance with OSHA mandated monitoring.

True/False: Carbon monoxide causes a shift in the hemoglobin-oxygen dissociation curve to the right. Because hemoglobin has a higher affinity for CO than O2, RBC cannot take up and deliver O2.

False. It is correct that hemoglobin has a higher affinity for CO than O2, but the remaining hemoglobins on an RBC will bind tighter to their O2 molecules and not release them. Therefore, the curve shifts to the left.

What is the treatment for cyanide poisoning?

Amyl nitrite capsules and sodium nitrite infusions are used to induce methemoglobinemia, which pulls the CN moiety from cytochrome oxidase. Sodium thiosulfate is then used to bind irreversibly to cyanide, preventing further toxicity. Hyperbaric therapy, w

True/False: Amyl nitrate is one of the treatments for cyanide poisoning.

False. Amyl nitrite is one of the treatments for cyanide poisoning.

True/False: Lead exposure has been associated with distal sensory loss.

False. Lead exposure has been associated with neuropathy and slowing of motor nerve conduction. Wrist drop may develop. Symptoms of sensory loss are not a feature of lead neuropathy.

What are some symptoms of tetraethyl lead (organic lead toxicity)?

Symptoms of severe toxicity include delusions, hallucinations, hyperactivity, and loud shouting and laughing.

True/False: Nickel exposure can cause peripheral neuropathy.


When converting mg/m3 to PPM, the number of liters of vapor per mole that is used in the calculation at 25oC and 760 mmHg is ____.

24.45 at 25oC. 22.4 is the volume one mole occupies at 0oC (i.e. STP).

True/False: When more than 33% of "maximum heart rate range" is required during the shift, the worker is likely to fatigue.


What does an alpha particle contain?

Two neutrons and two protons.

At what body core temperature (degrees F) is the worker in danger of developing severe hypothermia if his/her core temp drops further?

According to the 1996-7 TLV booklet, once the core body temperature falls below 91.4�F, severe hypothermia sets in rapidly.

True/False: The internal clock, which is driven by the bright light of the sun, changes significantly for the shift worker.

False. The internal clock, which is driven by the bright light of the sun, does not change significantly for the shift worker.

True/False: Aluminum is associated with cancers of the nasal cavities and sinuses.

False. Cancer of the nasal cavities and sinuses has been observed in workers exposed to chromium, nickel, and leather dusts. Aluminum has not been connected to cancer of the nasal cavities and sinuses.

Form R

The Toxic Chemical Release Inventory (TRI) form