WEEK 7: Physical Hazards

Question 1

What are physical hazards?

Answer 1

Factors within the environment that can harm the body without necessarily touching it.

Question 2

State the 6 types of physical hazards.

Answer 2

Noise
Vibration
Radiation
Temperature extremes
Lighting
Pressure

Question 3

What are the recommended noise thresholds according to OSHA and NIOSH?

Answer 3

The OSHA Permissible Exposure limit (PEL) is 90dB for 8hr time weighted average (TWA)

The NIOSH Recommended Exposure Limit (REL) is 85dB for 8hr TWA

Question 4

Ultrasound refers to sound frequencies:

A. Below 1 Hz
B. 1–20 Hz
C. Above 20 kHz
D. Between 20–200 Hz

Answer 4

C

Question 5

Which of the following workplaces commonly use ultrasound?

A. Farms and food storage
B. Diagnostic medicine, industrial defect detection, welding, cleaning
C. Schools and offices
D. Road construction sites only

Answer 5

B

Question 6

Infrasound (1–20 Hz) may be produced by:

A. Dental scaling tools
B. Earthquakes, industrial machines, ventilation systems, aircraft
C. Ultrasound imaging machines
D. Computers and printers

Answer 6

B

Question 7

Which of the following is an acute effect of ultrasound exposure?

A. Hyperglycemia
B. Headache, fatigue, nausea, loss of balance, tinnitus
C. Increased central and skin temperature
D. Vascular disturbances

Answer 7

B

Question 8

Chronic exposure to ultrasound may lead to:

A. Headache and nausea
B. Vascular disturbances, increased central and skin temperatures, hyperglycemia
C. Immediate hearing loss
D. Skin burns only

Answer 8

B

Question 9

Hyperglycemia
B. Headaches, fatigue, annoyance
C. Increased central and skin temperatures
D. Chronic kidney disease

Answer 9

B

Question 10

What is known about the chronic health effects of infrasound at normal environmental levels?

A. It causes permanent hearing loss
B. It causes cardiovascular disease
C. There is not enough evidence to confirm health effects
D. It always leads to headaches

Answer 10

C

Question 11

HOW TO PROTECT FROM ULTRASOUNDS AND INFRASOUND

Answer 11

1. By respecting the technical prophylactic measurements concerning noise exposure
2. In case of ultrasounds, wearing rubber cotton gloves may be of help

Question 12

Vibrations are defined as:

A. The sound produced by machinery
B. Mechanical oscillations of an object around an equilibrium point
C. Electrical currents passing through the body
D. Heat emitted by machines

Answer 12

B

Question 13

State the 2 situations of vibrations in workplace.

Answer 13

*Hand-arm vibration exposure, when a worker operates hand-held equipment such as a chain saw or jackhammer, the vibrations affect the hands and the arms.

*Whole-body vibration exposure, when a worker sits on a vibrating seat or stands on a vibrating floor, the vibrations exposure affects almost the entire body.

Question 14

What is the measurement of vibrations is made with?

Units?

Answer 14

The measurement of vibrations is made with an accelerometer and the established parameter according to legal standards is the acceleration in meters per second squared (m/s2)

Question 15

What are the radiation exposure limits for radiation workers and the general public

Answer 15

The Threshold Limit Values (TLVs) published by the ACGIH (American Conference of Governmental Industrial Hygienists) are:

*20 mSv - average annual dose for radiation workers, over an average of five years

*1 mSv - annual dose limit recommended for general public (ICRP - International Commission on Radiological Protection)
The risk of radiation-induced diseases depends on the total radiation dose that a person receives over the time

Question 16

1. What device is used to measure lighting levels?
2. What is the unit of measurement for lighting and what does it represent?
3. What is the usual range for adequate general lighting, and at what height is it measured?

Answer 16

1. A lux meter
2. Lighting is measured in lux, which represents the amount of light falling on a surface (illuminance).
3. Adequate general lighting typically ranges from 500 to 1000 lux, measured 76 cm above the floor.