Question 1
Based on the Appendix, the following corresponding figures are interpreted from the table as:
Time for Monitoring Worker 1 Worker 2 Worker 3
hours 80.5 =27.9 98.5 =2.3 92.5 = 5.3
hours 81.0 = 27.9 86.5 =12.1 85.0 =16
2 hours 82.0 = 24.3 84.5 =16 83.5 =18.4
1 hour 95.0=4 83.5=18.4 80.0 =32
Step 1; Calculating the D, for every worker.
Calculating the dose (D) (dose) = accumulated dose in percent exposure using the formula D = 100 (C1/T1 + C2/T2 + . . . + Cn/Tn).
D for Worker 1= 100 (3/27.9+4/27.9+2/24.3+ 1/4)
D for Worker 1= 58.32
D for Worker 2=100 (3/2.3+4/12.1+2/16+1/18)
D for Worker 2= 181.55
D for Worker 3=100 (3/5.3+4/16+2/18.4+1/32)
D for Worker 3= 95.60
Step II: Calculating the TWA for every worker
Formula, TWA = 16.61 log (10) (D/100) + 90,
TWA Worker 1 = 16.61 log (10) (D/100) + 90, where D=58.32
TWA= 16.61 log (10) (58.32/100) + 90
= 99.67 dBA
TWA Worker 2 = 16.61 log (10) (D/100) + 90, where D=181.55
TWA= 16.61 log (10) (181.55/100) + 90
= 120.16
TWA Worker 3 = 16.61 log (10) (D/100) + 90, where D=95.6
TWA=16.61 log (10) (95.6/100) + 90
= 105.89
b. 90 dBA is the permissible exposure limit (PEL) set by OSHA. The PEL is exceeded in all the three cases and, therefore, it is essential to ensure engineering controls.
Delegate your assignment to our experts and they will do the rest.
c. The temperature may have affected the accuracy of the noise measurements. Wrong calibration may have also affected the accuracy of the measurement especially after sterilization.
Question 2
Characteristics and abilities of sound level meters (SLMs) and noise dosimeters
A sound level meter (SLM) provides measurement for workers’ noise dose. SLM measures an operators’ ear while pointing at the source of the noise. It is a hand-held devise that measures the extent of the area’s exposure to noise. A type 1 SLM offers precision measurement. A type 2 SLM measures the place of action when there is isolated noise problems emanating from a specific area including a specific machine or work station. An equipped SLM also measures the octave band. A dosimeter is useful to measure inconsistent noise data received when using a decibel is useful to reveal noise levels over the period when it is measured. It is worn by the operator to measure his or her personal exposure to noise.
How they can be used to evaluate noise exposures at a facility
Both instruments have pre and post-use calibrations. They have periodic calibrations for the factory. SLM can be useful to measure and evaluate the operator’s exposure to noise pollution levels. SLMs can be useful in conducting spot-checks of noise levels in a facility. It can be used to evaluate the levels of noise produced by a machinery or equipment such as trucks. It is also used to measure noise across boundaries. They can measure sound across boundaries.
Dosimeter can be useful to measure weighted averages to show noise levels for specific areas.
Question 3
The hearing conservation program (HCP) is intended to protect employees who have significant levels of exposure to occupational noise hazards. It protects the employs from potential hearing impairments because of the exposure they have at their workplaces. Because the workers are exposed to TWA of 85.0 dBA and 89.0 dBA over their 8-hour work period, a HCP is necessary. For the HCP to be successful, the employer must establish and maintain an audiometric testing program. Audiometric testing should be freely available to employees at the workplace. The audiometric testing program is imperative to gauge is the employer’s programs are effective in the prevention of possible hearing loss. Second, the employer must provide baseline audiograms that will facilitate the measurement of the employees’ exposure to a TWA above 85dBA, for the first time. Besides, the program will be successful is the employer provides annual audiograms within the first twelve month of the baseline. Third, in any case an employee has signs of a standard threshold shift, the program will be successful is the employer provides the employee with the needed hearing protectors. Employees should be informed promptly should their tests reveal they have a standard threshold shift. All employees should have hearing protectors and wear them while on duty.
Question 4
a. Wavelength
A wavelength represents the measure of the length of time that the sound travels for every pressure cycle. Its unit of measure is in meters but can be expressed in feet. It is imperative in the design of engineering controls. In preventing noise pollution, material used in the building should have the ability to absorb at least a quarter of the measured wavelength of the sound it ought to prevent.
b. Frequency
It is a measure of the number of sound vibrations that are recoded every second expressed as hertz (Hz). Every hertz (Hz) represents a single cycle in a second of time. The pitch depicts the sound frequency. There are different frequencies of sound that individuals can sense using the ear, ranging from 500Hz to 20,000 Hz.
c. Sound Pressure
There are variations in sound vibrations that can be detected as the difference in its pressure. There are extremely weak sound pressure which is characterized by faint sounds. Sound pressure increases by advancements in vibrations. High levels and frequencies of vibrations sets the sound to have high pressure and be at loud level that is uncomfortable to the ear.
d. Decibel
A decibel is the measure of the level of sound pressure. It measures sound pressure based on the levels that humans can comfortably hear, expressed on a logarithmic scale. At the least, 0 dB is set as the minimum sound pressure that does not cause pain to humans. At the upper threshold, 140dB, sound pressure is likely to cause pain to humans and, therefore, potentially damaging to the hearing system.
e. Octave Band
An Octave Band is a range of values that are useful in measuring sound frequencies. An octave band is useful to analyze the sound pressures to determine the sound levels. The geometric mean (which is the center frequency) is used to describe the octave band.
