Occupational Noise Exposure at Construction Sites by htt39969


									                                                                            Effects of Noise Exposure
                                                                                   What Exposure to Loud Noise Will Do
       Occupational Noise Exposure at
            Construction Sites                                                                     • Exposure to loud noise will inevitably
                                                                                                   cause hearing loss over time.
                       Jenny Houlroyd, MSPH
                    Georgia Tech Research Institute                                                • Loud noise damages or destroys the nerves
                                                                                                   in the inner ear.

                                                                                                   • Another effect can be “tinnitus” or
                                                                                                   permanent ringing in the ear.


     Effects of Noise Exposure                                              Effects of Noise Exposure
                      When is Noise Too Loud?                                            Long Term Exposure to Noise
• Noise is measured in units called “decibels” or “dB”
                                                                       • Our ears can recover from short
                                                                       exposure to loud noise, but over time
                                                                       nerve damage will occur.
• If two people 3 feet apart must shout to be heard, the background
noise is too loud (above 85 decibels).
                                                                       • The longer and louder the noise, the
                                                                       greater chance permanent damage
                                                                       will occur.

• Noise above 140 decibels causes pain and immediate hearing loss.
                                                                       • There is really no such thing as
                                                                       “tough ears” or “getting used to it”.

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     Effects of Noise Exposure                                              Effects of Noise Exposure
              Hearing Loss From Noise Exposure                                          Tinnitus From Noise Exposure
                                                                      • Exposure to high noise levels can also
 • Hearing loss from noise exposure is                                cause permanent ringing in the ear or
 usually not noticed because it is so                                 “tinnitus”.

                                                                      • Tinnitus sufferers usually complain of
 • Usually a person loses the ability to                              constant whistling, squealing, roaring or
 hear higher pitches first.                                           buzzing in one or both ears.

 • Often the first noticeable effect is                               • Severe tinnitus may disrupt sleep, reduce
 difficulty in hearing speech.                                        concentration and cause irritability and

                                       5                                                                  6
   Effects of Noise Exposure                                                  Effects of Noise Exposure
               What is Too Much Noise Exposure?                                        What is Too Much Noise Exposure?

                                                                          • The risk of hearing loss increases
  • Damage from noise exposure
                                                                          dramatically as noise levels increase.
  depends on the loudness and
  length of exposure.
                                                                          • Exposure to noise levels above 115
                                                                          decibels for even 5 minutes is very risky.
  • Scientific studies have
  shown that hearing loss can
  occur when 8-hour average
                                                                          • Impact or banging noise above 140
  noise exposure exceeds 85
                                                                          decibels will cause immediate damage to
                                                                          nerves in the ear.

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   Effects of Noise Exposure                                                  Noise Levels
         Daily Allowable Exposure Times to Noise
                                                                                  Examples of Commonly Used Noisy Equipment
The table below shows noise levels and how long a person can be exposed
without hearing protection before there is damage to the ear.
                                                                           Equipment                 Noise Level
Noise Level                  Allowable Exposure Time                       Back Hoe                  85-95 decibels
                                                                           Chain Saw                 110 decibels
85 decibels                           8 hours                              Front-end Loader          90-95 decibels
                                                                           Gunshot                   140 decibels
90 decibels                           4 hours
                                                                           Jackhammer                112 decibels
100 decibels                          1 hour
                                                                           Lawn Mower                90 decibels
105 decibels                          30 minutes                           Tractor                   95-105 decibels
110 decibels                          15 minutes                           Circular Saw              90-100 decibels
115 decibels                          0 minutes

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   Hearing Protection                                                         Hearing Protection
                          Types of Hearing Protection                              Types of Hearing Protectors
                                There are three types of
                                 hearing protection – ear muffs,             All hearing protectors are
                                 earplugs and ear caps.                       designed to reduce the intensity
                                                                              (loudness) of noise to the inner
                                Ear muffs and earplugs provide
                                 about equal protection, ear                 They work much better than wads
                                 caps somewhat less.                          of cotton or bits of cloth stuffed in
   earmuffs                                                                   the ear.

                                                                             All three types have advantages
                                                                              and disadvantages and people
                                                                              vary on which they prefer to use.        Cotton doesn’t work!!

                                       12              ear caps                                                13
      Hearing Protection                                       Hearing Protection
             Hearing Protection – Ear Plugs                                               Ear Plug Comfort
                                                               Some people may find ear plugs
 Earplugs are made of foam,                                   uncomfortable to wear for long
   rubber or plastic and are                                   periods at first.
   either one-size-fits-all or in
   sizes small, medium and
   large.                                                      Ear plugs rarely cause infection
                                                               or prolonged irritation of the ear
 Some are disposable, some
   are reusable.
                                                               Most people can find a
                                                               comfortable fit by trying several
 They are lightweight, and                                    different sizes, types or brands.
   require no maintenance.
                                                               Custom-molded earplugs can be
 They are inserted into the ear                               obtained for maximum comfort.
                                                                                                                custom molded earplugs

                                               14                                              15

      Hearing Protection                                       Hearing Protection
                   Inserting Foam Earplugs                                  Inserting Foam Earplugs
    Foam type earplugs are one-size-fits-all and must be
               inserted properly into the ear.

                                                                Earplug incorrectly inserted             Earplug correctly inserted

Roll earplug into small cylinder first, then insert in ear.
                                              16                                                    17

      Hearing Protection                                       Hearing Protection
         Ear Muffs                                              Attached Earmuffs
    Ear muffs cover the whole
       ear and are preferred by                                Some muffs are attached to
       some people.                                            hardhats or goggles.

    They have replaceable
                                                               Some high-tech muffs can
       pads and some high-tech                                 filter out certain frequencies
       styles filter out specific                              or have radios inside for
       noise pitches.                                          communication in high
                                                               noise areas.
    They last longer than most

                                               18                                              19
    Hearing Protection                                                                             Hearing Protection
                 Ear Muff Comfort & Glasses                                                                             Ear Caps

                                                                                               Ear caps are like earplugs,
            Muffs can be
                                                                                                except they do not go into the
            uncomfortable in hot
            weather.                                                                            ear canal, they only block it.

                                                                                               They are good for occasional
                                                                                                use or for people who find
       Muffs don’t seal well for
                                                                                                earplugs uncomfortable.
        someone with glasses or heavy
        sideburns.                                                                             They are not as protective as
                                                                                                earplugs or muffs.


 Hearing Protection                                                                                Hearing Protection
 Noise Reduction of Hearing Protection                                                        How can you hear anything with earmuffs on?
   The “noise reduction
    rating” or “NRR” of                                                                        Using earmuffs or plugs in
                                                                                                noisy areas actually makes it
    hearing protection is
                                                                                                easier to hear coworkers or
    measured in decibels.                                                                       machinery.

   The NRR is found on the                                                                    They reduce overwhelming
    earmuff or earplug                                                                          loud background noise.
    package. The higher the
    number, the greater the                                                                    They are similar to dark
    protection.                                                                                 glasses that reduce the sun’s
                                                                                                glare making it easier to see.

                               22                                                                                          24

    Hearing Protection                                                                             Hearing Protection
      Proper Use of Hearing Protection                                                              Proper Use of Hearing Protection
 Earmuffs and plugs provide                                                                   It takes just a few minutes of
 good protection only when                                                                      unprotected exposure at noise
 used properly.                                                                                 above 115 decibels to risk
                                                                                                hearing damage.
 Sometimes people will
 remove hearing protection                                                                     Earplugs not well inserted into
 for “just a minute” in a                                                                       the ear canal will not provide
 noisy area.                                                                                    complete protection.

 In areas of very high noise                                                                  Likewise, earmuffs not snug
 exposure, this could result                                                                    against the head will “leak”
 in noise overexposure.             It won’t protect your ears if it is around your neck!!!
                                                                                                noise into the ear.

                          25                                                                                            26
    Hearing Protection                                                    Hearing Protection
     Hearing Aids Are Not Hearing Protection                                                 Turn it to the left…

   Hearing aids do not block out
    enough sound for most                                             In your daily life:
    workplace noise.
   Some hearing aids can actually
    increase the noise level at the
   Just turning off the hearing aids                                 http://www.youtube.com/watch?v=kLSYq5kau_w
    will not prevent further hearing
    loss from noise exposure.

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    Hearing Loss Among Construction
    Workers                                                               Reference Duration
                                                                      The OSHA Noise Standard (29 CFR              Example 1: A drill operator is
                                                                      1910.95) establishes permissible               exposed to noise levels of 90dBA.
                                                                      employee noise exposures in terms of           How long can he be exposed at
                                                                      duration (in hours per day) at various         this level?
                                                                      sound levels.
                                                                                                                   L=90: T=8/2(L-90)/5 = 8/2(90-90)/5
                                                                                                                         =8/20 = 8/1 = 8 hours
                                                                      Reference Duration (T) is the amount
                                                                      of time (in hours) an employee can be
                                                                      exposed at a certain sound level             Example 2: A jackhammer operator
                                                                      before exceeding the OSHA Noise                is exposed to noise levels of 110
                                                                      Standard.                                      dBA. How long can he be
                                                                                                                     exposed at this level?
                                                                      Where L is the measured A-weighted           L=110: T=8/2(L-90)/5 =
                                                                      sound level (in dB)                            8/2(110/90)/5 = 8/2(4) = 8/16 =
                                                                                                                     0.5 hours

    Distance from the sound source                                        Noise Dose and TWA
If the sound pressure level (dB0)    So if the sound pressure level   When employees are exposed to different      Now to convert the noise dose to
                                                                      noise levels during the day, the dose (D)
at distance d0 is known, it is       measured at 2 feet from the      is calculated using the following formula:   an equivalent time weighted
possible to calculate the sound      source is 90 dB, what will be    D = 100 (C1/T1 + C2/T2 +… +                  average (TWA) use the equation:
pressure level at position d1.       the sound pressure level at 6    Example: An employee is exposed to the               TWA = 16.61 log
dB1 = dB0 + 20 log (d0/d1)          feet?                            following noise levels:                      (D/100) + 90
                                                                                  85 dBA for 3.75 hours
If d1 is double d0 it will be seen                                                  90 dBA for 2 hours
that dB0-dB1 will be approx.         dB0=90 dB, d0=2ft:                             95 dBA for 2 hours             So for our example, D= 125:
6dB (20 log 2). This give us the     dB1= dB0 + 20 log (d0/d1)                   110 dBA for 0.25 hours                    TWA = 16.61 log
                                        = 90 dB + 20 log (2ft/6ft)    The daily dose is:                           (125/100) + 90
principle of a decrease in level                                      D = 100 (3.75/no limit + 2/8 + 2/4 +
of 6dB per doubling of distance         = 90 dB + -9.5                .25/.50) = 0+1/4+1/2+1/2 = 125%                            = 16.61 log (1.25)
(inverse square law).                   = 80.5 dB                                                                  + 90
                                                                                                                                 = 1.61 + 90
                                                                                                                                 = 91.61
    Noise Problem Example:                                                         When Must Hearing Protection
     A construction employee receives the following exposure to noise on a
      construction site during an 8-hour period:                                   be Provided?
          3 hours @ 92 dBA
          2 hours @ 95 dBA                                                              After implementing engineering and work practice
          3 hours @ 90 dBA                                                              controls
     The OSHA permissible exposures at these sound levels are: Sound Level
      Permissible Duration
          90 dBA 8 hours
                                                                                         When an employee’s noise exposure exceeds an 8-
          92 dBA 6 hours
                                                                                         hour time-weighted average (TWA) sound level of 90
          95 dBA 4 hours                                                                dBA
     What percent of the PEL is this exposure?


         Hazard Communication                                                        Introduction
              OTI 510
                                                                                    Hazard communication standard effective 1983

                                                                                    Originally only applied to general industry

                                                                                    Required for construction in 1989

3                                                                                   34

                                                                                    Purpose of Hazard
    The “So WHAT?” of it all…
                                                                                    Communication Standard
     Chemical exposure may cause or contribute to
         many serious health effects such as heart
                                                                                    To ensure that employers and
         ailments, central nervous system damage,
         kidney and lung damage, sterility, cancer….                                employees know about work hazards
                                                                                    and how to protect themselves

    35                                                                              36
    Main Components
                                     Material Safety
                                      Data Sheet        Employer Responsibilities
                                                        Identify and list hazardous chemicals in their
                                                        Obtain Material Safety Data Sheets (MSDSs) and
                                                         labels for each hazardous chemical
            Hazard                    Container
                                       Labeling         Implement a written HazCom program
           Program                                      Communicate hazard information to employees
              Program                                    through labels, MSDSs, and formal training
                                         Label           programs

    37                                                   38

                                                       Container Labeling in the Workplace
Written HazCom Program Requirements
                                                        The hazard warning can be any type of
  Describes container labeling, MSDSs, and employee     message, picture, or symbol that provides
   training for each workplace                           information on the hazards of the chemical(s)
                                                         and the targeted organs affected, if applicable
  List of the hazardous chemicals

                                                        Labels must be legible, in English (plus other
  Make information regarding hazards and protective
                                                         languages, if desired), and prominently
   measures available to other employers onsite

    39                                                   40

 Material Safety Data Sheets
 Physical hazards, such as fire and explosion
 Health hazards, such as signs of exposure
 Routes of exposure
 Precautions for safe handling and use
 Emergency and first-aid procedures
 Control measures


 Material Safety Data Sheets
 (cont’d)                                                    Training
 If no MSDS has been received for a hazardous
      chemical, employer must contact the supplier,   Training is required for employees who are
      manufacturer, or importer to obtain one and     exposed to hazardous chemicals in their
      maintain a record of the contact                work area:

                                                       At the time of initial assignment
                                                       Whenever a new hazard is introduced into their
                                                        work area

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 Explanation of the HazCom program, including         Training
  information on labels, MSDSs, and how to obtain
  and use available hazard information
                                                        Protective measures such as engineering controls,
                                                            work practices, and the use of PPE
 Hazards of chemicals

                                                        How to detect the presence or release of a hazardous
                                                            chemical (using monitoring devices, observation, or

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 Employees have both a need and a right to know the
  hazards and identities of the chemicals they are
  exposed to when working

 Employees also need to know what protective
  measures are available to prevent adverse effects from

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