Branch
Report:
12th April 2006
Hygiene –
The Maintenance of Health and Prevention of Disease.
Quarries
- Dust, Noise and Vibration
The branch enjoyed a
presentation by Kelwyn Williams, an independent consultant in occupational
hygiene.
Kelvin’s first topic was
that of dust and particularly crystalline silica, which is a very common
substance in our industry. Silicosis is the disease related to the over
exposure to respirable crystalline silica and research suggests that
workers that have silicosis are three times more likely to develop cancer
as crystalline silica is a known carcinogen. Images of a healthy lung and
a lung affected by silicosis showed the extent of the damage that can be
cause by the disease. A typical quarry worker exposures range from
<0.1mg/m3 to > 1mg/m3 (8 hr TWA), with between 5%
-10% of workers exceeding 0.3 mg/m3 (8 hr TWA).
The Workplace Exposure Limit
(WEL) is 0.3mg/m3 (8 hr TWA) although a recent chemical hazard
alert notice advised it should be controlled to 0.1mg/m3 (8 hr
TWA) and that if it can’t be controlled to that level, then respirable
protective equipment should be used. This is of course a last resort as
various control measures can be implemented to reduce exposure. The
various types of RPE and the correct application of them was then
discussed including the legal requirement to carryout face fit testing on
all employees.
The new Control of Noise at
Work Regulations (2005) were then discussed as they had only come into
force the week previous and they could have a massive affect on the
current noise zones on sites. The change to the regulations was the
reduction in the action values by 5 dB to 85dB and 80dB with a new
exposure limit of 87dB. Kevin went on to explain the need for specific
noise health surveillance to ensure the zones are identified correctly and
how to use the results from the health surveillance to identify noise
controls. The use of three spreadsheet from the HSE website (search
noise) allowed you to plug in information so that daily and weekly
exposure could be calculated for individuals and specific tasks. It
would also enable you to check the adequacy of the hearing protection that
was being provided on site. It was also highlighted that many of the
control measures used for dust double up for noise control.
The final topic of the
evening concerned the Vibration at Work Regulations (2005) and in
particular, Hand-Arm Vibration Syndrome (HAVS). HAVS is a disorder which
affects the blood vessels, nerves, muscles and joints of the hand, wrist
and arm and affects approximately 300,000 people. The most widely know
form of this disorder is vibration white finger (VWF), which can be
triggered by cold or wet weather and can cause severe pain. If the
condition is ignored it can become severely disabling. VWF is the most
commonly reported occupational disease. Kelvin provided actual examples
of how exposure can be reduced by updating tools, good maintenance,
training and health surveillance.
