following document outlines a typical fall-out dust monitor application.
OF THE PROPOSED PROGRAMME
the programme for the monitoring must be a credible and a representative
assessment of the prevailing fall-out conditions an operation, we propose
the following format for the exercise:
programme must initially establish as much good data on the conditions
as possible and thus it is important that the initial sampling period
covers the full spectrum of seasonal conditions throughout the year.
the seasonal conditions for a full year have been established it will
be possible to make predictions and to interpret the continuing
monitoring and relate this to climatic conditions, which play an
increasing part in the behaviour of fall-out dust.
discussions with occupational hygienists at the operation, we can
consider the full requirement for 4 bucket DustWatch units or 2 bucket
units as fixed units with a possible contingent of mobile units that
can be used as a mobile monitoring station to enable the operation to
carry out investigations on an ad hoc basis wherever an indication of
fall-out may be required to be assessed.
This may constitute a “nice to have” but will complement
the full programme.
the interest of cost saving we suggest that the client usually set up
an assessment facility with local persons trained to undertake the
sample collection, carry out vacuum filtering of the samples,
desiccation and weighing. In
this offer and quotation we have allowed for all supply items, all
training and the coaching required, after which we issue documentation
as proof of attendance in respect of all persons who have
undergone training, coaching and instruction in the use of DustWatch
units and the assessment of dust fall-out results.
the delivery and training trip to the operation we can assist in
locating the units at optimum positions.
While the fixed units are usually concreted in position, and
this could take the client some time, we use the mobile unit to effect
training and to coach the monitoring official.
FOR HEALTH & ENVIRONMENTAL PURPOSES
a legal viewpoint, a mine falls under the jurisdiction of the Department
of Minerals and Energy with the Mine Health and Safety Act forming the
the act does not indicate actual limits with regard to dust, it makes
provision for the issuing of guidelines by the Chief Inspector.
guidelines specify the following:
personnel dust sampling has to be carried out on a regular basis with the
frequency of monitoring related to the actual risk involved.
principal pollutant is silica or alpha quartz and the means of ingestion
is through the respiratory system and thus the monitoring is only of the
respirable or particulate of less than about 7µm.
the silica content of the respirable portion of dust is less than 5% the
allowable occupational exposure limit is 5mg/m3 but should the
quartz content exceed 5%, this OEL falls to 0,10mg/m3.
any other pollutant/s be present, these will have to be considered as well
in a combined air quality index (AQI).
guidelines do not specify what happens outside the property boundary,
although the act makes it clear that the mine's responsibility does not stop
at the boundary.
outside the boundary, the provisions of the Chief pollution control
officer as enacted and vested in the Prevention of Pollution Act and the
relevant regulations and guidelines.
guidelines outline a classification related to that of the American
Standard Test Methods, as these are universally accepted as an indication.
The procedures, the sampling method and equipment constitute full
compliance with ISO 14001.
indicate the relative classifications we have produced the following
and plants are subject to the provision of the Occupational Health and
Safety Act, which has similar provisions.
1 – VARIOUS CLASSIFICATION AND LIMITS – mg/m2/day
Classification – Chief pollution control officer
ASTM – Monthly limit levels
Din air quality – monthly limit levels
251 – 500
501 – 1200
HEAVY > 1200
particulate has been collected on a filter various options are available
to the mine and while the ASTM method stipulates only the mass of fall-out
dust and limits for this mass indicated as a mass per metre2
per day (m2/day), the samples can be subjected to:
examination for possible fibres.
examination for pollens and organics.
analysis using XRD, XRF or Infra red spectrometry.
quantitative or qualitative examination using S.E.M. microscopy
bucket DustWatch units
one of the units positioned on each of the 4 sides of the operation it will
be possible to establish the nett export and import dust in all directions
together with cross flow ambient levels cross checked at each position.
will also be possible to establish the extent of dust actually produced by
the mine, dumps, slimes dams etc on an ongoing basis by comparing an import
on one side of the mine with the export of the other side.
The difference will establish the degree of mine contribution to the
total fall-out dust.
dust samples are frequently scanned for ionising radiation in cases where
this is potentially problematic. Similarly biological windborne contaminations can be assessed
by varying the capture techniques and catch media.
with many operations using the DustWatch units, an additional 2 bucket unit
used as a mobile unit is valuable for use to determine immediate fall-out
emanating from a source, which may be sampled on an ad-hoc basis; i.e.
fall-out from a blast under various wind velocity conditions to establish
the precipitation pattern (open cast mining) or to establish precipitation
models. Assessment of
particulate and metal fume from a smelter or organic particulate from
refineries are also possible with the system.
part of our offer we have allowed to help your team to establish locations
for each unit to optimise the efficacy of dust collected.
have allowed for training of your personnel with regard to the undertaking
of the sampling and assessment of the samples.
procedural manual is made available, meeting the requirements of ISO 14001.
completion of the training, documentation providing proof of attendance is
provided to trained personnel.
have also allowed for time to assist the operation with setting up the
laboratory equipment and demonstrating the use of this equipment.
are offering use of the computer programme.