Fall-out dust monitoring is a legal requirement under
National Environmental Management Act, 1998. The act refers to the
fact that the
gazette must be used to set the standards. [Section 9(1)]. The
gazettes are published with subsequent gazettes providing amendments to the
standards.
If the dust levels measured are above the specified
limits then engineering solutions need to be implemented to decrease the
fall-out dust levels.
There are many factors that effect fall-out dust namely:
-
Rainfall: because dust is
attracted to the water vapour in the atmosphere and it then precipitates along
with the rain.
-
Wind: because dust is
carried by the wind and will only fall-out when there is absolutely no wind.
-
Geographical features or any
other factors that could influence the rainfall or the wind: for reasons
mentioned above.
-
Pollens and small insects:
because these add to the dust levels and precipitate out in the same way.
-
The most influential factors
are "dusty activities": such as dropping material from a conveyor onto a pile
without considering the fall height. These and countless other activities are
necessary in the mining and other industries. The challenge, once dust
problems are detected, is to engineer them away.
Generally
finer suspended dust (Greater than 0µm and less than 10µm) will remain airborne almost
indefinitely due to the dynamic nature of the air currents and thermal
activities on any given day, even if there is no wind at all. Particulate
larger than this range will settle on a very still day and this material can be
collected.
The
unit that we use to capture this dust is the
DustWatch,
designed and patented in South Africa by Gerry
Kuhn Environmental and Hygiene Engineering.
We
offer the full service package or parts of the package as the client requires.
We will also assist in getting existing fall-out monitoring systems up and
running again. Obviously the full package allows the client to sit back
and receive a report every month regarding their fall-out dust.
