It can be relaxing to watch dust particles slide down a
sunbeam streaming through the window on a summer day, but for people with
asthma or allergies, it might not be very healthy. Dust has been the subject of
many studies and recently was found to be a cause of irritation to
upper-respiratory airways and the reason behind increased
emergency room visits and hospital admissions. But for the most part, this
visible form of dust is considered larger particulate matter and not associated
with severe health risks. The dust we all take for granted as part of life,
especially those living in a desert environment, has a particle size greater
than 10 microns and is more a nuisance than a threat.
We commented on the use of mist systems or fog systems for
effective dust and odor control. The idea is that when you atomize water to
extremely small droplet sizes and distribute them into an area with airborne
dust particles, the water will bind with the dust particles and force them to
the ground. In many applications, this method of dust suppression is the most
efficient option available. The same principle applies for odor suppression.
When properly designed and operated, water in the form of
mist or fog is extremely effective at ‘filtering’ the air. One study even
showed where a mist system could substantially reduce the amount of CO2
in the air. So the concept is not limited to dust particles. It can also remove
airborne odors and gases.
Traditionally, this method of dust control worked best in an
indoor environment where conditions allowed for the installation of a typical
overhead mist system. It was not always practical to install such a system in a
facility where the dust control requirement was outdoors in an open area.
For these types of applications (which include waste
treatment facilities, rock crushing, mining, waste transfer, recycling,
construction sites, and structure demolition) a more specialized solution was
required. The solution is Spray stream.
The products are engineered for industrial use in the most
extreme environments. They include a variety of sizes and options including
wall mount units, portable cart units, and completely self-contained trailer
units. When developing dust-control solutions for unpaved roads, things to
consider include how long the road will be operational and the volume and type
of traffic it is expected to bear. There are basically three groups of control
options, including restricting vehicle traffic, improving the road surface, and
applying surface treatments, such as dust suppressants. Restrictions might
include setting speed limits or limiting the weight or number of vehicles that
may pass on the road. These measures have shown to provide moderate emission
reductions when they are strictly enforced. Paving is a surface improvement
that works well but is so costly that it often becomes unaffordable, and in
some cases, such as the Boise 8th Street example, it's undesirable for other
reasons. Paved roads also generally create more storm water runoff. Chemical
dust suppressants offer the least expensive and most efficient option.
Reapplication rates vary and are a major item to address in the development of
a dust-control solution.
Many office workers have long been aware of “sick building
syndrome”, and have suffered from it too. The syndrome occurs when problems
with the heating, ventilation, air conditioning systems and in many cases poor
lighting and the materials used to construct the building itself combine to
sour the atmosphere and produce ailments including eyes, nose, throat and skin
irritation, sneezes and sniffles, coughing, tiredness and nausea.
Office blocks are well known as the major culprit when it
comes to sick building syndrome, but apartment complexes have also been known
to cause it as well. In both cases, the solution is good quality exhaust
ventilation systems with effective dust extraction and fume
extraction capability.
At the design stage, sick building syndrome can be avoided
by making natural ventilation from the air and wind as great a part of the
architectural process as possible. However, nature can only go so far,
especially in urban areas, so it is incumbent upon the architects to
incorporate fume extraction into their designs from the get-go through the
addition of proper local exhaust ventilation.
A constant circulation of air throughout the building in
question will keep the atmosphere fresh and the occupants happy.
