White Card Update: Dealing With Dust on Construction Sites

Dust can be more than just an inconvenience on a construction site – it can be a matter of safety. Those in charge of a construction site need to implement dust control measures if they determine that dust poses a potential risk to air and water. Dust can travel in the air and the water causing pollution. Site controllers should implement dust control measures which are practices used to reduce or prevent dust pollution.

One of the best strategies employed by construction companies to do this is to clean and impact the least possible area. Where work is being carried out, it is best to conduct clearing and grubbing of the entire site all at once rather than in stages to minimise the impact.

Some of the methods that can be employed to combat these dust problems include,

Introducing mulch and vegetation to exposed soil in order to prevent erosion from wind and water.

The most commonly used method is applying water at least 3 times a day or more to prevent dust from becoming airborne. This is one of the lower cost methods but can be problematic during droughts when water conservation is necessary and when too much water is used or applied incorrectly it could actually cause erosion of soil and carry dust into waterways.

Sites that do not get a lot of traffic can implement the method that dry applies polymers for dust control. This method bonds the individual soil particles together and dries which then forms a flexible “crust” that strengthens the surface of the soil.

Another useful method would be to use chloride to retain moisture for a longer period of time thereby reducing dust problems. Chloride has the ability to hold down dust and stabilise unpaved road surfaces. For this reason it is used to create smooth roads that last longer.

Fencing or barriers are another way of minimising dust and erosion on site. A board fence, wind fence, sediment fence, or similar barrier can control air currents and blowing soil. Builders can construct these fences out of wood or use trees as a barrier to wind.

Stone could also be an effective method of controlling dust on construction roads and paths especially if there is no vegetation. In particularly windy areas larger stones can be used to be more effective because smaller ones will just be carried away by the wind.

One of the most dangerous forms of dust that can occur on construction sites is Silica dust. Silica Dust is a dangerous element of construction work and has the potential to cause Respiratory Disease. Many employers are unaware that common building products such as clay bricks, concrete, tiles and fibro cement products contain silica. Silica dust is usually created when such building products, sandstone or rocks are cut, drilled or worked on in a way that creates fine particles of silica in the air. It is breathing in this crystalline form (quartz) of silica that causes silicosis. In these cases PPE should be used, for example dust masks, to prevent harm from dust.

Dust levels in the air should be monitored by a competent person. The exposure limit for silica dust (respirable quartz) is 0.1 mg/m3. However, exposure levels in settings like construction sites are highly variable and air sampling alone is not enough to indicate the health risks from airborne silica dust.