Dust is generally understood to be an aerosol of solid particles, with individual particle diameters of 0.1µm upwards and can be a problem in almost any industry, from bakeries to building sites. With increasing awareness of the problems caused by dust generated from such works, many local authorities are now including dust monitoring as a planning requirement. Often there is a requirement to undertake a baseline survey, particularly as part of an EIA, in order to formulate acceptable thresholds.
Air Spectrum Environmental; together with our strategically chosen partners have experience in undertaking projects using a number of the methods. The work normally takes the form of an initial baseline survey of dust conditions in an area and then surveying during and after a project has been completed in order to indicate whether activities result in an increase in the levels of nuisance dust.
Generally, two different approaches are used to measure the amount of dust deposited on a surface;
- Determination of the soiling of a surface, by a change in its properties
- Determination of the quantity of dust deposited, by weight
Within these techniques there are a number of different methodologies, these include:
- Deposit gauges – simple and yet accurate methods for the measurement of nuisance dust. Dust is collected onto a horizontally mounted capture container, or in the case of the Directional Dust Gauge, into four vertical tubes aligned in different directions.
Dust samples collected are measured by washing the collecting container and foam insert through to a collecting bottle. The sample is passed through a pre-weighed filter, conditioned and re-weighed. The quantity collected over a known area and period can be calculated to give a deposition rate. We can also analyse the dust to determine content of particular substances.