Background asbestos air testing is a useful tool prior to an asbestos removal or remediation works. They establish a baseline from which later reassurance or near-source static sampling can be compared.
It can highlight pre-existing elevated levels of asbestos fibres or other similar asbestiform materials that are countable under the WHO (World Health Organisation) counting rules and also indicate that the current site conditions will provide difficulties in obtaining a meaningful count later on. Dusts and fumes in particular generated from other site works or neighbouring actives can ‘occlude’ sample filters, rendering them uncountable on site using PCM (Phase Contrast Microscopy).
This will allow us to investigate and control those variables, or employ alternative analytical techniques. SEM (Scanning Electron Microscopy) for example will allow fibre discrimination to distinguish asbestos fibres from morphologically similar material and will cope with filters occluded by dusts or fumes.
Background air tests can help save time and effort later on when asbestos is being remediated, particularly on building sites where refurbishments elsewhere are generating large amounts of dust or interfering fibres (mainly the use of man-made mineral fibre material, such as Rockwool insulation).