The undetected presence of asbestos mineral materials on former construction, manufacturing or heavy industrial sites can still pose a serious health risk to both nearby and local area residents. However, most likely to be directly affected by exposure are demolition, ground clearance and building contractors working on redeveloping a former site where asbestos would have been in general use during the greater part of the 20th century.
Up until the late 1970s and 80s, chrysotile, the white form of asbestos, was still continued to be used in a number of insulating materials, especially AIB, despite decades of asbestos awareness campaigns alerting employers and their workforce in affected industries to the fatal consequences of exposure to the killer mineral. A long legacy of losing thousands of victims to asbestos-related diseases, most notably, asbestosis and the aggressive malignant cancer, mesothelioma, continues with over 2,000 recorded deaths in 2008, a figure not yet expected to peak until 2050 at least. Currently, an estimated 4,000 fatalities per year are due to asbestos-related disease.
A common procedure before any work can commence on a construction site where asbestos was suspected of being in general use, is to take soil or air samples to assess the risk to all working on or visiting the site, or to residents who live near the area. A soil sample machine collects, filters and microscopically analyses particles to provide an accurate estimate of asbestos concentrations found in the soil sample and to also predict the quantity of airborne asbestos.
A new air sampling approach introduced in 2008 – known as activity-based sampling – more closely reflects the conditions created during actual construction by analysing breathing zone samples taken after the soil is mechanically disturbed. The quality of data collected must then be carefully evaluated and checked for completion to ensure submission of an accurate report.
The calculations are designed to be able to project the risk of developing an asbestos-related illness as well as ‘absolute risk’, i.e. the probability of death from a complication of cumulative asbestos exposure. The well-known long latency periods lasting between 15 – 50 years before asbestosis symptoms appear and diagnosed confirmed, often leaves an insufficient period of time to deal with a mesothelioma claim before the victim passes away.
Risk assessments for asbestos-related diseases are based on the level and degree of a person’s asbestos exposure, including the number of hours per day, days per year and total years spent within an asbestos-contaminated worksite. While the amount of time will vary between employees, the precise level of exposure at a given worksite can be determined by analysing an air or soil sample.