Construction products in the past contained asbestos, which exposed the construction workers working with them to the deadly asbestos fibres which over time can cause mesothelioma and other asbestos related diseases.
Those buildings constructed before 1980 are likely to still have asbestos in the walls, insulation and roofing mateials which can be released when construction and renovation work is being undertaken.
When left undisturbed, asbestos products do not present a huge threat, but when disturbed, the fibres are released into the air and can be inhaled by workers or anyone else who happens to be around. Demolition work is particularly high risk.
Unfortunately mesothelioma rates in Australia are high and thousands of workers have lost their lives due to the disease.
Read more about the disease and what can be done at http://www.examiner.com/article/mesothelioma-and-the-construction-worker