ASBESTOS

In an earlier post I discussed hidden dangers that appear in older buildings, with asbestos being a main culprit. Asbestos was widely used in construction beginning in the late 19th century because of its sound absorption, average tensile strength, and its resistance to heat, electrical and chemical damage (1). Having been built in 1957, the Quarry Visitor Center contained asbestos in pipe insulation, drywall, mud, and elsewhere. Much of that was identified with signs years ago. When time came to demolish the old building it was necessary to remove the asbestos before demolition of the walls and heating system. First with the second floor and second with the first, abatement involved using plastic to enclose rooms and using negative pressure to prevent asbestos escaping during removal. Removed materials were bagged and secured and loaded into a special trailer. Then it was taken for proper disposal. Certified contractors specializing in abatement do this work.

However, given the wide use of asbestos in the past, it was almost inevitable that unknown occurrences of asbestos would turn up. Such happened when removing the roof of the administrative wing and asbestos rich tar paper turned up beneath the wooden slats of the roof. This brings work to a halt while the discovery is sampled, its hazard analyzed, and a safe removal plan developed. Such matters take some time and demolition can be frustratingly halted --- but asbestos is a health hazard and so there is little choice. It was recognized as early as the first century AD that slaves weaving asbestos clothing in the Roman Empire often had a lung sickness (1).

Photos courtesy of Dinosaur National Monument

(1) “Asbestos” Wikipedia. http://en.wikipedia.org/wiki/Asbestos accessed 18 June 2010