A silicate is basically any combination of atoms based on silicon and oxygen, and silicate minerals make up about 90 per cent of the earth's crust.
Silicate minerals are rock-forming in nature and take many forms themselves. Quartz, for instance, is one very solid form of silicon dioxide (silica). In many parts of the world, silicon dioxide is also a major constituent of sand. However, when a silicate is one of six long and thin fibrous crystals categorised as asbestos, they are a severe health hazard.
Before the health effects were known, asbestos was thought to be a wondrous substance. There is archaeological evidence it was used as far back as the stone age, and for thousands of years, humans have used it to make flexible objects that resist fire. And once corporations started using asbestos in their products, it found its way into countless things.
Since the industrial revolution, asbestos has been mined on epic scales, and most frighteningly of all, it still is. Russia produced an estimated 790,000 tonnes of the stuff in 2020 alone.
There is no safe level of exposure, and when the fibres get into the lungs, which can happen if the asbestos product is damaged or disturbed, it is known to cause deadly conditions like mesothelioma, asbestosis, lung cancer and more.
These can take 10 to 50 years to develop, though, so it may be difficult to identify the exact source of one's exposure, especially when it is still found in so many places to this day. Even washing the clothing of someone who worked with asbestos puts you at risk.
Australia didn't fully ban all forms of asbestos until 2003, when they could no longer be used in any automotive parts. Its use in building materials was banned in 1989, but many millions of those structures still stand, so renovation and demolition works remain potential sources of exposure.
Many government buildings, including schools, still have asbestos in them, and as the 2021 theme for Asbestos Awareness Week (November 22 to 28) reminds us; Think twice about asbestos; it's in one in three homes.
"For anyone who thinks asbestos-related diseases are a thing of the past, think again. Asbestos is still causing cancer in Australians," said Justine Ross, CEO, Asbestos Safety and Eradication Agency.
"Every year in Australia, there are an estimated 4000 deaths from past asbestos exposure. That's one of the highest death rates of asbestos-related diseases in the world. Whether it's DIYers doing small or large jobs around the house, or tradies on a residential worksite, the Think Twice About Asbestos campaign reminds them of the dangers of damaged, disturbed or deteriorated asbestos."