The dangers of asbestos have been well known for several decades, but communities around the world have been slow to make themselves safe.
In New Zealand, regulations have established a framework for its removal from many thousands of structures throughout the country. The popularity of the microscopic natural rock fibres for their fire resistance, strength and insulation, is now far outweighed by their deadly effect on people. New Zealanders today are still losing their lives because of asbestos fibres inhaled in many cases, years before.
Suddenly removing all asbestos-contaminated structural materials from every location in the country would be an impossibly expensive task, notwithstanding the effect on the day to day operations of a national economy. Because asbestos is harmless if it remains tightly bound and undisturbed in a wide range of materials, it has permitted regulations which give building owners time to progressively remove asbestos materials over future years.
In the meantime, if every affected building is well managed under its own “asbestos management plan,” people can be safe.
A spokesman for Chemcare, a licensed asbestos removal company, says the regulations introduced in April 2018 appear to have been considered with the needs of property owners in mind. “But this has been carefully balanced with the need to keep occupants of buildings safe at all times,” he said.
The next big challenge
As the nation addresses the removal of asbestos from all areas of human activity, there exists another major challenge created by the progressive removal of the materials. How do we dispose of the materials?
Currently, the materials are carefully wrapped in plastic and buried in approved hazardous waste disposal sites. These sites are managed so that there can be no accidental disturbance of the materials. But is this the final solution for asbestos removal? Can New Zealand’s hazardous waste sites accommodate the volumes that will continue to arrive every year?
Chemcare, in 2018, made contact with seven of New Zealand’s largest local authorities in an attempt to discover just what volume of asbestos materials exists in the country. Because the materials had been in use since the start of the 20th century and were only ceased in the year 2000, Chemcare could obtain no real data from any local authority.
“We believe this was because asbestos products may not have been specifically identified as containing asbestos because the dangers were unknown,” said the Chemcare spokesman. “The best we could estimate is that there are tens of millions of tonnes of materials containing asbestos, still contained within communities nationwide.
“Which raises the question of whether burial of this total volume is an adequate solution? Are we deferring the problem of disposal for a future generation?” Chemcare began some research into alternatives to burial last year. So far, the company has concluded that permanent removal of asbestos products is a global issue and several alternatives are underway:
Asbestos management using natural fungi
A research team at Unitec, a tertiary institution in Auckland, is receiving worldwide attention for its investigative work to grow a natural form of fungi on the asbestos fibre. The fungi feed on elements contained in the fibres which appear to render the fibres non-carcinogenic.
Unitec is working in partnership with universities in the U.S. and Australia. If results proved positive, this natural process will be effective in cleaning surface soils which have accidentally collected asbestos fibres in past decades.
Chemcare is the first New Zealand company to offer its support to this research.
Asbestos waste treatment via heat technology
Asbestos can also be recycled by transforming it into harmless silicate glass. A process of thermal decomposition at 1000–1250 °C produces a mixture of non-hazardous silicate phases, and at temperatures above 1250 °C it produces silicate glass.
This enables asbestos-containing waste to be transformed into porcelain stoneware tiles, porous single-fired wall tiles, and ceramic bricks.
A British company has developed a heat-based plant which can burn asbestos material and grind the material down to be recycled as concrete aggregate.
In the Netherlands, the government released a study of options containing “techniques that make it possible to treat asbestos-containing waste and to reuse the remaining product, instead of having to send it to landfill sites.”
A French company has been applying heat conversion with plasma torches since 2001, converting over 30,000 tonnes of waste asbestos products into safe aggregate and fill for building sites.
A New Zealand company, Global Olivine, has developed technology to convert urban waste into energy and re-useable products and aimed at eliminating the need for landfill. Asbestos is among the waste products it can process. This technology is currently being assessed in two South American cities.