What is asbestos?
Asbestos is the commercial term to indicate any fibrous mineral with a fibrous form. The word asbestos started from Greek and it means ‘unbreakable”. In fact, there are many types of asbestos fibers which are divided into two families: the amphibole (blue and brown asbestos fiber) and the chrysotile (white asbestos fiber). These two groups of asbestos are completely different in chemical composition, color, physical properties, application and the level of impact on human health.
Chrysotile is in cylindrical shaped, contains small fibers bundled up and it is easy to be dissolved in acid (Von Kobell, 1834; Pundsack, 1955) Amphibole exists in macrophages, it is in density fiber form (Skinner and partner, 1988). The exterior of Amphibole has the same crystal structure and chemical durability as quartz. Amphiboles are not dissolved in acid environment (Speil and Leineweber, 1969). Amphibole has the ability to penetrate into human’s body and causes serious lung damage after 10 -20 years of incubation. Therefore, Amphibole has been globally banned under any form since 1980. Meanwhile, Chrysotile is still being used safely and under control in 147 countries and territories such as America, Canada, Russia, Mexico, Brazil, Ukraine, Kazakhstan, Kyrgyzstan, Uzbekistan, China, India, Thailand, Indonesia, Vietnam…
Using chrysotile in a safety and controlled way
Nowadays, to meet the safety requirements for community health and environmental protection, only products containing high levels of chrysotile are allowed to produce and use. An outstanding characteristic of chrysotile fiber is that it is firmly bonded to cement , in order to prevent the dispersion of fibers.
Over 90% of chrysotile over the world are being used in producing asbestos – cement construction materials. Especially in Russia and Brazil, over 60% of population are using water tanks and pipes made of asbestos – cement over hundred years. In India and Thailand, AC roof sheets are still allowed to produce by the government and people usually choose it because it’s reasonable price, high durable and products are flexible and diverse. (because of its reasonable price, high durability, flexibility and diversity).
In addition, in order to ensure safety chrysotile using which aimed to limit the fibers ‘s dust spread into the air. Governments required factories to constantly invest in technology lines, modernize every stage, the provisions on medical monitoring, environmental monitoring. Training on occupational safety has always been strictly done according to the highest world standards in order to protect workers and environment. (In addition, to ensure the safety in using chrysotile and limit the exposure, the Government requires the factories to invest in modern technology and conduct health examination and environment measurement.)
The ban on chrysotile is not based on scientific evidences.
However, with the sponsorship of international organizations especially from PVA fiber producing countries, some associations have acted in an extreme manner to call for the support of government on banning the import and use of chrysotile, despite scientific researches and useful practical applications of chrysotile fiber. With the reason of protecting community health and reducing the burden of chrysotile disease, they have promoted that the best way to eliminate asbestos-related diseases is to totally ban the use of chrysotile. However, global researches and researches in Vietnam over years confirmed that there have been no case of mesothelioma cancer or lung cancer related to chrysotile.
According to Doctor Le Thi Hang – Director of Construction hospital – Ministry of Construction, who have researched on asbestos-related diseases and examined workers’ health in AC roof sheets industry, the result of ministry – level scientific research conducted from 2002 to 2003 showed that the risk of occupational disease in AC roof sheets industry in Vietnam was very low. Only 4 cases of early-stage asbestosis were recorded (0,39%) in 1.032 scans of workers who directly exposed to chrysotile from 2 years to 28 years. This rating was much lower than many different industries such as silicosis in coal mining workers was 11,62%, the proportions in black metallurgy and cement industry were 9,7% and 11,87% respectively. The occupational examination and environmental measurement program in AC roof sheet industry has been developed scientifically methodically in the past 8 years (2008 – 2016) by Hospital of Construction. This program has examined a total of 3.590 workers in AC roof sheets factories who have been directly exposed to chrysotile during manufacturing.