No case of cancer has been found due to drinking water from AC roof sheets

(Lai Chau Newspaper) AC roof sheets have been produced in Vietnam since 1963 with the main blending components including 7-10 percent of chrysotile fiber, 90 percent of cement and other additives. With superior properties such as high elasticity and strength, good friction resistance, resistance to alkaline environment, electrical insulation, thermal insulation, persistence ect., chrysotile helps create over-50-year-old AC roof sheet products. In fact, this material has met rigorous consumer standards such as good thermal insulation, persistence under climate changes, sea steam, hoarfrost, kitchen smoke or acids in fences of cattle and poultry.

No case of cancer due to working or living under AC roof sheets has been found

The first subjects at risk of pneumonia due to exposure to chrysotile are workers in AC roof sheet factories. In the early days of the industry, in the 1960s and 2000s, most workers opened the bags, weighed, and mixed chrysotile manually. Today, when the industry has developed sustainably, most factories have advanced technology with a closed system, automatic bag opening. They also set labor safety standards and conduct periodic examination of occupational diseases for workers. Until now, domestic scientific studies have not found any case of cancer or dangerous lung disease related to exposure to chrysotile in AC roof sheets.

During 2009 – 2011, the Ministry of Health, in cooperation with the Ministry of Labor and Welfare of Japan, through the World Health Organization (WHO), to sponsor the Agency of Health Environment – Ministry of Health. Ministry-level in research: “Research on asbestos-related diseases in exposed people”. Of the 447 cases of asbestos-related diseases such as lung cancer, pleural thickening and mesothelioma, only 39 samples were screened and sent to Hiroshima Hospital, Japan for diagnosis. Here, Japanese experts also identified only 08 cases of the disease but none of them had a clear history of occupational exposure to asbestos.

In 11 years (2008 – 2018) of the Occupational Examination Program and the Working Environment Measurement for workers in the industry of AC roof sheet, the prestigious film reading council of Construction Hospital – Ministry of Construction came to conclusion that: No typical lesion of asbestos-related pneumonia were detected.

Anh Bai 1

Workers of Tan Thuan Cuong Factory participated in the occupational disease examination program in 2019.

In the world, studies have shown that diseases related to respiratory, health and longevity of people exposed to chrysotile in the production and use are not different from those who did not. In 2014, Dr. Jacques Dunnigan (Canada) with the topic: “Epidemiological and toxicological studies on chrysotile fibers and exposure risks” have confirmed chrysotile is safer than brown and green fibers. With a controlled manner, it can minimize the health risks for workers and consumers.

For people living under AC roof sheets, studies also confirm that it is difficult to be exposed or cancer. Research on asbestos concentrations in the air of areas with many chrysotile-cement roof sheets in Australia, Germany and Austria believe that asbestos concentrations are not different from the naturally occurring asbestos concentrations of 0.001 f/cc – levels rated by the WHO, the Royal Commission on Asbestos and the Royal Society of London as “acceptable”, “insignificant” and “… no basis for further control”.

AC roof sheets are still widely used in Thailand.

Doctor Le Thi Hang – Former Director of the Construction Hospital – the Ministry of Construction said there was a study on investigation of the health status and mortality of local residents in Tan Trinh commune, Quang Binh district, Ha Giang province where 69.4 percent of households are using AC roof sheets. An environmental survey of 30 locations in residential area of Tan Trinh indicated that chrysotile was not detected in the samples. The crude death rate in Quang Binh, Ha Giang is at average level compared to other regions in Vietnam and around the world. No cases of cancer have been reported due to living under chrysotile-cement roofing sheets.

Fiber cement products are still used in more than 100 countries

The industry of fiber cement products has flourished in many countries around the world. In the US, fiber cement products are rated by the US Environmental Protection Agency (EPA) as safe. EPA also does not prohibit plumbing products or chrysotile-cement products. More than 60 percent of the Brazilian, Russian, Chinese, Indian … use chrysotile-containing water tanks and AC roof sheets. In Germany, there has been more than 50,000 kilometers of domestic water pipes. Asian countries with economic and climate conditions similar to Vietnam such as Thailand, Indonesia, Malaysia ect., AC roof sheet seems to be the only option of people in rural and coastal areas.

The house was built from fiber cement materials in Russia.

Is drinking water from AC roof sheets a cause of cancer?

Due to the regional characteristics and severe weather conditions, many people in remote areas do not have tap water to use. Drilling wells in rocky areas is often not feasible or too expensive. For the Mekong Delta, the situation of saline water and alum contaminated water forces people to collect rainwater from the roof to the tanks to reserve for the dry seasons. This is also the popular situation of India, where there are crises about clean water every year. Local people still have to stored water in chrysotile-containing tanks.

According to Assoc. Prof. Dr. Luong Duc Long – Former Director of the Vietnam Institute for Building Materials, the Ministry of Construction, the amount of chrysotile in roofing sheets accounts for a very small proportion of mixing. The chrysotile fibers have a hollow structure so the cement-like binder will fill them up, creating a strong, tight, hard-to-break bond which is very difficult to disperse into the environment.

Many studies to determine the risk of chrysotile-containing drinking water to human health showed no evidence of cancer from drinking water with chrysotile.

In 2002, the World Health Organization (WHO) added to the report on asbestos in drinking water in 1996 and concluded that “Current epidemiological studies do not provide evidence of an increase in risks of human health related to asbestos in drinking water. Furthermore, studies on animals have shown that asbestos does not increase the risk of gastrointestinal cancers. Therefore, there is no conclusive evidence that drinking water containing asbestos is dangerous for human health. Therefore, it is not necessary to create a safety guide on asbestos in drinking water.”

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