As of last month, asbestos levels exceeding the World Health Organization’s safety limit were detected in 14 cases at sites where buildings damaged by last year’s Great East Japan Earthquake were being demolished, according to a government study.
Asbestos is a textile-like mineral that if inhaled by humans may lead to serious health problems including lung cancer. As the material is ideal for fireproofing and insulating against noise, a large quantity had been imported since the 1960s, with most used in construction.
In 2006, an ordinance of the Industrial Safety and Health Law was revised to prohibit the use of construction materials that contain more than 0.1 percent of asbestos. The risk of airborne asbestos to people’s health was pointed out after the 1995 Great Hanshin Earthquake.
Amid such concerns in the wake of last year’s devastating earthquake and tsunami disaster, the Environment Ministry is aiming to bolster its authority to inspect demolition sites. The Health, Labor and Welfare Ministry and the Environment Ministry conducted the study to measure the density of asbestos in the air at 114 demolition sites in Miyagi, Iwate, Fukushima, Tochigi, Ibaraki and other prefectures.
The study found that between 10.6 and 783.5 parts of asbestos per liter of air were detected at 14 sites, much higher than the WHO’s safety limit of 10. The largest level, 783.5, was found in a hotel being demolished in a business district in Aoba Ward, Sendai.
According to the Sendai city government, demolition of the building’s exterior started in November without measures to prevent asbestos from scattering, such as covering the walls with plastic sheets. As a result, the material spread to nearby areas.
Ministry inspectors confirmed that 360 parts per liter of air had been detected at the perimeter of the hotel and nearby. At a demolition site in Ibaraki Prefecture, 419.8 parts per liter of air of asbestos were detected in January. Airborne asbestos was also confirmed in Ishinomaki and Kesennuma in Miyagi Prefecture, and in Mooka, Tochigi Prefecture.
Asbestos was used as a construction material in many buildings until the 1990s. The Industrial Safety and Health Law stipulates that when such buildings are demolished, the sites should be covered with plastic sheets or special equipment should be used to keep the material from spreading.
However, such measures were not taken sufficiently at the sites where excessive amounts of asbestos were found. In the disaster-hit areas, a large amount of demolition work had to be conducted in a short period of time. The ministries thus assume demolition companies were too overwhelmed to take such precautions.
In the wake of the Hanshin quake, at least three workers involved in demolition activities developed tumors as a result of inhaling asbestos, and were recognized as victims of work-related health damage. The then Environment Agency conducted research on the spread of asbestos at 36 building demolition sites in Hyogo Prefecture.
The study showed that more than 10 parts per liter of air were found at three spots around the perimeters of the sites. The highest level detected was 21.2 parts, much lower than the level detected in Sendai in the latest study.
Following the new findings, the Environment Ministry plans to revise the Air Pollution Control Law, which stipulates measures to prevent asbestos-related health damage, to bolster the ministry’s authority to conduct on-the-spot inspections.
The current law obliges companies to notify local governments when they begin work to tear down buildings in which asbestos was used. However, if firms do not report their activities, local government inspectors have no authority to enter the sites.
To get around this, the ministry plans to revise the law to allow inspections at all work sites. It aims to submit a bill to this end in the next ordinary Diet session. The ministry recommends that people who are concerned about their health regarding airborne asbestos contact their local government or public health-care center.