Asbestos wallcoatings found in japan
‘Unused’ asbestos type found at 3 locations
A form of asbestos known as tremolite, thought never to have been used in this country, has been detected at three more Tokyo facilities, including a private nursery school, it has been learned.
Along with anthophyllite and actinolite, tremolite is one of three highly carcinogenic forms of asbestos that were thought to have been absent from Japan.
The discovery raises the possibility that tremolite has been widely used in Japan as a building material. Earlier this month, it was learned that surveys by municipal governments had found the three types at eight public facilities in Tokyo, Chiba and Niigata.
When repairing or demolishing a building, it is a legal requirement to check whether the building contains asbestos. However, many inspection companies have excluded tremolite from the checks, believing that there was no need to look for it.
It is likely that the existence of tremolite has thus been missed in many inspections, with such buildings continuing in use or being demolished without necessary safety precautions being taken–a likelihood that demonstrates the necessity of upgrading inspections.
The tremolite was detected on the ceiling of a boiler room at a private nursery school in December 2006, the ceiling of a pump room at a condominium in May 2007, and in the wall and beams of an office building in August 2007.
In all three cases, the tremolite had been contained in spray-on wall coatings. Concentrations of tremolite in the sprays used hit 60 percent at the nursery, 20 percent at the condominium and 7 to 10 percent at the office building. In all three cases, the tremolite was found during inspections conducted before demolition or alteration work.
Many inspection companies do not cover tremolite, anthophyllite and actinolite in inspections conducted ahead of demolition works.
This time, tremolite was found at the three facilities after two foreign-affiliated companies conducted inspections based on the U.S. standard, which covers all six asbestos varieties.
If the inspections had not been done to the U.S. standard, it is likely that the tremolite would have remained undetected, with no prevention measures taken, as no other asbestos had been used at the facilities.
The carcinogenicity of tremolite is said to be the same as blue asbestos (crocidolite)–the most carcinogenic of all asbestos.
If buildings containing tremolite are demolished without taking measures to prevent the dispersal of asbestos dust, it is likely that construction workers and neighborhood residents will face grave health dangers.
According to the ministry, the aging of buildings that contain asbestos means that more and more such buildings are facing demolition or repair each year.
The ministry estimates that the period from 2020 to 2040 will see such work peak.
(Jan. 31, 2008)
