Recent revelations that hundreds of workers at firms across Japan have died from asbestos-linked diseases over the past few decades have raised questions about whether the health risks of the unburnable mineral were duly recognized by the government and businesses.

Experts warn that the deaths reported so far are just the tip of the iceberg, and that the government's delay in fully banning asbestos unnecessarily exposed a greater segment of the population to the toxic fibers.

The flurry of announcements began on June 29, when major machinery maker Kubota Corp. said 79 people who worked at its plants had died of asbestos-related diseases between 1978 and 2004. Kubota also said three residents who lived near a now-defunct factory in Amagasaki, Hyogo Prefecture, were sick and that the wife of a factory employee had also died.