Accidents such as Bhopal in 1984, Chernobyl in 1986, Toulouse in 2001 or Fukushima in 2011 demonstrate the high risk of hazardous materials being released into the environment and the adverse effects on a large number of people in the immediate and wider environs.
Such chemical or radiological disasters, as well as dam failures, mainly result from human activity and consequently, their occurrence seems more foreseeable than natural catastrophes.