1.   Even now, shells (duds or live) which landed about 90 years back during World War I are found by farmers during ploughing. Special bomb disposal squads are being kept busy with hundreds of calls.

2.   There are, still more, unexploded  and hidden bombs allover the world that fell during

World War II

3.   Severed  limbs  and  dead  bodies  are  being  discovered  in  lands  filled  with  mines  in Cambodia and Vietnam in 1960s and70s.

4.   Anti-personnel   weapons  are  found  in  Afghanistan,   Angola,  Bosnia,  Mozambique, Nicaragua and Somalia.

5.   These weapons are easily spread by air but are very difficult and dangerous to detect and remove.

6.   About 100 million landmines remain still scattered in the above countries as per estimates by U.S.State dept.

7.   Landmines present a serious ethical dilemma to leaders who want to be ethical in wars also

8.   Design, mfr, deployment and eventually their disposal is a huge experiment.

9.   Widespread ignorance on radiation amongst the public

10. Gas warfare experiments,  Anthrax carriers, nuclear weapons all cause both known and unknown problems

11. Engineers dealing with dangerous material should consider both the intended use and also the unintended consequences and also their disposal