Hi Rina, the links below should be a start

As far as detecting it, there are tests for the various heavy metals and pesticides etc.

As far as proving it, it depends on what it is. If it is something rarely found outside of a workplace for example, then it is easier. If its something like mercury or lead which is more common, then it is much more difficult Plus of course the laws in your country may well be different from the laws here as far as standards of proof. That you would have to ask a lawyer in your country.



http://millercenter.uchicago.edu/lea...c/toxins.shtml http://findarticles.com/p/articles/m...601001045/pg_4
http://www.neuro.wustl.edu/neuromusc...ther/toxic.htm