He has tabled a discussion paper that asks EU member states to restrict the use of neonicotinoids to crops not attractive to bees and to prohibit the sale and use of seeds treated with products that contain the active substances.

BBC: Science & Environment

"This implies risk, since the absence of medical supervision and the variability of the active drug substances contained in the plant make it very difficult to ensure correct dosing and follow-up of consumption, " it says on its website.

BBC: NEWS | Europe | Ailing Catalans to try cannabis

Whether the presence of acid conditions or surface active digestive substances in the guts of such marine organisms can desorb and release contaminants in significant quantities to cause such effects, or whether such a response is to their physical presence, remains to be answered.

UNESCO: All Events | United Nations Educational, Scientific and Cultural Organization

The fat cells here are really active, producing toxic substances that cause damage which can lead to heart disease.

BBC: People can be fat yet fit, research suggests

Even minuscule differences in the substances that accompany, or contaminate, the active drug substance can be clinically significant.

FORBES: Commentary