Deadly compounds, but no magic bullets

IT is dangerous for Seán McGovern (Letters, May 31) to claim it would take a very large dose of rodenticide to kill a human; the fatal dose for Warfarin is less than 1/10th gram – it is more poisonous to other species than rodents.

There were 18,011 cases of rodenticide poisoning in humans in the US in 2005, and it is the most common form of poisoning in cats and dogs.

He refers to “old-style lethal poisons”, but modern poisons are lethal too; they wouldn’t be much good if they weren’t.