Beautifully explained, Nigel. You should go into teaching! Watermole+...as usual I was talking tripe....sorry old friend.Snape wrote: ↑Mon Jul 24, 2017 9:43 pm
The problem with the toxicity issue is that references to copper, lead etc being toxic refer to their ions (as compounds) not the metals themselves as the metal cannot interact with biological systems. If you ingested lumps of lead, copper or even drank mercury they would just pass through you as they are not affected by gastric juices so do not react and are not absorbed (lots of cases of toddlers swallowing copper coins).
Lead is pretty unreactive but over a long period of time could react slightly in the aquatic environment (hence banning lead water pipes), copper is less reactive and does not react with water (hence being used for water pipes etc) and mercury is less reactive still (hence being used in amalgam filings). These are all classed as heavy metals and once in compound form, their ions are highly toxic to all living things although toxicity is about dosage and not the actual substance. Everything is toxic at a high enough dosage...
The dosages to kill 50% of average men (assuming we are similar to rats!) are
Caffeine: around 170 cups of coffee.
Salt: about 1/2 lb
Ethanol: just over a pint of 40% spirits, 20 pints of beer.
Citric acid: 15,000 oranges.
Water: 15 pints
These would all need to be consumed rapidly before any is excreted.
I definitely think WM+ should go ahead and stick to copper plummets....
I love the 15,000 oranges.......