Pressure Treated Lumber

[Rch]

As said you can overload on Cu but ,generally we can metabolize and therefore excrete Cu. The lack of
excretion is a fairly rare inborn error of metabolism called Wilson's syndrome where Cu accumulates and presents as hepatitis, or worse, cirrhosis of the liver in an older adult. Remember we drink alot of water brought to you via copper pipes. There is quite abit of Cu in the enviorment. Copper sulfate is an algicide used in ponds and pools. Like sodium chloride(table salt), too much ( not enough free water) can be poisonous but we have evolutionary equipment to handle it in reasonable amounts. Think of all those pennys that have been swallowed [img]/forums/images/graemlins/smile.gif[/img] The definition of a poison is always at a certain dose over time in a given species. Moss/algae can't get rid of it. Cu in certain salts can be more poisonous than others.

[28RedHorses]

Pressure-treated lumber is rated by the amount of chemical retained by the wood. Lumber with a retention level of .40 is typically approved for direct ground contact. This is sometimes signified by the code "LP 22" stamped on the wood.

If in doubt ask at the lumber yard what these mean.

Hope this helps...

28Red