Hi Mark, I did not mean top imply that Ag and its salts are toxic for humans, but to bacteria. I would imagine one would like to ave bacteria at work in a landfill. That Romans got lead poisening from lead water pipes is an urban myth. I saw the water papes in Pompeii—totally encrusted almost to occlusion be deposits. The Pb-poisening happened to the roman upper-crust, because of drinking highly acidic wine [much ore so than today's wines] from Pb-containing vessels. Werner ************** Vote for your city's best dining and nightlife. City's Best 2008. (http://citysbest.aol.com?ncid=aolacg00050000000102)