_http://pubs.acs.org/subscribe/journals/esthag-w/2006/sep/science/nl_compostin g.html_ (http://pubs.acs.org/subscribe/journals/esthag-w/2006/sep/science/nl_composting.html) Now that we have developed the ability to test for contaminants in the ppb we can find nearly anything we are looking for at some concentration. Neal Van Milligen