This excerpt is from a Queensland web page. You can read the entire article by clicking on the link below. Peggy Murdock http://www.dpi.qld.gov.au/pigs/4568.html Over 40 different gases are produced in the decomposition of manure in all non-aerated liquid manure storage systems. These include shallow shed gutters, under-the-floor storage tanks and outdoor effluent dams. Of these gases hydrogen sulphide is one of the most consequential, with many sudden deaths resulting from the agitation and emptying of manure pits that have not been emptied on a regular basis. Hydrogen sulphide at a high concentration renders a person's sense of smell useless and has immediate affect, causing unconsciousness, breathing cessations, excess fluid on the lungs and death. The fact that hydrogen sulphide is only detectable to humans at low concentration is due to its paralysing effect on the nerve cells in the nose at moderate and high levels. At this low, detectable level the entire respiratory tract and eyes call be irritated, and the nervous, system depressed. While moderate levels will cause severe illness. - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - To get off the IOWA-TOPICS list, send any message to: [log in to unmask]