Ohio farm workers may suffer life-threatening health problems or death when exposed to gases produced by livestock manure. These gases include hydrogen sulfide, carbon dioxide and methane. Gases produced by manure are especially dangerous in enclosed areas. Last year, a farm worker died from exposure to hydrogen sulfide gas while helping fill a tank full of liquid pig manure. According to a coworker, the man was on top of a semi-truck, monitoring the progress as the tank fill