Levels in two of the New York communities ranged up to ppb for periods of several months. During these episodes there were frequent health complaints including eye, throat and lung irritation, nausea, headache, nasal blockage, sleeping difficulties, weight loss, chest pain, and asthma attacks. Although other chemicals may have been present in the air, these effects are consistent with those of hydrogen sulfide.
The main effects of short-term and long-term hydrogen sulfide exposure in laboratory animals are nasal and lung irritation and damage and effects on the brain. These effects are consistent with effects seen in people exposed to hydrogen sulfide. The effects of exposure to any chemical depend on the amount of the chemical to which a person is exposed and the length of exposure.
The effects may also be influenced by a person's age, sex and general health. The figures Portable Document Format PDF file - help for PDF summarize the relationship between exposure to hydrogen sulfide and known health effects, including those at very high levels of exposure.
The information comes from exposure of people as well as laboratory animals. Effects in humans are shown on the right side and effects in animals on the left side of each line in the diagrams. Federal workplace standards and state ambient air standards are also shown on the diagrams. Navigation menu.
For example, hydrogen sulfide occurs naturally in crude oil , natural gas, and in hot springs. Bacterial breakdown of human and animal waste also produced hydrogen sulfide. Humans release hydrogen sulfide through petroleum drilling and refining, wastewater treatment, and paper mills. The hydrogen sulfide content of natural gas is one of the main safety concerns associated with the use of natural gas. Natural gas with especially high levels of hydrogen sulfide is referred to as sour gas.
Some of this sulfur can be removed through a "sweetening" process, called the "amine process" or more commonly the "Girdler process". It is used in most gas sweetening operations and is done mainly using amine solutions that remove the hydrogen sulfide. Hydrogen sulfide is used primarily to produce sulfuric acid and sulfur. It is also used to create a variety of inorganic sulfides used to create pesticides, leather, dyes, and pharmaceuticals.
Hydrogen sulfide is used to produce heavy water for nuclear power plants like CANDU reactors specifically. Hydrogen sulfide can also be used in agriculture as a disinfectant. It is also widely used in chemical analysis. Iron smelters, landfills, food processing plants, and breweries are some examples of industrial sources that produce or use hydrogen sulfide. The gas must be disposed of properly as emissions of hydrogen sulfide can be dangerous.
Though it may be easily smelled by some people at small concentrations, continuous exposure to even low levels of H2S quickly deadens the sense of smell olfactory desensitization. Exposure to high levels of the gas can deaden the sense of smell instantly. Although the scent of H2S is a characteristic, smell is not a dependable indicator of H2S gas presence or for indicating increasing concentrations of the gas. H2S irritates the mucous membranes of the body and the respiratory tract, among other things.
Following exposure, short-term, or acute, symptoms may include a headache, nausea, convulsions, and eye and skin irritation. Injury to the central nervous system can be immediate and serious after exposure. At high concentrations, only a few breaths are needed to induce unconsciousness, coma, respiratory paralysis, seizures, even death. Those having prolonged exposure to high enough levels of H2S gas to cause unconsciousness may continue to experience headaches, reduced attention span and motor functions.
Pulmonary effects of H2S gas exposure may not be apparent for up to 72 hours following removal from the affected environment. Delayed pulmonary edema, a buildup of excess fluid in the lungs, may also occur following exposure to high concentrations.
Prolonged exposure to low levels may cause painful skin rashes and irritated eyes. Repeated exposure over time to high levels of H2S may cause convulsions, coma, brain and heart damage, even death. Heavier than air, H2S gas accumulates in low lying areas of poorly ventilated spaces.
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