hydrogen sulfide is deadly sewer gas
- related: Occupational Lung Disease
- tags: #literature #pulmonary
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Hydrogen sulfide (H2S) is a colorless gas with a characteristic odor of rotten eggs and a common cause of inhalational toxic exposure in an occupational environment, especially in the petroleum industry. It may also be seen in confined spaces in which organic matter is being broken down anaerobically, such as in sewers and swamps. The clinical effects of H2S depend on its concentration and the duration of exposure. H2S has been referred to as “knock down gas” because inhalation of high concentrations can cause immediate loss of consciousness and death mechanistically by displacement of air or, in the case of confined space exposures, by asphyxiation. However, prolonged exposure to lower concentrations, such as 10 to 500 ppm, can cause various respiratory symptoms that range from rhinitis to acute respiratory failure and may also affect multiple organs, causing temporary or permanent dysfunction of the neurological, cardiovascular, renal, hepatic, or hematological systems. The findings in this case are consistent with exposure to H2S, including a history of an irritating odor (described as a "rotten eggs" smell) emanating from "sour" crude oil (ie, when the total sulfur level in the oil is more than 0.5%) at the transfer site with related symptoms and clinical findings, including a characteristic discoloration of the nail beds, a spirometric pattern consistent with likely bronchiolitis obliterans (mixed obstructive and restrictive) (constrictive bronchiolitis is small airway disease), and neuropathic changes (choice C is correct).
As H2S is a potential problem in the transport and storage of crude oil, industrial hygiene measures remain important in preventing lethal exposure to hydrogen sulfide toxicity. Personal protective equipment should include safety glasses, respiratory protection or equipment, and long-sleeved shirts. In addition, the use of personal safety gas detectors may aid in the protection of employees working with potential gas exposure.1