HYDROGEN SULFIDE
The warning smell of hydrogen sulfide quickly “numbs” or blocks the ability of the nerve of smell (olfactory nerve) to detect further exposure. This prompt hydrogen sulfide loss of smell is dangerous because it allows exposure to continue without adequate warning.
Hydrogen sulfide exposure in humans can induce neurotoxicity, including brain damage[1]. Other human effects reported include headache, effects on the respiratory system at 2 ppm, with more significant changes in persons with asthma, changes in energy metabolism, and permanent brain and neurologic changes from either acute higher dose or chronic lower dose exposures[2],[3],[4],[5]. Hydrogen sulfide is an irritant to the respiratory system and can interact with proteins in the body (which could change enzyme functions, cell messengers, and all body cells).2
Hydrogen sulfide acts directly upon the nervous system, and can impair vision, induce heightened light sensitivity (which indicates that it can heighten incoming stimuli such as those coming from other incoming stimuli such as those coming from noise, touch, and/or chemical odors).[6] It also interferes with porphyrin metabolism6and is described as being capable of causing permanent injury after even short exposures to small quantities.[7] Toxic encephalopathy has been reported from only a one-day exposure to a concentration insufficient to cause loss of consciousness.[8] Increase in spontaneous abortions have been reported, indicating probable endocrine disruption.[9] Air supplies and respirators are recommended for exposures up to 100 ppm.6
[1] JL O'Donoghue, Neurotoxicity of Industrial and Commercial Chemicals, Vol I, 1985, CRC Press Boca Raton, Fl.
[2] Toxicologic Profile for Hydrogen Sulfide,US Dept HHS, ATSDR, July 1999.
[3] KH Kilburn, RH Warshaw, "Hydrogen sulfide and reduced-sulfur gases adversely affect neuropsychiologic functions", Toxicol
Ind Health 11:185-197, 1995.
[4] KH Kilburn, "Exposure to reduced sulfur gases impairs neurobehavioral function", South Med J 90:997-1006, 1997.
[5] G Ahlborg, "Hydrogen Sulfide poisoning in the shale oil industry". ArchInd Hgg Occ Med 3:247-266, 1951.
[6] Industrial exposure and control technologies for OSHA-regulated hazardous substances, U.S. Dept. of Labor, March 1989, section on
hydrogen sulfide.
[7] Fax I, Dangerous properties of industrial materials, 4th Ed. 1984, p. 1552
[8] Documentation of the threshold limit values, American Conference of Governmental Industrial Hygienists, 4th Ed. and Supplement 1980.
[9] Hemminki, K. and Niemi, M., Community study of spontaneous abortions: relation to occupation and air pollution by sulfer dioxide,
hydrogen sulfide, and carbon disulfide, Inp. Arch. Occup.Environ. Health, 51:55, 1982.