Hydrogen Sulfide (H2S)
History
The presence of H2S usually is apparent because of the characteristic rotten egg smell. However, concentrations above 150 ppm may overwhelm the olfactory nerve so that the victim may have no warning of exposure. Exposures can be subdivided into low-, high-, and very high-level categories.
CAFO Air Pollution and Children: A Prescription for Precaution
http://www.indianacafowatch.com/index.php?option=com_content&task=view&id=62&Itemid=40
“Children and infants are among the most susceptible to many of the air pollutants. In addition to associations between air pollution and respiratory symptoms, asthma exacerbations, and asthma hospitalizations, recent studies have found links between air pollution and pre-term birth, infant mortality, deficits in lung growth, and possible development of asthma.
(American Academy of Pediatrics Committee on Environmental Health. “Ambient Air Pollution: Health Hazards to Children.”
Pediatrics Vol. 114 (6). December 2004. http://aappolicy.aappublications.org/cgi/reprint/pediatrics;114/6/1699.pdf)
The presence of H2S usually is apparent because of the characteristic rotten egg smell. However, concentrations above 150 ppm may overwhelm the olfactory nerve so that the victim may have no warning of exposure. Exposures can be subdivided into low-, high-, and very high-level categories.
- Low-level exposure often is more chronic in nature and usually is seen in industrial settings. Chronic low-level exposure of hydrogen sulfide results primarily in irritation to mucous membranes and the respiratory system. Patients exposed to continuous low-level concentrations or after acute exposure to the very high concentrations of hydrogen sulfide can lose their ability to smell/detect the gas even though it is still present in the environment (olfactory fatigue/paralysis).
- Headaches
- Asthenia
- Bronchitis
- High-level exposures of hydrogen sulfide result in more neurologic and pulmonary symptoms.
- Cough
- Dyspnea
- Vertigo
- Confusion
- Nausea and vomiting
- Possible loss of consciousness
- Hemoptysis
- Very high concentrations lead to cardiorespiratory arrest because of brainstem toxicity.
- Myocardial infarction
- Sudden loss of consciousness ("knockdown")
- Seizure
- Cardiopulmonary arrest
- Low-level exposure of hydrogen sulfide most often affects the mucous membranes and may show the following few physical signs:
- Conjunctivitis (even at levels of only 4 ppm)
- Pharyngitis
- Green-gray line on gingiva
- Wheezing
- High-level exposure of hydrogen sulfide may elicit the following signs:
- Bradycardia
- Tremulousness
- Agitation
- Cyanosis
- Acute lung injury (may present with acute respiratory distress syndrome [ARDS])
CAFO Air Pollution and Children: A Prescription for Precaution
http://www.indianacafowatch.com/index.php?option=com_content&task=view&id=62&Itemid=40
“Children and infants are among the most susceptible to many of the air pollutants. In addition to associations between air pollution and respiratory symptoms, asthma exacerbations, and asthma hospitalizations, recent studies have found links between air pollution and pre-term birth, infant mortality, deficits in lung growth, and possible development of asthma.
(American Academy of Pediatrics Committee on Environmental Health. “Ambient Air Pollution: Health Hazards to Children.”
Pediatrics Vol. 114 (6). December 2004. http://aappolicy.aappublications.org/cgi/reprint/pediatrics;114/6/1699.pdf)
