Symptoms of selenium toxicity vary among individuals and are dependent on a number of factors such as the dose, type and form of selenium ingested, and the length of time the product was used. Symptoms of selenium poisoning can include two or more of the following symptoms: hair loss, muscle or joint pains, fingernail discoloration or changes, headache, foul breath, weakness, gastrointestinal symptoms (such as nausea, vomiting, diarrhea or abdominal pains), rash, oliguria/anuria or abnormal renal function tests, jaundice or abnormal liver function tests, anemia or hematological changes.
Acute selenium toxicity in humans is characterized by hypersalivation, emesis and a garlic aroma on the breath due to the excretion of volatile selenium metabolites. These effects may be accompanied by gastrointestinal effects (severe vomiting and diarrhea), hair loss, neurological disturbance (restlessness, spasms, tachycardia) and fatigue.
Chronic selenium poisoning, or selenosis, is associated with changes to the hair and nails, skin lesions and clinical neurological effects such as peripheral hypoaesthesia, acroparasthaesiae, pain and hyperreflexia; numbness, convulsions and paralysis may then develop.
Selenium levels greater than 200 µg/L in a 24-hour or random urine collection or serum levels greater than 190 µg/L.
Confirmed: a case that meets the clinical case definition, as reported by a health-care professional, and is supported by lab analysis or is linked to a confirmed source of exposure.
Suspect: a case that meets clinical definition without laboratory support.
(Note: ATSDR and the EPA have determined that 5 micrograms of selenium per kilogram of body weight taken daily would not be expected to cause any adverse health effects over a lifetime of such intake; .005mg/kg/day is the recommended daily allowance.
Date Posted: April 23, 2008