|
|
|
|
Trace
Elements Laboratory |
 |
|
A
Joint Venture of London Health Sciences Centre and St. Joseph's
Health Care London
|
|
Selenium (Se)
|
| Atomic Number: |
34 |
| Atomic Symbol: |
Se |
| Atomic Weight: |
78.96 |
| Electron Configuration: |
[Ar]4s23d104p4 |
| TITLE: |
Selenium (Se) |
| SYNONYMS/FORMS
|
|
| GENERAL
INFORMATION |
Selenium is a non-metallic element, naturally occuring in
the earth's crust at concentrations of approximately 0.09
mg/kg (1). Se is present in the environment in elemental form,
or in its inorganic forms selenide (Se2-), selenate (SeO42-),
or selenite (SeO32-). The most absorbable organic forms of
Se are selenomethionine and selenocystiene. (3) The RDI of
Se is 1 mg/kg of body weight per day. There is a small margin
of safety between deficient levels and toxic levels of Se
(2)Se is involved with the glutathione-peroxidase antioxidant
system, and function of the immune system.Se effectiveness
is increased by vitamin E and other antioxidant nutrients
that are involved in the glutathione-peroxidase function.Se
function is decreased with high doses of vitamin C. |
| SOURCES |
Most Canadians are exposed to Se from compounds in the air,
drinking water, soil, and mostly from food - more than 98%
of daily Se intake is from food (2). |
|
EXPOSURE
Short-term
|
High daily intake (0.1-0.2 mg/kg) -Dizziness, fatigue, irritation,
collection of fluid in lungs, pneumonia, severe bronchitis,
and injury to GIT.Inhalation - respiratory track irritationContact
with skin - rash, pain, swelling
|
|
Long-term
|
Selenosis
- garlic odor breath, thickened brittle nails, hair and nail
loss, reduced hemoglobin, mottled teeth, skin lesions, and
pain or numbness in limbs.No human evidence of reproductive
effects, developmental abnormalities, or cancer. |
|
TOXICITY
Signs/Symptoms
|
Abdominal pain, nausea, diarrhea, garlic-breath, fatigue,
tooth decay, and hair loss |
|
MONITORING
Adult
Testing
|
Plasma, adult 1.27-2.09 umol/L (100-165 ug/L)Erythrocytes:
2.53-5.07 umol/L (200-400 ug/L)Urine: 33.3-150 umol/mol creatinineUrine
(random): 0.25-1.14 umol/L (20-90 ug/L)Urine (24 hr): 0.38-1.65
umol/d (30-130 ug/d)Hair 6.3-22.8 umol/g (0.5-1.8 ug/g)
|
|
Pediatric
Testing
|
Plasma
0-1 yrs 0.72-1.21 umol/L (57-96 ug/L)Estimated that doses
> 900 µg Se/day are necessary to cause selenium toxicity
in children |
|
Alert/Action
Levels
|
Clinical
manifestations of Se toxicity occur when intake exceeds 900
mcg/day and intake >1000 leads to selenosis (3) |
| TREATMENT
OPTIONS |
There
is no known treatment to reverse effects of selenium poisoning |
|
Precautions
|
|
|
Interactions
|
|
| REFERENCES
|
- http://www.hc-sc.gc.ca/hecs-sesc/water/pdf/dwg/selenium.pdf
- http://www.ec.gc.ca/ceqg-rcqe/English/Pdf/GAAG_Selenium_e.pdf
-
http://www.vitaminherbuniversity.com/topic.asp?categoryid=2
&topicid=1028#subcatid13
|
Sample Requirements (click on cell)
Reference range
|
Serum
|
Erythrocytes
|
Random
Urine
|
Urine
|
24 Hour
Urine
|
|
0-1
yr: 0.72-1.21 (preterm infant: 0.44 - 1.19)
1 Year - 5 Year: 1.22 - 1.82 umol/L
5 Year - 9 Year: 1.28 - 2.05 umol/L
9 Year - 124 Year: 1.32 - 2.35 umol/L
|
2.53-5.07
umol/L
|
0.25-1.14
umol/L
|
33.3-150
umol/mol creatinine
|
0.38-1.65
umol/d
|
|
|
