| Atomic Number: |
33 |
| Atomic Symbol: |
As |
| Atomic Weight: |
74.9216 |
| Electron Configuration: |
[Ar]4s23d104p3 |
| TITLE:
|
Arsenic
(As) |
| SYNONYMS/FORMS |
Arsen, Arsenic-75, Grey Arsenic, Metallic Arsenic |
| GENERAL
INFORMATION |
Arsenic
(As) is distributed in nature primarily as inorganic As +3 and
organic As +5 compounds. Inorganic arsenic poisoning, usually
occurring from occupational exposure, is more toxic than organic
arsenic.The half-life of inorganic arsenic in humans is estimated
to be up to 40 days.Inorganic As is methylated to monomethylarsonic
acid and dimethylarsinic acid (75%) for excretion into the urine.The
most toxic form is Arsine gas, AsH3, and the least toxic is
Arsenobetaine as found in shellfish and fish. Total urine arsenic
is increased between 2 and 7 times from ingestion of seafood
above those not consuming these products. Approximately 25%
of the intake of arsenic from food is inorganic and 75% is organic.Garlic-like
smell to breath can occur from high As intake. |
| SOURCES |
In the environment, arsenic is converted by microorganisms into
organoarsenics such as found in fish. It is absorbed by the
GI tract (>80%), and excreted in urine within a few days.
As is used as pesticides, wood preservatives, hide tanning,
glass production, gold smelting, from coal burning, in transistors
of computers/cell phones, and in some contaminated water supplies
(i.e. wells). As found in tobacco smoke may be a causative factor
in lung cancer. |
|
EXPOSURE
Short-term
|
The
normal body burden for As is 0.01 - 0.46 mg/kg (1) The WHO tolerable
daily intake is 0.05 mg As/kg body wt. from food and 50 mg/L
in drinking water.As binds to hemoglobin in the RBC, then distributes
to the kidneys, liver, and spleen. As concentrates in hair,
nails and skin within 2 weeks of exposure.
|
|
Long-term
|
Chronic
signs of toxicity to As are insidious and difficult to diagnose.Repeated
or prolonged contact with skin may cause sensitization and dermatitis.
White stria (Mees lines) in nails.As exposure can result in
skin pigmentation, neuropathy, and is carcinogenic to humans
(IARC-Group 1). |
|
|
Sudden
and explosive gastroenteritis develops in 30 minutes to 2 hrs.
after oral intake. Vomiting, diarrhea with bloody stool from
severe hemorrhage. Loss of fluids and electrolytes can result
in shock and death. As main mode of toxicity is inhibition of
enzyme activity by binding to sulfhydryl groups (SH), and uncouple
oxidative phosphorylation to reduce high-energy phosphate in
ATP. |
|
MONITORING
|
Due
to the rapid clearance of As from blood (90% within 2 hrs (2),
urine is the preferred specimen for analysis. Total As in 24
h urine is up to 60 ug/day (0.8 umol/d or 70 umol/mol creatinine).
Total As in random urine is up to 40 ug/L (0.53 umol/L or 70
umol/mol creatinine). This includes inorganic, mono- and dimethylated
As, and trimethylated As such as arsenobetaine. Inorganic As
includes mono- and dimethylated As which represents the group
monitored for occupational exposure (American Conference of
Governmental Industrial Hygienist, ACGIH), and the biological
exposure index (BEI). In 24 h urine Inorg. As is 15 ug/d (0.2
umol/d or 25 umol/mol creatinine) and in random urine is up
to 10 ug/L ( 0.13 umol/L or 25 umol/mol creatinine).
Pediatric Testing Values to be determined.
Alert/Action
Levels Occupational alert 80 umol/mol creatinine (3)
|
| TREATMENT
OPTIONS |
Remove
subject from As source. After acute ingestion, gastric decontamination
is indicated with gastric lavage, not induced emesis. Supportive
measures include isotonic IV fluids. Chelation (4) may be required
with agents such as BAL (British anti-Lewisite), Penicillamine,
Dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane-1-sulfonate
(DMPS) (5). |
|
Precautions
|
Subjects
must have adequate urine flow, and used with caution in those
with renal insufficiency. Proper supplementation is required
with nutritional mineral and trace elements to replace those
lost by chelation (6).
|
|
Interactions
|
NB |
| REFERENCES
|
- http://www.prn.usm.my/sites/arsenic.html
- Rev
Environ Contam Toxicol 2001;169:165-214.
- Ontario
Ministry of Labour, 1995
- Human
Exp Toxicol 1997;16:460-465.
- Pam
Floener, Heyltex Scientific. HEYLdmps@aol.com
- J
Nutritional & Environ Med 2002;12:53-67
|
Sample Requirements (click on cell)
Reference range
| Analyte
Arsenic |
|
Random
Urine |
Random
Urine |
Random
Urine |
24
Hour Urine |
Whole
Blood |
Red
Cells |
Hair |
| Total
|
0.00
- 0.53 umol/L |
0.0
- 70.0 umol/mol creatinine |
0.0
- 46.4 ng/mg creatinine |
0.00
- 0.80 umol/d |
0.0
- 21.4 nmol/L |
0.0
- 40.1 nmol/L |
0.0
- 2.0 nmol/g |
| Inorganic
Arsenic* |
0.00
- 0.13 umol/L |
0.0
-25.0 umol/mol creatinine |
0.0
-16.6 ng/mg creatinine |
0.00
- 0.20 umol/d |
|
|
. |
Notes: This value represents inorganic,
mono and dimethylated arsenic species correlating with occupational
and environmental exposure. Organic, trimethylated species
such as arsenobetaine, arising from seafood contamination, are
not measured.
Method of Analysis: High Resolution ICP/MS
Test available: Monday - Friday 0800 - 1600 h
Turnaround Time: Average 5-10 days
Maximum 10 days
|
