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DEFINITION
Metalloid:
An element (e.g., germanium or
silicon) whose properties are
intermediate between those of
metals and solid nonmetal
Organic arsenic:
Arsenic combined with any
organic compound (containing
large amount of carbon)
Inorganic arsenic:
Arsenic combined with elements
other than carbon
BACKGROUND
HEALTH EFFECT
Arsenic is a metalloid that occurs in different
forms: inorganic and organic, which are found in
the environment both from natural occurrence and
from anthropogenic activity1. Most inorganic and
organic arsenic compounds are white or
colourless powders that do not evaporate. They
have no smell, and most have no special taste 2.
The inorganic forms of arsenic are more toxic as
compared to the organic arsenic.
 IARC have classified inorganic arsenic as a
known human carcinogen1. The toxicity of
inorganic arsenic compounds is generally linked
to the soluble inorganic trivalent forms, arsenite.
The toxicity of pentavalent inorganic compounds
seems related to the in vivo reduction of
pentavalent arsenic (arsenate , As(V)) to trivalent
arsenic (As(III)) 5
 Toxicity effects of inorganic arsenic are6:
a. Acute toxicity: Gastrointestinal symptoms,
disturbances of cardiovascular and nervous
system functions and may eventually cause
death
b. Chronic
effect:
Skin
lesions,
cardiovascular disease, neurotoxicity and
diabetes
c. Carcinogenicity: Cancers of urinary
bladder, lung and skin in human
INTRODUCTION
Anthropogenic
Caused or influenced by humans
In vivo reduction
Chemical species decreases its
oxidation number which occur
in living organism



Biotransformed
Chemical modification (or
modifications) made by an
organism on a chemical
compound
Inorganic arsenic exists in four main chemical
forms known as valency or oxidation states.
The dominant forms of inorganic arsenic are
Arsenite ((trivalent arsenic (As (III), As+3)) and
Arsenate ((pentavalent arsenic (As (V), As+5))3.
Both arsenite and arsenate are readily absorbed
in the gastrointestinal tract. The absorbed
inorganic arsenic is biotransformed in most
mammals by reduction and methylation reaction,
as illustrated below3.
ROUTE OF EXPOSURE AND ELIMINATION


ABBREVIATION
DMA :Dimethylarsenic acid

MMA :Monomethylarsenic

TMAO :Trimethyl arsenic oxide
SAM
:Sadenosylmethione
SAH
:S-adenosylhomocysteine
GSH
:Reduced glutathione
Primary routes of arsenic entry into the body
are ingestion and inhalation. Dermal
absorption also occurs, but to a lesser extent 7.
Approximately 70% of arsenic is excreted,
mainly in the urine as DMA (60%), MMA
(20%) and inorganic arsenic6.
Other routes of elimination are hair, nails,
sweat and faeces6.
The half-life of inorganic arsenic in humans is
about 10 hours7. Most of the inorganic arsenic
will be gone within several days, although
some will remain in the body for several
months or even longer8.
REGULATION

AS3MT:Arsenic
methyltransferase
GSTO1:Glutathione
SEDITORIAL BOARD
transferase omega-1
The main contributors to overall dietary exposure
to inorganic arsenic in the food chain are cereal
grains and cereal-based products, food for
special dietary uses (such as algae), bottled
water, coffee and beer, rice and rice-based
products, fish and vegetables4.
Malaysia: Standard for inorganic arsenic is 1 mg/kg
in seafood, crustacean, cephalopods (without
viscera), bivalve mollusks, predatory fish and
others excluding bivalve mollusks and cephalopods
(without viscera)9.
Advisor
Pn. Shamsinar Abdul Talib
REFERENCES
Managing Editor
En. Mazlan Isa
Chief Editor
Cik Zawiyah Sharif
Cik Laila Rabaah Ahmad
Suhaimi
Associate Editors
Cik Asmah Omar
Pn. Syahnaz Mohd Azali
Cik Nur Hidayah Jamaludin
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2.
3.
4.
5.
6.
7.
8.
9.
IARC. Agents Classified by the IARC Monographs. 2012;Vol 1-104.
Maryland Department of Health & Mental Hygiene. Health Information About Arsenic. 2007 April 2007.
Mechanism of arsenic toxicity and carcinogenesis. Africal Journal of Biochemistry Research. 2009;Vol.3 (5):232237.
EFSA. Scientific Opinion on Arsenic in Food. 2009 27th September 2010.
INCHEM. Arsenic, Inorganic. 1992.
WHO. Arsenic and Arsenic Compounds. Environmental Health Criteria. 2001;2nd edition.
ATSDR. Toxicological Profile for Arsenic. 2007 3rd March 2011
ATSDR. Public Health Statement for Arsenic. 2007 3rd March 2011
Food Act 1983 & Regulations1985: 20th February 2012