Arsenic Green Facts

8/14/2019 Arsenic Green Facts

1/30

Arsenic: Questions on Arsenic

ome > Studies > Arsenic

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Questions and Answers presented in 3 levels of increasing detail.

Context - Arsenic is a poisonous substance,which is released both from certain humanactivities and naturally from the earth's crust.Humans may be exposed to arsenic mainlythrough food and water, particularly in certainareas where the groundwater is in contact witharsenic-containing minerals.

To what extent can arsenic exposure affecthuman health or the environment?

Questions on Arsenic

1. What is arsenic?

2. Where does environmental arsenic come from?

3. What are the levels of exposure to arsenic?

4. What happens to arsenic in the body?

5. What are the effects of arsenic on laboratory

animals?

6. What are the effects of arsenic on the environmen

7. What are the effects of arsenic on human health?

8. What has happened in areas where drinking wateris heavily contaminated?

9. What have WHO and IARC established about

arsenic?

10. Conclusions

11. Other views

This is a faithful summary of the leading scientific consensus report

produced in 2001 by the IPCS (International Programme on Chemical Safety):

"Executive Summary of the Environmental Health Criteria for Arsenic and Arsenic Compounds" More...

More info on our 3-level structure

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/index.htm (1 of 2) [20/12/2004 11:27:42]

8/14/2019 Arsenic Green Facts

2/30

Arsenic: Level 1 - Summary on Arsenic

ome > Studies > Arsenic > Level 1

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Info on our studies structure

Level 1 - Summary on Arsenic

1. What is arsenic?

2. Where does environmental arsenic come from?

3. What are the levels of exposure to arsenic?

4. What happens to arsenic in the body?

5. What are the effects of arsenic on laboratory animals?

6. What are the effects of arsenic on the environment?

7. What are the effects of arsenic on human health?

8. What has happened in areas where drinking water is heavily contaminated?

9. What have WHO and IARC established about arsenic?10. Conclusions

11. Other views

Level 1 Questions More in Details

Next Question Top

. What is arsenic?

1.1 Arsenic is a natural element which behaves like a metal. It is present in the environment both naturally and due

to certain human activities. It has many different forms. It can exist in inorganic or organic form, inorganic arsenic

being generally considered more toxic. More...

1.2 Arsenic can be measured by a variety of laboratory methods. Some of these can distinguish between differentforms of arsenic and some methods allow very small amounts to be measured accurately. More...

Conclusion Level 1 Questions More in Details

ttp://www.greenfacts.org/arsenic/arsenic-1.htm (1 of 6) [20/12/2004 11:34:12]

8/14/2019 Arsenic Green Facts

3/30

Arsenic: Level 1 - Summary on Arsenic

Next Question Top

2. Where does environmental arsenic come from?

2.1 Arsenic is found in the natural environment in some abundance in the earths crust and in small quantities inrock, soil, water and air. It is present in many different minerals. About one third of the arsenic in the atmosphere

comes from natural sources, such as volcanoes, and the rest comes from man-made sources. Due to naturalgeological contamination, high levels of arsenic can be found in drinking water that has come from deep drilled wellsThis is particularly true for Bangladesh. More...

2.2 Industrial processes such as mining, smelting and coal-fired power plants all contribute to the presence of arsenin air, water and soil. Environmental contamination also occurs because it is used in agricultural pesticides and inchemicals for timber preservation. More...

2.3 Arsenic occurs in different forms and some is transported between different parts of the environment where itmay change its form. Arsenic in weathered rock or soil can be picked up and moved by the wind and water. Manyarsenic compounds bind to soil and only move short distances when water percolates down through the soil. Ifarsenic is released into the atmosphere by industrial processes or volcanic activity, it attaches to particles that aredispersed by the wind and fall back to the ground. Microbes in soil and sediment also release substances containing

arsenic into the atmosphere. These are then converted to other arsenic compounds that settle back onto the groundMore...

Conclusion Level 1 Questions More in Details

Next Question Top

3. What are the levels of exposure to arsenic?

3.1 Environmental levels of arsenic vary. In air, levels are lowest in remote and rural areas, higher in urban areas,and highest close to industrial sources. In water, levels of arsenic are lowest in seawater, higher in rivers and lakesand highest in water from underground areas containing volcanic rock or arsenic-rich mineral deposits. Thebackground levels of arsenic in soil and sediment increase if there are natural and/or man-made sources of arsenic

contamination present. More...

3.2 The amounts of arsenic found in living animals, plants and microbes vary. The quantities depend on the level oflocal contamination and on the type of organism, as certain organisms tend to accumulate arsenic in their bodies.

Arsenic is generally present in sea-living animals at higher levels than in freshwater animals, or plants and animalsthat live on land. Plants on land can accumulate arsenic compounds via uptake from soil and/or deposition from aironto leaves. More...

3.3 Humans are exposed mainly through food and water. Food is usually the largest source except in areas where

drinking water is naturally contaminated with arsenic. The quantities of arsenic breathed in by non-smokers are versmall, except in industrially polluted areas. Smokers inhale more because arsenic is one of many hundreds of

chemicals present in cigarette smoke. Exposure to arsenic in the workplace can be quite high, but the amounts

present in the air in the workplace are controlled in many countries. More...

Conclusion Level 1 Questions More in Details

ttp://www.greenfacts.org/arsenic/arsenic-1.htm (2 of 6) [20/12/2004 11:34:12]

8/14/2019 Arsenic Green Facts

4/30

Arsenic: Level 1 - Summary on Arsenic

Next Question Top

4. What happens to arsenic in the body?

4.1 When arsenic is inhaled due to its presence in airborne particles, the amount absorbed into the blood stream

depends on two things how soluble the particular form of arsenic is and how small the particles are. This said, mo

arsenic in the body comes from the diet. In the gut, soluble arsenic compounds present in food are rapidly absorbedinto the blood stream. Many arsenic compounds are quickly transformed and eliminated from the body via the urineHowever, there are differences from one person to another in the ability to get rid of arsenic compounds. More...

4.2 The amount of arsenic in the body can be estimated by taking samples of blood, urine, hair, or nails andmeasuring the arsenic - or arsenic-containing substances - present. Arsenic disappears rapidly from blood, someasurements in blood only tell you about recent high exposures, such as poisonings, or long-term exposures if the

are repeated and high. Levels in urine are the best measure of recent exposure, whereas levels in hair and nails cantell you about past exposure. More...

Conclusion Level 1 Questions More in Details

Next Question Top

5. What are the effects of arsenic on laboratory animals?

Arsenic can have adverse effects on laboratory animals but some forms of arsenic are more toxic than others. The

consequences include death when exposures are high enough to cause poisoning and cancer. Many parts of the bod

may also be damaged by arsenic, including the skin, gut, lungs, heart, blood vessels, immune system, urinary

system, reproductive organs and the nervous system. Arsenic can also damage chromosomes, which contain the

genetic material inside the cells of the body. More...

Conclusion Level 1 Questions More in Details

Next Question Top

6. What are the effects of arsenic on the environment?

Living organisms, both on land and in water, react in a variety of ways to arsenic exposure. The effects depend on

the chemical form of the arsenic, the nature of the surrounding environment and their own particular biologicalsensitivity. Individual organisms or whole populations may be affected. Adverse effects include death, poor growth

and failure to reproduce. Where arsenic has contaminated a natural environment, the number of different speciesfound is much reduced. More...

Conclusion Level 1 Questions More in Details

Next Question Top

ttp://www.greenfacts.org/arsenic/arsenic-1.htm (3 of 6) [20/12/2004 11:34:12]

8/14/2019 Arsenic Green Facts

5/30

Arsenic: Level 1 - Summary on Arsenic

7. What are the effects of arsenic on human health?

7.1 If a large amount of arsenic is swallowed by humans, in a form that is readily absorbed, it can cause rapid

poisoning and death. The gut, the heart and the nervous system are affected. Those who survive acute poisoningmay develop pigment spots in the skin and damage to red blood cells, bone marrow (where blood cells are made),

liver, nerves and brain. Long-term exposure to high levels of arsenic in drinking water can cause thickening and

pigment spots in the skin, and cancer of the skin, lungs, bladder or kidney. Exposure in the workplace mainly via

the air breathed in can cause lung cancer. Smoking further increases the risk. More...

7.2 Long-term ingestion of arsenic, mainly from drinking of contaminated well water, has caused a disease called

blackfoot in Taiwan. Blood vessels of the leg and foot become damaged, resulting in coldness, loss of feeling and

eventually gangrene in the foot. More...

Conclusion Level 1 Questions More in Details

Next Question Top

8. What has happened in areas where drinking water is heavily contaminated?

Drinking water from unpolluted sources normally contains only small amounts of arsenic. Drinking water fromunderground wells can become heavily contaminated in certain areas where the groundwater is in contact with

natural arsenic from minerals. This can be a serious problem in countries like Bangladesh, West Bengal in India, andTaiwan. In Bangladesh, large numbers of people are regularly drinking water containing more than 5 times and up tmore than 100 times the usual concentration of arsenic. Adverse effects on health, such as skin changes and cance

have been experienced by people living in these regions. More...

Conclusion Level 1 Questions More in Details

Next Question Top

9. What have WHO and IARC established about arsenic?

International bodies have previously evaluated arsenic: the World Health Organization (WHO) has set a provisional

guideline value of 10 g/litre for arsenic in drinking-water and according to the International Agency for Research o

Cancer (IARC) there is enough evidence to conclude that arsenic and arsenic compoundscan cause cancer in

humans. More...

Conclusion Level 1 Questions More in Details

Next Question Top

ttp://www.greenfacts.org/arsenic/arsenic-1.htm (4 of 6) [20/12/2004 11:34:12]

8/14/2019 Arsenic Green Facts

6/30

Arsenic: Level 1 - Summary on Arsenic

0. Conclusions

Arsenic is a chemical substance, which is released from the earths crust via natural processes and from certainhuman activities. It can exist in inorganic or organic form, inorganic arsenic being generally considered more toxic.

(see 1. and 2.)

Environmental levels of arsenic vary. Concentrations of the generally more toxicinorganic arsenic are highest in

air close to industrial sources, in underground water in areas with natural geological contamination, and in soils or

sediments near contamination sources. Concentrations of the less toxic organic arsenic are particularly high in sea-living animals and therefore in seafood.

Humans are exposed mainly through food and water, but arsenic can also be inhaled. After absorption into the

blood stream, arsenic is rapidly transformed and eliminated from the body via urine. (see 3. and 4.)

Organisms living in the environment react in a variety of ways to arsenic exposure. It can even lead to death,

poor growth and failure to reproduce. Where arsenic has contaminated a natural environment, the number ofdifferent species found is reduced. (see 5. and 6.)

In humans, if a large amount of the more toxicinorganic arsenic is swallowed in a form that is readily absorbed, it

can affect the gut, the heart and the nervous system, causing rapid poisoning and death. Drinking water fromunpolluted sources normally contains only small amounts of arsenic. However, in areas with natural geologicalcontamination, such as Bangladesh, drinking water from wells can contain high levels of inorganic arsenic; suchlevels can harm the skin and are associated with increased risk of cancer in the skin, lungs, bladder and kidney.

Exposure to contaminated air at the workplace can cause lung cancer. (see 7. and 8.)

Arsenic and arsenic compounds have been classified as carcinogenic to humans and guideline values for drinking-

water have been set. (see 9.)

Conclusion Level 1 Questions

Top

1. Other views

This summary is based on the 2001 IPCS Environmental Health Criteria 224 "Arsenic and Arsenic Compounds". It is

considered by most scientists as a consensus document and other recent scientific assessments reach similar

conclusions - click here for some links

However, some people and organizations put forward views suggesting that Arsenic poses less risk - click here for

some links.

Conclusion Level 1 Questions

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/arsenic-1.htm (5 of 6) [20/12/2004 11:34:12]

8/14/2019 Arsenic Green Facts

7/30

Other views on Arsenic

About the Toolbox | Back | Print | Forward

Other Views onArsenic

The links on this page are selected as examples of views that differ from that of the IPCS.

This list of links is only a sample and neither pretends to be complete nor fully representative of all the views available.

GreenFacts takes no position concerning the views expressed in these linked documents.

ost scientists globally agree with the conclusions of the Executive summary of the EHC for Arsenic and Ars

mpounds , produced in 2001.

ome of the sites suggesting that arsenic poses less risk

The American Council on Science and Health (ACSH) concludes that "there is little, if any, evidence of a

detrimental health effect in humans from inorganic arsenic in drinking water at the current MCL of 50 g/below, either in the United States or elsewhere.":

www.acsh.org/healthissues/newsID.157/healthissue_detail.asp.

The Competitive Enterprise Institute (CEI) "applauds the US Consumer Product Safety Commissions unanim

decision (...) not to ban the pesticide, chromated copper arsenate, in playground equipment." It states t"for more than 70 years, wood treated with the preservative that includes trace levels of arsenic has been uin commercial and residential products without ill health effects. The chemical prevents decay and insectdamage."

www.cei.org/gencon/003,03739.cfm

The links on this page are selected as examples of views that differ from that of the IPCS.

This list of links is only a sample and neither pretends to be complete nor fully representative of all the views available.

GreenFacts takes no position concerning the views expressed in these linked documents.

Back | Print | Forward Top

17-Dec-2004

ttp://www.greenfacts.org/arsenic/links/other-views.htm (1 of 2) [20/12/2004 11:34:59]

8/14/2019 Arsenic Green Facts

8/30

Arsenic: Level 2 - Details on Arsenic

ome > Studies > Arsenic > Level 2 > Questions

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Info on our studies structure

Level 2 - Details on Arsenic

q 1. What is arsenic?

r 1.1 What are the properties of arsenic?

r 1.2 How are arsenic levels measured?

q 2. Where does environmental arsenic come from??

r 2.1 What are the natural sources of environmental arsenic?

r 2.2 What are the man-made sources of environmental arsenic?

r 2.3 How is arsenic transported and distributed in the environment?

q 3 . What are the levels of exposure to arsenic?

r 3.1 How much arsenic is there in the environment?

r 3.2 What levels of arsenic are found in living organisms?

r 3.3 What levels of arsenic are humans exposed to?

q 4. What happens to arsenic in the body?

r 4.1 What happens to arsenic absorbed by the body?

r 4.2 What are the indicators of arsenic exposure?

q 5. What are the effects of arsenic on laboratory animals?

q 6. What are the effects of arsenic on the environment?

q 7. What are the effects of arsenic on human health?

r 7.1 Can arsenic cause cancer and skin changes?

r 7.2 What other health problems can arsenic cause?

q 8. What has happened in areas where drinking water is heavily contaminated?

q 9. What have WHO and IARC established about arsenic?

q 10. Conclusions (level 1 only)

ttp://www.greenfacts.org/arsenic/l-2/index.htm (1 of 2) [20/12/2004 11:35:37]

8/14/2019 Arsenic Green Facts

9/30

Arsenic: Level 2 - Details on Arsenic

q 11. Other views (level 1 only)

Back to Summary Level 2 Questions More in the Source Document

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/index.htm (2 of 2) [20/12/2004 11:35:37]

8/14/2019 Arsenic Green Facts

10/30

Arsenic: 1. What is arsenic?

ome > Studies > Arsenic > Level 2 > Question 1

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Level 1 Questions Next Question

. What is arsenic?

1.1 What are the properties of arsenic?

1.2 How are arsenic levels measured?

.1 What are the properties of arsenic?

Arsenic is a metalloid - a natural element that is not actually a metal but which has some of the properties of a

metal. It is a natural component of the earths crust, generally found in trace quantities in all rock, soil, water andair. However, concentrations may be higher in certain areas due to either natural conditions or human activities.

Arsenic can exist in many different chemical forms in combination with other elements. Some forms are inorganic,

which do not contain carbon, and others are organic, which always contain carbon. Inorganic arsenic exists in four

main chemical forms known as valency or oxidation states. Valency is a measure of the ability of a compound to

combine with other elements, such as hydrogen. The dominant forms are arsenite, with a valency of 3, and arsenat

with a valency of 5.

The element arsenic itself is not soluble in water. Arsenic in combination with other elements (as salts) has a wide

range of solubilities depending on the surrounding acidity and the presence of other chemicals. More...

Back to Summary Level 2 Questions More in the Source Document

Top

ttp://www.greenfacts.org/arsenic/l-2/arsenic-1.htm (1 of 2) [20/12/2004 11:35:44]

8/14/2019 Arsenic Green Facts

11/30

Arsenic: 1. What is arsenic?

.2 How are arsenic levels measured?

There are various laboratory methods for the detection and measurement of arsenic. Some of these methods candistinguish between the different chemical forms (valency) of the arsenic. Sensitive measuring techniques exist for a

limited range of arsenic compounds. A test kit based on a color reaction is currently used for groundwater testing in

Bangladesh that is suitable for use under field conditions. More...

Back to Summary Level 2 Questions More in the Source Document

Level 1 Questions Next Question

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/arsenic-1.htm (2 of 2) [20/12/2004 11:35:44]

8/14/2019 Arsenic Green Facts

12/30

Arsenic: 2. Where does environmental arsenic come from?

ome > Studies > Arsenic > Level 2 > Question 2

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Previous Question Level 1 Questions Next Question

2. Where does environmental arsenic come from?

2.1 What are the natural sources of environmental arsenic?

2.2 What are the man-made sources of environmental arsenic?

2.3 How is arsenic transported and distributed in the environment?

2.1 What are the natural sources of environmental arsenic?

The earths crust is an abundant natural source of arsenic. It is present in more than 200 different minerals, the mocommon of which is called arsenopyrite.

About one-third of the arsenic in the earths atmosphere is of natural origin. Volcanic action is the most important

natural source. The next most important source is arsenic-containing vapor that is generated from solid or liquidforms of arsenic salts at low temperatures.

Inorganic arsenic of geological origin is found in groundwater used as drinking water in several parts of the world, fo

example Bangladesh, India and Taiwan (1).

Organic arsenic compounds, that is, those containing carbon, are mainly found in sea-living organisms, although

some of these compounds have also been found in species living on land. More...

As seen in questions 5 to 8, inorganic arsenic poses more problems than organic arsenic.

Back to Summary Level 2 Questions More in the Source Document

Next Sub-Question Top

ttp://www.greenfacts.org/arsenic/l-2/arsenic-2.htm (1 of 3) [20/12/2004 11:35:50]

8/14/2019 Arsenic Green Facts

13/30

Arsenic: 2. Where does environmental arsenic come from?

2.2 What are the man-made sources of environmental arsenic?

Elemental arsenic is produced commercially from arsenic trioxide. Arsenic trioxide is a by-product of metal smelting

operations. About 70% of the world production of arsenic is used in timber treatment, 22% in agricultural chemicalsand the remainder in glass, pharmaceuticals and metallic alloys.

Mining, metal smelting and burning offossil fuels are the major industrial processes that contribute to arsenic

contamination of air, water and soil. The use of arsenic-containing pesticides in the past has left large areas of

agricultural land contaminated. The use of arsenic in the preservation of timber has also led to contamination of theenvironment. More...

Back to Summary Level 2 Questions More in the Source Document

Top

2.3 How is arsenic transported and distributed in the environment?

The transport and distribution of arsenic in the environment is complex, due to the many chemical forms in which itmay be present and because there is continuous cycling of different forms of arsenic through air, soil and water.

Much of the arsenic in the atmosphere comes from high-temperature processes such as coal-fired power plants,burning vegetation and volcanic activity. The arsenic is released into the atmosphere primarily as arsenic trioxide

where it adheres readily onto the surface of particles. These particles are dispersed by the wind and eventually fallback to the earth due to their weight or during rain.

Natural, low-temperature biological reactions involving microbes also release arsenic into the atmosphere. Microbesacting on arsenic in soils and sediments generate arsine gas or other volatile arsenic compounds. Arsine reacts with

oxygen in the air and is converted back to non-volatile forms of arsenic, which settle back to the ground.

Arsenic dissolved in water can be present in several different forms. In well-oxygenated water and sediments, nearlall arsenic is present in the stable form ofarsenate. Some arsenite and arsenate forms are less stable and are

interchangeable, depending on the chemical and biological conditions. Some chemical forms of arsenic adherestrongly to clay and organic matter and this can affect how they behave in the environment. There is potential forarsenic to be released from water and sediments, again depending on the chemical and biological conditions.

Lastly, weathered rock and soil containing arsenic may be transported by wind or water erosion. Since many arseniccompounds tend to adhere strongly to soils, water percolating down does not usually move arsenic through morethan a short distance in soil. More...

Back to Summary Level 2 Questions More in the Source Document

Previous Question Level 1 Questions Next Question

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/arsenic-2.htm (2 of 3) [20/12/2004 11:35:50]

8/14/2019 Arsenic Green Facts

14/30

Arsenic: 3. What are the levels of exposure to arsenic?

ome > Studies > Arsenic > Level 2 > Question 3

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Previous Question Level 1 Questions Next Question

3. What are the levels of exposure to arsenic?

3.1 How much arsenic is there in the environment?

3.2 What levels of arsenic are found in living organisms?

3.3 What levels of arsenic are humans exposed to?

3.1 How much arsenic is there in the environment?

Arsenic concentrations in air range from very low (0.02 to 4 ng/m3) in remote and rural areas, to low (3 to about

200 ng/m3) in urban areas. Much higher concentrations (more than 1000 ng/m3) can be found near some industria

sources such as smelters, although in some countries, very high levels are no longer found because of measurestaken to reduce pollution.

Concentrations of arsenic in open ocean seawater are typically low (12 g/litre). In rivers and lakes, concentration

are somewhat higher but generally below 10 g/litre. Exceptions are near man-made sources such as pesticide

manufacturing or mining, where individual samples in surface waters may be 1000 times higher (up to 5000g/litre). Arsenic levels in groundwater are typically as low as in open ocean water (about 12 g/litre), except in

areas with volcanic rock and sulphide mineral deposits where arsenic levels can range up to 3000 g/litre.

In sediment, arsenic concentrations range from 5 to 3000 mg/kg. The higher levels are found in areas contaminated

by mining and smelting. In soil, concentrations range from 1 to 40 mg/kg, usually averaging around 5 mg/kg.

Naturally elevated levels of arsenic in soils may be associated with the presence of sulphide ores in the rock layersbelow the soil. Soils heavily contaminated by activities such as mining of gold and arsenic, metal smelting andagricultural chemical application can have concentrations of arsenic up to several thousand milligrams per kg

(mg/kg) or more. More...

Back to Summary Level 2 Questions More in the Source Document

Next Sub-Question Top

ttp://www.greenfacts.org/arsenic/l-2/arsenic-3.htm (1 of 3) [20/12/2004 11:35:52]

8/14/2019 Arsenic Green Facts

15/30

Arsenic: 3. What are the levels of exposure to arsenic?

3.2 What levels of arsenic are found in living organisms?

Sea-living plants and animals normally contain organic arsenic residues. These are generated from inorganic forms

arsenic, either by microbes or by the plants and animals themselves. Amounts range from less than 1 to more than

100 mg/kg. Arsenic can build up (bioaccumulate) in the bodies of aquatic organisms, particularly those living in the

sea. Arsenic concentrations in freshwater and land-living animals and plants are usually less than 1 mg/kg. Land-

living plants may accumulate arsenic via uptake through the roots from the soil or by deposition of airborne arsenic

on the leaves. Arsenic levels are higher in living organisms collected near man-made sources of arsenic or in areas

with volcanic activity. Up to 3000 mg/kg has been found in some species at arsenical mine sites. More...

Back to Summary Level 2 Questions More in the Source Document

Top

3.3 What levels of arsenic are humans exposed to?

Exposure of the general population to arsenic occurs mainly through food and water and in most areas, food is the

main source. The daily intake of arsenic from food and beverages is generally between 20 and 300 g/day. Arsenic

food is mainly in the form oforganic arsenic, which is generally thought to pose less health problems than inorganic

arsenic(see questions 5 to 8). About one-quarter of the arsenic present in the diet is inorganic arsenic, mainly from

foods such as meat, poultry, dairy products and cereals. Fish and shellfish contain the highest concentrations of

arsenic, but the proportion of inorganic arsenic in fish is very low, below 1%. In some areas, where levels of arsenicin groundwater are high, drinking water may be the main source ofintake. In drinking water, arsenic is present in

the more toxic, inorganic form.

Arsenic which is breathed in contributes around 1 g/day in a non-smoker, 10 times as much in a smoker, and more

in polluted areas. Contaminated soils such as mine tailings are also a potential source of arsenic exposure

The amount of arsenic absorbed into the body from all sources can be assessed on an individual basis by measuringthe concentration ofinorganic arsenic and its metabolites in urine. Generally, it ranges from 5 to 20 g arsenic per

litre of urine (g/litre), but may even exceed 1000 g/litre. (see 4.2)

In workplaces with up-to-date occupational hygiene practices, exposureconcentrations generally do not exceed 10

micrograms per cubic meter of air (g/m3). However, in some workplaces arsenic concentrations several hundred

times higher have been reported. More...

Back to Summary Level 2 Questions More in the Source Document

Previous questionLevel 1 Questions

Next question

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/arsenic-3.htm (2 of 3) [20/12/2004 11:35:52]

8/14/2019 Arsenic Green Facts

16/30

Arsenic: 4. What happens to arsenic in the body?

ome > Studies > Arsenic > Level 2 > Question 4

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Previous Question Level 1 Questions Next Question

4. What happens to arsenic in the body?

4.1 What happens to arsenic absorbed by the body?

4.2 What are the indicators of arsenic exposure?

4.1 What happens to arsenic absorbed by the body?

The amount of arsenic absorbed into the body from inhaled airborne particles is highly dependent on two factors, th

size of particles and their solubility. The size of the particles determines how far into the lungs they can penetrate

the further they penetrate the more likely arsenic is to be absorbed. The solubility of the particles in the fluid liningthe lungs determines how easily arsenic will be absorbed into the blood stream. In the gut, soluble arsenic

compounds from food and beverages are rapidly and extensively absorbed into the blood stream.

In humans and most common laboratory animals, inorganic arsenic is metabolized via two main types of reaction:

(1) conversion of the pentavalent form of arsenic - arsenate - to the trivalent form - arsenite, and (2) methylation,

i.e. addition of a methyl group comprising one atom of carbon and three of hydrogen (-CH3) to the trivalent form.

After methylation arsenic can be rapidly eliminated from the body with the urine. There can be large differencesbetween individual humans in their capacity for methylation that is most likely due to differences in enzyme capacit

in the body. It is not clear if children have a reduced capacity for methylation compared with adults. Studies suggesthat the main pathway for getting rid of arsenic from the body, methylation, may be inhibited at high exposures.

The uptake and elimination of arsenic depends on its chemical form, particularly at high exposures. For example,

ingestedorganic arsenic compounds are much less extensively metabolized and more rapidly eliminated in urine tha

inorganic arsenic in both laboratory animals and humans. In the case of inorganic arsenic, the trivalent forms pass

more rapidly into the tissues compared with the pentavalent forms. More...

Back to Summary Level 2 Questions More in the Source Document

Top

ttp://www.greenfacts.org/arsenic/l-2/arsenic-4.htm (1 of 2) [20/12/2004 11:35:54]

8/14/2019 Arsenic Green Facts

17/30

Arsenic: 4. What happens to arsenic in the body?

4.2 What are the indicators of arsenic exposure?

The amounts of arsenic or its metabolites in blood, hair, nails and urine are used as indicators - biomarkers - of

arsenic exposure. Blood arsenic is only useful for indicating either acute poisoning or repeated high-level exposures

occurring over a long period. This is because arsenic rapidly disappears from blood.

Arsenic persists longer in hair and nails, which can, therefore, be used as indicators of past exposure. The

concentration of arsenic, along a hair may be used to estimate the timing of an exposure.

The best estimate of recent exposure to inorganic arsenic is to measure it and its specific chemical metabolites in

urine. However, consumption of certain seafood high in organic arsenic, such as seaweed or mollusks, produces one

of the same metabolites as inorganic arsenic and may therefore exaggerate estimates of inorganic arsenic exposurein some people at certain times. Such foods should be avoided for 23 days before urine sampling. More...

Back to Summary Level 2 Questions More in the Source Document

Previous Question Level 1 Questions Next Question

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/arsenic-4.htm (2 of 2) [20/12/2004 11:35:54]

8/14/2019 Arsenic Green Facts

18/30

Arsenic: 5. What are the effects of arsenic on laboratory animals?

ome > Studies > Arsenic > Level 2 > Question 5

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Previous Question Level 1 Questions Next Question

5. What are the effects of arsenic on laboratory animals?

Both inorganic and organic forms of arsenic may affect the health of laboratory animals. The effects range from rapi

death to effects which only emerge later, such as cancer. The degree oftoxicity depends whether the arsenic is

inorganic or organic and on its chemical form (valency). Inorganic arsenic is generally more toxic than organic

arsenic, and in the case of inorganic arsenic, trivalent forms are more toxic than pentavalent forms, at least at highdoses. Many different parts of the body can be affected by arsenic, including the skin, lungs, heart, blood vessels,

immune system, kidney, reproductive system, gut and nervous system.

According to IPCS, studies to investigate whether arsenic causes cancer in animals have been inconclusive. Howeve

IARC now considers there is limited evidence for cancer in laboratory animals. For example, female mice of a

particular type, given high levels of arsenic in drinking water for 2 years, developed tumors of the lung, liver, gut an

skin. (Very recent studies show arsenic causes cancer in several organs and tissues of animals exposed before birth

via their mothers during pregnancy.) Other laboratory studies have investigated how cancer might be caused.Inorganic arsenic does not directly damage DNA, the inherited genetic material in cells. However, arsenic can

damage whole chromosomes in cells grown in the laboratory, affect the repair of damaged DNA, cause cells to

multiply, and promote the development oftumors induced by other chemicals. One study has indicated that one of

the metabolites of arsenic found in the body may cause cancer of the bladder in male rats at high doses. More...

Back to Summary Level 2 Questions More in the Source Document

Previous Question Level 1 Questions Next Question

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/arsenic-5.htm (1 of 2) [20/12/2004 11:35:57]

8/14/2019 Arsenic Green Facts

19/30

Arsenic: 6. What are the effects of arsenic on the environment?

ome > Studies > Arsenic > Level 2 > Question 6

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Previous Question Level 1 Questions Next Question

6. What are the effects of arsenic on the environment?

Water and land-living plants and animals show a wide range of sensitivities to different chemical forms of arsenic.Their sensitivity is modified both by biological factors and by their surrounding physical and chemical environment. Igeneral, inorganic forms of arsenic are more toxic to the environment than organic forms and, among inorganic

forms, arsenite is more toxic than arsenate. This is probably because the way in which the various forms are taken

up into the body differs and once taken up, they act in different ways in the body. The reason why arsenite is toxic

thought to be because it binds to particular chemical groups - sulfhydryl groups - found on proteins. Arsenate, on thother hand, affects the key energy producing process that take place in all cells.

Arsenic compounds cause short-term and long-term effects in individual plants and animals and in populations andcommunities of organisms. These effects are evident, for example, in aquatic species at concentrations ranging from

a few micrograms to milligrams per litre. The nature of the effects depends on the species and time of exposure. Th

effects include death, inhibition of growth, photosynthesis and reproduction, and behavioral effects. Environmentscontaminated with arsenic contain only a few species and fewer numbers within species. If levels ofarsenate are hig

enough, only resistant organisms, such as certain microbes, may be present. More...

Back to Summary Level 2 Questions More in the Source Document

Previous Question Level 1 Questions Next Question

Send this page Subscribe to our newsletter Download this study

17-Dec-2004 Contact | Copyright | Glossary | Sitemap | Link to us | Feedback | About Top

GreenFacts is a registered trademark of GreenFacts asbl

ttp://www.greenfacts.org/arsenic/l-2/arsenic-6.htm (1 of 2) [20/12/2004 11:36:00]

8/14/2019 Arsenic Green Facts

20/30

Arsenic: 7. What are the effects of arsenic on human health?

ome > Studies > Arsenic > Level 2 > Question 7

Scientific Facts on

Arsenic

Source document:IPCS (2002)

Summary & Details:GreenFacts (2004)

About this study

Previous Question Level 1 Questions Next Question

7. What are the effects of arsenic on human health?

7.1 Can arsenic cause cancer and skin changes?

7.2 What other health problems can arsenic cause?

7.1 Can arsenic cause cancer and skin changes?

Long-term exposure to arsenic in drinking water can cause cancer in the skin, lungs, bladder and kidney. It can also

cause other skin changes such as thickening and pigmentation. The likelihood of effects is related to the level of

exposure to arsenic and in areas where drinking water is heavily contaminated, these effects can be seen in manyindividuals in the population. Increased risks of lung and bladder cancer and skin changes have been reported in

people ingesting arsenic in drinking water at concentrations of 50 g/litre, or even lower.

Exposure to arsenic in the workplace