|
|
| |
|
|
|
|
| |
Hazardous Chemicals
: |
|
 |
| |
|
|
| |
Hazardous
Chemicals
In modern societies, synthetic chemicals dominate people's lives.
Textiles, plastic goods, detergents, cleaners, toiletries, batteries,
packaging material, vehicles, daily newspapers, medicines, computers-almost
every item that you use has either gone through chemical processes
or contains some amount of chemicals.
Most of the chemicals used by humankind are hazardous to some
part of, or to the entire biosphere. Some chemicals affect all
species, while others affect only a few. Some cause only minor
problems, some can kill instantly. Some are dangerous only when
exposure to them is prolonged, while others are toxic only in
high concentrations. We do not have complete information about
the effects of many of these chemicals on humans and other organisms.
There are broadly two categories of hazardous chemicals that
can significantly affect humans and the environment:
Pesticides and herbicides that are deliberately introduced into
the environment: Beginning with DDT, we have experimented with
a whole range of chemicals to kill pests and unwanted weeds.
Industrial chemicals that are disposed off as waste or discharged
accidentally into the environment: These include organic solvents,
waste oil, polychlorinated biphenyls (PCBs), paints, glues,
preservatives, and metal residues.
The use and impact of some of these chemicals and substances,
such as asbestos, lead, and mercury are discussed below.
What are the chemicals used as pesticides and what is their
impact?
Pesticide is a general term for any chemical used to kill unwanted
organisms. The term covers insecticides, herbicides, fungicides,
and other chemicals that kill pests (spiders, mites, worms,
rodents, etc ). Modern agriculture and sanitation depend heavily
on pesticides. Pesticides have saved millions of lives by killing
disease-carrying insects. They have also increased our crop
yields by eliminating pests that attack plants.
Until the middle of the last century, most pesticides in common
use were simple, naturally occurring substances such as arsenic
and nicotine. Then came new chemical compounds like DDT that
were much more effective against crop pests and disease-carrying
insects. The new chemical pesticides, however, remain in the
environment for much longer than the natural ones. Many are
also toxic to humans.
As far back as 1995, the WHO estimated that every year there
were three million cases of pesticide poisoning worldwide, including
220,000 deaths. According to another WHO report in 1991, 25
million farm workers in developing countries were suffering
from pesticide poisoning. An example is the Endosulfan case
in Kerala, India
Poison
from the sky?
Seven-year-old Shruti cannot go to school. She was born with
three deformed limbs and she hops around on one leg. Her mother
died of cancer and her father is an agricultural labourer. In
fact, every family in that area of four sq km has people suffering
from diseases that were never seen before locally.
Mohana Kumar, a doctor practising for a decade in that area,
the Padre village in Kasaragod District of Kerala, was a puzzled
man. Among the patients coming to him from just two wards of
the panchayat, he found a very high incidence of cancer, psychiatric
problems, mental retardation, epilepsy, congenital anomalies,
to name a few. Surprisingly, almost all the ailments were restricted
to people under the age of 25 and all were difficult to cure.
Several people in Padre believed that the local guardian spirit
was angry with them and had let loose the diseases on them.
Dr Kumar, however, had to find a scientific explanation. He
began keeping detailed records and felt that the effects could
be due to the pesticide Endosulfan. He wrote to some leading
doctors and also to the Kerala Medical Journal asking for help,
but there was no response.
Endosulfan is effective against a variety of pests that attack
crops of cereals, coffee, potato, tea, and vegetables. It is
easily absorbed by the stomach and lungs and through the skin.
Being anywhere near the area of use is enough to get contaminated.
It is highly toxic to humans, birds, and animals. The US, Canada,
12 European countries, and some countries in the Asia-Pacific
region have banned it, while others have restricted its use.
Since 1976, the government-owned Plantation Corporation of Kerala
(PCK) had been carrying out aerial spraying of Endosulfan over
cashew plantations in an area of nearly 4700 acres in Kasaragod,
including the hills around Padre. The pesticide residues settled
on the soil and got washed away into the drinking water streams
below. Though it is mandatory to cover all water sources, such
as wells, tanks, and other water bodies during the spraying
of such a toxic pesticide, this was not done.
After cows in the area started giving birth to deformed calves,
there were sporadic protests against aerial spraying. In December
2000, the villagers tried to prevent spraying, but the police
thwarted them.
Meanwhile, Kumar and a farmer-journalist Shree Padre found enough
published evidence to connect Endosulfan with the people's ailments.
Samples of blood, fruits, and animal tissues from Padre were
tested at the Indian Institute of Technology (lIT), Kanpur,
and found to contain extremely high levels of the pesticide.
Kumar and Padre began holding public meetings to explain their
findings to the public. A media war ensued with PCK and pesticide
manufacturers denying the role of Endosulfan in causing the
ailments. The Kerala Government banned the aerial spraying of
Endosulfan.
The issue became a national one with the intervention of the
National Human Rights Commission and a study by the National
Institute of Occupational Health. The latter study showed that
Endosulfan was the causative factor in the incidence of illnesses
in Padre. There were counter studies too, absolving Endosulfan.
The pesticide industry was quick to declare that Endosulfan
had nothing to do with the health problems.
In August 2001, the Kerala government suspended the use of Endosulfan,
but lifted the ban in March 2002. The ban on aerial spraying
was continued. Some months later, the Kerala High Court banned
its use, pending a final decision by the Central Insecticides
Board. The Dubey Committee set up by this Board gave Endosulfan
a clean chit in March
In November 2004, the committee set up by the Union Agriculture
Ministry reviewed various reports on the crisis, including those
of the Dubey Committee and the National Institute of Occupational
Health. The members agreed that Endosulfan was a carcinogen.
In December 2004, on the basis of a Kerala High Court Order,
the State Pollution Control Board banned its use.
The last word on this controversy has not been said yet. However,
what about the people of Padre? Who is going to help them or
compensate them?
Chemical pesticides also kill non-target species, including
the predators of the very organisms they are supposed to eliminate.
Moreover, many pests are able to develop a resistance to these
chemicals. This leads to the use of even greater amounts of
the chemicals or more powerful chemicals, resulting in more
problems. The only way out of this vicious cycle is to shift
to organic pesticides and biological control.
There is great risk in the manufacture and storage of large
amounts of pesticides. Several disasters have already occurred,
the Bhopal Gas Tragedy (Box 16.1) being the worst on record.
Many of the new pesticides have been banned in industrialized
countries. However, the same countries continue to manufacture
and sell banned pesticides to poorer countries, where regulations
and enforcement are often lax. The US is the world's largest
exporter of pesticides, followed by Germany and the UK. Often,
whole pesticide operations are shifted or sold to poorer countries
to avoid environmental regulations.
It is not that the populations of developing countries alone
suffer from pesticide poisoning. With freer and increasing global
trade, the pesticides come back to the industrialized countries
in imported food products and in other ways. (This is known
as the 'boomerang effect'.)
Herbicides have also been used in wars with disastrous effects.
An example is the use of Agent Orange by the US in Vietnam .
The deadly agent
The assignment given to Agent Orange was to clear the countryside
of all vegetation, thus denying cover to guerrilla forces. The
agent did the job only too well. Not only was the vegetation
destroyed, so was the health of thousands and thousands of people
for years to come. In fact, it was a case of a 'double agent':
as the soldiers on the agent's side were also affected.
Agent Orange was not the codename of a spy. It was a compound
herbicide, a defoliant used extensively by the US Army in the
Vietnam War. As admitted by the US, 72 million liters of Agent
Orange were sprayed over parts of Vietnam (between 1962 and
1970) to defoliate the jungle and flush out the Vietcong guerrillas.
The name Agent Orange was derived from the orange markings on
the drums in which the chemical was shipped.
The herbicide, however, contained one of the most virulent poisons
known to man, a strain of dioxin called TCDD. A small 80-gram
tin of TCDD can destroy New York City. The US dropped 170 kilograms
of it on parts of Vietnam!
After stripping the jungle bare, the dioxin gradually spread
into the food chain. This has had serious effects on the health
of the Vietnamese people as well as that of the US soldiers:
defective births, Down's syndrome, skin diseases, liver cancer,
mental disorders, and so on.
In a village in the heavily sprayed Cu Chi district, it is a
perpetual struggle for 21-year-old Tran Anh Kiet. His feet,
hands, and limbs are twisted and deformed. He can only make
plaintive and pitiful grunts. He is an adult stuck inside the
stunted body of a 15-year-old, with a mental age of around six.
He is what the local villagers refer to as an Agent Orange baby.
There are 150,000 other children like him, whose birth defects
can be traced back to their parents' exposure to Agent Orange
during the war, or the consumption of dioxin-contaminated food
and water since 1975. About three million Vietnamese were exposed
to the chemical during the war, and at least one million suffer
serious health problems today. Some are war veterans, who were
exposed to the chemical clouds. Many are farmers who lived off
land that was sprayed. Others are second- and third-generation
victims, affected by their parents' exposure.
In the early 1980s, 2.5 million Vietnam War veterans in the
US filed compensation claims against the US government and the
manufacturers of Agent Orange. The companies paid out US$ 180
million in an out of court settlement, but never admitted any
liability. American victims of Agent Orange get up to US$ 1500
a month. However, most Vietnamese families affected receive
around 80,000 Dong a month Must over US$ 5) in government support
for each disabled child.
Since the end of the Vietnam War, Washington has denied any
moral or legal responsibility for the toxic legacy said to have
been caused by Agent Orange in Vietnam. In January 2004, three
Vietnamese filed cases against Monsanto Corporation, Dow Chemicals,
and eight other companies that manufactured Agent Orange and
other defoliants used in Vietnam.
The efficient Agent Orange refuses to stop working. Some of
the victims live near former US military bases such as Bien
Hoa, where Agent Orange was stored in large quantities. Dr Arnold
Schecter, a leading expert in dioxin contamination in the US,
sampled the soil there in 2003, and found it contained TCDD
levels that were 180 million times above the safe level set
by the US Environmental Protection Agency.
How long will the Vietnamese continue to suffer? How many US
war veterans have been victims of their own Agent Orange? To
what purpose?
What is special about DDT? Dichloro-diphenol-trichloroethane
(DDT) is an insecticide, which was first introduced in the US
in the 1940s and later in many parts of the world to protect
crops and human beings from insects. It is cheap, easy to make,
and chemically stable.
The spraying of DDT was a very important part of the Green Revolution
package. It is effective against a wide spectrum of insects
in agriculture. It also kills the typhus carrying body lice,
and mosquitoes, which transmit malaria and yellow fever.
DDT is initially very effective against pests, but over a period
of time the insects develop a resistance to the chemical. It
is now recognized as a dangerous pollutant and is also a suspected
carcinogen (cancer-causing substance). It is highly toxic to
vertebrate mammals and some species of fish and birds and is
passed along the food chain. It affects the breeding patterns
of some predatory birds.
DDT was banned in the US in 1973, thanks primarily to the book
Silent Spring (Read Module 3: Prologue) by Rachel Carson. Many
other industrialized countries have followed suit. In most developing
countries, however, DDT continues to be used against malaria.
What are the alternatives to using pesticides from the chemical
industry? In the long run, chemical pesticides will only ruin
the soils and the health of nations. The only alternative is
to shift to organic farming and the use of traditional organic
pesticides.
In California in the US, where environmental awareness is greater
than in other parts of the country, more than 40 farmers are
using giant vacuum machines to suck insects off the plants.
These machines move slowly over the rows of crops and remove
certain types of insects. They remove some beneficial insects
too, but fewer than the numbers killed by chemical pesticides.
Each vacuuming eliminates the need for an application of pesticide.
What are Polychlorinated Biphenyls
(PCBs)?
PCBs are chemical compounds that are very stable, have good
insulation qualities, are fire resistant, and have low electrical
conductivity. They are widely used in electrical capacitors,
transformers, hydraulic systems, fluorescent lamps, etc.
PCBs persist for long in the environment and are extremely toxic.
They can cause cancers in animals and liver and nervous disorders
in humans. When burnt, they leave toxic ash and when buried,
they leach into the groundwater. Rainfall deposits PCBs in the
atmosphere into rivers and seas.
PCBs are found in high concentrations in many marine mammals.
They have a serious effect on the reproductive capacity of these
animals and could lead to the extinction of many species Humans
who mainly consume fish are at risk from PCBs. These chemicals
are said to have caused defects in children in the Great Lakes
area of Canada. Surprisingly, PCBs have even been found in the
breast milk of Arctic women
PCBs have been banned in industrialized countries. Yet, thousands
of tons of PCBs are still present in storage, landfills, or
abandoned electrical equipment. A substantial portion is in
developing countries, with a high risk of contamination
How dangerous is contamination
by lead or mercury?
Lead is an extremely poisonous metal that accumulates in organisms.
Large doses of lead can cause paralysis, blindness, and even
death in humans. If a pregnant woman carries even a small amount
of lead in her body, the mental development of the baby could
be affected. Lead in the atmosphere contaminates leafy vegetables
and fruits.
The lead that we breathe in comes mostly from the exhaust of
vehicles. For long, lead has been added to petrol to prevent
the 'knocking' of the engine. Lead-free petrol is now available
in India and is mandatory for most new cars. Lead is also found
in batteries, paints, bullets, and certain alloys. There is
a global effort to phase out lead from products and processes.
Mercury is a liquid metal that is poisonous for humans and animals.
While small doses cause headaches, large ones could lead to
death. If inhaled, swallowed, or absorbed through the skin,
mercury can damage the human nervous system. It accumulates
easily in the body and is nonexcretable.
The chemical and plastics industries use large amounts of mercury
and release it along with other effluents into rivers, lakes,
and seas or they dump it on the land as waste. This has led
to the poisoning of fish and people (read Box 16.4 on the Minamata
case).
Even small amounts of mercury used in thermometers and scientific
and medical equipment can cause poisoning, if leaked under warm
conditions
The dancing cats
It started out in the 1950s quite simply, but somewhat strangely:
Cats were found 'dancing' in the streets and sometimes collapsing
and dying. Friends or family members occasionally shouted uncontrollably,
slurred their speech, or dropped their chopsticks at dinner.
When such scattered, apparently unconnected, and mildly mysterious
events began to haunt the fishing town of Minamata, Japan, the
people did not realize that they were the first signs of one
of the most dramatic and emotionally moving cases of industrial
pollution in history.
A chemical plant of the Chisso Corporation had been dumping
mercury into Minamata Bay. Between 1953 and 1983, 300 inhabitants
of Minamata died by eating fish contaminated with methyl mercury.
Hundreds of others suffered from blindness, convulsions, and
brain damage. Children of victims were born with the disease.
Minamata is an extraordinary
tragedy with environmental, social, and political aspects:
Chisso persistently denied any connection between the mercury
discharge and the disease and the government went on supporting
the company. By 1959 Chisso had knowledge of the connection,
but withheld the information.
The dumping of mercury went on for a long time, even after the
strange disease started spreading among the fisher folk. Neither
the company, nor the local and central governments acted to
stop the discharge of mercury.
Chisso was very much a part of the town, providing employment
and bringing prosperity. The loyal workers refused to blame
the company for causing the disease. In fact, the company doctor
who discovered the connection revealed it only on his deathbed.
Since it was a strange disease, the sufferers were stigmatized
by their neighbors, until of course the latter too caught the
disease.
Denying any responsibility, the company paid a token compensation
only to those victims who signed away their right to further
legal action. Many victims took the company to court, but they
had, to wait a long time for justice. The first damages were
awarded only in 1973. In fact, the Japanese government officially
accepted mercury discharge as the cause of the disease only
in 1983!
About 3000 people were recognized as victims of mercury poisoning,
making them eligible for a variety of health benefits, but over
16,000 were refused recognition.
A persistent group of sufferers kept up pressure on Chisso through
continued petitioning, recruiting of grass roots support across
Japan, months of sit-ins at Chisso headquarters, etc. They ultimately
did get some justice, but it required an enormous amount of
patience and effort.
Nearly 50 years passed before the victims scored a moral victory:
In October 2004, Japan's Supreme Court held the government responsible
for the spread of the disease. Giving its judgment in the last
pending case, the Court awarded a compensation of US$ 650,000
to 37 victims.
One fish in Minamata, one night on a street in Bhopal, or a
breath of air near Chernobyl was enough to cause for a lifetime
of suffering for generations. How can we still continue to support
the use of toxic pesticides or nuclear power?
What
is the problem with asbestos
Asbestos is a fibrous silicate mineral. The fibers are woven
into a cloth, a binder like cement is added, and the resulting
rigid material can be shaped into many forms. It is a non-corrosive,
non-flammable, and non-conducting material and is inexpensive.
Asbestos is widely used in construction, most commonly as corrugated
roofing and sometimes also for doors and partitions. Asbestos
wool is used as insulation.
Asbestos is very dangerous for the health if its fibres are
inhaled. They can be as short as 0.0000025 cm in length and
they get lodged in the lungs and bronchial tubes. They cause
a disease called asbestosis, which affects the respiratory tissues.
Chronic shortage of breath and sometimes-premature death is
the result. The fibres can also cause lung and intestinal cancer.
Diseases caused by asbestos exposure take a long time to develop.
Most cases of lung cancer or asbestosis in asbestos workers
occur 15 or more years after initial exposure to asbestos.
In 2003, asbestos was included in the Rotterdam Convention list.
This means that all forms of asbestos will now be subject to
trade controls. The exporting countries must provide importers
with information on its potential health and environmental effects.
There is now a worldwide movement against the use of asbestos.
In 2003, conferences held in Ottawa, London, and Dresden called
for a ban on asbestos, and for providing assistance and compensation
to those suffering from asbestos-related diseases.
There is still an active and large asbestos industry in India.
Out of 125,000 tons of asbestos used in India, 100,000 tons
are imported, mainly from Russia and Canada. Efforts to ban
at least some forms of asbestos in India have so far not been
successful.
What are dioxins
Dioxins are a group of chemical compounds that occur accidentally
as contaminants in a number of industrial processes and products.
They are carcinogens and are highly toxic to humans and animals.
Dioxins are formed due to the incomplete incineration of waste
and the burning of plastics, coal, or cigarettes. When fuel
is partially burnt in a vehicle, dioxins are released. Dioxins
are deposited on plants and soil and in water thereby entering
the food chain.
Dioxins are also produced during the manufacture of paper. The
pearly white color of paper is the result of bleaching, which
uses highly toxic chemicals. Bleaching uses chlorine, which
produces toxins including dioxins. Ultimately the toxic effluents
from the paper factory end up in water bodies everywhere. |
|
| |
|
|
|
|
 |
Adds |
|
