This article is submitted by My friend Bruce Tan & Cheng Li Tan In Malaysia.
According to the "I-Medical Sutra" Sea Shell fish are good for those people who
need to replenish the "Yin" of their body.
However, there were many cases found that hepatitis A,B,C, are due to eating
of contaminated Sea Shell Fish.
In Hong Kong, Taiwan, USA, Canada, Australia, Korea, Japan, Thailand, Singapore,
Malaysia, Vietnam, Burma, Cambodia, Indonesia, Phillipines, there are still many
people like to eat the Sea Shell mentioned.
Perhaps. FDA, Department of Health, Department of Fisheries shall research as on the
source of Sea Shell fish & it contaminations, If necessary, there must be put to a
stop for the consumption.
Don't Eat Sea Shells
Cockles, Soft-Shell Clams & Green Mussels
they are contaminated.
The strange phenomenon is tied up with marine pollution and one
contaminant in particular, is culprit: tributyltin or TBT. TBT is an
organotin (compounds of tin and carbon) and is used as a biocide
(substance that kills living organisms) in anti-fouling marine paints
sprayed on ships, buoys, nets, fish cages, quays, jetties and offshore
installations to prevent growth of algae, barnacles and other marine
organisms.
By Ir. Bruce Tan K.L. Malaysia
________________________________________________________________________
Foul (TBT) spray
By TAN CHENG LI
SOMETHING bizarre is happening in mudflats along the Selangor coastline.
Female rock shells which thrive in the muddy plains are developing
abnormal sexual organs - sperm ducts, in fact.
In a sampling of 700 Thai gradata rock shells, biologist Dr Ahmad
Ismail found all to suffer from imposex, the scientific term describing
growths of male reproductive organs, such as penises and sperm ducts, in
female species.
"The imposex condition is widespread, affecting all the female rock
shells we collected at the Selangor coastline," says Ahmad, an associate
professor at Universiti Putra Malaysia.
The strange phenomenon is tied up with marine pollution and one
contaminant in particular, is culprit: tributyltin or TBT. TBT is an
organotin (compounds of tin and carbon) and is used as a biocide
(substance that kills living organisms) in anti-fouling marine paints
sprayed on ships, buoys, nets, fish cages, quays, jetties and offshore
installations to prevent growth of algae, barnacles and other marine
organisms. The organotin leaches from the paint to prevent foulant
growths but at the same time, also enters the marine environment and
affect non-targeted marine organisms.
TBT is believed to suppress the immune system and disrupt hormonal
balance, thereby causing abnormalities in reproductive organs. The
effect of TBT on marine snails is well established, having been first
highlighted in 1976 with the discovery of abnormal organ growths and
thickening of shells in oysters along the French coast.
Since then, TBT-induced deformities and imposex have been observed in
dog whelks and other gastropods worldwide. Marine snails appear to be
the most sensitive to TBT, mainly because they feed in the seabed.
In Selangor, female rock shells collected by Ahmad from Sungai Burong,
Pantai Remis, Kuala Sungai Sekincan, Bagan Pasir Sungai Tengi, Sungai
Janggut, Batu Laut and Bagan Lalang have grown sperm ducts between
0.74mm to 1.85mm long.
Although strange, the find is hardly surprising. "Considering the high
sea traffic in the Straits of Malacca, TBT is certainly entering our
seas," says Ahmad.
Indeed, TBT traces have showed up in mussels and sediment at eight
sites in the straits. Ahmad found levels range from 22 to 730 nanogram
per gram (ng/g) in mussels and 5.6 to 1,100 ng/g in sediment.
Contamination was highest in busy shipping areas and narrow sections of
the sea channel.
Ahmad's findings add to the growing body of evidence that TBT is
fouling Malaysian seas and poisoning its marine life.
One Universiti Malaya study in 1991 and 1992 had shown TBT pollution
off Port Klang to be in the same range as major ports in Greece and
Japan. It also detected TBT residues in cockles, soft-shell clams and
green mussels sold in local markets, at levels ranging from 0.5 to 23.5
parts per billion (ppb).
In 2000, Universiti Teknologi Malaysia (UTM) marine biologist Dr Mohd
Ismid Mohd Said and then PhD student Sukarno Wagiman found severe
imposex in both juvenile and adult rock shells collected from rocky
beaches in Chendering, Terengganu.
In 1996, Ismid had detected 27.6ng/g of TBT in sediment off Port
Dickson but by 2001, the level had surged to 700ng/l. He had also found
gastropods with imposex in Pasir Gudang, Johor.
Another study in Kemaman, Terengganu, showed marine TBT levels of 62.1
nanogram per litre (ng/l). In comparison, levels at the Pulau Redang
Marine Park where there is less boating activity, were between 9.5 and
13.7ng/l.
Ahmad says a comparison of these finds point to one thing: worsening
TBT contamination in the marine environment. His study found imposex
occurrence of 100% - all 700 rock shells sampled had abnormal sperm
duct growths. He also notes an imbalance in the rock shell population.
"The sex ratio is bias towards the males and this is a deviation from
the norm."
If imposex is severe, the species will die off as the newly-grown penis
and sperm duct can obstruct the female reproductive organs and prevent
egg-laying. In some sites such as Bagan Datoh and Lumut in Perak, Ahmad
did not find a single rock shell. He believes a sudden acute exposure of
TBT could have killed the larvae or prevented breeding.
As TBT persists in the sea, scientists fear that the long-term effects
of TBT contamination may be more pervasive. When other aquatic species
or birds feed on TBT-contaminated gastropods, the toxic substance builds
up in the food chain. Indeed, increased levels of TBT have been recorded
in fish, marine mammals (whales, dolphins, seals, porpoises, sea lions
and sea otters) and seabirds all around the world. And as TBT stunts
growth of microalgae, the food of most marine species, the marine food
chain may be disrupted. Ultimately, the marine ecology in general will
also be affected.
With organotins or the breakdown products - dibutyl tin (DBT) and
monobutyl tin (MBT) - being found in many fish species, there is concern
that organotins may threaten humans who consume large quantities of fish
in their normal diet. The World Wide Fund for Nature says significant
levels of organotins have been found in human blood samples from the
United States.
Many scientists consider TBT to be among the most toxic chemicals ever
released into the marine environment. The Organotin Environmental
Programme Association, an international grouping of producers of
organotin compounds, however, dismisses the threats of TBT. It says in
its website http://www.ortepa.org/ that a two-generation study in rats did not
give any evidence of disturbance in fertility or reproductivity and that
a reduction in reproduction ability has been proven only for dog whelks.
It insists that other groups of organisms, including mammals, are not
expected to be affected by endocrine disruption of TBT exposure.
Curbing TBT Use
Following reports on the toxicity of TBT, many industrialised countries
now regulate use of organotin anti-fouling paints. These include Alaska
and California in the United States, Australia, New Zealand, Japan,
South Korea and the European Union.
The International Maritime Organisation (IMO) in 2002 adopted the
Convention on the Control of Harmful Anti-fouling Systems. Since January
2003, the treaty has curtailed spraying of TBT anti-fouling coatings on
ships. By January 2008, ships must not bear such coatings on their hulls
or external surfaces. Alternatively, they must wear a coating which
seals the underlying layer of TBT paint.
But the restrictions can come into force only if the treaty is ratified
by at least 25 states representing not less that 25% of the world's
merchant shipping tonnage. To date, only nine countries, representing
less than 10% of the world tonnage, have done so; and Malaysia is not
one of them.
"Malaysia has not done anything concrete on the TBT issue," says Ainul
Raihan Ahmad, a researcher at the Maritime Institute of Malaysia. "None
of the laws that govern the protection of Malaysia's marine environment
from pollution address TBTs. The contaminant is also not measured in the
monitoring of marine water quality."
In a survey of local shipping companies, Ainul found small operators
whose vessels ply only local waters, to be ignorant and blatantly
disinterested in the issue. Main players in the industry, however, have
sensibly eliminated TBT coatings for otherwise, their vessels would be
barred from foreign ports with TBT restrictions in place. The Malaysia
International Shipping Corporation Berhad (MISC) for instance, changed
to tin-free coatings in 1994.
Major deterrents to a switch is the time vessels have to spend in the
dock for respraying and the higher cost of alternative anti-fouling
paints such as ultrasonic or electrolytic devices, as well as copper and
silicon-based coatings.
Figures from MISC show that protecting a vessel with TBT-free paint
will cost from RM484,000 to RM964,000 (depending on how the coating is
applied) compared with RM364,000 for conventional TBT-based paint.
With the impending ban, many marine coating producers have moved away
from TBT products but Ainul believes small manufacturers are still at it
since there exists a local market that is not covered by the IMO treaty.
There is also a gap in the treaty - it only applies to sea-going vessels
and not marine structures such as platforms, floating storage and
production units, jetties and offshore oil platforms, installations
which all require anti-fouling coatings.
To stem the worsening TBT contamination in Malaysian waters, Ainul
urges for regulations, such as the following:
*Rank TBT paints as "scheduled wastes" in the Environmental Quality Act
1974 to ensure proper handling, treatment, storage and disposal when old
layers of anti-foulants are stripped off;
*Have a code of practice for application, maintenance, removal and
disposal of anti-fouling paints to check indiscriminate practices such
as careless discard of TBT paint tins;
*Register anti-fouling paints produced and applied in Malaysia to keep
track of production, marketing, sales and application of this toxic
substance; and
*Draft a regulation prohibiting organotin compound coatings on ships
entering Malaysian waters.
These rules, even if enacted, will still leave a hole - they do not
control use of TBT as a wood preservative, disinfectant and biocide in
industrial cooling systems, power station cooling towers, pulp and paper
mills, breweries, tanneries and textile mills. Perhaps a complete ban on
TBT as a biocide may be the wisest move.
According to the "I-Medical Sutra" Sea Shell fish are good for those people who
need to replenish the "Yin" of their body.
However, there were many cases found that hepatitis A,B,C, are due to eating
of contaminated Sea Shell Fish.
In Hong Kong, Taiwan, USA, Canada, Australia, Korea, Japan, Thailand, Singapore,
Malaysia, Vietnam, Burma, Cambodia, Indonesia, Phillipines, there are still many
people like to eat the Sea Shell mentioned.
Perhaps. FDA, Department of Health, Department of Fisheries shall research as on the
source of Sea Shell fish & it contaminations, If necessary, there must be put to a
stop for the consumption.
Don't Eat Sea Shells
Cockles, Soft-Shell Clams & Green Mussels
they are contaminated.
The strange phenomenon is tied up with marine pollution and one
contaminant in particular, is culprit: tributyltin or TBT. TBT is an
organotin (compounds of tin and carbon) and is used as a biocide
(substance that kills living organisms) in anti-fouling marine paints
sprayed on ships, buoys, nets, fish cages, quays, jetties and offshore
installations to prevent growth of algae, barnacles and other marine
organisms.
By Ir. Bruce Tan K.L. Malaysia
________________________________________________________________________
Foul (TBT) spray
By TAN CHENG LI
SOMETHING bizarre is happening in mudflats along the Selangor coastline.
Female rock shells which thrive in the muddy plains are developing
abnormal sexual organs - sperm ducts, in fact.
In a sampling of 700 Thai gradata rock shells, biologist Dr Ahmad
Ismail found all to suffer from imposex, the scientific term describing
growths of male reproductive organs, such as penises and sperm ducts, in
female species.
"The imposex condition is widespread, affecting all the female rock
shells we collected at the Selangor coastline," says Ahmad, an associate
professor at Universiti Putra Malaysia.
The strange phenomenon is tied up with marine pollution and one
contaminant in particular, is culprit: tributyltin or TBT. TBT is an
organotin (compounds of tin and carbon) and is used as a biocide
(substance that kills living organisms) in anti-fouling marine paints
sprayed on ships, buoys, nets, fish cages, quays, jetties and offshore
installations to prevent growth of algae, barnacles and other marine
organisms. The organotin leaches from the paint to prevent foulant
growths but at the same time, also enters the marine environment and
affect non-targeted marine organisms.
TBT is believed to suppress the immune system and disrupt hormonal
balance, thereby causing abnormalities in reproductive organs. The
effect of TBT on marine snails is well established, having been first
highlighted in 1976 with the discovery of abnormal organ growths and
thickening of shells in oysters along the French coast.
Since then, TBT-induced deformities and imposex have been observed in
dog whelks and other gastropods worldwide. Marine snails appear to be
the most sensitive to TBT, mainly because they feed in the seabed.
In Selangor, female rock shells collected by Ahmad from Sungai Burong,
Pantai Remis, Kuala Sungai Sekincan, Bagan Pasir Sungai Tengi, Sungai
Janggut, Batu Laut and Bagan Lalang have grown sperm ducts between
0.74mm to 1.85mm long.
Although strange, the find is hardly surprising. "Considering the high
sea traffic in the Straits of Malacca, TBT is certainly entering our
seas," says Ahmad.
Indeed, TBT traces have showed up in mussels and sediment at eight
sites in the straits. Ahmad found levels range from 22 to 730 nanogram
per gram (ng/g) in mussels and 5.6 to 1,100 ng/g in sediment.
Contamination was highest in busy shipping areas and narrow sections of
the sea channel.
Ahmad's findings add to the growing body of evidence that TBT is
fouling Malaysian seas and poisoning its marine life.
One Universiti Malaya study in 1991 and 1992 had shown TBT pollution
off Port Klang to be in the same range as major ports in Greece and
Japan. It also detected TBT residues in cockles, soft-shell clams and
green mussels sold in local markets, at levels ranging from 0.5 to 23.5
parts per billion (ppb).
In 2000, Universiti Teknologi Malaysia (UTM) marine biologist Dr Mohd
Ismid Mohd Said and then PhD student Sukarno Wagiman found severe
imposex in both juvenile and adult rock shells collected from rocky
beaches in Chendering, Terengganu.
In 1996, Ismid had detected 27.6ng/g of TBT in sediment off Port
Dickson but by 2001, the level had surged to 700ng/l. He had also found
gastropods with imposex in Pasir Gudang, Johor.
Another study in Kemaman, Terengganu, showed marine TBT levels of 62.1
nanogram per litre (ng/l). In comparison, levels at the Pulau Redang
Marine Park where there is less boating activity, were between 9.5 and
13.7ng/l.
Ahmad says a comparison of these finds point to one thing: worsening
TBT contamination in the marine environment. His study found imposex
occurrence of 100% - all 700 rock shells sampled had abnormal sperm
duct growths. He also notes an imbalance in the rock shell population.
"The sex ratio is bias towards the males and this is a deviation from
the norm."
If imposex is severe, the species will die off as the newly-grown penis
and sperm duct can obstruct the female reproductive organs and prevent
egg-laying. In some sites such as Bagan Datoh and Lumut in Perak, Ahmad
did not find a single rock shell. He believes a sudden acute exposure of
TBT could have killed the larvae or prevented breeding.
As TBT persists in the sea, scientists fear that the long-term effects
of TBT contamination may be more pervasive. When other aquatic species
or birds feed on TBT-contaminated gastropods, the toxic substance builds
up in the food chain. Indeed, increased levels of TBT have been recorded
in fish, marine mammals (whales, dolphins, seals, porpoises, sea lions
and sea otters) and seabirds all around the world. And as TBT stunts
growth of microalgae, the food of most marine species, the marine food
chain may be disrupted. Ultimately, the marine ecology in general will
also be affected.
With organotins or the breakdown products - dibutyl tin (DBT) and
monobutyl tin (MBT) - being found in many fish species, there is concern
that organotins may threaten humans who consume large quantities of fish
in their normal diet. The World Wide Fund for Nature says significant
levels of organotins have been found in human blood samples from the
United States.
Many scientists consider TBT to be among the most toxic chemicals ever
released into the marine environment. The Organotin Environmental
Programme Association, an international grouping of producers of
organotin compounds, however, dismisses the threats of TBT. It says in
its website http://www.ortepa.org/ that a two-generation study in rats did not
give any evidence of disturbance in fertility or reproductivity and that
a reduction in reproduction ability has been proven only for dog whelks.
It insists that other groups of organisms, including mammals, are not
expected to be affected by endocrine disruption of TBT exposure.
Curbing TBT Use
Following reports on the toxicity of TBT, many industrialised countries
now regulate use of organotin anti-fouling paints. These include Alaska
and California in the United States, Australia, New Zealand, Japan,
South Korea and the European Union.
The International Maritime Organisation (IMO) in 2002 adopted the
Convention on the Control of Harmful Anti-fouling Systems. Since January
2003, the treaty has curtailed spraying of TBT anti-fouling coatings on
ships. By January 2008, ships must not bear such coatings on their hulls
or external surfaces. Alternatively, they must wear a coating which
seals the underlying layer of TBT paint.
But the restrictions can come into force only if the treaty is ratified
by at least 25 states representing not less that 25% of the world's
merchant shipping tonnage. To date, only nine countries, representing
less than 10% of the world tonnage, have done so; and Malaysia is not
one of them.
"Malaysia has not done anything concrete on the TBT issue," says Ainul
Raihan Ahmad, a researcher at the Maritime Institute of Malaysia. "None
of the laws that govern the protection of Malaysia's marine environment
from pollution address TBTs. The contaminant is also not measured in the
monitoring of marine water quality."
In a survey of local shipping companies, Ainul found small operators
whose vessels ply only local waters, to be ignorant and blatantly
disinterested in the issue. Main players in the industry, however, have
sensibly eliminated TBT coatings for otherwise, their vessels would be
barred from foreign ports with TBT restrictions in place. The Malaysia
International Shipping Corporation Berhad (MISC) for instance, changed
to tin-free coatings in 1994.
Major deterrents to a switch is the time vessels have to spend in the
dock for respraying and the higher cost of alternative anti-fouling
paints such as ultrasonic or electrolytic devices, as well as copper and
silicon-based coatings.
Figures from MISC show that protecting a vessel with TBT-free paint
will cost from RM484,000 to RM964,000 (depending on how the coating is
applied) compared with RM364,000 for conventional TBT-based paint.
With the impending ban, many marine coating producers have moved away
from TBT products but Ainul believes small manufacturers are still at it
since there exists a local market that is not covered by the IMO treaty.
There is also a gap in the treaty - it only applies to sea-going vessels
and not marine structures such as platforms, floating storage and
production units, jetties and offshore oil platforms, installations
which all require anti-fouling coatings.
To stem the worsening TBT contamination in Malaysian waters, Ainul
urges for regulations, such as the following:
*Rank TBT paints as "scheduled wastes" in the Environmental Quality Act
1974 to ensure proper handling, treatment, storage and disposal when old
layers of anti-foulants are stripped off;
*Have a code of practice for application, maintenance, removal and
disposal of anti-fouling paints to check indiscriminate practices such
as careless discard of TBT paint tins;
*Register anti-fouling paints produced and applied in Malaysia to keep
track of production, marketing, sales and application of this toxic
substance; and
*Draft a regulation prohibiting organotin compound coatings on ships
entering Malaysian waters.
These rules, even if enacted, will still leave a hole - they do not
control use of TBT as a wood preservative, disinfectant and biocide in
industrial cooling systems, power station cooling towers, pulp and paper
mills, breweries, tanneries and textile mills. Perhaps a complete ban on
TBT as a biocide may be the wisest move.
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