High level of toxins found in Gulf

The Nation
Jan 13, 1996
 
Increasing quantities of mercury, a dangerous neurotoxin, have been
found in fish around natural gas platforms in the central Gulf of
Thailand, a marine scientist said yesterday.
        ``Most of the fish around the Erawan and Plaathong platforms
have higher than natural levels of mercury. And the levels are rising,'
said Dr Piamsak Menasveta, a professor of marine science at
Chulalongkorn University, who has carried out fish surveys over the last
five years.
        People who eat contaminated fish in sufficient quantities will
suffer a build-up of mercury in their bodies, eventually causing chronic
damage to the nervous system. Mercury passes through the placenta of
pregnant women to affect the brains of developing fetuses and cause
birth defects.
        Piamsak found fish with high mercury levels, in some cases over
the standard of 0.5 parts per million (ppm), both in the central gulf
and off Bang Salae on the Eastern Seaboard, about 40 kms west of Map Ta
Phut industrial estate.
        The highest mercury levels are found in carnivorous, long-living
fish such as plaa chon talae (snake-head fish), groupers and red
snappers, said Piamsak.
        Shark fins, considered a delicacy, are also likely to have a
high mercury content, said Piamsak. Surprisingly, however, he was unable
to catch any sharks in the central gulf.
        Natural gas from the Erawan field is contaminated by mercury and
other heavy metals, which are taken out at both the drilling platforms
run by Unocal and the gas separation plant run by Petroleum Authority of
Thailand at Map Ta Phut. Representatives of both firms claim they have
carefully controlled the toxic waste.
        A recent study has found mercury and cyanide (which does not
build up in the food chain) in the sediment around the port at Map Ta
Phut, but the source of the toxic substances remains unknown.
        Piamsak said he could not reveal the data from the most recent
fish surveys because it is the property of Unocal, which hired him to
carry out the studies.
        Konthi Kulachol, public relations manager for Unocal, said the
company has been aware of the problem from the start and has been
studying it since 1990. A comprehensive report has been submitted to the
Department of Mineral Resources, he said.
        ``Consumption of fish from the gulf, as represented by the fish
in our study, is safe for human health,' he stated.
        However, he said the company could not release the data to the
public.
        Piamsak called on the Minister of Industry to authorize the
release of the information to the public, under authority granted to him
by the Petroleum Law. Minister Chaiwat Sinsuwong could not be reached
for comment yesterday.
        The Fisheries Department has also refused to release information
on mercury contamination. A source at the Ministry of Public Health's
Food Analysis Division said studies in the gulf carried out five years
ago found mercury levels in fish ``almost' reached the limit, but he
would not reveal the data.
        Piamsak, who also serves as the director of the Aquatec
Resources Research Institute, noted that the natural mercury level of
fish in the Gulf of Thailand is 0.1 ppm.
        Studies around the Erawan field in 1990 found fish with mercury
levels of 0.3 ppm. Two studies of 25 species of fish carried out since
then revealed some had mercury levels over the standard of 0.5 ppm.
        ``A study in 1994 found greater mercury levels than previously,'
he said. ``The problem exists and is increasing.
        ``I would like the Ministry of Industry to acknowledge the data
and set up some countermeasures before the situation becomes truly
dangerous,' he said.
        Piamsak declined to offer any advice on what fish people should
eat. Asked what he personally would do, he said he would not eat fish
from the central Gulf of Thailand.
        Toxics A to Z, a guidebook on hazardous substances, recommends
that, ``People who frequently eat fish and other seafood should pay
special attention to reports of high levels of mercury in local fish and
should reduce their consumption of those varieties accordingly.'
        Mild cases of mercury poisoning result in symptoms described as
malaise, blurred vision, and pins-and-needles tingling. More severe
cases result in loss of vision and hearing, speech disorders and shaky
movements.