Malaysia: Scientists warn about eating shellfish from heavy metal contaminated Straits of Malacca

Bernama New Straits Times 8 Apr 19;

KUALA LUMPUR: Seafood lovers living on the west coast of Peninsular Malaysia are being warned to reduce their shellfish consumption because of the risk of heavy metal poisoning.

Universiti Malaysia Terengganu (UMT) School of Marine & Environmental Sciences marine biology programme senior lecturer, Assoc Prof Dr Ong Meng Chuan, said a team of 25 scientists and researcher detected a high concentration of heavy metals like arsenic, cadmium, plumbum and mercury around estuaries and harbours in the Straits of Malacca during a scientific voyage from March 13-22.

He said findings reveal the waters off Johor, Port Klang and Pulau Pinang are at a higher risk of heavy metal contamination.

"This situation indirectly leads to the contamination of a food source because it is in the nature of shellfish to stay put and not migrate in search of food.

"Obviously, if the water is contaminated with heavy metals, it will be passed up the food chain," he told Bernama.

The marine expedition using UMT’s research vessel, RV Discovery, was carried out in conjunction with the Langkawi International Maritime and Aerospace 2019 (LIMA'19) exhibition and sailed from Kuala Terengganu to Tanjung Lembung, Langkawi.

The team collected samples from more than 45 stations along two shipping routes: the Straits of Malacca and South China Sea.

Ong said many don’t realise the long-term health consequences of eating contaminated food from the sea.

"Heavy metal bioaccumulation takes a long time to be detected. The build-up from eating arsenic- or mercury-contaminated food can lead to various disorders," he said.

He said the Straits of Malacca is more polluted compared to the South China Sea because it is shallow and narrow, and experiencing growth in industrial activities in the port and estuary area.

He said river currents in estuarine waters were weaker, allowing heavy metals to easily sink and accumulate on the floor of the estuary.

Ong said the government and relevant powers should ensure strict enforcement of the law to tackle heavy metal pollution in earnest.

"Perhaps a heavier penalty or tougher sentence is needed … because we don’t want another Sg Kim Kim incident which affected the health of over 2,000 people,” he said. — BERNAMA


Lecturer denies issuing warning against eating shellfish from Straits of Malacca
Satiman Jamin New Straits Times 9 Apr 19;

KUALA TERENGGANU: Like most Malaysians, Associate Prof Dr Ong Meng Chan was shocked after reading the news on Monday that seashells from some sections in the Straits of Malacca were unsafe for consumption.

The lecturer at Universiti Malaysia Terengganu’s School of Marine and Environmental Sciences, who was quoted in the Bernama story, said had never issued such warning and now found himself inundated with requests for interviews to clarify the matter.

“I did not issue such warning and the article is certainly not related to the sample collection we conducted en route to LIMA 2019 because we have yet to even start processing the samples we obtained during the trip,” he said in an interview.

He showed a stack of clear plastic tubes that contain the sediment samples from 45 stations along the route that UMT’s research vessel RV Discovery took on its way to LIMA 2019.

“We will have to cut up the samples, send them for dating and analyses. Only then will we be able to know the heavy metal concentration in each sample according to the relevant timeline.

“There are huge differences between the heavy metal concentrations in marine sediment and marine organisms, as the organisms’ uptake of heavy metals is very complex with various parameters that differ between species,” he said.

He said although a study in 2015 showed that the heavy metals pollution level in sediments taken along the Straits of Malacca was higher than samples taken around the South China Sea, it does not indicate that shellfish reared or caught in the former are unsafe.

“The South China Sea is a huge area with strong currents that can disperse pollutants to a bigger area much faster compared to the estuarine on the West Coast of Peninsular Malaysia.

“The effects of ocean currents also contributed to lower readings of pollutants at the northern part of the Malacca Strait as it meets the Indian ocean,” he said.

Ong said he loved eating shellfish and did so regularly.

“My hometown is also on the West Coast and I regularly eat shellfish and other seafood varieties whenever I go back there on holidays,” he said.

He said the permissible levels of heavy metals in shellfish were normally based on their contents in raw specimens.

“In Europe, especially in France where I studied for my PhD it is the norm to consume shellfish like oysters raw. Cooking the shellfish, as practiced in Malaysia will remove most of the heavy metals,” he said.

On another note, he said it is good that Malaysians are more aware of the presence of pollutants in the environment but care should be taken to not blow things out of proportion.

“Pollutants, including heavy metals are on the rise globally with the increase in human activities. Industrial and agricultural runoffs from heavily populated areas are of course higher than sparsely populated areas.

“What we should do is increase our monitoring and take steps to reduce the pollutants from human activities,” he said.

A press statement from the Department of Fisheries (DOF) director general Datuk Munir Mohd Nawi echoes what Ong said about the presence of heavy metal pollutants in shellfish.

He said Malaysia produced three main shellfish species with cockles leading at 12,482 metric tons while mussels and oysters at 2,274 and 1,402 metric tons respectively.

“Since 2013, the DOF have conducted safety monitoring of shellfish under the National Shellfish Sanitation Program (NSSP) involving samples from farms and specimens harvested from the wild.

Last year some 1,128 shellfish samples were taken from all over Malaysia to monitor the parameters set under the NSSP for heavy metal analyses for cadmium, lead and mercury,” he said.

He said the levels of heavy metals in shellfish samples taken in Malacca (Sebatu), Johor (Air Baloi, Teluk Jawa and Teluk Kabong) and Penang (Seberang Prai Selatan) were within the limits sets under the Foods Act 1983.

“In Selangor (Sungai Besar, Jeram and Kapar) the levels for lead and mercury have not exceeded

the limit, but the level of cadmium was found to be above the limit for cockles samples taken in Sungai Besar at the end of last year.

“The DOF have our own Standard Operation Procedure for cases where the NSSP went above the limits, including informing the local communities about such occurrences and continuous monitoring will be conducted in the affected areas.” he said.