BUTTERWORTH (THE STAR/ASIA NEWS NETWORK) - The mercury spill at a secondary school in Guar Perahu which led to 56 students being quarantined and 16 residents of six houses in Kampung Baru being hospitalised is believed to have originated from a nearby oil palm plantation in Bukit Tok Alang.
Tasek Gelugor Fire and Rescue Department station chief Muhammad Hayazi Taib said several SMK Guar Perahu students had obtained the mercury from an abandoned water meter room in the plantation.
"They told us that they were in the room taking shelter from the rain when they stumbled upon the silvery liquid on the ground.
"They then collected about 300ml of it and took it to the school in a plastic bag to show their friends on Wednesday.
"We do not know what they did to cause the mercury to spill in two classrooms on the third floor of the school building," he told reporters at the oil palm plantation on Monday (May 30).
The department's Hazardous Materials Squad (Hazmat) spent five hours cleaning up the meter room from 10.30am, using sulphur to contain the mercury around the premises to reduce evaporation before collecting it for disposal.
Penang Education Department director Shaari Osman said the case was an isolated one and it has never happened before in the state's schools.
"Schools have no use for the heavy metal except for the mercury in thermometers."
State Welfare, Caring Society and Environment Committee chairman Phee Boon Poh said a police report on the matter has been lodged and investigations were pending.
On Thursday, 56 students were quarantined after mercury was found in the classrooms. Six students were taken to the Bukit Mertajam Hospital for further medical checks.
Two days later, 16 people - including 10 said to be family members of the six students - were evacuated from their homes. The Hazmat team then conducted a clean-up to remove the mercury toxicity from the houses.
Mercury is a type of heavy metal that is liquid at room temperature and can be harmfully absorbed into the body via skin absorption, inhalation and ingestion.
Once in the human body, mercury acts as a neurotoxin, interfering with the brain and nervous system. Exposure to mercury can be particularly hazardous for pregnant women and small children.
Mercury is used in laboratories for making thermometers, barometers, and many other instruments. It is also used for mercury switches and other electrical apparatus while gaseous mercury is used in mercury-vapour lamps and advertising signs.
Universiti Sains Malaysia's School of Chemical Sciences senior lecturer Oo Chuan Wei said heavy metals including mercury were non-biodegradable.
"Wearing gloves as a safety measure in handling heavy metals is definitely a must because heavy metals do not evaporate easily," he added.