143 workers have been found to have excessive mercury in their bodies following a potential leak at a factory, china.com.cn reported today.

Nine people are suspected to have mercury poisoning and one in four staff tested positive for high levels of the substance at Foshan Electrical and Lighting (FELCO), a cash cow manufacturer of lighting products in Guangdong province, China.

The company has been offering high dividends for the past 16 years, but had reportedly fallen short in investments in production lines, production security and occupational disease prevention.

A liquid mercury production line is believed to be the cause of the scandal.

"It is a mass occupational disease case," an unnamed expert of Shanghai Chemical Industry Institution of Occupational Disease Prevention, told China Business News yesterday.

"All lighting companies should change their liquid mercury production lines to solid production lines to better the health of workers," said Chen Yansheng, head of China's Lighting Association.