Cadmium contamination: where is the next vulnerable region?
The cadmium spill in Guangxi province has been the headlines for a few days now and there could be more to come. With two out of the three main tributaries of the Pearl River (西江和北江，the west and the north tributary Xijiang and Beijiang) now contaminated with cadmium, will the Dongjiang (东江，the east tributary) be next?
Many people in the Pearl River basin are very concerned about the current situation in Guangxi but few remember that seven years ago there was an even worse cadmium spill close by, on a section of Beijiang that runs past Shaoguan 韶关市) in Guangdong province. It took more than a month to completely control the contamination and ten people were prosecuted.
Seven years later, many of the leaders and experts who worked on the Beijiang case are now fighting restlessly in one of the Xijiang’s main tributaries, the Longjiang (龙江). Thus far, seven people have been arrested, and the story is not yet over.
It’s yesterday once more
Why cadmium? Why similar time coincidence? Why the Pearl River watershed again？
Looking into the distribution of non-ferrous mineral reserves and refineries in China, it is not hard to understand where the risks are. Understanding why history is repeating is the key to prevent future contamination.
Guangdong and Guangxi provinces are rich in lead and zinc deposits (respectively the 4th and 6th nationwide). The two provinces emerged among China’s leading lead-zinc mine and smelt production bases in the 1970s. Cadmium is a side product of lead and zinc mining and refining.
The Shaoguan Smelter (韶关冶炼厂) in Guangdong, which ranks as the third largest in China, was the source of the 2005 Beijiang cadmium contamination. Guangxi’s cadmium contamination happened in Hechi (河池), famous as a "hometown of non-ferrous metals of China”. It accounts for a large proportion of Guangxi of non-ferrous mineral deposits, with its tin, lead and antimony reserves are among the highest in the country.
Dongjiang River supplies drinking water for more than 40 million people in Guangdong and Hong Kong. It is the most important tributary of the Pearl River. Given what happened and is happening in Beijiang and Xijiang’s main tributary, how safe is Dongjiang?
In late October and early November last year I took a field trip along Dongjiang watershed and saw signs that require immediate attention, especially as urbanization picks up speed in what used to be remote areas.
At the top of the agenda is the issue of industrial relocation in Guangdong and its threats to water resources. Guangdong must guard against repeating the mistakes of the earlier industrial relocation from Hong Kong to the PRD, to avoid sinking even deeper into environmental crisis.
Currently, Guangdong is speeding up the practice of relocating labor-intensive industries from PRD to northern, western and eastern regions of the province, including Dongjiang watershed. The current pattern, scale and speed of industrial relocation pose clear threats to the province's water resources. If not managed properly, industries relocating to the upper reaches of Guangdong’s rivers will only spread water pollution and other environmental problems further up-river thereby widening the threats to more areas including ecologically vulnerable ones.
Heyuan is the first line of defense for the Dongjiang River. The rapid industrial development in the city of Heyuan and its satellite counties presents direct risks to the ecological system of the Dongjiang. While the so-called "new development" of industrial relocation in Heyuan has gained recognition as a success story, hidden risks appear to have been largely overlooked.