Many Hong Kong Vegetables Contaminated With Heavy Metals

Hong Kong vegetables, mostly imported from the mainland, contain high levels of lead and traces of other metals, including cadmium, according to research released last week by the Hong Kong Baptist University. This followed last month’s revelation by Chinese government scientists that 12 million tons of Chinese rice are contaminated with heavy metals.

The Baptist University tests were of 93 vegetables imported from the mainland and bought at local Hong Kong street markets or supermarkets, as well as of produce grown on Hong Kong farms, between September and December last year.

The most contaminated vegetable was apparently mainland-grown choy sum, which is also one of Hong Kong’s most consumed vegetables.

An article in the South China Morning Post on Friday showed that although the levels of lead in the study were 2.8 times higher than the global standard, they were acceptable under Hong Kong regulations. Traces of Cadmium also were found in some vegetables.

According to the SCMP, Hong Kong’s standards are shockingly 20 times less stringent than those of the World Health Organization, the European Union or Australia.

Author of the study, Professor Jonathan Wong Woon-Chung of Baptist University’s Hong Kong Organic Resource Centre told the Standard that ninety percent of vegetables in Hong Kong were imported from the mainland.

“The result demonstrates that lead pollution in mainland farm produce is serious,” he was quoted as saying.

In China, heavy metal pollution in crops comes mostly from contaminated irrigation water, pesticides or excessive application of chemical fertilizers and hormones as well as direct heavy metal contamination of the soil as a result of emissions from nearby factories.

Long-term consumption of vegetables polluted with heavy metals can contribute to cancers as well as damage the nervous system. Excess cadmium can also cause kidney stones, while excess lead can affect brain activity in children.

Wong pointed out in the SCMP article that leaf vegetables such as choy sum and spinach were more likely to absorb heavy metals. He suggested people alternate between these and fruit vegetables such as tomatoes and eggplants.

China has recognized that food security is a real issue for the country, following scandals over melamine in baby milk and many others that have caused unrest in many parts of China following discovery of contamination.

In February the SCMP reported that government scientists revealed millions of acres of Chinese agricultural land and 12 million tons of grain, or about 10 percent of the country’s rice crop, were contaminated by heavy metals. China’s southwestern provinces, where much of the country’s export manufacturing is concentrated, were particularly contaminated, according to the article.

Potential economic losses from the contaminated rice, which is enough to feed more than 40 million people, hit 20 billion yuan or HK$23.66 billion a year, the China Economic Weekly said, citing 2007 statistics from the Ministry of Land and Resources.

China is also confronting a serious and potentially costly health crisis, with clusters of “cancer villages” springing up downstream from factories and near mines.

At  the annual plenary session of China’s parliament this past week, soil contamination was a topic of urgent discussion.  In a news report on China.org Jia Kang, a CPPCC National Committee member and head of fiscal science at the Ministry of Finance, called for legislators to begin drafting a soil protection law.

Jia was quoted as saying that land pollution already threatens the sustainability of economic growth and social stability.

Meanwhile, the same site quoted Health Minister Chen Zhu as saying that comprehensive evaluations of health risks from soil pollution are underway. Environment Minister Zhou Shengxian in recent months has said he will work to curb soil pollution during the period of the current, or 12th, Five-Year Plan – a framework for China’s economic development over the period.

The most recent plan, introduced at the parliamentary session this past week, calls for China to step away from exclusive focus on rapid economic growth to a more balanced development model that includes more benefit sharing and recognizes the environmental challenges the country faces.

The annual parliamentary gathering generally sets the country’s political tone and government priorities.

Let’s hope that food security stays at the forefront of China’s agenda and that we see action from officials both on the mainland and in Hong Kong to protect public health.