Survey to seek source of contamination Following widespread reports on the mainland that serious heavy-metal contamination had been found in vegetables from the Pearl River Delta, Guangdong's environment chief admitted yesterday there was a problem with soil contamination. However, Li Qing, director of the Guangdong Environmental Protection Bureau, stressed that a comprehensive soil survey needed to be carried out before the extent, structure and distribution of the contamination could be identified. The survey, which was also hoped to shed light on the sources of contamination, was expected to be completed in 2010, he said. The seriousness of the problem was brought to light after the result of soil sampling, initiated by Guangdong's Agriculture Department, which revealed the problem in a number of cities, was reported by Guangzhou Daily on Thursday. Another study by Sun Yat-sen University found contaminated vegetables in samples taken from 12 wet markets. 'Soil contamination affects the ecosystem as well as food safety, which is why it has caused much concern in society,' Mr Li said on the sidelines of the Guangdong People's Congress. In a reference to the surveys, he said researchers could only conduct sampling to explore the phenomenon. 'This does not represent the whole picture,' he said. 'We will carry out a survey on soil contamination in the province so as to investigate the extent, distribution and structure of the situation in order to plan for various measures in tackling this problem. 'We would also strengthen the monitoring of the possible sources of contamination, especially the treatment of industrial waste.' He also sought to allay Hong Kong fears over contamination problems by stressing all vegetables exported to the city were safe to eat. Yang Xian, head of the vegetable department at South China Agriculture University in Guangzhou, said suggestions that the contamination might not be serious enough to lead to food poisoning because most chemicals could be washed off before consumption, were 'absolutely wrong'. 'Those materials have already been absorbed by the vegetables instead of just being attached on the surface. How can you get rid of them simply by rinsing them with water?' Professor Yang said. He also warned that heavy metals including lead, cadmium, copper, zinc and chromium could be found in some vegetables exported to Hong Kong, because suppliers might have sourced the vegetables from different farmers instead of buying via so-called pollution-free farmlands in the province. 'What Hong Kong residents can do is choose the brand to buy. Just avoid vegetables without labels of origin,' he suggested, pointing out that ordinary buyers could not tell pollution-free vegetables from polluted ones by appearance alone. He suggested setting up a mechanism to check the level of heavy metals in vegetables supplied to Hong Kong on top of current tests for pesticide residues, even though results might not be known for three days. 'At least, we can trace the origin of the polluted produces and take action,' he said. He was also concerned about soil pollution, which caused the contamination of vegetables, in the province.