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HK to tighten safe level for lead in food

Nick Gentle

Post probe of food safety, quality and value has surprising results

The government is to slash the maximum level of lead allowed in food after a Sunday Morning Post investigation found Hong Kong's standard is 60 times that recommended by the World Health Organisation.

As part of our investigation, we asked a laboratory to test for heavy metals, pesticide residue and nutritional value in several food items - apples, tomatoes, carrots, broccoli and pork - bought from various supermarkets and a wet market.

The items included organic and non-organic produce.

The tests exploded the commonly held myth that Hong Kong's vegetables are riddled with heavy metals and pesticides. Traces of the latter were not found on any of the produce; low levels of heavy metals were found in just three items.

They also showed that organic produce, while much more expensive than non-organic produce, is not proportionally more nutritious - and in some cases is less nutritious.

We bought the produce from a Central wet market and branches of the Wellcome, Great, City'super and ThreeSixty supermarkets and tested it for heavy metals, pesticide residue and nutrition. The tests were carried out by CMA Testing and Certification Laboratories.

The results of the tests support the government's claim on Friday that the vast majority of foods entering Hong Kong are safe to eat.

Three of the 25 items we tested had lead levels marginally above the level the World Health Organisation considers safe (below 0.1milligrams per kilogram for vegetables), but well within the maximum level of 6mg/kg permitted in Hong Kong.

The Food and Environmental Hygiene Department (FEHD) was unable to explain why Hong Kong's limit was 60 times that of the WHO. It pledged to rectify the problem as soon as possible.

'We will take the earliest opportunity to harmonise our standards with the international ones, having regard to other competing priorities,' it said.

Hani El-Nezami, associate professor of food toxicology in the University of Hong Kong's school of biological sciences, was surprised how high Hong Kong's threshold for lead contamination is.

'I was shocked when I found out,' Professor Nezami said. 'That's a huge amount if you consider the average body weight of Hong Kong people.'

Lead poisoning can cause permanent neurological damage, gastrointestinal problems, behavioural changes and, in extreme cases, put someone in a coma.

Lam Ching-wan, a toxicology expert in the university's department of pathology, said the city's lead limit was considered fairly safe for adults.

'I think this regulation is OK for adults,' Professor Lam said. 'But we should consider whether it needs to be revised downwards for children.'

Other jurisdictions had steadily reduced the maximum allowable levels of lead in food as successive studies had shown that children's bodies absorbed more lead than adults, he said.

'For children, they need to keep lead intake at a very low level,' Professor Lam said.

'Lead is not an essential mineral, and everyone is quite aware of how it has a negative effect on intelligence.

'Not many good things come from lead poisoning.'

A 2005 study issued by the Food and Environmental Hygiene Department found blood-lead levels in high school students to be well within acceptable levels.

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