The New Zealand Food Safety Authority (NZFSA) says that it has come across lead contamination in cornflour milled from imported corn following routine food safety tests on a number of food products. The organisation says that it has now traced the contamination to a batch of cornflour, stating that the source of contamination is probably China.
"About 50 tests have been completed on all potentially affected batches of the Penfords milled cornflour," said NZFSA director of Domestic and Imported Food, Tim Knox.
"Three batches have been found to have unacceptable levels of lead. All of the cornflour has been traced, and the food in which it was used as an ingredient has been assessed to determine the likely levels of lead in the final food product. All of the products that are assessed to have potentially had levels of lead higher than the maximum permitted level for that food type have been recalled." Knox went on to state that because cornflour is generally used as an ingredient, the risk that the lead contamination poses is generally deemed to be very low as vast quantities of the product would have to be consumed before any ill-effects might be detected. He added that a 70kg person would have to consume one 400gm packet of the most-affected batch of cornflour each week for some time before lead levels would rise enough to cause a health risk.
Although NZFSA has traced all of the cornflour affected, the body said that investigations are continuing to double-check the information received as well as to trace the source of the contamination.
"It is possible that the imported corn was contaminated somewhere in transit between China and the mill," said Knox. "We are working with all concerned to try and isolate the most probable causes of the problem. Although the corn was imported 10 months ago and we are unlikely ever to know the exact cause, we will be identifying weaknesses and working with the relevant local and international authorities to address issues."
The three affected batches were milled from a portion of a one-off 6,000 tonne shipment of corn from China, imported in September 2003. The affected batches, about 45 tonnes each, were milled between October 2 and 4.
The contamination was found during testing by NZFSA as part of its Total Diet Survey. The manufacturer of the affected product, 100gm Robinsons Step Up Egg Custard, was immediately informed, and issued a recall notice for all batches, even though not all would have used the affected cornflour as an ingredient.
Of the 105.78 tonnes of cornflour, 22.1 were exported to Australia (authorities there have been alerted and supplied with all information). Another 25.1 tonnes was exported to Fiji and NZFSA is working with authorities there as well as the two importers to assist in tracing where and how the product was used.
"While high levels of lead in food are unacceptable, it is important to remember that not all the cornflour in each batch may have been affected. In addition, the bulk of the product was used as an ingredient and, as such, makes up a small proportion of the food in which it has been used. Our assessment shows that, in all but the recalled products, lead levels are likely to be within the acceptable limits for the foods concerned," said Knox.
NZFSA Programme Manager (Toxicology and Residues), John Reeve, says confusion of regulatory levels and human health needs to be addressed so people can judge for themselves the real risk.
"This issue has highlighted once again the fact that regulatory limits for contaminants in foods are not set on the basis of health risk, but on the basis of ensuring the best practices in the production of foods," Reeve said. "The fact is that the recalled products have unacceptably high levels of lead in them and are therefore subject to recall. However, it is not correct to claim that they pose an immediate health risk. The measure of this is whether the dietary intake exceeds the level identified by the World Health Organisation as being acceptable, and not simply whether the product contains contaminants at levels exceeding regulatory limits."
Knox added that a low level of lead is not unexpected as lead is present in the environment, from both natural and man-made sources. However, the levels detected during targeted monitoring for the Total Diet Survey were unacceptable.
"International trade in food and food-related products continues to grow at a rapid rate. Foods imports into New Zealand have increased significantly since 1996," Knox said This has led to an emergence of new risks and concerns over the safety and security of the food supply. A number of countries have reviewed and strengthened the measures they have in place to ensure food imports are safe and secure and it is timely for New Zealand to do the same."