Australia Minimizes Cadmium Levels in Crops

DONALD - Jul 3/01 - STAT -- Australia's agriculture industry is working hard to ensure levels of cadmium found in crops and foods its exports are among the lowest in the world.

"We have long recognized cadmium contamination as a potential threat to 'clean' agricultural systems," said Dr Mike McLaughlin, National Cadmium Coordinator for the Standing Committee on Agriculture and Resource Management (SCARM).

Australia has also provided input to international standards for cadmium concentrations in traded food commodities.

Dr McLaughlin said cadmium was a naturally occurring element, present in all soils and rocks, plants and animals. It is found in relatively high concentrations in phosphate based fertilizers, and can be taken up by plant crops and so becomes part of the human food chain.

There is some possibility that cadmium can accumulate in the human kidneys and liver, and cause health problems if there is long-term exposure.

"Many countries recognize cadmium as a health risk, and the international Codex Committee on Food Additives and Contaminants is developing recognized guidelines for cadmium in major traded commodities," Dr McLaughlin said.

"There have been several instances where world food trade has been disrupted by violations of the cadmium standards."

Dr McLaughlin said plant breeders could play an important role in the minimization of cadmium contamination.

"It is important that new crop cultivars be screened to check on their cadmium uptake characteristics," he said. "Breeders who are looking for crop disease resistance and nutrient efficiency should be careful not to inadvertently select for cadmium accumulation.

"Plant breeding also offers a way to select cultivars which have very low cadmium accumulation characteristics."

Dr McLaughlin said cadmium minimization would take a long-term and concerted effort involving State and federal regulation, industry codes of practice, research, quality assurance programs, and the co-operation of growers.

The fertilizer industry in Australia has also played a significant role in addressing the management of cadmium as it affects agriculture in Australia.

In the early 1990s the industry established a program to reduce the cadmium content of fertilizers used in Australia by changing to lower cadmium sources of imported phosphorus fertilizers and changing the source of phosphate rock used in superphosphate manufacture to achieve lower cadmium content.

As a consequence, the overall amount of cadmium introduced into agricultural soils from mineral fertilizers has reduced by more than 80% in the past decade.

In addition, Australia's newest source of phosphate fertilizers produced at Phosphate Hill in north-west Queensland has one of the lowest cadmium contents of any phosphate fertilizer in the world and this will assist in keeping cadmium levels at a minimum.

"Australia has taken a pro-active role in combating the insidious problem of cadmium in our food," Dr McLaughlin said.

"It is essential for us to maintain and enhance our reputation as a clean and green supplier of food commodities to the world market, just as it is essential for us to maintain the healthy diet available to all Australians."

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