Heavy metals in plastic no immediate food safety threat, but may lead to environmental problems

Aug. 30--Small amounts of heavy metals in plastic containers may not contaminate its food or beverages, but could pose an environmental threat down the road.

Keith Vorst, associate professor of food science and human nutrition at ISU, said metals like lead, mercury, chromium, cadmium and antimony could cause damage to humans at high levels, but there are few health concerns for trace amounts found in plastic food packaging. But if the plastics are then left in a landfill or in a body of water rather than recycled, the metals could cause damage over the years.

Vorst said he and his research team have been looking at the research for years, as consumers grow more concerned with potential contamination from metals finding a way into their plastic containers.

"We've also been looking at triggers for neurological diseases, endocrine disruptors and all those things. A lot of folks have been pointing fingers at plastic bottles. We've been reading a lot of data and I don't know if the methods are sound," he said. "It's one thing to have contamination in the bottle, it's another to have it go from the bottle to the food. People are just looking at toxic chemicals in the bottle."

The research, recently published in the Journal of Plastic Film and Sheeting, experimented with a range of plastics and exposed them to heat, microwaves and a range of pH and acidic levels. While there were a few outliers, Vorst said the research found there was no significant leaching of contaminants into the food. But the plastics did pose an "end-of-life" issue, where the metals could find their way out of the plastics as they aged.

The metals could find a way into plastics after production or the reclamation process for recycled plastics.

But Vorst said the metals could leach out of the plastic over the years and if left in a landfill or ocean, the metals could potentially pollute drinking water.

"When you start leaving plastics in solution for years, we're no longer talking about an inventory turnaround for humans," he said. "The water bottles you buy in a store don't have a 50-year shelf life."

Vorst also leads the Polymer and Food Protection Consortium at ISU, which helps to improve food safety and the function of plastics. He recently helped develop a sensor capable of tracking any potentially harmful materials in plastics, and several manufacturers are already using it. But along with the use of technology like his sensor, Vorst said consumers and retailers alike can be doing more to prevent any potential contamination by increasing their recycling practices.

"We really shouldn't be sending this stuff to the landfill, we should be recycling them," he said. "If we have contaminated material that starts degrading through the recycling chain, we can build that plastic back up and rebuild that. But there's no reason it should be going to the landfill. There's a good chance we're doing more damage to our environment and health when we don't recycle."

___

(c)2015 the Ames Tribune, Iowa

Visit the Ames Tribune, Iowa at www.amestrib.com

Distributed by Tribune Content Agency, LLC.