The next time you're throwing out an old laptop or smartphone, make sure you recycle the batteries.
That's because a new study by the University of Minnesota and University of Wisconsin-Madison found the lithium ion batteries used to power computers, phones and electric car are harmful to soil.
These types of batteries are increasingly using "nanonscale materials" that contain cobalt and nickel – cheap to use and good at storing energy, but toxic to bacteria in soil.
As such, disposing of them in landfills could have significant environmental consequences, because these materials were found to restrict growth and respiration in soil.
At this stage the full impact of the contamination can't be assessed.
The study by the universities is thought to be the first of its kind to look at this specific issue, and more research will be required before the full implications are known, but lead researcher Professor Robert J. Hamers said it could be the first "red flag" of a wider problem.
He said it's imperative that recycling services improve as these materials become more widely used in technology. He also called on the tech industry to look for "environmentally benign" alternatives that could replace these materials in future years.
"There is a really good national infrastructure for recycling lead batteries,” he said. “However, as we move toward these cheaper materials there is no longer a strong economic force for recycling, but even if the economic drivers are such that you can use these new engineered materials, the idea is to keep them out of the landfills."