Officials are warning of a potential public health risk after children were seen playing in spilled fracking sand at an industrial area in the central Alberta town of Bashaw.

A container holding the sand collapsed near the CN railway in mid-June and wasn’t cleaned up for a month, Alberta Health Services said.

Frac sand is a very fine crystalline silica material that could easily be mistaken for sand suitable for use in children’s sandboxes or playgrounds, AHS said.

One or two exposures to the sand would not cause any ill effects, said medical officer Dr. Deana Hinshaw.

“But having repeated exposure over long periods of time, breathing in that dust can cause damage to the lungs,” she said.

“We know that there were children playing in it and so there's a small possibility that somebody might have thought this was regular sand and could be used for a home sandbox, that kind of thing.”

Hinshaw said anyone who took the sand should wear protective clothing to collect and contain it and take it to a landfill.