An Ontario teachers' union is calling for an end to new Wi-Fi setups in the province's 1,400-plus Catholic schools.
The Ontario English Catholic Teacher's Association says computers in all new schools should be hardwired instead of setting up wireless networks.
It also says Wi-Fi should not be installed in any more classrooms.
In a position paper released on Monday, the union — which represents 45,000 teachers — cites research by the World Health Organization.
Last year the global health agency warned about a possible link between radiation from wireless devices such as cellphones and cancer.
Some believe wireless access to the Internet could pose similar risks.
But while Health Canada cautioned parents to limit the use of cellphones by children, it said that based on scientific evidence, low-level exposure to Wi-Fi is not dangerous.
The OECTA, in its paper, said the "safety of this technology has not thoroughly been researched and therefore the precautionary principle and prudent avoidance of exposure should be practised."
The Ontario government has said it would examine the WHO warning but wouldn't take any immediate action to require warnings on wireless devices. The province said it's up to school boards in the province to make decisions about whether to use Wi-Fi or not.
Some Canadian private schools and at least one public school board in British Columbia have removed or strictly limited Wi-Fi due to safety concerns. But many other public school boards across Canada continue to use it.