Families should switch off all gadgets at night to prevent potentially deadly risks from light pollution, the Chief Medical Officer has warned.

Dame Sally Davies said exposure to a “daily cocktail of pollutants” – including poor air, light, noise and chemicals – is fuelling tens of thousands of cancer, lung and heart deaths.

And she said a “horrifying” lack of awareness of the dangers meant families were putting themselves at risk on a daily basis.

Her annual report will today make a “clarion call” for urgent action to reduce exposure to pollution, and call for far more research into specific threats, such as that which may be posed by blue light from smartphones.

Dame Sally said air pollution is contributing to around 30,000 deaths annually – a toll which was likely to be far larger if the effects of other contaminants are properly calculated.