"Earth, and all life on it, are being saturated with man-made chemicals in an event unlike anything in the planet's entire history," says Julian Cribb, author of 'Surviving the 21st Century' (Springer International 2017).

"Every moment of our lives we are exposed to thousands of these substances. They enter our bodies with each breath, meal or drink we take, the clothes and cosmetics we wear, the things we encounter every day in our homes, workplaces and travel.

Mr Cribb says that the poisoning of the planet through man-made chemical emissions is probably the largest human impact – and the one that is least understood or regulated. It is one of ten major existential risks now confronting humanity, he describes in Surviving the 21st Century.

"The European Chemicals agency estimates there are more than 144,000 man-made chemicals in existence. The US Department of Health estimates 2000 new chemicals are being released every year. The UN Environment Program warns most of these have never been screened for human health safety," he says.

"The World Health Organisation estimates that 12 million people – one in 4 – die every year from diseases caused by 'air water and soil pollution, chemical exposures, climate change and ultraviolet radiation', all of which result from human activity."