Chemicals in the environment may be behind the dramatic drop in male fertility rates, but there is debate over what exactly is behind lower sperm rates.

The concentration of active sperm in male semen samples has reportedly halved in the past 50 years, leading to a mass of research into what modern factors are affecting men.

Press PLAY to hear more about the sperm slump

IVF Australia Medical Director Doctor Peter Illingworth told Millsy and Karl on 6PR Breakfast there are possible connections to the use of plastics, tin cans and other daily products.

“It’s likely there’s something real going on, but the extent of it is not totally clear,” Dr Illingworth said.