New research suggests that sperm counts have fallen by half in the last 50 years
| By Teresa Carr, 24 May 2019
The Guardian – Surprising new research into dog sperm has reproductive biologists concerned about the fate of their own species.
In a March study, scientists at Nottingham University found that two chemicals common in home environments damage the quality of sperm in both men and dogs.
The culprits implicated are diethylhexyl phthalate (DEHP), used to make new plastics more pliable, and polychlorinated biphenyl 153 (PCB153), found in older plastics and electrical equipment.
Companies stopped producing PCBs in the late 1970s due to their health risks – including a possible increased risk of cancer, hormone disruption, liver damage and behavioral or cognitive deficits in children exposed to the chemical in utero – but the chemical persists in the environment.
The Nottingham study is just one in a mounting pile of research indicating that the quality and quantity of men’s sperm is on the decline.
Research suggests that sperm counts have dropped by half in the last 50 years or so and that a higher percentage are poor swimmers – slow, ungainly or beset by genetic flaws.
The exact cause of that decline is not well understood. One culprit may be increasingly unhealthy lifestyles.
The same factors that affect general health – being overweight or obese, smoking, stress and alcohol or recreational drug use – also affect the quality of sperm.
But many researchers suspect chemical residues in the environment may be partly to blame. 9 In 10 Americans Have Pesticides In Their Bodies
To test that theory, the Nottingham researchers first removed contaminants from semen samples of men and dogs then exposed the manmade chemicals.
Results showed that exposure to chemicals at levels found in the environment reduced sperm motility (ability to swim) and fragmented DNA carried in the head of the sperm … Read more.
The last (plastic) straw?
James Philp, March 2019
Organisation for Economic Co-operation and Development
“I just want to say one word to you. Are you listening? Plastics.”
This infamous advice, delivered to Ben, played by Dustin Hoffman in the 1967 film, The Graduate, foresaw a great career in plastics.
And indeed, plastic is one of the most successful materials ever produced. So much so that about 300 million tonnes are produced each year.
But the gloss has faded a little too, because of severe environmental problems which plastics pose.
They are generally not biodegradable and hang around in the environment for decades or much longer.
In 2018, a Pacific Ocean garbage patch was estimated to be 16 times larger than previously thought–it is 2 times the size of France. In the oceans, they can break down to microplastics, which can be taken up by, and interfere with, marine life.
A report in January 2019 showed that every marine mammal in a survey contained microplastics, and the effects of this are largely unknown. Read more.