Chemicals found in carpets, floors, clothes damage sperm, make them weaker swimmers in both men, dogs
Chemicals found in household items are damaging the sperm of both men and their dogs, research has found.Sperm quality in men has fallen by 50 per cent in the past 80 years.
And, intriguingly, it has also been found to have fallen by 30 per cent in domestic dogs.This has led researchers to believe the common factor damaging both species’ fertility is living in the home environment.They found chemicals known as DEHP and PCB 153 are found in similar levels in humans and dogs – suggesting that, despite very different diets and activities, both are having their fertility damaged in the same way.
Researchers from the University of Nottingham tested the effects of the two chemicals on sperm count and quality of men and dogs.PCB was banned in the United Kingdom (U.K.) and Europe in 2004 but it lasts a long time in the environment and can be found in fatty foods.
DEHP, full name diethylhexyl phthalate, is found in many items containing plastic, including carpets, flooring, furniture, clothes and toys.
Scientists tested the effects on semen in a lab using concentrations of the chemicals found in human and dogs – and found that they led sperm quality to decline. Sperm had reduced motility – they were less able to swim – and also showed more signs of DNA damage.The chemicals have similar effects to the female sex hormone, oestrogen, meaning they cause problems during sperm production – a testosterone-led process.
Professor Richard Lea said: “This new study supports our theory that the domestic dog is indeed a ‘sentinel’ or mirror for human male reproductive decline.“And our findings suggest that man-made chemicals that have been widely used in the home and working environment may be responsible for the fall in sperm quality reported in both man and dog that share the same environment.
“Our previous study in dogs showed that the chemical pollutants found in the sperm of adult dogs, and in some pet foods, had a detrimental effect on sperm function at the concentrations previously found in the male reproductive tract.
“This new study is the first to test the effect of two known environmental contaminants, DEHP and PCB153, on both dog and human sperm, in the levels found occurring in samples.” The impact of the chemicals was on motility – a measure of how the sperm are of moving and on how much the DNA carried in the sperm is fragmented.
Rebecca Sumner, who carried out the experimental work as part of her PhD, said: “In both cases and in both subjects, the effect was reduced sperm motility and increased fragmentation of DNA.“We know that when human sperm motility is poor, DNA fragmentation is increased and that human male infertility is linked to increased levels of DNA damage in sperm.
“We now believe this is the same in pet dogs because they live in the same domestic environment and are exposed to the same household contaminants.“This means that dogs may be an effective model for future research into the effects of pollutants on declining fertility, particularly because external influences such as diet are more easily controlled than in humans.”
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