The couch you sit on, the carpets you walk on, and even some of your kids’ toys may pose health risks due to the chemicals they are made with. In some of the latest research, it was found that a commonly-used household chemical known as DEHP may be harming fertility not only for men – but also for dogs.
The chemical DEHP – used in carpets, flooring, upholstery, clothes, wires and toys – and the industrial chemical polychlorinated biphenyl 153 (PCB153), may harm male fertility in humans and dogs, researchers from the University of Nottingham found. And even though PCB153 is banned worldwide, it remains widely detectable in the environment. In fact, both chemicals have been found in commercially-available dog food. 
Laboratory tests with sperm taken from male humans and dogs showed levels of the 2 chemicals consistent with environmental exposure reduced sperm motility and increased fragmentation of DNA in both species.
Scientists have established that poor human sperm motility leads to increased DNA fragmentation in both men and dogs, which increases the likelihood of male infertility.
The findings are especially concerning in light of previous studies that show a 50% decline in human sperm quality worldwide in the past 8 decades. Another study by the same group of researchers showed a similar decline in dogs, which suggests that household chemicals are at least partly to blame. 
Study leader Richard Lea said in a university news release:
“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.”
The new study is the first to test the effect of DEHP and PCB153 on both human and dog sperm in the lab, in real-world concentrations.
The scientists think there is a good chance that location determines the extent to which males are affected by the chemicals. This is because the chemicals are a large part of Western industries. Previous studies have been unable to find the same sperm decline in men and dogs living in Asia, Africa, or South America, which suggests the problem is a predominantly Western one. 
As well, other factors may be involved in the declining sperm quality of men and pups, such as air pollution and obesity. Still, it’s reasonable to conclude that since men and dogs are exposed to household contaminants at the same levels, those contaminants are likely affecting their sperm.
“Demonstrating such effects of chemicals at environmental concentrations raises awareness of these pollutants, and my hope is this will lead to steps in our personal lives to reduce or at least limit further exposures.”