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.