Environmental contaminants found in our homes are not only harmful to men's fertility. According to a new study, sperm quality in domestic dogs is also affected.
Men are not the only ones to suffer from pollution in homes: their faithful companions too. This is highlighted by a new study conducted by scientists at the University of Nottingham, England. Published in the journal Scientific Reports, it suggests that the chemical pollutants used in our daily products but also in certain food packaging have the same adverse effects on male fertility, whether that of humans or domestic dogs.
The dog, "mirror" of the decline of reproduction in humans
Two chemicals have particularly caught the attention of researchers: first the common plasticizer DEHP. This phthalate, known to be an endocrine disruptor, is widely used in our everyday products to increase the flexibility of plastics. Today banned in all toys and childcare articles for children, it is found in many utensils such as shower curtains, garden hoses, plastic films and containers to preserve food, but also in carpets, floor coverings or in the upholstery of some furniture. The other chemical component to be analyzed is polychlorobiphenyl 153 (PCB 153), a persistent industrial product that is currently banned but remains largely detectable in the environment and in food.
The researchers conducted identical experiments in humans and dogs and used sperm samples from donors and breeding dogs living in the same area in the UK. The results show that chemicals, at concentrations relevant for environmental exposure, have the same adverse effect on human sperm as the dog.
"This new study supports our theory that the domestic dog is indeed a 'sentinel' or a mirror of male reproductive decline," says Richard Lea, Associate Professor and Lecturer in Reproductive Biology at the University of Michigan. School of Veterinary Medicine and Science. "Our findings suggest that human-made chemicals that have been widely used at home and at work could be responsible for lowering sperm quality reported in humans and dogs, who share the same environment."
Less mobile spermatozoa
Researchers have found that human subjects, such as dogs exposed to these chemical components, have reduced sperm motility and increased fragmentation of DNA.
"We know that when the motility of human spermatozoa is low, DNA fragmentation increases ... We now believe that it is the same thing in pet dogs because they live in the same domestic environment and are exposed to the same contaminants, "says doctoral student Rebecca Sumner, who participated in the study.
According to her, this discovery could mean that dogs are an effective model for future research on the effects of pollutants on fertility decline, "especially because external influences such as diet are easier to control than in the man".