Dog days: how our best friends affect IAQ

In what will come as no surprise to any dog owner who has ever watched in dismay while their four-legged friend makes a beeline to the nearest mud patch at the park, a new study has confirmed that dogs are significant sources of indoor emissions that affect air quality.

Our Best Friends: How Dogs Alter Indoor Air Quality, published in Environmental Science & Technology, is the first study to focus specifically on dogs, measuring their contribution to indoor air contaminants across a range of categories: carbon dioxide (CO₂), ammonia (NH₃), ozonised volatile organic compounds (VOCs), coarse and fine particulate matter, and bacteria and fungi.

The experiments took part in a 62m³ climate-controlled laboratory in Lausanne, Switzerland, using four small dogs – all chihuahuas – and three large dogs: a mastiff, a Tibetan mastiff, and a newfoundland. Tests were conducted in two-hour blocks using various regimented conditions, with control tests to identify human contributions to emissions.

Researchers found that big dogs emitted significantly more contaminants than small dogs, and in some cases more than seated adult humans. Perhaps most noticeably, testing showed that large dogs emit between two and four times more bacteria and fungi than a seated person, while generating roughly the same levels of CO₂ and NH₃.

While the paper’s authors acknowledged that there were significant limitations to their method, they said the results show that dogs are major sources of indoor emissions and that further research is needed to determine health effects for humans and potential management and mitigation strategies.

In the meantime, perhaps it’s time to finally move Spot’s bed into the backyard …

Image courtesy of Wirestock via Freepik

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