How dogs may be shaping the air inside your home

When thinking about indoor air quality, most people focus on ventilation systems, outdoor pollution, or household products. But researchers say another everyday factor may play a role: pets.Many households today include one or more pets, and dogs in particular spend most of their time sharing the same living spaces as their owners. Because of their close coexistence, their presence may subtly influence the indoor environment.Dogs spend much of their time moving around the same indoor spaces as their owners. They breathe, shed fur, carry dirt from outside, and interact closely with people. All of these small activities can introduce substances into the air inside a home. Scientists now suggest that pets should be considered part of the indoor environment, just like human occupants. Their presence can subtly change the mixture of gases, particles, and microorganisms floating in the air.This is according to a study published in Environmental Science & Technology. The research was undertaken by scientists to understand how dogs impact indoor air composition. They were led by Dr Dusan Licina of the Swiss Federal Institute of Technology in Lausanne (EPFL).Experiments were set up in a controlled room to conduct the research. By using a closed room, scientists were able to measure minute variations in indoor air composition as dogs and their owners spent time in it.Seven dogs were used in conducting the research. Four of them were of small breeds known as Chihuahuas. The others were larger breeds. By using dogs of varying sizes, scientists were able to ascertain whether size impacted composition.There were variations in indoor composition when dogs were around. Larger dogs were more impactful since they emit more gas and particles.One of the clearest findings related to gas emissions. The levels of carbon dioxide, according to the study, increased during the presence of dogs inside the experimental chamber.This is understandable since animals tend to emit carbon dioxide as they breathe. The interesting part is that large dogs can do this at a rate similar to that of a seated adult human.Ammonia levels were also increased during the dog experiments. This gas is usually emitted during processes involving human skin as proteins are broken down over time.In homes with poor ventilation, gases emitted by pets can build up more quickly, especially if there are multiple pets in one home. However, it is important to note that this does not mean it is unhealthy in those households.Dogs may also affect the air through movement. For example, walking on the floor, scratching, or even petting may lead to the emission of particles into the air.These particles may be dust, fur, or other materials that have accumulated on the dog’s coat. From the experiment, it is evident that there is an increase in particles when the dog is active or when it is with its owner.Some cases showed that there were more particles emanating from the dog compared to the number of particles emanating from the humans sitting next to it. Most of the particles were large, meaning they would settle on surfaces after a short period of time.Therefore, air conditions may change frequently during the day.Another interesting result involved microbes such as bacteria and fungi. According to the study, these microorganisms increased in the air when dogs were present in the chamber.Dogs often bring microbes indoors from the outside environment. Soil, plant material, and other organic matter can cling to their fur or paws during walks.Once inside the home, these microbes may become airborne when the dog moves around or shakes its coat. Larger dogs in the study released noticeably higher levels of airborne microbes than the seated humans.Researchers noted that the study did not link these microbes to any specific health problems. Indoor environments naturally contain many types of microorganisms.The researchers say the findings highlight an overlooked factor in indoor air studies. Many models used to estimate indoor air quality focus mainly on human occupants.However, pets are also active sources of gases, particles, and biological material. Ignoring them could lead to incomplete estimates of what people are actually breathing indoors.The U.S. Environmental Protection Agency guide estimates that people spend around 90 per cent of their time indoors. Because of this, understanding all the contributors to indoor air is increasingly important.Other pets that future research might investigate include cats, rabbits, or rodents and their impact on our indoor environment. Another area of future research is to investigate pets in our homes, not in a laboratory setting, but in a normal environment where cooking, cleaning, and outdoor pollutants are also present.What this research tells us is that pets are not just our companions in our home, but also a part of our intricate indoor ecosystems that affect our breathing every day.