Depending on where you live, your air pollution levels will vary. It is my observation that a lot of people do not open their windows, but it is very important to do so to shift the energy and the air through the house.
If you are on a major road or live in the city or in an area where smoke is impacting your air quality due to forest fires, an air purifier is a fabulous investment for the family and your pets. We noticed a massive difference in our breathing and sleeping when we introduced them to every floor of our house. The dirty filters said it all! Gross!
Tsai W. T. (2019). An overview of health hazards of volatile organic compounds regulated as indoor air pollutants. Reviews on environmental health, 34(1), 81–89. https://doi.org/10.1515/reveh-2018-0046
https://www.blueair.com/us/air-purifiers(Can be found in most countries via Amazon)