Now that we are heading into summer, we thought we’d check in on how the spring cleaning went—and what kind of difference our community members are finding between their indoor and outdoor air quality.

How we did it

To do this experiment, we analysed 70 000 sets of continuous measures (6 millions individual data points) collected by Flow community members from around the world in March, April, and May. We were able to compare these measures with the outdoor air quality taken from our environmental data platform.

What we discovered

When we look at the data, it becomes clear that particulate matter is, on average, much higher outdoors. The same holds true for NO2 but in a slightly less dramatic way. VOCs are virtually 0 outdoors and approach moderate levels inside.

You’re probably thinking, that’s not so groundbreaking—particulate matter and NO2 are generally considered to be an outdoor problem. True, but it’s important to note is that PM10 and VOC levels are hovering around the moderate level of the Plume Air Quality Index. At this level (21-50), air quality is considered acceptable, though over the recommended WHO threshold for one year. This means that, unless you have these kinds of conditions all year round, you shouldn’t be experiencing adverse health effects. The problem is, according to the EPA, “Americans, on average, spend approximately 90 percent of their time indoors” making these moderate levels more important.

So what can I do about it?

Volatile organic compounds (or VOCs) are the main culprit identified in this experiment. These are mainly carbon-based molecules found as gases in the air—originating from household products, cooking processes or indoor mold. At high concentrations, they can cause irritations and decreased breathing capacity. Some are classified as carcinogenic.

Simple actions can help improve the air you breathe at home. Here’s our best advice to vanquish VOCs.

1. Ventilate: Ideally you should open all external windows and doors in your home for 10 to 15 minutes a day—whatever the season. Pro tip: Use the Plume Air Report to choose the best moment to ventilate when outdoor air pollution is lowest
2. Cooking? Turn on the extractor fan: It’s also a good idea to ventilate after cooking as indoor pollution can worsen due to oil and other ingredients evaporating into the air. The above two work for particulate matter as well!
3. Choose cleaning products wisely: Keep an eye on the label! It’s better to go for multi-use products, to avoid combining multiple irritants. Make sure to store these products in a safe, ventilated area. Avoid sprays, and try savon noir or white vinegar instead!
4. Scented Products: They smell good, but many fragrances are allergy-inducing. There are official lists of safe-to-use products, and harmful substances should be mentioned on product labels.

Anything pique your interest? Want to learn more about a topic in particular? Send us your suggestions for future science stories!