In my Fundamentals of Environmental Engineering class on Friday, we were discussing Micro and Macro Air Pollution problems including indoor air quality, acid rain, stratospheric ozone depletion and climate change.  I opened it up for an AMA (ask me anything) and I got 3 questions about how can we keep our indoor air quality healthy while we are all social distancing and staying at home?  Here are the questions and my brief answers to the students:

1. How can people who live in cold climates (like myself) combat indoor air pollution, especially during a time like this where people are spending the majority of their time inside? It’s been snowing for the past 2 days where I live…

It is so tough in the winter. Minimize sources of air pollution inside is the main thing. The biggest source is typically cooking, especially with natural gas stoves, so use your exhaust hood all the time when cooking. Cook over lower heat too. If you don’t have an exhaust hood that exhausts directly outside, you can and should open a window or you can leave on your bathroom fans, but this will typically cause more cold air to leak into your home and you will need heat more. make sure to take off your shoes indoors, have track mats at each door also helps. And when cleaning use simple products with 60% alcohol and fragrance free (if you can find them!).

2. How are indoor air quality levels monitored and maintained? Should I be worried about and paying attention to the levels of lead, bioaerosols in addition to the carbon monoxide that we monitor? Can changing my choices as a consumer (non-flame retardant furniture, no aerosols, electric stove) lead to lower levels of indoor air pollutants?

The main source of lead in a home is paint. And you may find this kind of paint in homes that are older than 1978. Here is what the EPA says about this topic: Lead Paint. As long as you do not disturb the paint, and the paint will typically be under layers of newer paint and if it is good shape or it is not flaking off of surfaces it should be ok…it can get in the dust if it is flaking or peeling. Some main bioaerosols of concern in homes are indoor allergens: dust mites, pet allergens, cockroaches, indoor and outdoor molds. But if you home is newer there should not be lead paint. if you do not have allergies or asthma, then bioaerosols are typically not a worry, except of course these days when we have this highly infectious virus spreading around. Which is why we should and are all staying home – a selfless act to protect public health and for the greater good – so make sure you wash your hands and do everything the CDC recommends. You can definitely change your consumer habits and reduce toxic sources in your home. purchase non-flame retardant furniture, buy fragrance-free household products, minimize carpeting in your home and do not purchase textiles treated with PFAS, use your exhaust hood while cooking…

3. Now that my family is all inside the home, how do we minimize indoor air pollution (not just spread of viruses, but also other hazards like CO). I live in a fairly old home, so our ventilation system is not very good – should we be changing our air filters more? Do those air filters in homes really help at all?

Older homes are actually typically leakier, which is a good thing. That means more outside air can leak into and out of your home if there is a pressure/temperature differential between indoors and outdoors. Your air exchange rate will be higher (so more like 1 (air changes per hour (1/hour, ach), compared to a tighter home that has a lower air exchange rate, like 0.2 ach). To increase ventilation you can leave on bathroom fans and also use your stove exhaust hood a lot (as long as they vent directly outdoors) especially when cooking. you can also leave on your whole house fan to run continuously and yes change the filters more often. The filters do help, bt they are not very efficient typically but better than nothing. There is not much evidence that running a whole house fan will improve indoor air quality by the way but it does mix your indoor air and run it through a coarse filter so might be beneficial (need more research here!).  You could also upgrade to an electret filter or purchase an air cleaner. make sure you have a CO alarm.