Children in schools are especially vulnerable to indoor air pollution. Treating the air through building or portable air cleaners can improve air quality.
Photo by Dusan Sapic, courtesy iStockphoto
Outdoor air pollution receives a lot of much-deserved attention because of its overwhelming threat to human health. But the dangers posed by air people breathe inside are often overlooked and underestimated.
A new report from the National Academies of Sciences, Engineering, and Medicine may help change that. Released in January, the report links indoor air pollution sources such as chemicals, cleaning agents and cooking to risks that include asthma, cancer and high blood pressure.
The Nation's Health spoke with the report's committee chair, Richard Corsi, PhD, MS, dean of the College of Engineering at the University of California-Davis.
What are the most common causes of indoor air pollution?
No. 1 is outdoor pollution. When we see pollution levels go up outdoors, we see those same pollutants go up indoors, because those pollutants are transported into buildings.
Cooking is an important one. If we're cooking with natural gas, its pollutants — these very small particles — can move up the nose and deposit directly in the brain.
People are a source of air pollution. Our respiratory aerosols, the skin we shed constantly in our homes all suspend particles that deposit on surfaces and get resuspended when we (agitate) them.
Chemical reactions that occur indoors can generate lots of ultra-fine particles.
Beyond smoking, the dangers of indoor air pollution have not previously received much attention. Why is that?
Removing tobacco smoke from a lot of indoor spaces has been a massive success story in terms of improving indoor air quality.
“The reason why we haven't advanced more on indoor air relative to outdoor air is that it's a lot more complicated.”
— Richard Corsi
The reason why we haven't advanced more on indoor air relative to outdoor air is that it's a lot more complicated. The U.S. has millions of residential, commercial and institutional buildings. Every one of those is different. Trying to wrap our heads around how we deal indoor air pollution within buildings is simply impossible because of the scale.
Seniors and children are among those most at risk from indoor air pollution. What can be done to protect them?
If nursing homes or schools are near industrial facilities or busy roadways where there's lots of transportation-related air pollution, the best thing you can do is have an air intake to treat the air coming in. When conditions are really bad, you can use portable air cleaners that will reduce anything that gets through the primary filtration system — the central mechanical system taking in outdoor air.
It will also help to reduce ventilation to stave off the spread of infectious disease from pathogens. If the main sources are indoor, the best thing to do is identify those sources and get rid of them if you can. If you can't do that, use good air filtration systems.
How concerned should we be about wildfire smoke coming indoors?
We should be extremely concerned about wildfire smoke, only because we're going to keep seeing more of it. We see a general trend with improvement in fine particulate matter across cities in the U.S., except during wildfire season. Then, we see huge spikes that wipe out all the gains that we've made over the years in improving outdoor air quality.
There seems to be emerging data that wildfire smoke does have impacts on early births and birth weight of children. In the coming couple of years, we're going to learn a lot more about additional health impacts of wildfire smoke.
What actions can policy-makers take to improve indoor air quality?
The No. 1 thing that can be done is to acknowledge that it's an important issue. We saw improvements in the U.S. through the Clean Water Act. We need to do the same thing with indoor air and have the same laser focus and acknowledgment of the issue by policymakers.
There's lots of different organizations that are doing things that are related to indoor air, but they're not united in their approach. We need all of those agencies and organizations and institutions to come together to improve this issue.
Common cleaning products can contribute to indoor air pollution, as can cooking, fireplaces and candles. Outdoor air pollution can seep inside through poorly sealed doors and windows.
Photo by FatCamera, courtesy iStockphoto
What about indoor pollution risks for underrepresented groups?
All logic would say that there are disparities and a greater impact on underserved communities than those that have the resources to help themselves.
But having said that, because we haven't done enough research on underserved communities, we haven't been able to prove that definitively. And so that research is needed to say, “Yes, not only do we think there are disparities, but there are significant health impacts of those disparities.” We need to focus research on them.
We also need to focus applications in those areas. And that's incumbent upon states, counties and policy-makers to provide block grants to help folks in underserved communities improve their buildings.
And make sure they're able to filter outdoor air that comes indoors and remove indoor gases and sources of particles.
What strategies can people use to protect themselves from indoor air pollution?
The No. 1 thing is to understand sources that are particularly harmful and not have them in your house if possible. The second is improved ventilation. I would include local exhaust ventilation. Everybody should have a functional exhaust fan above the burners on their stove. Three is proper filtration.
In extreme cases such as wildfire smoke or high incidence of COVID-19, wear personal protective equipment, high-quality masks or respirators.
For more information on “Health Risks of Indoor Exposure to Fine Particulate Matter and Practical Mitigation Solutions,” visit www.nationalacademies.org.
The interview was edited for style, space and clarity.
- Copyright The Nation’s Health, American Public Health Association
Jump to section
- Top
- What are the most common causes of indoor air pollution?
- Beyond smoking, the dangers of indoor air pollution have not previously received much attention. Why is that?
- Seniors and children are among those most at risk from indoor air pollution. What can be done to protect them?
- How concerned should we be about wildfire smoke coming indoors?
- What actions can policy-makers take to improve indoor air quality?
- What about indoor pollution risks for underrepresented groups?
- What strategies can people use to protect themselves from indoor air pollution?