Air Pollution Lurks Inside Your Home

Photograph courtesy of kfisto via Creative Commons licensing.
Photograph courtesy of kfisto via Creative Commons licensing.

How would you like a job that involves shopping at the grocery store with the company credit card and cooking dishes like stir-fry? This describes Tosh Hotchi’s job, but he isn’t a chef. He is part of a research team that studies how to build healthy, efficient homes, including how to improve the quality of air inside a home through better ventilation. Hotchi is helping to study a major source of indoor pollution: cooking.

When people think of air pollution, they usually picture a factory spewing a plume of toxic chemicals into the air. But indoor air pollution causes significant health effects such as respiratory illness, asthma attacks, cancer and premature death. Californians spend over 45 billion dollars each year on these health impacts, according to a study by the California Air Resources Board. This is in part because they spend about 90% of their time indoors, which is typical for people living in a developed country.

Scientists at the Lawrence Berkeley National Laboratory (Berkeley Lab) have identified which indoor air pollutants cause the greatest health consequences. In a paper published in Environmental Health Perspectives, they reported that fine particles with a diameter of 2.5 μm or less, formaldehyde and acrolein are the worst indoor contaminants for non-smoking households.

Fine particulates are found indoors mainly due to cooking, burning candles or incense, tobacco smoke and outdoor sources that leak inside. These fine particulates cause significant health problems – stroke, heart disease, chronic bronchitis and premature death.

Formaldehyde is mainly emitted by materials used in home construction and furniture, such as particle board, paneling and foam insulation. It also comes from cooking and tobacco smoke. Formaldehyde is a lung irritant that can trigger asthma attacks and it may cause cancer.


Acrolein was used as a chemical weapon in World War I. Acrolein in the home is primarily from cooking (especially oils) and tobacco smoke. It is a strong irritant for the skin, eyes and nasal passages.

“Think about what you're putting in your home,” says Melissa Lunden, a Berkeley Lab staff engineer. “Most of us have to cook, but do you need the candles, incense and air fresheners? Freshening your air requires taking stuff out, not putting more stuff in.”

Berkeley Lab scientists are now looking for ways to improve indoor air quality by developing better standards for residential buildings and new tests to measure these hazardous pollutants. For example, their Berkeley Lab report recommends to regulators that whole-residence ventilation rates should focus on controlling formaldehyde and acrolein, whereas filtration should be used to remove fine particle pollutants.

Since cooking is a major source of indoor air pollutants, Berkeley Lab scientists have also evaluated the effectiveness of cooking exhaust hoods. Their study results showed that cooking hoods should be redesigned and new rating standards are needed to help consumers know how effective a cooking hood is at removing pollutants. However, they also found that indoor air quality can be significantly improved by simply cooking on the back burners of your stove, using higher fan settings and turning the fan on before you start cooking. Further research on cooking-induced pollutants is underway using a new demonstration kitchen to study real-life cooking conditions. During these studies, Tosh Hotchi’s stir-fries and cookies are just a happy bonus for his co-workers like Melissa Lunden.

Learn more about how air quality affects your health this week during Air Quality Awareness Week.