"Poor air quality affects everyone" — How to protect yourself and clean the air

I remember when you could ride BART for free on a “Spare the Air” day, when smog was expected to reach unhealthy levels based on standards set by the Environmental Protection Agency. Now, there are too many of these days — 26 in the Bay Area last year — to enjoy that perk.

This bad air is making us sick, according to Stanford allergy specialist and clinical associate professor Sharon Chinthrajah, MD. In a recent episode of the Sirius radio show “The Future of Everything,” she spoke with Stanford professor and radio host Russ Altman, MD, PhD, about how we can combat the negative health impacts of air pollution.

“Poor air quality affects everybody: healthy people and people with chronic heart and lung conditions,” said Chinthrajah. “And you know, in my lung clinic I see people coming in with exacerbations of their underlying lung diseases like asthma or COPD.”

On Spare the Air days, Chinthrajah said even healthy people can suffer from eye, nose, throat and skin irritations caused by air pollution. And the health impacts can be far more serious for her patients. So she tells them to prepare for bad air quality days and to monitor the air quality index (AQI) in their area, she said.

The AQI measures the levels of ozone and other tiny pollutants in the air. The air is considered unhealthy when the AQI is above 100 for sensitive groups — like people with chronic illnesses, older adults and children. It’s unhealthy for everyone when the AQI is above 150.

On these unhealthy air days, Chinthrajah recommends taking precautions:

  • Limit the time you spend outdoors.
  • When outside, use a well-fitted air mask that filters out pollutants larger than 2.5 microns (which is about 20 times smaller than the thickness of an average human hair).
  • When driving, recirculate the air in your car and keep your windows closed.
  • Stay hydrated.
  • Once inside, change your clothes and take a quick shower before you go to bed, removing any air particulates that collected on you during the day.

In the radio show, Chinthrajah explained that published studies by the World Health organization and others demonstrate that people who live in developing countries like India and Asia — where they suffer poor air quality many days of the year — have a shortened life span.

“You know, there’s premature deaths. There’s exacerbation of underlying lung issues and cardiovascular issues. There’s more deaths from heart attacks and strokes in countries where there is poor air quality,” she said.

She admitted that it is difficult to definitively say these health problems are due to poor air quality — given the other problems in the developing country

es like limited access to clean water, food and health care — but she thinks poor air quality is a major contributor.

Chinthrajah said she believes we need to address the problem of air pollution at a societal level. And that means we need to target cars that burn fossil fuel, which account for much of the air pollution in California, she said. Instead, we need to move towards using public transportation and electric vehicles, as well as generating electricity from clean energy sources like solar, wind and water.

She noted that California is now offering a $9,5000 subsidy to qualifying low-income families to purchase low emission vehicles like all-electric cars or plug-in hybrids, on top of the standard federal and state rebates.

“So it seems like an overwhelming, daunting task, right? But I think we each have to take ownership of what we can do to reduce our carbon footprint. And then lobby within our local organizations to create practices that are sustainable,” she said.

Chinthrajah hopes that addressing air pollution and energy consumption at a societal level will lead to less asthma and other health problems, she said.

Image by U.S. Environmental Protection Agency 

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Use your range hood for a healthier home, advises indoor air quality expert Brett Singer

Photo courtesy of Brett Singer.

Most Americans don’t realize cooking can be a major source of indoor air pollutants, unless they’ve recently burned something on the stove. But studies have shown that cooking-related contaminants can cause health problems such as respiratory illness and asthma attacks.

To learn more, I spoke with Brett Singer, PhD, a scientist at Berkeley Lab who investigates indoor air quality. Recently, he measured the levels of pollutants emitted from gas cooking burners and ovens in several Bay Area homes. I asked him about this study and for advice on how to reduce cooking pollutants.

Are harmful pollutants emitted when cooking?

“A gas burner almost always produces significant quantities of nitrogen dioxide, which is a respiratory irritant. Depending on the burner configuration, it can also produce carbon monoxide, which is regulated by the Environmental Protection Agency. In general, newer cooktop burners don’t produce much carbon monoxide because of design improvements. Finally, the gas produces ultrafine particles, smaller than 100 nanometers, which are dangerous because they can move around your body in ways that larger particles can’t.

Electric burners don’t produce carbon monoxide and produce only small amounts of nitrogen dioxide. But an electrical coil burner can produce ultrafine particles, particularly when you first turn it on.

Cooking food on either type of burner also produces fine particles and some organic chemicals, including acrolein and polynuclear aromatic hydrocarbons that are known to be hazardous. Frying, broiling and other cooking at high temperatures generally produces more pollutants.

However, these pollutants can be easily addressed with good kitchen ventilation, which is especially important if you live in a small home.”

What did your in-home study find?

“We went into moderately sized homes — eight 1,400 to 2,500-square-foot homes and one small apartment — with common, well-functioning equipment that had been in use for a few years. We measured the concentrations of pollutants in the kitchen and elsewhere as we boiled and steamed water on the cooktop and/or oven, with and without ventilation. We found issues in half of these homes and that’s not good. In four of the homes, we showed that the gas-cooking burners emitted enough nitrogen dioxide to exceed the health standards for outdoor air.”

What are your tips to minimize these cooking pollutants?

“The first tip is to ventilate when you cook, and to ventilate more the more you cook. Range hoods are the most effective way to do this, if your range hood actually moves air out of the kitchen. If you have a range hood that just recirculates air back into the kitchen, you need to use another exhaust fan — for example, from a nearby bathroom — or open windows.

You also need to use your hood or exhaust fan regularly. Based on several surveys, many people only occasionally use them. People report not using them because they’re noisy, because people forget to turn them on or because they aren’t needed unless removing smoke, odors and moisture — like when frying something stinky. Those are good reasons to use ventilation, but people can’t sense pollutants, so they may not be ventilating sometimes when it’s really needed.

If you’re buying a new range hood, buy a quiet one that you like. If it isn’t quite as efficient but you’re happy with it and you’ll use it, then great. To improve on that, a range hood needs to have higher flow rates and cover the front burners.

Beyond that, almost any range hood works better if you cook on the back burners. If you put it on a low speed and cook on a single back burner, then you’ll typically capture 50 to 70 percent of the pollutants.”

What is the ultimate goal of your research?

“The goal of our work on kitchen ventilation is to help people cook all they want  — with gas or electric — without exposing themselves to harmful air pollutants. This is an important part of our broader work on high performance homes that use very little energy and provide a healthier environment for their occupants. We try to provide the science to inform builders, retrofit contractors and the general public.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Air Pollution Lurks Inside Your Home

photo of stir-frying
Photograph by kfisto via Creative Commons licensing.

How would you like a job that involves grocery shopping at Trader Joes 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 pollutants – cooking.

When people think of air pollution, they usually picture a factory spewing a plume of toxic chemicals. 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.

Scientists at the Lawrence Berkeley National Laboratory (Berkeley Lab) have investigated 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 mm or less, formaldehyde and acrolein are the worst indoor contaminants for nonsmoking households.

Fine particulates are found indoors mainly due to cooking, burning candles or incense, and outdoor sources that leak inside. Formaldehyde is mainly emitted by materials used in home construction and furniture, such as particle board, paneling and foam insulation. Acrolein in the home is primarily from cooking, especially oils. All three of these contaminates also come from tobacco smoke.

“Think about what your 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. Since cooking is a major source of indoor air pollutants, they have also evaluated the effectiveness of cooking exhaust hoods. Their study results showed 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-fry and cookies are just a happy bonus for his coworkers like Melissa Lunden.

For more information about indoor air pollution, check out my KQED Quest blog.