Air pollution to many might conjure images of the famous London Fog or smoggy Los Angeles of 1970s. But I get to experience it firsthand during my periodic trips to Delhi (India) to visit my grandparents. Sometimes the pollution levels increase to high enough levels that a brown haze forms around the entire city for days at a stretch. According to medical experts, a person in Delhi could be smoking up to 20 cigarettes — without even touching one — on a bad day. It therefore came as a shock to me when I recently discovered that cooking dinner in our home in McLean could generate indoor air pollution as unhealthy as outdoor air in the world's dirtiest cities.
The root cause is found in frying, grilling, or toasting foods with gas and electric appliances as they generate pollution particles such as, nitrogen dioxide, carbon monoxide, carbon dioxide, and other volatile organic compounds.
Researchers at the Lawrence Berkeley National Laboratory (Berkeley Lab) have conducted studies demonstrating that cooking could generate particle concentrations four times higher than major haze events in Beijing.
This news piqued my interest to test and understand my levels of exposure to pollution particles both inside my home and outdoors in the McLean community. How bad could it be? With the availability of portable devices in the market that measure personal air pollution exposures across various microenvironments, I was able to test this very question.
I conducted this research for my high school project, where I collaborated with the researchers at the Johns Hopkins University’s School of Public Health to experiment, analyze, and compare my exposure to particle concentrations in various indoor and outdoor environments in and around McLean.
What makes air pollution one of the biggest global concerns today? Air pollution generates airborne particles and exposure to these fine particles (particles usually less than 2.5 μm in diameter) and ultrafine particles (particles less than 0.1 μm in diameter) present in our immediate environments can cause significant health damage. These tiny particles are often able to travel deeply into the respiratory tract, reaching and depositing in the alveolar region of the lungs. Exposures over a period of time could lead to asthma, lung cancer and other respiratory diseases, as well as heart diseases. In addition, recent studies have correlated air pollution with increased incidences of diabetes and childhood stunting.
According to a recent Lancet Commission report, air pollution is the largest environmental cause of disease and death in the world, responsible for an estimated 9 million premature deaths and 16 percent of all deaths worldwide annually. This is almost 15 times more than deaths from all war and other forms of violence. Surprisingly, recent research indicates that indoor air pollution should be as much of a concern if not more compared to exposure outdoors.
My experiments indeed corroborate the recent research findings. I found that my exposure to pollution particles was almost three times higher indoors than in outdoor locations in McLean. As expected, the largest concentration of pollution particles was found in the kitchen. Also, I found that particle exposure was particularly high during cooking times. In terms of outdoors, the McLean Commercial District and the Mclean High School parking area during school drop-off had high concentration of pollution particles, but the particle numbers were still far less than the indoor levels at home. However, with adequate ventilation, there was a considerable improvement in measured indoor pollution levels.
Understanding such personal exposure has significant value in terms of raising awareness of people's activities and habits and the resulting potential exposures to air pollution. This also shows that we need not be in Delhi or Beijing but can be inhaling bad air even when cooking our favorite food inside our homes in McLean.
But what could be done to reduce our exposure? Experts at the Berkeley Lab suggest that we should ventilate when we cook and ventilate more, the more we cook. A range hood is the most effective ways to do this, especially if it moves air out of the kitchen. Other effective means for reducing indoor pollution levels are use of kitchen fans and open windows. On a cautionary note, both young children and seniors should be particularly careful as they are the ones spending most time indoors.