Stir-frying has long been celebrated for its delicious dishes, but what if this popular cooking method is also polluting our indoor air and posing health risks? A team of researchers, including an air-quality expert from Johns Hopkins University, has developed a groundbreaking model that can accurately estimate and predict the concentration of particulate matter released during stir-frying. This innovative approach addresses the limitations of traditional methods, which often fail to capture real-world settings such as private homes and restaurants. By understanding and measuring these cooking emissions, we can better simulate exposure and establish health guidelines to ensure the well-being of individuals.
Originating in China during the 14th century, stir-frying has become a popular cooking technique worldwide due to its convenience and relatively healthy nature. However, this method, which involves cooking food in sizzling oil in a hot wok or pan, releases tiny particles of oil and other chemicals into the air. These particles contain a wide range of organic materials, such as triglycerides, fatty acids, and proteins, as well as various compounds that arise when substances are exposed to heat and hot oil. Additionally, some chemical compounds are emitted as gases, and their volatility determines whether they remain in the gas phase or attach to particles. It raises the question of whether indoor exposure to particulate matter, especially cooking-related emissions, poses similar risks to outdoor air pollution and its adverse effects on cardiovascular and respiratory health.
To gain a comprehensive understanding of cooking emissions, Peter DeCarlo, an associate professor of environmental health and engineering at Johns Hopkins, led a team of researchers in conducting detailed measurements. They focused on the composition of cooking particles resulting from stir-frying various vegetables in soybean oil, using both nonstick woks and cast-iron skillets on electric and gas stoves. By monitoring particle concentrations and chemical composition in real-time, the team identified two main types of emissions. The first type resembled cooking oil in its chemical properties, while the second type resembled particles from burning wood containing partially burned sugars, likely arising from the cooking of vegetables and stir-fry sauce.
Building upon previous research, the team developed a two-zoned computer model that aimed to simulate indoor conditions. Their model was inspired by a laboratory “house” at the University of Texas at Austin, where the House Observations of Microbial and Environmental Chemistry (HOMEChem) campaign investigated how everyday activities impact indoor air quality. Unlike previous models that assumed emitted particles and gases remained static after cooking ceased, the new model factored in natural thermodynamics and how pollutants disperse as air moves. This improved understanding allows for a more accurate characterization of the composition and concentrations of cooking particles as they spread throughout indoor spaces.
The newly developed model not only provides valuable insights into pollution levels, airflow patterns, and particle concentrations within homes and buildings but also serves as crucial input data for assessing potential exposures and risks at a broader population level. By understanding the dynamics of cooking-related emissions, health authorities can establish guidelines and public health recommendations to mitigate exposure and reduce risks to individuals and communities. While ventilation remains the best solution for reducing exposure to cooking emissions, the model also highlights the significance of air filtration and other measures to further enhance indoor air quality.
With the aid of this innovative model, researchers and policymakers can gain a better understanding of the potential risks associated with cooking emissions in various indoor settings. By accurately estimating these emissions and their impacts on human health, we can ensure the development of effective control strategies and guidelines. Ultimately, this progress will contribute to creating healthier homes and cooking environments, safeguarding the well-being of individuals and families.