Simple boxes from Corsi-Rosenthal can help reduce exposure to indoor air pollutants

A team of researchers from the Brown University School of Public Health, the Brown School of Engineering and the Silent Spring Institute found that simple air filtration devices called Corsi-Rosenthal boxes are effective in reducing indoor air pollutants. .

The study, which looked at the effectiveness of the Corsi-Rosenthal boxes installed at the School of Public Health in helping prevent the spread of COVID-19, is the first peer-reviewed study on the effectiveness of the boxes on indoor pollutants, according to the authors. .

Reducing indoor air concentrations of commonly encountered chemicals known to pose a risk to human health is one way to improve occupant health, according to lead author Joseph Braun, an associate professor of epidemiology at Brown.

The findings show that an inexpensive and easy-to-build air filter can protect against diseases caused not only by viruses but also by chemical contaminants. This type of highly accessible public health intervention can empower community groups to take action to improve air quality and therefore their health.”

Joseph Braun, Associate Professor of Epidemiology, Brown University

Corsi-Rosenthal boxes or cubes can be built with materials found at hardware stores: four MERV-13 filters, duct tape, a 20-inch box fan, and a cardboard box. As part of a school-wide project, students and members of the campus community assembled the boxes and installed them in the School of Public Health, as well as other buildings on the Brown University campus.

To assess the effectiveness of the cubes in removing chemicals from the air, Braun and his team compared the concentrations of semi-volatile organic compounds in a room before and during the box’s operation.

The results, published in Environmental science and technology, showed that the Corsi-Rosenthal boxes significantly decreased the concentrations of several PFASs and phthalates in 17 rooms of the School of Public Health during the period in which they were used (February to March 2022). PFAS, a type of synthetic chemical found in a range of products including cleaners, textiles, and cable insulation, decreased by 40-60%; Phthalates, commonly found in building materials and personal care products, were reduced by 30-60%.

PFAS and phthalates have been linked to various health problems, including asthma, reduced response to vaccines, decreased birth weight, impaired brain development in children, impaired metabolism, and some types of cancer. said Braun, who studies the effect of these chemicals on human health. They are also considered endocrine disrupting chemicals that can mimic or interfere with hormones in the body. Additionally, PFAS have been associated with a reduced vaccine response in children and may also increase the severity and susceptibility to COVID-19 in adults.

“Reduced levels of PFAS and phthalates is a wonderful co-benefit for Corsi-Rosenthal boxes,” said study co-author Robin Dodson, a Silent Spring Institute research scientist and an expert in indoor chemical exposures. “These boxes are affordable, easy to make, and relatively inexpensive, and are currently used in universities and homes across the country.”

“The Corsi-Rosenthal box was designed to be a simple and cost-effective tool to promote accessible and effective air cleaning during the COVID-19 pandemic; the fact that the boxes are also effective in filtering air pollutants is a fantastic discovery.” said Richard Corsi, one of the inventors of the boxes and dean of the College of Engineering at the University of California, Davis. “I am delighted that researchers at Brown University and the Silent Spring Institute have identified a significant co-benefit of boxes in terms of reducing exposure to two harmful classes of indoor pollutants: PFAS and phthalates.

The sentiment was echoed by Jim Rosenthal, a Corsi collaborator and CEO of Air Relief Technologies, the company that makes the MERV-13 filters used in Corsi-Rosenthal boxes.

“This exciting research showing that air filters not only reduce particles that carry the SARS-CoV-2 virus, but also reduce other indoor air pollutants could be very important as we continue to work to create cleaner indoor air.” clean and safe,” Rosenthal said.

The researchers also found that the Corsi-Rosenthal boxes increase sound levels by an average of 5 decibels during the day and 10 decibels at night, which could be considered distracting in certain settings, such as classrooms. However, Braun said, the health benefits of the box likely outweigh the side effects of the audio.

“Box filters do make some noise,” Braun said. “But you can build them quickly for around $100 a unit, with materials from the hardware store. They’re not only highly effective but also scalable.”

Authors of the Brown study include Kate Manz and Kurt Pennell from the School of Engineering, and Jamie Liu, Shaunessey Burks and Richa Gairola from the School of Public Health. This research was supported by the National Science Foundation and the National Institute of Environmental Health Sciences.