Cooking on a gas stove can emit more nano-sized particles into the air than vehicles that run on gas or diesel, possibly increasing the risk of developing asthma or other respiratory illnesses, a new Purdue University study has found.

The study, published in the journal PNAS Nexus, focused on tiny airborne nanoparticles that are only 1-3 nanometers in diameter, which is just the right size for reaching certain parts of the respiratory system and spreading to other organs.

“These super tiny nanoparticles are so small that you’re not able to see them. They’re not like dust particles that you would see floating in the air,” said Brandon Boor, an associate professor in Purdue’s Lyles School of Civil Engineering, who led this research. “After observing such high concentrations of nanocluster aerosol during gas cooking, we can’t ignore these nano-sized particles anymore.”

Using state-of-the-art air quality instrumentation provided by the German company GRIMM AEROSOL TECHNIK, Purdue researchers were able to measure these tiny particles down to a single nanometer while cooking on a gas stove in a “tiny house” lab. They collaborated with Gerhard Steiner, a senior scientist and product manager for nano measurement at GRIMM AEROSOL.

This magnitude of high-quality data allowed the researchers to compare their findings with known outdoor air pollution levels. They found that as many as 10 quadrillion nanocluster aerosol particles could be emitted per kilogram of cooking fuel — matching or exceeding those produced from vehicles with internal combustion engines.

This would mean that adults and children could be breathing in 10-100 times more nanocluster aerosol from cooking on a gas stove indoors than they would from car exhaust while standing on a busy street.

Purdue civil engineering PhD student Satya Patra made these findings by looking at data collected in the tiny house lab and modeling the various ways that nanocluster aerosol could transform indoors and deposit into a person’s respiratory system.

The models showed that nanocluster aerosol particles are very persistent in their journey from the gas stove to the rest of the house. Trillions of these particles were emitted within just 20 minutes of boiling water or making grilled cheese sandwiches on a gas stove.

Even though many particles rapidly diffused to other surfaces, the models indicated that approximately 10 billion to 1 trillion particles could deposit into an adult’s head airways and tracheobronchial region of the lungs. These doses would be even higher for children — the smaller the human, the more concentrated the dose.

Source: “You may be breathing in more tiny nanoparticles from your gas stove than from car exhaust,” Purdue University, Feb. 27, 2024

Dangerous devices.

Smartwatches and rings that claim to measure blood sugar levels for medical purposes without piercing the skin could be dangerous and should be avoided, according to a warning from the U.S. Food and Drug Administration.

This caution applies to any watch or ring—regardless of brand—that claims to measure blood glucose levels in a noninvasive way, the agency said. The FDA said it has not authorized any such device.

However, the notice does not apply to smartwatch apps linked to sensors, such as continuous glucose monitoring systems that measure blood sugar directly.

People with diabetes need to regularly check their blood sugar levels with a finger prick blood test or with a sensor that places needles just under the skin to monitor glucose levels continuously. Using the unapproved smartwatch and smart ring devices could result in inaccurate blood sugar measurements, with “potentially devastating” consequences, Dr. Robert Gabbay of the American Diabetes Association told the Associated Press. That could cause patients to take the wrong doses of medication, leading to dangerous levels of blood sugar and possibly mental confusion, coma or even death.

Several companies are working on noninvasive devices to measure blood sugar, but none has created a product accurate and secure enough to get FDA approval, said Dr. David Klonoff, who has researched diabetes technology for 25 years.

The technology that allows smartwatches and rings to measure metrics like heart rate and blood oxygen is not accurate enough to measure blood sugar, said Klonoff, of the Sutter Health Mills-Peninsula Medical Center in San Mateo, Calif. Efforts to measure blood sugar in body fluids such as tears, sweat and saliva are also not ready.

In the meantime, consumers who want to measure their blood sugar accurately can buy an FDA-cleared blood glucose monitor at any pharmacy.

Source: “FDA warns against smartwatches and rings that claim to measure blood sugar without needles,” Associated Press, Feb. 21, 2024

PFAS in deodorant.

Six deodorants have been found to have detectable levels of organic fluorine, an indicator of the group of chemicals known as PFAS, according to a new report from Mamavation.

Partnering with, the environmental wellness blog and community had 15 deodorants from 14 brands tested by a U.S. Environmental Protection Agency-certified lab and found levels of organic fluorine ranging from 11 parts per million to 32 ppm. Both “natural” and conventional deodorants had evidence of the chemicals.

Organic fluorine is a strong indicator of per- and polyfluoroalkyl substances, also known as PFAS or “forever chemicals”— which have been linked to health effects including reduced immune system function and vaccine response, developmental and learning problems for infants and children, certain cancers, lowered fertility, endocrine disruption and other impacts.

Scott Belcher, associate professor with the Center for Environmental & Health Effects of PFAS at North Carolina State University, told Mamavation that testing for organic fluorine is a good “spot-check” of products for evidence of PFAS because testing for individual PFAS compounds would miss some of other common forms of the chemicals.

The exposure risk to PFAS through the skin is not entirely clear, however, previous lab research by the National Institute for Occupational Safety and Health found that PFAS skin exposure poses similar health risks as ingesting the chemicals via food or water.

Source: “Are you putting PFAS on your armpits?” Environmental Health News, Feb. 28, 2024

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