A recent study conducted by researchers at Purdue University reveals that common hair care products, when combined with the heat from styling tools, can generate nanoparticle air pollution comparable to that found near busy roads. The research highlights that particles measuring up to 500 nanometers—about 200 times smaller than a human hair—are released during styling processes. These fine particles can penetrate deep into the lungs, raising significant concerns about the health implications of everyday hair care routines.
The study, published in the journal Environmental Science & Technology, utilized a specially designed tiny house lab to analyze the air pollution associated with hair care products. This facility had previously been used to investigate chemicals emitted by these products, but the current research focused specifically on the nanoparticle pollution produced during styling.
Nusrat Jung, a civil engineer involved in the study, stated, “The number of nanoparticles inhaled from using typical, store-bought hair care products was far greater than we ever anticipated.” This research fills a critical gap, as such studies have not been conducted before, leaving the public unaware of the potential health risks linked to their hair care routines.
To conduct the study, researchers recruited seven volunteers who performed a total of 21 different hair care routines. These included the use of five different products along with various styling devices such as straighteners, curlers, and wavers. The results indicated that routines lasting between 10 to 20 minutes could produce over 100,000 nanoparticles per cubic centimeter of air.
Simulation models further suggested that these concentrations could lead to the inhalation of more than 10 billion nanoparticles, many of which reach the deepest parts of the lungs. The generation of these particles was significantly influenced by temperatures exceeding 300 °F (149 °C). At lower temperatures, fewer nanoparticles were produced, and those that were tended to remain in the hair.
Jianghui Liu, another civil engineer on the team, noted, “Atmospheric nanoparticle formation was especially responsive to these heat applications.” He explained that heat causes cyclic siloxanes and other low-volatility ingredients to volatilize, nucleate, and grow into new nanoparticles, most of which are smaller than 100 nanometers.
While the specific health impacts of these nanoparticles are not yet fully understood, research indicates that exposure to similar micrometer-sized particles can lead to various health issues. The small size of nanoparticles makes it challenging to trace their health impacts. Nonetheless, animal studies have demonstrated that nanoparticles in the lungs can lead to increased inflammation and other forms of tissue damage.
To mitigate these risks, researchers advise ensuring adequate ventilation when using hair products that involve high heat. They also emphasize the need for further research to monitor nanoparticle pollution more closely and to understand the chemical makeup of these airborne particles.
Jung concluded, “By addressing these research gaps, future studies can provide a more holistic understanding of the emissions and exposures associated with heat-based hair styling, contributing to improved indoor air pollution assessments and mitigation strategies.” This groundbreaking research underscores the importance of evaluating the environmental and health impacts of seemingly benign daily activities such as hair care.
