Your Hairstyle Could Cause Air Pollution Comparable To Busy Traffic, Study Warns

A new study from Purdue University reveals that using common hair care products combined with heated styling tools can produce nanoparticle air pollution comparable to standing next to a busy road.

The research, published in Environmental Science & Technology, shows that particles up to 500 nanometres, about 200 times smaller than a human hair, are released during hairstyling. These tiny particles can penetrate deep into the lungs, raising health concerns.

The study was conducted by a Purdue research team led by Nusrat Jung, an assistant professor in the Lyles School of Civil and Construction Engineering, and her PhD student Jianghui Liuin, in a specially designed tiny house lab, previously used to analyse chemicals from hair products. Researchers focused on the air pollution generated by the heat and product combination during typical hairstyling routines.

The findings suggest that everyday hair care habits may unknowingly expose people to significant levels of harmful airborne nanoparticles. This raises important questions about indoor air quality and health risks linked to personal grooming practices.

"This is really quite concerning," civil engineer Nusrat Jung said. "The number of nanoparticles inhaled from using typical, store-bought hair care products was far greater than we ever anticipated."

Until this study, Jung said, no real-time measurements on nanoparticle formation during heat-based hair styling had been conducted in full-scale residential settings. Their research addresses this gap by examining temporal changes in indoor nanoparticle number concentrations and size distributions during realistic heat-based hair styling routines.

"By providing a detailed characterization of indoor nanoparticle emissions during these personal care routines, our research lays the groundwork for future investigations into their impact on indoor atmospheric chemistry and inhalation toxicity," Jung said. "Studies of this kind have not been done before, so until now, the public has had little understanding of the potential health risks posed by their everyday hair care routines."

What makes these hair care products so harmful, Liu said, is when they are combined with large amounts of heat from styling appliances such as curling irons and straighteners. When combined with heat exceeding 300 degrees Fahrenheit, the chemicals not only rapidly release into the air but also lead to the formation of substantial numbers of new airborne nanoparticles.

"Atmospheric nanoparticle formation was especially responsive to these heat applications," Liu said. "Heat is the main driver - cyclic siloxanes and other low-volatility ingredients volatilize, nucleate and grow into new nanoparticles, most of them smaller than 100 nanometers."