A link has been drawn between exposure to air pollution and the loss of hair growth and regeneration, according to preliminary research presented at the 2019 European Academy of Dermatology and Venereology Congress.
Particulate matter (particle pollution, or PM) is made up of pollutants that form a complex mixture of small solid particles and liquid droplets in the air. The smaller the PM, the more harmful the particles are as they can pass more easily into the human body. In particular, PM10 are those that measure 10 micrometers or smaller and typically come from industrial sources that can cause negative health effects when a person becomes exposed to, inhales, or consumes them.
To study the effects of PM on hair growth and regeneration, researchers exposed the cells at the base of hair follicles in a human scalp to concentrations of dust containing PM10 and diesel pollution. Twenty-four hours later, researchers performed a technique common to cell and molecular biology known as western blotting allowing them to identify proteins extracted from cells. They found that the presence of PM10 and diesel particulate decreased Beta-catenin, an essential protein for hair growth and the formation of hair follicles, as well as three other important proteins for growing and keeping hair (cyclin D1, cyclin E, and CDK2). The levels of exposure were directly tied to how much loss was observed – more pollutants resulted in a greater decrease in proteins.
"The results of this study show that exposure to PM10 and diesel particulate reduced the levels of proteins required for hair growth and hair retention. It is, therefore, possible to hypothesize that at certain levels of exposure this could lead to baldness but further population-based research needs to be undertaken to confirm this," a spokesperson told IFLScience.
Outdoor air pollution is linked to the deteriorating health or deaths of more than 4 million people every year, but understanding the effects on the skin and hair is relatively little understood.
"Ambient particulate matter (PM) represents an environmental threat to which millions of humans worldwide are exposed. The adverse effects of PM on human health are currently a serious concern, and they have been shown to increase the risk of cancer, and pulmonary and cardiovascular diseases," wrote the researchers in an abstract sent to IFLScience. Differences between men and women were not identified.
According to the researchers, reducing exposure to pollution, whether ambient or indoor, can help to protect health.
"While it is difficult to escape ambient pollution, limiting time walking on busy streets, especially during rush hour, should help to reduce exposure. If you are exercising outdoors, try to do so in areas that are less polluted and do not spend too much time waiting at traffic hotspots such as traffic lights," said the spokesperson.
Particulate matter is ubiquitous and has been linked to a number of health conditions in recent years. A study last month found that the placentas of pregnant women contained microscopic black carbon particles, or soot. This year, for the first time, the UK even considered it a possible listing for an official cause of death. It's linked to higher rates of miscarriage, and may be contributing to abnormal fetal brain development during pregnancy. Estimates suggest that air pollution now kills more people than smoking and could raise the risk of emphysema by as much as smoking a pack of cigarettes a day. Impacts on mental health and intelligence have been linked to air pollution as well. Teenagers living in urban areas with high levels of pollution have been shown to be more likely to experience psychosis while greater exposure levels have seen a worsening of verbal and math skills. Links have also been drawn between air pollution and obesity, dementia, autism, and a shorter lifespan.