New study links traffic-related air pollution to facial dark spots

After I started wearing gloves when I went out in the sun, I stopped getting more brown spots on my hands.

Public Release: 8-Feb-2016
New study links traffic-related air pollution to facial dark spots
Effects seen in German Caucasian and Chinese Asian women, according to a report in the Journal of Investigative Dermatology
Elsevier

A largescale study that included women from Germany and China has demonstrated a link between levels of traffic-related air pollution and air pollution-associated gases with the formation of dark spots on the skin, known as lentigenes. The most pronounced changes were observed on the cheeks of Asian women over the age of 50. The report is published in the Journal of Investigative Dermatology.

"In addition to particulate matter, traffic-related air pollution is characterized by increased concentration of nitrogen dioxide (NO2). While NO2 exposure is known to be associated with low lung function and lung cancer, the effect of NO2 on human skin has never been investigated. This is important because environmentally-induced lung and skin aging appear to be closely related," explained lead investigator Jean Krutmann, MD, of the IUF-Leibniz Research Institute for Environmental Medicine, Dusseldorf, Germany.

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No association was seen between levels of NO2 and lentigenes' formation on the back of the hands or forearms, however, exposure to NO2 was significantly associated with more lentigenes on the cheeks in both German and Chinese women older than 50 years. Overall, an increase of 10 µg/m3 in NO2 concentration was associated with approximately 25% more dark spots. The spots were visually evaluated by trained personnel according to photo reference scales and quantified using a validated skin aging score system (SCINEXA).

The investigators performed sensitivity analysis to see whether they could pinpoint whether it was the concentration of particulate matter or NO2 gas that had a greater impact on dark spot formation. They found that the NO2 gas had a slightly stronger effect than the particulate matter concentration.

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