Traffic-related Air pollution Linked to Facial Lentigenes
High levels of traffic-related air pollution and air pollution-associated gases may increase risk of developing facial lentigenes, new research suggests.
"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," explains lead investigator Jean Krutmann, MD, of the IUF-Leibniz Research Institute for Environmental Medicine in Dusseldorf, Germany, in a news release.
The most pronounced changes were observed on the cheeks of Asian women aged 50 and older. Overall, an increase of 10 µg/m3 in NO2 concentration was associated with approximately 25 percent more dark spots, the study showed. That said, there was no association was seen between levels of NO2 and lentigenes' formation on the back of the hands or forearms.
The findings appear in the Journal of Investigative Dermatology.
The study included two groups of women. One group of 806 Caucasian German women who were part of the SALIA study (Study on the influence of Air pollution on Lung function, Inflammation and Aging). The average age of women in this study was 73.5 years and 20 percent had a history of smoking. These women reportedly spent an average of 2.6 hours a day in the sun.
The second group included 743 Han Chinese women from the Taizhou region who were somewhat younger than the SALIA group, with an average age of 59. Twenty percent of this group had a history of smoking, with a reported average daily sun exposure of 3.5 hours. Many more women in the SALIA group reported using cosmetics with sun protection (61 percent vs. 4.2 percent). The mean levels of NO2 exposure were 28.8 µg/m3 in the SALIA study and 24.1 µg/m3 in the Taizhou China group, the researchers report.
The spots were visually evaluated by trained personnel according to photo reference scales and quantified using 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.