The facial skin of 354 women, aged 18-80, living in Shanghai, was investigated over two successive 6-month periods, summer and winter. Results from clinical assessments indicate that aging signs, such as wrinkling and sagging, are unaffected over such period. However, physical measurements revealed alterations in some functional criteria of the skin, such as sebum output, skin colour, melanin content of pigmented spots, skin hydration, all being increased during summer. The relationships between all criteria, as well as technical or applied inferences/consequences from this study, are discussed.

This study demonstrated a significant impact of the pollution upon the skin status, as illustrated by changes in superficial biochemical parameters and volunteers' perception.

The facial skin tone of two groups of Chinese women from Shanghai was compared using standard colorimetric space techniques during a 6-month interval between January and July 2011. During the study period, one group of women (n = 40) applied a potent sun-protective cosmetic product daily, while the other group (n = 40) did not use any sun protection. The results, based on images taken using a standardized digital camera coupled to a spectroradiometer, showed that sun protection largely mitigated changes in the components of skin tone, ie, lightness, melanization, and individual typology angle parameters. The skin darkening process appeared to be reduced or prevented in the sun-protected group when compared with the control group. The sun-protected women had participated in an earlier study in 2008, which confirmed that seasonal skin darkening occurs from winter through summer in Shanghaiese women. Comparing the data obtained in the winters of 2008 and 2011, we were able to identify better the impact of 3 years of aging on the components of skin tone. Comparing data between seasons on the same women with (2011 study) and without (2008 study) sun protection highlights the role of the test product in preventing skin darkening.