TLDR Pollution exposure speeds up hair damage.
The document summarizes a study that examined the effect of polycyclic aromatic hydrocarbons (PAHs) pollution on the structural integrity of human hair fibers. Researchers analyzed 204 hair samples from women in two Chinese cities with varying pollution levels. They found that hair with higher PAH concentrations showed more significant degradation of the hair cortex and cuticle, with a faster rate of damage observed in the more contaminated group. The study also revealed that UV irradiation intensified the damage, particularly around melanosomes. The results suggest that PAHs contribute to the degradation of hair fibers and potentially other human tissues. The study used various sample sizes, including n=25 for subgroup damage ratio, n=100 for pooled sample analysis, and n=60 for cuticle layer counts, to support its conclusions.
40 citations,
May 2016 in “Proceedings of the National Academy of Sciences of the United States of America” Changes in keratin make hair follicles stiffer.
49 citations,
April 2010 in “International Journal of Cosmetic Science” Hair ages as the cuticle wears down, especially beyond 1 meter from the root, affecting its strength and shine.
40 citations,
February 2002 in “International Journal of Dermatology” Permanent hair dye damages hair but it mostly recovers after 8 weeks; using certain hair care products can help repair it.
September 2022 in “Cosmetics” 1 citations,
December 2018 in “IntechOpen eBooks” Human hair shows promise for non-invasive medical testing, but more research is needed to standardize its use.
January 2020 in “Cosmetics” Ecklonia cava extract may protect the scalp from pollution and improve its health.
77 citations,
July 2020 in “Journal of the European Academy of Dermatology and Venereology” Environmental factors, hormones, nutrition, and stress all significantly affect skin health and aging.
1 citations,
December 2023 in “Environmental pollution” Hair analysis shows infants and mothers in north-western Spain are exposed to environmental pollutants, with factors like diet and residence affecting pollutant levels.