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.
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