Shim Ji-Yu, Lee Han-Seul, Shin Woo-Jin, Park Sanghee, Choi Hye-Bin, Shin Hyung Seon, Lee Kwang-Sik
Research Center for Geochronology and Isotope Analysis, Korea Basic Science Institute, Cheongju-si, Chungbuk, 28119, Republic of Korea.
Graduate School of Analytical Science and Technology, Chungnam National University, Daejeon, 34134, Republic of Korea.
Environ Geochem Health. 2023 May;45(5):2349-2358. doi: 10.1007/s10653-022-01358-x. Epub 2022 Aug 12.
Trace element concentrations and isotope ratios of hair reflect the blood levels at the time of hair formation, but can be affected by external factors such as dyeing, bleaching, and bathing. To investigate the effect of dyeing, bleaching, and bathing on hair, hair was immersed in tap water, and changes in trace element concentrations and the Sr isotope ratio were observed over time. During soaking, alkaline earth metals (Ca, Mg, and Sr) from tap water were gradually absorbed into the hair over time. After about one day, the adsorption capacity of hair reached a maximum and the reverse reaction started to occur. In contrast, alkaline metals (Na and K) behaved in reverse. In dyed and bleached hair, Na was significantly desorbed from the hair and gradually migrated to the water over time. The adsorption and desorption of trace elements were minimal in untreated original hair, but much higher in dyed and bleached hair. Thus, dyeing and bleaching appear to damage the hair surface structure and greatly promote the exchange of trace elements. The rapid exchange of trace elements, including Sr, between hair and tap water observed in this study indicates that hair samples can be easily contaminated during bathing.
头发中的微量元素浓度和同位素比值反映了头发生成时的血液水平，但可能会受到染发、漂白和洗发等外部因素的影响。为了研究染发、漂白和洗发对头发的影响，将头发浸泡在自来水中，并观察微量元素浓度和锶同位素比值随时间的变化。浸泡过程中，自来水中的碱土金属（钙、镁和锶）会随着时间逐渐被头发吸收。大约一天后，头发的吸附能力达到最大值，随后开始发生逆向反应。相比之下，碱金属（钠和钾）的行为则相反。在染发和漂白过的头发中，钠会从头发中显著解吸，并随着时间逐渐迁移到水中。在未处理的原始头发中，微量元素的吸附和解吸极少，但在染发和漂白过的头发中则要高得多。因此，染发和漂白似乎会破坏头发的表面结构，并极大地促进微量元素的交换。本研究中观察到的头发与自来水之间包括锶在内的微量元素的快速交换表明，头发样本在洗发过程中很容易受到污染。
