Luxury at a Cost: Portable XRF-Based Bioaccessible Chromium in Sweat Predicts Dermal Exposure Risk to Chromate in
Can Liu1, Wenjie Dong1, Aaron J Specht2
1State Key Laboratory of Soil Pollution Control and Safety, and Institute of Soil and Water Resources and Environmental Science, College of Environmental and Resource Sciences, Zhejiang University, Hangzhou 310058 Zhejiang, China.
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Extensive use of chromium (Cr) in leather tanning poses a potential dermal exposure risk to consumers from carcinogenic chromate (CrVI) in leather products. To enable rapid screening, we analyzed 470 commercial genuine leather products from 7 countries using a calibrated portable X-ray fluorescence spectrometer (pXRF). Measurements revealed exceptionally high total Cr, with 93% of samples exceeding 10,000 mg kg-1 and the highest being 60,200 mg kg-1. A positive correlation was found between product price and total Cr content (R2 = 0.65), indicating higher Cr levels in luxury full-grain leathers. To assess potential risk to humans, we quantified bioaccessible Cr in artificial sweat extracts using pXRF (474-4460 mg kg-1), achieving excellent agreement with ICP-OES data. Critically, the bioaccessible Cr pool showed a strong correlation with the CrVI content based on ICP-MS (R2 = 0.77). Leveraging this correlation, we established a pXRF-based risk threshold of 1000 mg kg-1 of bioaccessible Cr in sweat extract. This threshold can be used as a proxy for identifying leather products likely exceeding the regulatory limit of 3 mg kg-1 CrVI. This work transforms pXRF into a validated tool for rapid, risk-based screening of leather products, helping to monitor and mitigate Cr exposure from global leather consumer market.
