Soot nanoparticles (SNPs) are airborne contaminants that could potentially penetrate skin, but their aggregation after contact with sweat may lower their health risks. This study investigated SNP aggregation kinetics in 4 artificial sweat standards and 21 human sweat samples. Effects of sweat inorganic (NaCl, Na₂HPO₄, and NaH₂PO₄) and organic (L-histidine, lactic acid, and urea) constituents, pH, temperature, and concentrations were examined. Results showed that SNP aggregation rates in 4 standards followed American Association of Textile Chemists and Colorists (AATCC) > British Standard (EN) > International Standard Organization (ISO) pH 5.5 > ISO pH 8.0, and could be described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory. The aggregation rates increased with concentrations of SNPs, inorganic salts, L-histidine, and lactic acid, decreased with increasing pH and concentration of urea, and were weakly influenced by temperature. Systematic characterizations revealed SNP adsorption for organic sweat constituents. SNPs aggregated rapidly to ∼1000 nm in AATCC, but remained stable in ISO pH 8.0 and > 14/21 human sweat fluids over 20 min. The SNP aggregation rates correlated negatively with pH (r = -0.531*) and |ζ potential| (r = -0.464*) of human sweat samples. Sweat evaporation could promote aggregation of SNPs, hence lowering their potential harm via dermal exposure.

烟尘纳米颗粒（SNP）是空气传播的污染物，可能会渗透皮肤，但接触汗液后其聚集会降低其健康风险。这项研究调查了4种人工汗液标准品和21种人类汗液样品中SNP的聚集动力学。无机无机汗液（NaCl，Na ₂ HPO ₄和NaH ₂ PO _4的影响）和有机（L-组氨酸，乳酸和尿素）成分，pH，温度和浓度进行了检查。结果表明，四种标准物中的SNP聚集率遵循美国纺织化学和着色师协会（AATCC）>英国标准（EN）>国际标准组织（ISO）pH 5.5> ISO pH 8.0，并且可以用Derjaguin-Landau- Verwey-Overbeek（DLVO）理论。聚集速率随SNP，无机盐，L-组氨酸和乳酸的浓度增加而增加，随pH和尿素浓度的增加而降低，并且受温度的影响较小。系统表征表明SNP对有机汗液成分的吸附。SNP在AATCC中迅速聚集至约1000 nm，但在20分钟内在ISO pH 8.0和> 14/21人汗液中保持稳定。r = -0.531 *）和| ζ电势| （r = -0.464 *）人汗液样本。汗液蒸发可以促进SNP的聚集，从而降低其通过皮肤暴露的潜在危害。