Elon University, Department of Chemistry, Elon, NC 27244, USA.
Pegasus Technical Services Inc, Cincinnati, OH, USA.
Sci Total Environ. 2019 Dec 1;694:133669. doi: 10.1016/j.scitotenv.2019.133669. Epub 2019 Jul 30.
Production and marketing of "nano-enabled" products for consumer purchase has continued to expand. However, many questions remain about the potential release and transformation of these nanoparticle (NP) additives from products throughout their lifecycle. In this work, two surface coating products advertised as containing ZnO NPs as active ingredients, were applied to micronized copper azol (MCA) and aqueous copper azol (ACA) pressure treated lumber. Coated lumber was weathered outdoors for a period of six months and the surface was sampled using a method developed by the Consumer Product Safety Commission (CPSC) to track potential human exposure to ZnO NPs and byproducts through simulated dermal contact. Using this method, the total amount of zinc extracted during a single sampling event was <1 mg/m and no evidence of free ZnO NPs was found. Approximately 0.5% of applied zinc was removed via simulated dermal contact over 6-months, with increased weathering periods resulting in increased zinc release. XAFS analysis found that only 27% of the zinc in the as received coating could be described as crystalline ZnO and highlights the transformation of these mineral phases to organically bound zinc complexes during the six-month weathering period. Additionally, SEM images collected after sampling found no evidence of free NP ZnO release during simulated dermal contact. Both simulated dermal contact experiments, and separate leaching studies demonstrate the application of surface coating solutions to either MCA and ACA lumber will reduce the release of copper from the pressure treated lumber. This work provides clear evidence of the transformation of NP additives in consumer products during their use stage.
“纳米化”产品的生产和销售继续扩大，这些纳米颗粒（NP）添加剂在产品整个生命周期中的潜在释放和转化仍然存在许多问题。在这项工作中，将两种广告中含有氧化锌 NP 作为活性成分的表面涂层产品应用于微米化铜唑（MCA）和水性铜唑（ACA）压力处理木材。涂覆木材在户外风化了六个月，并使用消费者产品安全委员会（CPSC）开发的方法对表面进行了采样，以跟踪通过模拟皮肤接触对潜在人类暴露于 ZnO NPs 和副产物的情况。使用这种方法，在单次采样事件中提取的锌总量<1mg/m，未发现游离 ZnO NPs 的证据。大约 0.5%的应用锌通过 6 个月的模拟皮肤接触被去除，随着风化期的延长，锌的释放量增加。XAFS 分析发现，在收到的涂层中，只有 27%的锌可以被描述为结晶 ZnO，并强调了这些矿物相在六个月的风化期间向有机结合的锌络合物的转化。此外，采样后收集的 SEM 图像没有发现游离 NP ZnO 在模拟皮肤接触期间释放的证据。模拟皮肤接触实验和单独的浸出研究都表明，将表面涂层溶液应用于 MCA 和 ACA 木材将减少压力处理木材中铜的释放。这项工作为消费者产品中 NP 添加剂在使用阶段的转化提供了明确的证据。
