热喷涂包括喷涂产品(通常是金属),该产品在极高的温度下熔化,然后在压力下施加到表面上。大量复杂的金属气溶胶(例如,Fe,Cr,Ni,Zn)在此过程中形成,给操作员带来潜在的严重风险。缺乏与暴露于这些气溶胶相关的健康影响的信息。对这些气溶胶的化学和物理性质知之甚少。目标是开发和测试一种模拟工作场所暴露的自动热喷涂气溶胶发生器和吸入暴露系统。设计了一种电弧丝-热喷涂气溶胶发生器和暴露系统,并将其分为两个区域:(1)发生喷涂的封闭房间;(2)具有不同测量设备和控制器的暴露室。检查了使用五种不同的消耗性焊丝在电弧丝热喷涂过程中产生的气溶胶的物理化学性质。通过电感耦合等离子体-原子发射光谱法(ICP-AES)测定每一种的金属组成,包括两根不锈钢丝[PMET720(82%铁,13%Cr);PMET731(66%Fe,26%Cr)],两根镍基导线[PMET876(55%镍,17%Cr);PMET885(97%Ni)],和一根Zn基导线[PMET540(99%Zn)]。无论组成如何,产生的颗粒都是难溶的,复杂的金属氧化物,主要排列成链状团聚体,尺寸分布相似,由微孔均匀沉积物冲击器(MOUDI)和电低压冲击器(ELPI)确定。为了允许连续,在4小时的暴露期间连续喷涂,电机使金属管在圆形和上下方向上旋转以进行涂覆。在一项动物试验研究中,雄性Sprague-Dawley大鼠暴露于使用不锈钢PMET720可消耗焊丝从电弧线热喷涂产生的气溶胶(25mg/m3×4h/d×9d)。在4小时期间实现并维持目标暴露室浓度。暴露后1d,与空气对照组相比,暴露于热喷涂气溶胶组的肺损伤和炎症明显升高。该系统是为未来的动物暴露研究而设计和构建的,可以在目标浓度下长时间不间断地产生连续的金属喷涂气雾剂。
Thermal spray coating involves spraying a product (oftentimes metal) that is melted by extremely high temperatures and then applied under pressure onto a surface. Large amounts of a complex metal aerosol (e.g., Fe, Cr, Ni, Zn) are formed during the process, presenting a potentially serious risk to the operator. Information about the health effects associated with exposure to these aerosols is lacking. Even less is known about the chemical and physical properties of these aerosols. The goal was to develop and test an automated thermal spray coating aerosol generator and inhalation exposure system that would simulate workplace exposures. An electric arc wire-thermal spray coating aerosol generator and exposure system was designed and separated into two areas: (1) an enclosed room where the spray coating occurs; (2) an exposure chamber with different measurement devices and controllers. The physicochemical properties of aerosols generated during electric arc wire-thermal spray coating using five different consumable wires were examined. The metal composition of each was determined by inductively coupled plasma-atomic emission spectroscopy (ICP-AES), including two stainless-steel wires [PMET720 (82 % Fe, 13 % Cr); PMET731(66 % Fe, 26 % Cr)], two Ni-based wires [PMET876 (55 % Ni, 17 % Cr); PMET885 (97 % Ni)], and one Zn-based wire [PMET540 (99 % Zn)]. The particles generated regardless of composition were poorly soluble, complex metal oxides and mostly arranged as chain-like agglomerates and similar in size distribution as determined by micro-orifice uniform deposit impactor (MOUDI) and electrical low-pressure impactor (ELPI). To allow for continuous, sequential spray coating during a 4-hr exposure period, a motor rotated the metal pipe to be coated in a circular and up-and-down direction. In a pilot animal study, male Sprague-Dawley rats were exposed to aerosols (25 mg/m3 × 4 h/d × 9 d) generated from electric arc wire- thermal spray coating using the stainless-steel PMET720 consumable wire. The targeted exposure chamber concentration was achieved and maintained during a 4-hr period. At 1 d after exposure, lung injury and inflammation were significantly elevated in the group exposed to the thermal spray coating aerosol compared to the air control group. The system was designed and constructed for future animal exposure studies to generate continuous metal spray coating aerosols at a targeted concentration for extended periods of time without interruption.