Inhalation exposure to three-dimensional printer emissions stimulates acute hypertension and microvascular dysfunction

Abstract

Fused deposition modeling (FDM™), or three-dimensional (3D) printing has become routine in industrial, occupational and domestic environments. We have recently reported that 3D printing emissions (3DPE) are complex mixtures, with a large ultrafine particulate matter component. We and others have reported that inhalation of xenobiotic particles in this size range is associated with an array of cardiovascular dysfunctions. Sprague-Dawley rats were exposed to 3DPE aerosols via nose-only exposure for ~3 hours. Twenty-four hours later, intravital microscopy was performed to assess microvascular function in the spinotrapezius muscle. Endothelium-dependent and -independent arteriolar dilation were stimulated by local microiontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP). At the time of experiments, animals exposed to 3DPE inhalation presented with a mean arterial pressure of 125±4 mm Hg, and this was significantly higher than that for the sham-control group (94±3 mm Hg). Consistent with this pressor response in the 3DPE group, was an elevation of ~12% in resting arteriolar tone. Endothelium-dependent arteriolar dilation was significantly impaired after 3DPE inhalation across all iontophoretic ejection currents (0–27±15%, compared to sham-control: 15–120±21%). Endothelium-independent dilation was not affected by 3DPE inhalation. These alterations in peripheral microvascular resistance and reactivity are consistent with elevations in arterial pressure that follow 3DPE inhalation. Future studies must identify the specific toxicants generated by FDM™ that drive this acute pressor response.

Evaluation of emissions and exposures at workplaces using desktop 3-dimensional printers

“…4 In an animal toxicology study, rats that inhaled ABS emissions from a desktop FFF 3-d printer developed acute hypertension. 5 At this point in time, it is unclear if these respiratory and cardiovascular endpoints are associated with inhalation of emitted particles, organic vapors, or both. Given these emerging reports of adverse health effects, there is a need to understand the magnitude and characteristics of emissions and exposures from AM processes in workplaces so that informed decisions can be made with regard to risk management.…”

Insights Into Emissions and Exposures From Use of Industrial-Scale Additive Manufacturing Machines

“…Personal breathing zone samples for metals and VOCs were collected at Facilities A and B only. Prior laboratory studies have reported iron, nickel, chromium, and zinc in particulate emissions from desktop-scale material extrusion printers using ABS and PL filaments [7], [21], [27]. As such, we used nanoparticle respiratory deposition (NRD, Zefon International, Inc., Ocala, FL, USA) samplers to collect metal-containing particles with diameters from about 15 to 300 nm [30].…”

“…In a survey of AM workers who primarily used material extrusion machines, 59% reported respiratory symptoms [6]. In an animal toxicology study, rats who inhaled ABS emissions from a material extrusion machine developed acute hypertension [7]. It is unclear if these respiratory and cardiovascular endpoints are associated with inhalation of airborne particles, organic vapors, or both.…”

NIOSH’s Respiratory Health Division: 50 years of science and service

“…RHD continues to maintain several research laboratories dedicated to conducting original inhalation exposure assessment research and providing support for field investigations by developing novel and innovative approaches for the sampling and analysis of chemical and biological agents. Recent examples of this research include development of methods for measuring diacetyl and 2,3-pentanedione in air, 68 and quaternary ammonium compounds in air and on surfaces, 69 assessing 3-dimensional printer emissions, 70 and characterizing fungi and fungal products in settled dust samples. 71…”