The Zhaoshan long-baseline Atom Interferometer Gravitation Antenna (ZAIGA) is a new type of underground laser-linked interferometer facility, and is currently under construction. It is in the 200-meter-on-average underground of a mountain named Zhaoshan which is about 80 km southeast to Wuhan. ZAIGA will be equipped with long-baseline atom interferometers, high-precision atom clocks, and large-scale gyros. ZAIGA facility will take an equilateral triangle configuration with two 1-km-apart atom interferometers in each arm, a 300-meter vertical tunnel with atom fountain and atom clocks mounted, and a tracking-and-ranging 1-km-arm-length prototype with lattice optical clocks linked by locked lasers. The ZAIGA facility will be used for experimental research on gravitation and related problems including gravitational wave detection, high-precision test of the equivalence principle of micro-particles, clock based gravitational red-shift measurement, rotation measurement and gravito-magnetic effect. arXiv:1903.09288v4 [physics.atom-ph]

3D printing, a technology that allows the layer-bylayer construction of complex 3D structures from a range of precursor materials, has shown promising applicability in construction and in the automotive, aerospace, defense, biomedicine, and consumer electronics industries. A key concern, however, is the health effects and safety problems due to its emission of fine particles (PM 2.5 , particles with aerodynamic diameters of <2.5 μm) and volatile organic compounds (VOCs). Understanding the characteristics and relevant toxicological effects of 3D printing-emitted PM 2.5 and VOCs is important for its health risk assessment and safe application. Here, we thoroughly review the emission levels of PM 2.5 and VOCs in workplaces, the simulation tests of laboratory environment, and the in vitro and in vivo evaluation of 3D printing-emitted PM 2.5 and VOCs. Meanwhile, standard protocols are recommended in the assessment of hazard risks of 3D printers to obtain better comparability of the results. Some safety guidance for 3D printer users is also provided. Finally, we point out the current research gaps and discuss the challenges encountered in this field. This review will be beneficial for the understanding of the health risks of emitted PM 2.5 and VOCs from 3D printing for the development of safer 3D printing technologies.

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