This tool presents the development work for a portable cost-efficient transmission microscope, compatible with hyperspectral imaging. The goal is to provide a portable tool for a quick and preliminary cost-efficient assessment of particle exposure, with the focus on respirable particles (below 15 µm). The first report describes the portable microscope development, its specifications and required components. The second report presents the validation work done with the portable microscope in combination with imec multispectral snapshot cameras in the near infrared (NIR). The report shows the high accuracy obtained in particle material discrimination based on the particle spectral signature. Additionally, pointers are given to related publications and presentations on particle exposure assessment where traditional microscopes and different type of hyperspectral cameras in the visual near infrared range (460-900 nm) are used.  Pointers are given as well for the published work done on microplastic discrimination based on microscopy and short wavelength infrared cameras (1100-1700 nm). Finally, an appendix document introducing to hyperspectral imaging and cameras is provided.