People are increasingly aware of the deleterious effects of particulates on human health. Therefore, the identification and source of particulate material in our environments take on added significance. Particle Characterization by Light Microscopy, also called Particulate Analysis, can provide the hygienist a broad overview of the particulate state of the environment that is of concern to his clients. The quality of reports of particulate analysis is significantly dependent on the analyst. For best results, it requires broad training, lots of experience and aptitude. Hence, it is important to have your samples done by a lab and an analyst you can trust.