Summary Goals The widespread application of nano-enabled products and the increasing likelihood of exposure in the workplace make understanding the effects of man-made nanomaterials (ENMs) on exposed workers a public and occupational health priority. The objective of this study was to report on the current state of knowledge about possible adverse effects induced by NMD in humans to determine the toxicological profile of each type of NMD and possible biomarkers for the early detection of these effects in workers. Methods A systematic review of human studies and epidemiological investigations of exposed workers in relation to the possible adverse effects of the most widely used ENM was carried out by searching the main scientific databases, including Web of Science, Scopus and PubMed. Results Twenty-seven studies were identified. Most of the epidemiological investigations were cross-sectional. The review found limited evidence of adverse effects in workers exposed to the most commonly used ENM. However, some biological alterations suggest possible adverse impacts. The primary targets of some NMD exposures were the respiratory and cardiovascular systems. Changes in biomarker levels were also observed compared to controls; however, limited exposure data and the relatively short period from first exposure may have influenced the incidence of adverse effects found in epidemiological studies. Conclusions There is a need for longitudinal epidemiological investigations with clear exposure characterizations for various NMDs to discover possible adverse health effects and identify possible indicators of early biological disturbances. In this state of uncertainty. Extracted from the National Library of Medicine, National Center for Biotechnology Information https://pubmed.ncbi.nlm.nih.gov/30653633/