The issue of nanoplastics (NPs) in the environment, following that of microplastics (MPs), is receiving increasing attention in the scientific community. Due to their size, these particles require the development and application of new methods for both quantitative and qualitative determination. Consequently, techniques commonly used for analyzing MPs may prove ineffective in the context of NPs. Isolating NPs from samples with complex matrices poses a significant challenge that directly affects analytical outcomes. This paper aims to discuss the main challenges encountered during the analysis of NPs in environmental samples. Various methods for the visualization and identification of NPs are examined, with a focus on microscopic, spectroscopic, and thermal techniques. The advantages and limitations of analytical approaches reported in the literature are summarized, offering guidance for the future development and standardization of methods used to determine NPs in environmental contexts.

Environmental pollution with microplastics (MPs) and nanoplastics (NPs) continues to increase. These pollutants have been found in the environment (water, soil, and air) as well as in human tissues and biological fluids. Oral, inhalation, and dermal pathways play key roles in human exposure to plastic particles. The primary sources of exposure are foods, beverages, air, and dust. Polymers can penetrate the skin primarily via endocytosis, exocytosis, passages through cell-to-cell junctions, and interaction with the extracellular matrix. However, the health effects of dermal exposure remain poorly understood. Microplastics and NPs have been detected in the gastrointestinal, respiratory, circulatory, urinary, reproductive, and nervous systems, causing detrimental effects in each. Such effects include oxidative stress, inflammation, cellular damage, and protein aggregation. Furthermore, their presence has been linked to cardiovascular and neurodegenerative diseases. However, standardized protocols for analyzing NPs and MPs in human organs and tissues have not yet been established or legally regulated. Further research is needed to fully determine exposure thresholds, but legislative and lifestyle changes can already be implemented.