Enrico Bergamaschi

Although cumulative evidence from in vitro and in vivo studies indicates that micro- and nano-plastics (MNPs) can perturb biological systems, and MNPs have been detected in several human fluids and tissues, the consequences of MNPs exposure to human health still remain unknown. To date, reliable human exposure estimates are hindered by the lack of standardized processing and analytical methods to detect MNPs in complex human biological matrices tissues, and limited evidence on the MNP-related adverse health effects exists. Work environments where plastic materials are produced/handled may represent prioritised settings for evaluating potential health effects on humans because workers experience higher level of exposure - by inhalation - as compared to the general population. To develop effective preventive strategies preventing human exposure to MNPs, it is essential to identify and validate sensitive and specific biomarkers of exposure and early changes in biological systems, which could be precursors to more serious health effects. Biomarkers should ideally be measured in biological matrices collected non-invasively (such as exhaled breath condensate – EBC and urine), or by minimally-invasive procedures (e.g., blood) to enable a periodical health assessment. For a more comprehensive understanding of the potential health risks associated with MNPs exposures, it is recommended using standardized research protocols which integrate exposure monitoring with human biomonitoring to harmonize the methodological approach across studies (Catalán et al, 2025). Future occupational studies aimed at addressing the causal relationship between MNPs exposure and health effects should basically follow the stepwise approach described in the OECD guidance document (Hopf et al, 2024) (Figure 1). Despite the progress achieved, several challenges should still be overcome in future studies. Figure 1. The main stages of a human biomonitoring study involving the MNPs assessment. These include the need of working with international multicenter prospective cohorts, whose members should be deeply involved in the design and execution of the study, allowing proper sample sizes and the assessment of causal relationships. Furthermore, classical validated biomarkers of (early) health effects should be complemented with more specific biomarkers of MNPs´ effects, which still need high-throughput methods and further standardization efforts. This work was supported by European Union’s Horizon 2020 research and innovation programme under grant agreement No. 965367 (PlasticsFatE). References Catalán, J., Afanou, A.K., Arranz. J.A., et al. (2025) NanoImpact 40, 100600. Hopf, N.B., Rousselle, C., Poddalgoda, D., et al. (2024). Environment Int. 191, 108990.

An integrated approach to assess exposure and early health effects in human populations exposed to micro- and nano-plastics

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