Micro[nano]plastic particles and cancer: challenges and opportunities for epidemiology studies

Micro[nano]plastic (MNP) particles are ubiquitous, persistent environmental contaminants that can enter the human body through inhalation, consumption, and skin contact. These particles have been detected in several organs and tissues, including lungs, brain, liver, kidney, bone, placenta, blood, sputum, urine and stool. Recent studies have also identified MNP particles in a wide range of human cancer tissues including lungs, stomach, colon, endometrium, penis, breast, cervix, and prostate. Furthermore, data from in-vitro studies, in-vivo models, and occupational studies suggest that MNP particles may impact carcinogenesis pathways and potentially increase cancer risk. However, the epidemiological evidence linking MNP exposure to cancer risk or cancer related causal pathways is scarce. This gap is mainly attributable to substantial methodological challenges, including inadequate measurement methods and a lack of standardization. With ongoing advances in detection and measurement technologies of MNP particles in human biological samples, along with progress in addressing key methodological barriers, research on MNPs and cancer is poised for major advancement.