Exploring alternatives for detecting microplastics in the human body: questionnaire survey

Microplastics (MPs) can enter the body via plastic products. Given modern plastic exposure, we seek to assess MP exposure in large populations through epidemiological tools. In this quasi-experimental study, every participant filled out a questionnaire, and those who satisfied any of the following requirements were not allowed to continue in the study: Diabetes, ulcerative colitis, Crohn's disease, infectious diseases. Participants in the exposure and control groups were provided three hot meals in disposable plastic tableware (DPT) (n = 30) or non-DPT (n = 30), respectively. After a month of observation, individuals in the exposure group discontinued the three meals provided in DPT (n = 27) for 1 month as the post-exposure group. Each Participant in the three groups received a questionnaire survey and fecal sample collection. We compared the differences in MP levels between different groups and used the Bland-Altman analysis method to evaluate the consistency of the results obtained by different measurement methods. Statistically significant differences in the total quantity (P (0.80 matching degree) = 0.020; P (0.65 matching degree) < 0.001) and types (Polyethylene Terephthalate (EVA) (P = 0.039), Polyethylene Terephthalate (PET) (P = 0.022), Polyvinyl Butyral (PVB) (P = 0.013), Chlorinated Polyethylene (CPE) (P = 0.039), phenolic epoxy resin (P = 0.012)) of MPs were observed between the exposure and post-exposure groups. The Bland-Altman analysis results indicate that the two methods exhibit good consistency in the three groups (control group: mean difference = 0.54, agreement limits (95% CI) = - 0.44 ~ 1.54; exposure group: mean difference = 0.41, agreement limits (95% CI) =  - 0.19 ~ 1.01; post-exposure group: mean difference = 0.19, agreement limits (95% CI) =  - 0.63 ~ 1.02). The method based on questionnaire surveys can substitute the method of fecal sample detection to evaluate the exposure of MP particles.