Characterizing oral exposure to nano- and microplastics - EXaMINA
- Cristina Villanueva, PhD
- The Barcelona Institute for Global Health, ISGlobal; The Spanish National Research Council (CSIC)
Nano and microplastics (NMPs) constitute an emerging environmental and health concern (1). Growing evidence show the presence of NMPs in drinking water and food, but the magnitude of human exposure is unknown, which is the first step to elucidate effects on human health. Although exposure through drinking water is suggested to be a main route, few studies have quantified the concentrations of NMP in water. In addition, NMPs constitute a complex environmental exposure involving the plastic particle in addition to chemicals such as plastic additives, that are linked to adverse health outcomes (2, 3). Gastrointestinal uptake has been described for microplastics up to 130 μm, and nanoplastics <100 nm, which are absorbed through the intestinal barrier, suggesting NMP may reach the bloodstream and systemic circulation. Still, there is lack of knowledge about main sources of human exposure to NMPs as well as there is a need for basic research to elucidate the transferability of NMPs in the gastrointestinal tract
To characterize human exposure to NMPs and plastic additives through lifestyles, food and drinking water. Specific objectives:
1. Quantify NMPs and plastic additives in biological samples (stool, urine) and residential drinking water in an observational population-based study.
2. Identify individual characteristics and behaviors predictive of NMPs and plastic additives, including diet and drinking water habits.
METHODOLOGY (please include Subjects, Ethics, Confidentiality, Return Of Results and Incidental Findings management)
Study design. We will conduct an observational cross-sectional population-based study in 48 adult participants to evaluate human NMP exposure in real-life conditions.
Participants. Adult volunteers (≥18 yrs.) living in Barcelona (Spain) will be selected, based on their drinking habits (50% tap water, 50% bottled water) and food habits (50% vegetarian).
Data and sample collection. Participants will provide single samples of drinking water (from their residences), stool, and urine. At baseline, participants will answer a general questionnaire, which includes a validated food frequency questionnaire. In addition, during the 4 days prior to sample collection, participants will answer daily a food diary aided with photo-based data collection.
Sample analysis. After appropriate pre-treatment of samples, NMPs will be characterized in water and stool samples through micro-Fourier transform infrared spectroscopy (particles >10 mm), and concentration of different polymers will be determined through size exclusion chromatography - high resolution mass spectrometry (HRMS). Plastic additives will be quantified in water, urine, and stool through suspect screening followed by confirmatory analysis by reverse phase liquid chromatography-HRMS
Data processing. We will estimate oral exposure to MNP and their chemical additives based on the drinking water samples collected and on the personal information provided by the volunteers (diet, drinking water). Literature on MNP and chemical additive concentrations in food will be reviewed. We will estimate the association between oral exposure to MNP/plastic additives and concentration in stool and urine, and between urine and stool measurements.
Risk minimization. Strategies to minimize the impact of any risk include: i) all researchers involved have extensive experience in management of research projects and will advise on strategic scientific issues; and ii) the work plan will proactively be adjusted for any risk eventuality before its implementation. Alternative tasks of the contingency plan will be identified in order to react quickly if adaptation of the work plan is required.
Ethical issues. The study has been submitted for approval at the CEIC-PSMar. The study subjects will be volunteers, who will only participate after giving a written and informed consent. The project will be carried out in accordance with international and national legal and ethical standards.
All ISGlobal researchers are self-regulated by the Code of Good Scientific Practice (https://prbbgoodpractice.wordpress.com/the-code/)
Confidentiality. Adequate measures to ensure personal data protection and confidentiality will be taken, according to the Regulation (EU) 2016/679 on the protection of natural persons with regard to the processing of personal data and on the free movement of such data, and the Spanish Law of Personal Data Protection and Digital Rights Guarantee (3/2018, of 5th December). National regulations on personal data protection will be implemented to guarantee the highest standards in personal data management. The following principles will be applied when processing personal data: lawfulness, fairness and transparency; purpose limitation; data minimization (necessary and proportionate for the research objective); accuracy; storage limitation and integrity and confidentiality. Data will be shared after being pseudo-anonymized.
- Vethaak AD, Legler J. Microplastics and human health. Science 2021;371(6530):672-4. doi: 10.1126/science.abe5041
- Ballesteros V, Costa O, Iniguez C, Fletcher T, Ballester F, Lopez-Espinosa MJ. Exposure to perfluoroalkyl substances and thyroid function in pregnant women and children: A systematic review of epidemiologic studies. Environ Int 2017;99:15-28. doi: 10.1016/j.envint.2016.10.015.
- Wazir U, Mokbel K. Bisphenol A: a concise review of literature and a discussion of health and regulatory implications. In vivo 2019;33(5):1421-3.