Cohort Profile: Zhuhai Microplastics Exposure Cohort (Z-MEC), a Hospital-Based Prospective Cohort of Patients with Respiratory Diseases

Abstract

Increasing evidences have indicated a human internal exposure of Microplastics (MPs), whereas epidemiological evidence linking MPs to health outcomes remains limited, especially from prospective cohort studies. We established the Zhuhai Microplastics Exposure Cohort (Z-MEC), a hospital-based prospective cohort of 700 patients with respiratory diseases between October 2020 and November 2022. Apart from blood and urine sampling, bronchoalveolar lavage fluid (BALF) of patients undergoing bronchoscopy was further collected to evaluate MPs burden using both the laser direct infrared (LDIR) and scanning electron microscopy. Clinical data, laboratory indices, and questionnaire information were also obtained at baseline, and repeatedly collected during the scheduled follow-up according to the individual medical care. Among 479 participants with BALF, the detection rate of total MPs reached 96.12%, with a median abundance of 115.02 (IQR, 34.77–303.43) particles per gram of BALF. The most prevalent polymers included polyethylene (PE), high-density polyethylene (HDPE), polyurethane (PU), and polyvinyl chloride (PVC). Detailed morphological analysis revealed that inhaled MPs are typically irregular in shape, and larger-sized particles have been found deep within the lungs. In summary, the ongoing Z-MEC study serves as a vital platform for research on MPs exposure assessment and their potential health impacts.