Understanding the occurrence and fate of atmospheric microplastics and their potential risks to human health: A study protocol for cross-sectional analysis (Preprint)

Abstract

Plastic pollution has reached alarming magnitude, defining the contemporary era as the ‘Plastic Age.’ Uncontrolled plastic production and inadequate recycling processes have led to widespread contamination of the environment with micro and nanoplastics.

Understanding the extent of environmental exposure to plastic additives and consequential health outcomes for providing knowledge and developing effective control measures.

A cross-sectional exploratory study design was used, consisting of exposed and non-exposed groups in plastic recycling sites in Dhaka city. With a systematic approach involving plastic recycling hotspot detection, management pathway mapping, and detecting the presence of environmental microplastic (MP), the study will establish possible associations between different health consequences and MP exposure. MPs and heavy metals will be detected from environmental samples using fluorescence microscopy, Fourier-transform infrared spectroscopy (FTIR), and inductively coupled plasma mass spectrometry (ICP-MS). Human exposure will be assessed by detecting the metabolites of bisphenol and phthalates from urine samples using Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) and thoroughly evaluating endocrine, reproductive, respiratory, and renal functions. The sample size was derived from the mean concentrations of urinary bisphenol and phthalates metabolites, requiring the participation of 168 respondents. A 1:1 exposure to non-exposed stratification would be sufficient to meet our study objectives, considering the conventional level of power and confidence interval.

This study protocol (PR#22111) has received approval from the Research Review Committee and Ethical Review Committee of the icddr,b. We enrolled 84 adult plastic recycling workers with at least five years of exposure history and 84 non-exposed participants who were not involved with plastic recycling activities. We anticipate completing the sample analysis by the second half of 2024.

The findings would provide valuable insights into the adverse impacts of microplastic pollution on both the environment and human health, aiding in better understanding the extent of the issue.