NCEH/ATSDR Microplastic Working Group: Identifying and Addressing Data Needs to Evaluate Human Exposures to Microplastics

Abstract

Microplastics are environmentally persistent pollutants characterized by their diverse composition and small size (<5mm). Microplastics can be manufactured like microbeads, tire crumb, polyester fibers from clothing and carpets, and result from fragmentation processes of plastics disposed in the environment. Microplastics pervade our environment and human exposure is certain. However, exposure-dose and possible health effects have not been established. Some microplastic fibers and particles are small enough to become internalized and transported within our bodies (e.g. respirable particles PM10 and 2.5; particles 0.02-0.05 µm in size can passively drain through lymphatics). However, most of the environmental samples collected have been characterized as larger particles that are unlikely to be absorbed. Other relevant considerations include the composition and physicochemical characteristics of plastics (shape, density, and surface chemistry), and the composition of additives and absorbed or adsorbed contaminants. The array of variables, and uncertainty as to which may be most relevant to health pose challenges for exposure assessment. The CDC National Center for Environmental Health (NCEH) and the Agency for Toxic Substances and Disease registry (ATSDR) developed a microplastics working group with a vision and objectives to: 1. Identify the scientific information and data that are lacking to define health risks; 2. Create constructive partnerships to broaden outreach;3. Energize communities and institutions to develop initiatives to stop harmful microplastic exposures in our environment. In this poster, we will highlight activities that the NCEH/ATSDR working group has conducted to accomplish the objectives. We will also present an overview of what is known about the fate and transport of microplastics in the environment, and potential human exposures from drinking water, air, and food. Data gaps will be highlighted that may inform policy-relevant research roadmap to address the many uncertainties in this important area.