Numerous studies in recent years have provided more evidence on the presence, distribution, and starting sources of microplastic. However, the current stage of knowledge does not provide a definitive explanation of how microplastic contaminants interact chemically and physiologically with various organisms at different trophic levels. Ultimately, the risks microplastics pose to human health through consumption of contaminated food need to be considered, but these are still difficult to determine. Researchers are attempting to answer these questions with focus on specific areas. First is the level of exposure.