Microplastics may be contaminating our drinking water, according to a study published by researchers at the Geological Society of America. Their chemical threat stems largely from their ability to transport harmful compounds on their surfaces, meaning that when organisms at the base of the food chain ingest microplastics, they ingest toxins too. These toxins can build up and eventually result in responses like organ dysfunction, genetic mutation or even death. The researchers found bisphenol A (BPA), a chemical used to make plastics, in all 47 human samples.