While the threat that microplastics pose to human and ecological health has been richly documented and is well known, nanoplastics, which are smaller than one micrometer (1/50th the thickness of an average human hair), are far more reactive, far more mobile and vastly more capable of crossing biolog ical membranes. Yet, because they are so tiny and so mobile, researchers don't yet have an accurate understanding of just how toxic these particles are. ...read more read less