Letter to the Editor pubs.acs.org/est
Cite This: Environ. Sci. Technol. XXXX, XXX, XXX−XXX
Are the Risks from Microplastics Truly Trivial? n his Viewpoint “Stressor Exposures Determine Risk: So, Why Do Fellow Scientists Continue To Focus on Superficial Microplastics Risk?”, Burton admonished scientists for their “superficial” concerns over environmental risks of microplastics.1 I agree that microbeads in rinse-off personal products, while readily eliminated, are likely less hazardous than other pollutants. However, I have less confidence in his thesis that microplastic risks should be deemed inconsequential because exposure is limited. Massive amounts of plastics have been released into the environment. Indeed, plastic debris in the oceans has been projected to double in the next 10 years.2 The dose makes the poison and it is increasing. Polymers inevitably fragment into a multitude of microplastics depending on their age, properties and ambient conditions. As Burton notes, our ability to even measure microplastics is inadequate.1 Hence exposure is likely greater than assumed. It is not just particle size and abundance that merit consideration. Polymeric composition, particle shape, surface area, density, persistence, sorbed pollutants and additive content affect microplastic fate and toxicological consequences. Better understanding of these parameters is a prerequisite to assessing risks. Recent findings confirm that microplastic abundance increases with decreasing particle size.3 Burton correctly points out that the smallest particles are the least studied.1 These exhibit greatest surface areas, chemical reactivity and are assimilable by a larger segment of the food chain. Hence, they may present additional risks: consider inhalation toxicology, where
