Improving microplastic research

There has been a virtual explosion of research on microplastics. Every week new articles are published in scientific journals. However, not all of them are original or important. Dozens of papers come out monthly that report the number of microplastic particles found in some water body, but they cannot be compared because there are no standardized methods for collection or analysis. However, it has become clear that collecting microplastics with nets misses most of the microplastics, since microfibers, which are by far the most abundant type when whole water samples are analyzed, pass through nets. These microfibers are derived primarily from synthetic clothing via wastewater from washing machines. Another common study documents that some species consumes microplastics. It seems that every animal studied eats them; it would be of greater interest to find one that does not ingest them. Although animals consume them, few studies have examined how soon and how many are egested. Most may pass through the gut without causing any noticeable effects. This is an important area to study. Microplastics are considered vectors for transferring contaminants to animals and up the food chain, but few studies demonstrate this with realistic scenarios such as providing the animals some “real” food and time to egest. Effects attributed to microplastics may be symptoms of inadequate nutrition or a clogged digestive tract. It is also important to learn how much of the adsorbed contaminants the gut can desorb during the time that microplastics are passing through. Future feeding studies should not use spherical microplastics which are rare in aquatic environments but should use primarily microfibers which are the predominant shape found, provide real food, and allow time for egestion to occur. Other research needs include additional studies on soil and terrestrial biota and developing ways to modify the manufacture of textiles to shed fewer microfibers.