Why Plastics Are Harmful

What happens when plastics end up in the marine environment?

In a study funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore (first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018), a team of scientists from the National University of Singapore (NUS) found that plastic nanoparticles – tiny pieces of plastic less than one micrometre in size – are easily ingested by marine organisms and accumulate in the organisms over time, potentially contaminating food chains, threatening food safety and posing health risks. The NUS research team at the Tropical Marine Science Institute (TMSI) used the acorn barnacle Amphibalanus amphitrite as the model organism in its tests to demonstrate that nanoplastics ingested during the larval stage are retained and accumulated inside the bodies of the barnacle larvae until they reach adulthood. The acorn barnacles were used as test subjects because their short life cycle and transparent bodies made it easy to trace and visualise the movement of nanoplastics in their bodies within a short span of time. Barnacle larvae were incubated by the team with regular feed and 100-nanometre sized plastics, tagged with green fluorescent tags in two different treatments – “acute” and “chronic” According to Dr Neo Mei Lin from TMSI, because the barnacles are at the bottom of the food chain, the nanoplastics they consume are transferred to the organisms that eat them. Plastics also absorb pollutants and chemicals from the water, and these toxins are therefore transferred to the organisms when they consume contaminated plastics and can cause further damage to marine ecosystems – and ultimately, human health.

“Acute” treatment: Larvae solution with 25 times more nanoplastics than ocean average for three hours Even with barnacles’ waste removal, moulting and excretion, the nanoplastics remained in their bodies throughout their growth until adulthood