Have Micro and Nanoplastics Become Part of Our Diet?
Text Rachel Kwek and Terence Koh
It is a well-known fact that microplastics swimming in our oceans are a huge problem but have they already found their way into our stomachs?
Ocean plastic pollution is a major and growing global problem. Scientists estimate that the Earth’s oceans may already contain more than 150 million metric tonnes of plastic, with eight million metric tonnes more entering the oceans each year. Plastics do not degrade easily. In the marine environment, plastics are usually broken down into smaller pieces by the sun, waves, wind and microbial action. These micro- and nanoplastic particles in the water may be ingested by filter-feeding marine organisms such as barnacles, tube worms and sea squirts.
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 organs over time, potentially contaminating food chains, threatening food safety and posing
The NUS research team, comprising scientists from the Tropical Marine Science Institute (TMSI) and Department of Chemistry, used the acorn barnacle Amphibalanus amphitrite in its tests to demonstrate for the first time that nanoplastics ingested during the larval stage are retained and accumulated inside the bodies of the barnacle larvae until they reached adulthood. “We opted to study acorn barnacles as their short life cycle and transparent bodies made it easy to track and visualise the movement of nanoplastics
in their bodies within a short span of time,” said Mr Samarth Bhargava, a PhD student from the Department of Chemistry in the NUS Faculty of Science.
Barnacle larvae were incubated in two solutions containing their regular feed and different amounts of 200-nanometre-wide plastics marked with green fluorescent tags:
- “Acute” treatment: Solution with regular feed and 25 times more nanoplastics than the current estimate of what is present in the oceans on average for three hours
- “Chronic” treatment: Solution with regular feed and a low amount of nanoplastics for four days
The 25th anniversary of the largest and longest running dive show, Asia Dive Expo (ADEX) is set to occur on the 11-14th April 2019. Centred on the theme – Plastic free Future, ADEX is more than just a dive show with its commitment to the environment. Among an exciting lineup of programs, attendees can look forward to a Future Forward Series of Panel Discussion on the Single-Use Plastic Conundrum in Asia, on 13th April.
So join us at the event, get inspired and for all you know, you might just liberate the inner diver in you! More details of the event here.