Nanoplastics can accumulate in marine life and threaten human health: NUS study

CHEN LIN Today Online 31 May 18;

SINGAPORE — Tiny plastic particles called nanoplastics from everyday items such as plastic containers and straws could accumulate in marine organisms, transfer up the food chain and threaten food safety and human health, said researchers from the National University of Singapore (NUS).

For the first time, a NUS research team working with the acorn barnacle, Amphibalanus amphitrite, demonstrated that nanoplastics – which are less than one micrometre in size and invisible to the naked eye – consumed during the larval stage are retained and accumulated inside the barnacle larvae until they reach adulthood.

In an experiment conducted in November 2016, the team incubated the barnacle larvae in solutions of their regular feed with plastics that were about 200 nanometres in size. The larvae were exposed to two different treatments: acute and chronic.

Barnacle larvae in the acute treatment were kept for three hours in a solution that contained 25 times more nanoplastics than what is currently present in oceans, while those under the chronic treatment were exposed to a solution with low concentrations of nanoplastics for up to four days.

The larvae were then filtered from the solution and examined under a microscope.

“Our results showed that after exposing the barnacle larvae to nanoplastics in both treatments, the larvae had not only ingested the plastic particles, but the tiny particles were found to be distributed throughout the bodies of the larvae,” said Ms Serina Lee from the Tropical Marine Science Institute at NUS on Thursday (May 31). She is the second author of the research paper.

While the barnacles had removed some nanoplastics through moulting and excretion, the team detected continued presence of nanoplastics inside the barnacles as they grew and reached adulthood.

According to the researchers, it is estimated that the oceans may already contain over 150 million tonnes of plastic. Each year, about eight million tonnes of plastic end up in the ocean.

Plastics of all sizes 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 marine organisms such as barnacles, tube worms and sea-squirts.

“Barnacles may be at the lower levels of the food chain, but what they consume will be transferred to the organisms that eat them,” said marine biologist Dr Neo Mei Lin, who is also from NUS’s Tropical Marine Science Institute, and one of the authors of the paper.

“In addition, plastics are capable of absorbing pollutants and chemicals from the water. These toxins may be transferred to the organisms if the particles of plastics are consumed, and can cause further damage to marine ecosystems and human health.”

Associate Professor in Department of Chemistry at the NUS Faculty of Science, Suresh Valiyaveettil, who co-supervised the research, said that nanoplastics can “enter into animal cells and induce adverse health effects”. He added that further investigation was required for scientists to understand the mechanism.

The NUS team’s research findings were first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018. The study was funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore.

The team is also examining how nanoplastics affect other invertebrate model organisms to understand the impact of plastics on marine ecosystems.

Nanoplastics found to accumulate in marine organisms, risk being transferred up food chain: NUS study
Liyana Othman Channel NewsAsia 31 May 18;

SINGAPORE: Plastic nanoparticles - plastic pieces smaller than 1 micrometre - have been found to accumulate in certain marine organisms and could be transferred up the food chain, according to a study by scientists from the National University of Singapore (NUS).

It is estimated that there are more than 150 million tonnes of plastic in the world's oceans, with 8 million tonnes ending up there every year.

This plastic can get broken down into smaller pieces and eaten by marine animals that mistake them for food.

The NUS research team looked at smaller pieces of plastic - nanoplastics - using barnacles and their larvae to understand how nanoplastics could impact marine organisms.

As barnacle larvae are transparent until they mature, feeding them with fluorescent, non-toxic nanoplastics meant the researchers could easily spot these under the microscope.

"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 Chemistry PhD student who contributed to the research paper.

The team demonstrated for the first time that nanoplastics consumed during the larval stage are retained and accumulated inside the barnacle larvae until they reach adulthood.

This was the case even when the organisms were exposed to a high concentration of nanoplastics for just three hours.

"It's worrying, because this suggests that the organisms have a problem excreting and removing the nanoplastics, which increases the risk of bioaccummulation in the organisms, and subsequently into the rest of the food chain," said Dr Serena Teo, a Senior Research Fellow from the NUS Tropical Marine Science Institute who co-supervised the research.

The nanoplastics were found to have spread all over the larvae's bodies.

According to the researchers, this was because the nanoplastics - which are about 1,000 to 10,000 times smaller than the larvae - are small enough to enter the organisms' bloodstreams and infiltrate cell walls. These nanoplastics can absorb pollutants and chemicals from the water.

“Barnacles may be at the lower levels of the food chain, but what they consume will be transferred to the organisms that eat them," said one of the authors of paper's authors, marine biologist Dr Neo Mei Lin from the Tropical Marine Science Institute at NUS. "In addition, plastics are capable of absorbing pollutants and chemicals from the water."

"These toxins may be transferred to the organisms if the particles of plastics are consumed, and can cause further damage to marine ecosystems and human health."

Associate Professor Suresh Valiyaveettil, who also supervised the research, said that plastic waste is a big concern.

"The lifespan and fate of plastic waste materials in marine environment is a big concern at the moment, owing to the large amounts of plastic waste and its potential impact on marine ecosystem and food security around the world," he said.

However plastics are so prevalent in modern life that we cannot really get rid of them, said Dr Teo.

Instead, she said the study emphasises the importance of waste management - not letting the plastics get into the ocean in the first place.

"It also opens the doors for a lot of ways in how we shall now design new advanced materials," she added, giving the example of green plastics that degrade into inert molecules.

The next step for these researchers is to understand how nanoplastics affect other marine organisms such as tubeworms and sea urchins and, ultimately, how they impact human beings.

The team’s research findings were first published online in the journal ACS Sustainable Chemistry & Engineering in March 2018. The study was funded under the Marine Science Research and Development Programme of the National Research Foundation Singapore.

Source: CNA/nc(aj)


Nanoplastics can accumulate in marine organisms' bodies, NUS research finds
Kimberley Chia Straits Times 31 May 18;

SINGAPORE - Researchers here have found that some marine organisms may be able to retain tiny pieces of plastic in their bodies for several days.

This means that if these plastic pieces carry hazardous chemicals and are eaten by these organisms, aquatic food chains could be contaminated if these organisms are, in turn, eaten by others, say researchers.

National University of Singapore (NUS) scientists have found that one particular marine organism, the acorn barnacle, retained tiny plastics from larvae to adulthood, a span of about seven days.

Dr Serena Teo, senior research fellow from the Tropical Marine Science Institute at NUS who co-supervised the research, said at a media briefing on Thursday (May 31): "Hazardous chemicals can also be absorbed by the particles. So when the particles are eaten, they can be transferred from the particle to the organism."

The 1½-year research, which started in November 2016, aimed to track the accumulation and retention of nanoplastics in marine organisms throughout their lifespans.

Nanoplastic particles, which are less than one micrometre in size, are about a thousand times smaller than the plastic beads in facial scrubs and toothpastes.

The team used the acorn barnacle as a model organism in order to track the movement of the particles.

Mr Samarth Bhargava, one of the researchers, said: "We wanted to use barnacles as the model organism because the larvae are transparent, so while taking an image of them, we can actually see the plastics through imaging techniques."

The research team incubated the barnacle larvae in solutions with non-toxic nanoplastics, along with their regular feed under two different conditions.

The nanoplastics were created by the team themselves before being tagged with a fluorescent dye for visibility.

In the first condition, termed "acute", larvae were exposed to high concentrations of nanoplastics for about three hours.

Under the second, "chronic" condition, which is closer to a common marine environment, larvae were exposed to a low concentration of nanoplastics for up to four days.

In both cases, plastic particles were found to have accumulated and been distributed throughout the entire body of the larvae after being ingested.

Substantial traces of plastic were also retained in their bodies until they reached adulthood. Barnacles that had been exposed to plastics under the "chronic" condition generally retained a higher amount of nanoplastics.

The study was funded under the Marine Science Research and Development Programme run by the National Research Foundation Singapore.

The findings were published online in March in science journal ACS Sustainable Chemistry & Engineering.

The team hopes to use the study as a launch pad for further understanding of the pathways of such plastic particles within the marine ecosystem, including the potential of these nanoplastics to move up the food chain.

NUS Department of Chemistry Associate Professor Suresh Valiyaveettil, who co-supervised the research, said: "The lifespan and fate of plastic waste materials in a marine environment are a big concern at the moment, owing to the large amounts of plastic waste.

"The team would like to explore such topics in the near future and possibly come up with pathways to address such problems."

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