zeedieren marine life

Transfer microplastic chemicals to marine life relatively small

It has often been said that microplastics will transfer chemicals to marine life. A new study addresses the question ‘to what extent plastic ingestion leads to increased uptake of chemicals in nature’. The conclusion is that microplastic ingestion is not likely to increase the exposure to hydrophobic organic chemicals in marine environments. The study was recently published in the science journal Environmental Science and Technology.

More specifically the researchers concluded that:

  • The amount of plastic in marine environments is negligible compared to other media that can transfer toxic chemicals
  • The amount of toxic chemicals carried by plastic is negligible compared to the amount carried by other media
  • Natural pathways (e.g. natural prey) play a bigger role in toxic chemical accumulation in marine organisms.

Because the abundance and potential hazards of nanoplastics have not yet been addressed, the authors consider nanoplastics one of the uncertain factors. The authors also underline that although microplastic seem to have a minor role in the accumulation of toxic chemicals, this does not imply that plastics in general do not have a destructive effect on marine life.

Consumptie fish markets
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Fish from fish markets contains plastic

A quarter of the fish bought at local fish markets has plastic in their digestive tracts. Scientists concluded this from researching fish from fish markets in Indonesia and California, USA. The results were published in the journal Nature Scientific Reports.

To get a clear image of plastic pollution in fish meant for consumption, the scientists researched the stomachs of fish from different habitats: benthic fish, reef fish and pelagic fish. Both herbivores and carnivores were studied.

16 out of 64 fish from the Californian fish market (25%) was polluted. Most of the pollution (80%) consisted of fibers. The researchers could not be sure if the fibres were made from synthetic material (plastic) or natural materials like cotton.

From the Indonesian market, 21 out of 76 fish contained plastics. However, most of the plastics here were little fragments (60%) and plastic foam (37%), items that rarely occurred in Californian fish. In contrast to California, there were no fibers found in Indonesian fish.

The researchers emphasized the differences in wastewater management in both countries as possible explanation why there were no fibers found in Indonesian fish.

BPA
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“Hospitals must become BPA-free”

The use of the chemical substance Bisphenol-A (BPA) is increasingly coming under pressure. BPA is added to many plastics and can disrupt the hormonal balance in humans. Pregnant women in particular are at risk. In addition to BPA, plasticisers (DEHP) are also harmful.

In the spring, the Dutch National Institute for Public Health and the Environment (RIVM) reevaluated BPA and concluded that there is enough evidence to tighten European standards.

Health Minister Edith Schippers (of the conservative liberal VVD party) has responded. The Dutch government will work to towards reducing the use of BPA and getting manufacturers to develop safer alternatives. Pregnant women will be better informed about the risks.

A paediatrician, toxicologist and an oncologist have decided not to wait for the government to take action. They have raised the alarm in the journal Medisch Contact and have called for:

  • All equipment in hospitals to be made BPA and DEHP-free
  • The government to take more measures.

The authors say that around 80 diseases can be connected to exposure to substances which disrupt hormonal balances and that the evidence for this is mounting. These diseases include testicular cancer, obesity and reproductive disorders. A causal relationship, however, has not been proven (as it is impossible to do research with a target group which is not exposed to these substances, because everyone is exposed to them in their daily lives).

Photo by David McNew/Getty Images

zeevogels seabirds

Seabirds absorb chemicals from ocean plastic

Scientists from three Japanese institutes have linked plastic-derived chemicals found in seabirds to the plastic in their stomachs. They published their results in Environmental Science and Technology.

Plastic products contain chemical additives such as the flame retardant polybrominated diphenyl ether (PBDE) and have been shown to leach these chemicals into the surrounding environment. However, are those plastic-derived chemicals directly absorbed into the bodies of the seabirds? Or is the PBDE coming from the marine organisms that are the natural prey of these seabirds?

To find answers to these questions, Japanese scientists analysed 18 wild seabirds. Their analysis showed that in three birds specific plastic chemicals in both fat and liver matched those found in the plastics from the stomach, suggesting a direct transfer of chemicals from plastic to bird tissues.

To gain better understanding of this transfer the scientists studied leaching of PBDE from plastics into several different digestive solutions including stomach oil of seabirds. Experiments showed that:

  • Only trace amounts were leached into distilled water, seawater, and acidic pepsin solution
  • In comparison chemical leaching was over 20 times greater into stomach oil, and over 50 times greater into fish oil which is a major component of stomach oil.

Model calculations based on the results of the leaching experiments combined with field observations suggest the exposure from plastic is dominant over exposure via prey. The scientists point out that other digestive fluids such as bile may also facilitate leaching and bio accumulation of PBDE’s from ingested plastics.

europese zeebaars intestines european sea bass

PVC damages intestines of European sea bass

The ingestion of polyvinyl chloride (PVC) can damage the intestines of European sea bass. This is the outcome of research by Italian scientists from the Institute for Environmental Protection and Research and the Institute for Coastal Marine Environment and other institutions. Their research was published in the journal Environmental Pollution.

162 fish were divided into three groups with different diets. During a period of 90 days, the researchers fed the fish:

  • Normal feed (group 1)
  • New PVC pellets (group 2)
  • Contaminated PVC pellets (from the sea) (group 3).

It appeared that the intestinal epithelium and intestinal villi, which covers the small intestine to absorb as many nutrients as possible, are harmed by plastic pellets:

  • After 30 days, changes in the epithelium of 67% of the fish in group 2 were observed, such as swelling and smaller villi. In group 3, serious changes were observed in 85%, such as the peeling of epithelium and destruction of the villi.
  • After 60 days, the changes of the epithelium had worsened in fish from both groups 2 and 3.
  • After 90 days, half of the fish in group 3 had very serious damage to their intestine. The structure of the intestinal epithelium had disappeared and the villi had been destroyed. The other half of groups 2 and 3 showed the same result after 60 days.
Cross section of the fish intestines after 90 days feeding with a: normal feed, b: new PVC, c: contaminated PVC. Source: Pedà et al., 2016.

Cross section of the fish intestines after 90 days feeding with a: normal feed, b: new PVC, c: contaminated PVC. Source: Pedà et al., 2016.

The researchers conclude that plastic which has absorbed chemical substances can cause serious damage to bodies. According to the researchers, this property of plastic is a huge risk to the marine environment, because changes may already take place after just 30 days.

tafelzout table salt

Table salt contaminated with microplastics

Along with fish and shellfish, table salt also appears to be contaminated with microplastics. This is the conclusion of Chinese scientists at the State Key Laboratory of Estuarine and Coastal Research and the Research Center for Analysis and Measurement following research into various salt brands from Chinese supermarkets. The results were published on 20 October 2015 in the journal Environmental Science & Technology.

The scientists researched fifteen Chinese salt brands from different salt sources: the sea, salt lakes and salt mines.

Results (on average per kilogram salt):

  • Sea salt: 615 microplastic particles
  • Salt lake: 204 microplastic particles
  • Salt mine: 105 microplastic particles.

Table salt appeared to contain several types of plastic particles, a large majority being fibres and small fragments (94%). The rest 6% consisted of plastic film, pellets and other particles. In addition to the type of particles, the researchers also determined which kinds of plastic they found in the salt. In sea salts, the most common microplastics were polyethylene terephthalate (PET) and polyethylene (PE), followed by cellophane. Salts from salt lakes and salt mines, on the other hand, contained more cellophane particles.

The plastics, together with the toxic chemicals and heavy metals are possibly harmful to human health and a risk to food safety. The World Health Organisation (WHO) recommends consuming less than 5 grams of salt per day. Based on this recommendation, we could be ingesting 1000 microplastic particles per person per year from table salt alone.

Breathe
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“We may breathe harmful microplastics”

Microplastics in the air are potentially dangerous for human health. Professor Kelly of King’s College London: “If we breathe them in they could potentially deliver chemicals to the lower parts of our lungs and maybe even across into our circulation, in the same way as we worry about all the other vehicle-related emissions”.  Recently, he informed the Environmental Audit Committee of the Parliament about the issue.

The plastic microparticles could enter the air through degradation of plastic items or after sewage sludge is spread on fields and dries out. The amount of microplastics in the air is increasing. And the question about them causing physical and chemical harm should be asked.

Monitoring methods should be adapted to detect microplastics in the air. Kelly also stated that “dietary exposure to microplastic particles is likely to be relatively low compared with inhalation of microplastics”. Read more in this article written by The Guardian.

livers levers fish

Microplastics can damage fish livers

Ingestion of microplastics can have a negative impact on fish by causing damage and changes to their livers. These effects were first observed by scientists from the University of California and San Diego State University, USA and published in Nature Scientific Reports.

The scientists set up an experiment where they divided fish into 3 groups – each having a different diet. For a period of 2 months, fish either had a plastic free diet, were fed with food containing virgin plastic or food containing marine plastic. Due to keeping the marine plastic particles in the sea for 3 months prior to the experiments the marine plastic particles contained additional toxic chemicals.

Experiment results showed that:

  • Livers from fish with a plastic diet showed signs of toxicity
  • One fish that was fed with virgin plastic developed a precursor to a liver tumor
  • One fish that was fed the marine plastic developed a tumor comprising 25% of the liver
  • Negative effects on the liver were in general greater in fish that ate marine plastic particles, which scientists linked to additional toxic chemicals found on these particles.

By doing an experiment close to natural conditions scientists showed that such effects probably also occur in the natural environment. The scientists conclude that the plastics used can act as a vector for the bio-accumulation of toxic substances in fish, and that toxicity resulting from plastic ingestion is a consequence of both the sorbed contaminants and plastic material.