Microplastics now found in underground drinking water reservoirs

Amsterdam, 05 February 2019 – Microplastics are found in surface water all over the world. Now for the first time they have also been found in underground layers of soil and rock that contain water. About one quarter of the drinking water provision in the world depends on underground water reservoirs. These reservoirs are filled with surface water that slowly seeps through the porous layers. As these reservoirs are connected to surface water sources, these latter sources can becomepolluted.

Researchers studied 17 samples from two separate underground reservoir systems in Illinois, USA. Their research was published this month in the journal Groundwater. All the samples bar one showed microplastics. The maximum concentration was 15 microplastics per litre. All microplastics were fibres. Given the combination of the microplastics and other substances that included phosphates, chloride and triclosan, the researchers believe that the source of the pollution is primarily household septic tanks.

Households that are not connected to the sewage system use these tanks for waste water as a purification system. The sludge is regularly removed and the purified water is discharged in the surface water. The waste water of washing machines and dryers also enters these tanks first. Machine washing and drying synthetic clothing releases millions of plastic microfibres. Given that these fibres are virtually weightless, they do not sink to the bottom. In an interview, one of the authors stated, “Imagine how many thousands of polyester fibres find their way into the septic tanks in only one wash. And then imagine how easily the water from the septic tanks can enter the groundwater, and certainly in the places where the surface water and the groundwater are directly

In the Netherlands, households that are further than 40 metres from a sewer may discharge purified waste water from a septic tank into the surface water. Nothing is set down by law in the Besluit lozing afvalwater huishoudens (provision on discharging household waste water, in Dutch) to prevent plastic microfibres from entering the environment in this way.

Maria Westerbos, Director of the Plastic Soup Foundation: “It is extremely worrying that groundwater appears to contain microplastics. To what extent are septic tanks indeed the source? We expect questions to be asked in the House of Representatives so that the scale of this source of pollution and what can be done about it are made known.”

Plastic soup on land: agricultural compost is polluted with plastic

Amsterdam, 29 September 2018 – The Dutch regulations do not consider plastic waste as an emission problematic to the environment. As a result, plastic soup also occurs on land. Farmers buy compost that is contaminated with small pieces of plastic and pollute their own ground. The main cause is that green waste handed in by consumers is often polluted with plastic: composting companies cannot remove all of this plastic. Verge clippings polluted with litter are also mentioned as a cause.

A farmer from Abbenes, North Holland, is very concerned about this plastic in the compost. He has now stopped using it to improve the fertility of his soil. NH News reported about the farmer and found that the law allows a maximum of five kilos of plastic in 1000 kilos of compost.

The legal quality requirements for compost are laid down in the Implementation Order Manure Law, but in practice these requirements do not prevent large amounts of (micro)plastics being present in compost. Clear Government rules with a control and enforcement system are lacking. The Trade Association Organic Residues (BVOR) uses the hallmark Keurcompost. This hallmark has three quality categories (A, B, and C) that have different standards for contaminants like glass and plastic. All three categories are stricter than the Dutch laws. According to the sector only the classes A and B should be used as organic soil improver as from 1 January 2017. But even the Keurcompost hallmark still allows 0.05% pollution in every 1000 kilos of the strictest variant of quality compost: that is half a kilo of plastic chips.

In fact, far worse quality compost appears to be on sale than the quality recommended by the sector. For the time being there is no legal framework to regulate this. In addition, there is no knowledge whatsoever about the presence of microplastics.

At the beginning of this year German researchers warned that microplastics on land are an underexposed problem and can eventually lead to greater damage than the plastic in the sea. They found microplastics on agricultural land all over the world.

Even earlier, in 2015, PSF pleaded for a legal standard for plastic leakage to the environment, then following diaper plastic in compost.

Suzanne Kröger, Member of Parliament for GroenLinks, announced Parliamentary questions on the legal standards.

Also read: Nieuwe vrijstellingsregeling zorgt voor meer verspreiding van zwerfplastic
Also read: CPB: ‘meer plastic inzamelen helt niet in strijd tegen plastic soup’

Photo: Mountain of plastic taken out of green waste by a composting company.

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Trophic transfer of microplastics in seals confirmed

Amsterdam, 06 September 2018 – Marine animals eat microplastics when they mistake it for food. When they themselves are eaten, the microplastics are unintentionally ingested by the predator. This process is called the ‘trophic transfer’ of microplastics. The trophic transfer could potentially spread microplastics throughout the entire food chain. In a recently published study in Environmental Pollution, the trophic transfer of microplastics in seals, higher up in the food chain, is confirmed. This is an indirect but potentially important form of ingestion of microplastics.

To research the trophic transfer of microplastics, four captive grey seals were fed with mackerel caught off the English coast. The digestive tracts of 31 mackerels were examined to gain an impression of the presence of microplastics. The faeces of the seals were also collected twice a week for 16 weeks and examined for the presence of microplastics. The types of plastic that were found in the mackerel and the faeces showed significant overlap, with ethylene propylene the most commonly occurring type of plastic. There were some differences too, however. Ten of the 31 mackerels had 18 types of microplastics, 72% of which were plastic fibres and 28% small plastic fragments. In 15 of the 31 faeces, 26 microplastics were found, mostly consisting of small plastic fragments (69%) and, to a lesser degree, plastic fibres (31%).

The most important explanation for the differences is that the mackerel whose digestive tracts were examined were not the mackerel that were fed to the seals. Direct ingestion of the microplastics is unlikely as the seals had already resided in the centre for four years and were thus not recently exposed to plastic debris in the ocean. The researchers therefore concluded that this research confirms the trophic transfer of microplastics in seals.

The potential effects of the microplastics on the seals was also discussed. Previous research showed that microplastics in the digestive system reduces nutrition absorption, energy reserves and reproduction which could have a negative impact on the animals. Whether this also applies to seals is not known. Further, during the production process, added chemicals and organic substances that later attach to the plastic in the water may also have negative effects on the health of seals. Finally, the authors state the possible effects on human health. We too consume marine animals are thus exposed to microplastics through the trophic transfer. A recent survey mapped the potential health hazards of microplastics for humans.




Marine microplastic pollution: possible threat to public health

Amsterdam, 29 August 2018 – Possible hazards of marine microplastics are increasingly brought to our attention. A recently published outline study in Marine Pollution Bulletin mapped these potential hazards with respect to food safety and health. As plastics break up into ever smaller particles, their concentration in the environment continuously increases. The presence of microplastics in many types of fish and shellfish has already been demonstrated. Laboratory experiments show that marine organisms exposed to relatively high concentrations may suffer health problems, including reduced fertility and damage to the gastrointestinal tract. Should these effects also occur in organisms in the environment, microplastics could have negative consequences for marine populations and ecosystems. The researchers point out that the food supply for humans may then also be threatened.

We as humans are not only exposed to micro plastics by consuming fish and shellfish. They are in the air we breathe and in products we use, such as beer, honey, salt and tap water. The smallest microplastics are potentially capable of leaving the gastrointestinal tract and entering the so-called lymphatic and cardiovascular system. As a result, microplastics could spread throughout the body, including the organs. At these locations microplastics can then cause damage to cells.

There are also other possible health risks related to micro plastics. Chemicals added to plastics during the production process may leak from the plastics at a later stage. And organic toxins, present in the environment, attach themselves to plastic like iron to a magnet. Furthermore, the presence of bacteria, including potential pathogens, on plastic has been demonstrated. Especially in areas with a lot of plastic waste and poor sanitation this can have major consequences.

There is therefore every reason to consider microplastics as a possible threat to public health. However, there is a lot of uncertainty. For example, no methods are so far available to measure the smallest microplastic particles, which makes it therefore impossible to determine to what extent we are exposed. In addition, there is still scientific uncertainty about the question of whether the microplastics that enter our body actually cause health problems.

The recommendations of the authors include: a risk analysis on food safety, further studies on the toxicity of microplastics, and improving techniques to detect the smallest microplastic particles in particular.


Also read: How damaging is breathing in microplastics?