Marine Litter Vital Graphics

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IMPACTS

synthetic fibres), polyvinylchloride (PVC used in pipes, bottles and non-food packaging), epoxy resins (adhesives and metal coatings) and styrenic polymers (styrene foam insulation) as posing the highest human health risk (Lithner et al., 2011). These plastic polymers (apart from epoxy resin) are amongst the most common microplastic litter encountered in the marine environment. Plastic, a magnet for other contaminants and harmful organisms In the marine environment plastic can be both a source and sink for contaminants. As well as releasing chemicals, microplastics have been shown to adsorb compounds like polycyclic aromatic hydrocarbons (PAHs) and metals from the surrounding sea water. Due to their high surface area to volume ratio, microplastics can concentrate contaminants to orders of magnitude higher than in the surrounding sea water (Mato et al., 2001). Substances referred to as persistent, bioaccumulative and toxic (PBTs), such as dichlorodiphenyltrichloroethane (DDT), polychlorinated biphenyls (PCBs) and persistent organic pollutants (POPs) are of particular concern. There is evidence that hydrophobic contaminants such as POPs

are more likely to be adsorbed onto plastic polymers than marine sediments (Tueten et al., 2007). Furthermore, older plastic particles have been found to have higher levels of POPs, suggesting that they continue to adsorb and concentrate contaminants for as long as they remain in the marine environment (Frias et al., 2010). The ingestion of marine debris carrying these concentrated toxins has potential to bioaccumulate up the food chain and enter the human diet. However, although there is evidence of the harmful impacts of these chemicals on marine biota and human health (in men, women and children), there is uncertainty regarding their bioavailability once ingested. There is little research yet available on gender- differentiated effects of these secondary chemicals that are transferred up the food chain to humans along with the microbeads. Bouwmeester et al. (2015) conclude that, from available evidence, the dietary intake of POPs and other additives adhering to marine microplastics will constitute a minor component of exposure to these contaminants compared to other exposure pathways (such as ingestion of crops treated with herbicide, burning of waste, chemical fires and industrial exposure).

An example of howmicroplastics could end up on a consumer's plate An example of howmicroplastics could end up on a consumer's plate

Oyster culture Oyster culture

Mussel culture Mussel culture

Because they lter water, bivalves (such as mussels, oysters, clams and others) can absorb and excrete microplastic present in the sea water where they are cultivated Because they lter water, bivalves (such as mussels, oysters, clams and others) can absorb and excrete microplastic present in the sea water where they are cultivated

After harvesting, shell sh are usually kept in clean water to get rid of contaminants. The shell sh expel some microplastics, while others remain inside, reach the market and end up on the consumer’s plate After harvesting, shell sh are usually kept in clean water to get rid of contaminants. The shell sh expel some microplastics, while others remain inside, reach the market and end up on the consumer’s plate

Water exhaled Water exhaled

Sea water inhaled Sea water inhaled

Nutrients Nutrients

Microplastics Microplastics

Sources:Tjärnö Marine Biological Laboratory, Strömstad, Sweden; personal communication with Dr. Sarah Dudas

Marine Litter Vital Graphics

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