20 Jun

Map of the Week: Global Distribution of Microplastics

Microplastics are major environmental health hazards that have been found in every corner of the globe and across every biota. Plastic debris and microplastics, which are small pieces of plastic less than 5 mm in length, currently make up around 75 percent of the debris in the world’s oceans. They have also been found in rivers, soils, and air, and in some of the world’s most remote locations like Arctic ice and deep ocean sediments. Recent studies have even found the presence of microplastics in the human body, which experts theorize could be transmitted through food and water, inhalation of airborne particles, or contact through the skin.

Once microplastics enter aquatic systems, they are carried by ocean currents and gyres, accumulating in regions where ocean currents circulate. Circulation patterns give rise to hotspots of high microplastic concentrations. One of the most notable is the Great Pacific Garbage Patch, which is located in the North Pacific Gyre. Garbage patches are particularly threatening to marine life due to increased risk of ingestion and entanglement. High concentrations of plastic contamination can also be seen in the Mediterranean due to its semi-closed shape and proximity to dense coastal populations that contribute to pollution.

Plastic particles primarily enter water bodies via runoff from urban areas and industrial discharges, or directly through fishing activities. Airborne particles can disperse over long distances before settling back into terrestrial or aquatic environments. The largest sources of microplastics in the world’s oceans are synthetic textiles, followed by car tires, city dust, road markings, marine coatings, and personal care products. Once plastic pollution is broken down into small pieces, they can be ingested by marine organisms, which poses both physical harms, such as blockages to digestive systems, and chemical harm from the leaching of toxic substances used in plastic production. The accumulation of plastic contaminants in the food web can have cascading effects on ecosystem health and biodiversity. 

As plastics enter the environments we interact with, humans are also at risk. While the full extent of human health implications from ingesting microplastic is not fully known, it is hypothesized that particles can carry harmful chemicals and pollutants into the body. Studies have suggested that microplastics can cause inflammation, disrupt the endocrine system, and cross cellular barriers to cause cellular damage. The presence of these materials in the body could potentially increase vulnerability to cancer, heart disease, and kidney disease. There are also theories that microplastics might play a role in Alzheimer’s disease or affect fertility. With hundreds of millions of tons of plastics entering the environment each year, scientists are racing to find answers.

 

Map Source: Global distribution of microplastics | GRID-Arendal 

Sources:

With microplastics, scientists are in a race against time 

Chart: Where the Ocean’s Microplastics Come From | Statista 

Where do microplastics come from? – HORIBA