Plastic is the most common type of marine debris in our ocean and Great Lakes. Even though plastic pollution is a well-known worldwide problem, the discovery of the presence of microplastics in seas and oceans represents an unexpected and alarming turn of events. Plastic debris come in several shapes and diverse sizes, but those with a diameter of less than five millimeters referred to as “microplastics.” Is the subject of this piece. Microplastics are small plastic particles in the environment. They can come from a wide-variety of sources, including clothing, cosmetics, and industrial processes. Current figures indicate that microplastics presently constitute an estimated 92.4% of the total global particle count of plastic litter. This pollutants are finding their way into the marine environment and adding more pressure to an already clustered system. As an emerging field of study, not much is known about microplastics and their environmental impact. Microplastics are likely the most numerically abundant items of plastic debris in the oceans today. Unfortunately, the quantities of these minute but significant pollutants will continue to increase.
According to United Nations News, as many as 51 trillion microplastic particles litter the oceans and seas, this is 500 times more than the stars in our galaxy. Their presence in this already saturated environment is seriously threatening marine wildlife, and possibly humans.
Sources Of Microplastics
Microplastics come from two main sources; primary and secondary. Primary microplastics refer to those plastics that that are manufactured principally for use including plastic pellets – or ‘nurdles’ – that act as base material for plastic production. Microbeads from plastic industries are often added as exfoliants to produce house hold products such as toothpastes, cleansers and household cleaning products.
According reports, around 15 and 31% of the estimated 9.5 million tonnes of plastic discharged into the oceans every year could be primary microplastics. Worthy of note however is the fact almost two-thirds of these come from the washing of synthetic textiles and the abrasion of tyres.
Distribution and impact of microplastics
Microplastics are widely dispersed throughout the world’s ocean. They have been found distributed in large concentrations in, North America, Europe, Africa, Asia, Southeast Asia, India, and South Africa. Often found in shorelines, seabed sediments, inland waters, soils, food webs, beaches, indoor and outdoor, air frozen ice and wastewater effluents. Some float on surface waters and some are found within the Antarctic and Artic regions transported by wind and ocean currents. The small size of microplastics makes them easily available for ingestion by a good number of the marine organisms. Fish and seabirds mistake pollutants for prey, while filter feeders such as whales and mussels filter them from the water alongside particles of food. By this mechanism these pollutants find their way into human food chain.
Several studies have demonstrated that marine organisms can take up microplastics often with serious consequences. As these pollutants accumulate in the tissues they serve as channels for the transport of pathogens. Microplastics have the potential to cause many adverse effects such;
- Pathological stress
- False satiation
- Reproductive complications
- Oxidative stress
- Block enzyme production
- Decreased growth rate
- Impaired reproductive activity
- Genetic disruption
- Decreased immune response, and
- Malformation in animals and potentially in humans if ingested in high quantities.
Results from studies which exposed fish to microplastics during their development recorded increased mortality rates and stunted growth as well as behavioral changes that could endanger their survival. Reports have it that by the year 2050, there will be more microplastics in our oceans than fish. Fish is an excellent source of protein. The fatty fish are a great source of vitamin They also serve as a great source of omega-3 fats and iron that are really important for cardiovascular health.
Abiotic sea products such as sea salt, is a source of food for humans and there is a possibility that the presence of microplastics in the sea could lead to the contamination of sea products and potential transfer to humans. Several scientific studies have confirmed the presence of microplastics in sea salt. This demonstrates that along shellfish (seafood) and fish table salt also appears to be contaminated by this pollutants.
The Pollution of the marine environment by microplastics is a potential health economic and health problem. Possible management and prevention measures have been listed as a challenge because these particles are very small and hard to visualize, which makes their manual removal very difficult, if not impossible.
Helen Shnada Auta is a PhD Student at the Institute of Biological Sciences Faculty of Science, University of Malaya, Kuala Lumpur Malaysia