Microplastics (MPs) Occurence and Definition

Microplastics (MPs) are emerging pollutants, defined as plastic particles smaller than 5 mm and larger than 1 µm where the nanoplastics (NPs) range begins. Recently they have received much more attention since the results of different studies identified MP abundance in the environment and considering they are more likely to increase due to the growing production of plastics nowadays. MPs are also being detected in drinking water, thus more treatment should be done to pose barrier to prevent the risks they could be possibly lead to human cells.

Plastic became unavoidable in modern life, and many of the products and the object we use in our life is made out of plastic. The main problem is their improper waste, which has led to its widespread presence in the environment.

Microplastics are categorized into primary and secondary microplastics

Primary microplastics are small pieces of plastic that are purposefully manufactured. They are usually used in facial cleansers and cosmetics, or in air blasting technology. Microplastic “scrubbers”, used in exfoliating hand cleansers and facial scrubs, have replaced traditionally used natural ingredients, including ground almonds, oatmeal, and pumice. Primary microplastics have also been produced for use in air blasting technology. This process involves blasting acrylic, melamine, or polyester microplastic scrubbers at machinery, engines, and boat hulls to remove rust and paint. Although many companies have committed to reducing the production of microbeads, there are still many bioplastic microbeads that also have a long degradation life cycle similar to normal plastic.

Secondary plastics are small pieces of plastic derived from the breakdown of larger plastic debris, both at sea and on land. Over time, mechanical and photodegradation caused by the wave power and the sunlight exposure, respectively, can reduce the structural integrity of plastic debris to a size that is eventually undetectable to the naked eye. This process of breaking down large plastic material into much smaller pieces is known as fragmentation.

Why are we concern about Microplastics in the environment?

Microplastics’ health impact is still under study. However, there is much uncertainty associated with this issue.

The three main concerns are:

1. Because of their plastic nature, they attract on their surface other hydrophobic persistent organic pollutants (POPs) and carry them into the human body where they can attack organs and tissues.

2. Another significant concern is that very often plastic contains additives, which can be estrogen, such as Bisphenol A, BPA, and interact with the hormonal process of the human body leading to carcinogenic, teratogenic, and mutagenic effect.

3. Microorganisms could colonise the microparticles forming successional biofilms and infecting the human body once they enter in the organism.