Rotas de exposição aos micro e nanoplásticos e suas consequências para a saúde humana

Abstract

The use of plastics has brought several advances mainly related to medical and food biosafety; however, it has become an environmental problem, due to inadequate disposal. These residues accumulate in environments, making them susceptible to fragmentation mechanisms, originating microplastics (MPs) and nanoplastics (NPs). These, resulting from the fragmentation of macroplastics, can be classified as secondary, and those produced in reduced size are primary MPs and NPs. Humans are exposed to macroplastics, microplastics and nanoplastics via ingestion, inhalation, and dermal contact, which will be discussed in this work. Exposure via ingestion can occur in the consumption of food, such as sugar, honey, table salt, and seafood; and also in the consumption of bottled and tap water, and can reach 52,000 particles of MPs ingested annually. Inhalation is the most important route of exposure, and can reach 30,000,000 MPs inhaled annually, due to the concentrations of MPs in the atmosphere. Exposure via dermal contact is related to the use of cosmetics with plastic microspheres, or due to the MPs present in water. MPs and NPs can have several consequences for human health, for example: acting as carriers of microorganisms and toxic species, oxidative stress, apoptosis, inflammation, cytotoxicity, interference with homeostasis, metabolism, and immune system, translocation and neurotoxicity. Occupational diseases resulting from exposure to plastic materials were also reported. Although the indiscriminate use of plastic has negative impact on the environment and on humans, its use continues to grow. This makes it necessary to implement harm reduction policies and programs, such as the concept of the 5Rs.