The detrimental effect of microplastics on critical periods of development in the neuroendocrine system.

Abstract

As a result of human socio-economic activity, industrial wastes have increased alarmingly. Plastic pollution is globally distributed across the world due to its properties of buoyancy and durability. Two broad classes of plastic-related chemicals are of critical concern for human health-bisphenol-A or BPA, and additives used in the synthesis of plastics, which are known as phthalates. Our exposure to them is ubiquitous because they are used in the production of materials that we use daily such as polycarbonate plastics, epoxy resins, flooring, automotive parts, medical devices, dental sealants, and children's toys. Since these compounds are not covalently bound to the products, they easily leach from them, leading to high human exposure. Both, BPA and phthalates, are endocrine-disruptor compounds (EDCs) with steroidogenic activity, and can bind to different receptors, such as estrogen, androgen, PPAR-γ, and AhR. These pathways are part of the complex regulatory neuroendocrine network, since its cellular components not only express neuroendocrine receptors, but synthesize and respond to several hormones and other endocrine ligands. On the other hand, the effects of BPA and phthalates on neuroendocrine diseases have been poorly studied and the available data are inconclusive. This can be attributed to the enormous variety of animal models and the different doses used in experiments or levels found in humans. However, what is clear is that exposure to both EDCs during critical life stages induces many changes in the neuroendocrine system of exposed humans that are correlated with different reproductive and neurological diseases.