What body structures are attacked by micro and nanoplastics?
What damage and by what mechanisms does it produce?
Plastic brain
Neurotoxicity of micro and nano plastics
- These effects may be related to neurodevelopmental disorders and/or neurodegenerative effects, as occurs in the case of metal nanoparticles.
- Plastic particles induce oxidative stress, inhibit Acetylcholinesterase activity, alter neurotransmitter levels, and change behavior in various species.
https://particleandfibretoxicology.biomedcentral.com/articles/10.1186/s12989-020-00358-y
Plastic heart
In a pilot experiment, the researchers collected heart tissue samples from 15 people during cardiac surgeries, as well as pre- and post-operation blood specimens from half of the participants. Then the team analyzed the samples with laser direct infrared imaging and identified 20 to 500 micrometer-wide particles made from eight types of plastic, including polyethylene terephthalate, polyvinyl chloride and poly(methyl methacrylate). This technique detected tens to thousands of individual microplastic pieces in most tissue samples, though the amounts and materials varied between participants. All of the blood samples also contained plastic particles, but after surgery their average size decreased, and the particles came from more diverse types of plastics.
Potential association with the development of
- angina pectoris
- arrhythmias
- hypertension
- heart attacks
- pericardial edema
- myocardial fibrosis
- endothelial damage
- edema pericárdico
https://doi.org/10.1016/j.envint.2022.107662
Plastic lung
Presence of microplastics in the lung tissue of living patients, obtained by biopsy. The number of inflammatory cells, the production of reactive oxygen species (ROS), and the levels of inflammatory cytokines and chemokines in mice instilled with PP (2.5 or 5 mg/kg) were significantly increased compared with control mice. . Histopathologic analysis of lung tissue revealed lung lesions, including inflammatory cell infiltration into the perivascular/parenchymal space, alveolar epithelial hyperplasia, and foamy macrophage aggregates.
https://particleandfibretoxicology.biomedcentral.com/articles/10.1186/s12989-022-00512-8
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7998604/
Endocrine system
Bisphenol A (BPA), a monomer widely used in the plastics industry, has been described as a substance with great potential for endocrine disruption. Its exposure has been associated with an increase in estrogenic activity even at very low concentrations. The binding of BPA to androgen receptors has also been described, which prevents gene transcription dependent on these androgens, which is associated with pathophysiological problems in the prostate.
Regarding its association with thyroid hormones, its exposure is associated with a stimulation of the TSH hormone in newborn males and a decrease in the production of T4 in pregnant women.
Increased estrogenic activity
Pathophysiological problems in the prostate
TSH stimulation in newborn males
Decreased production of T4 in pregnant women
An effect of BPA on pancreatic activity has been described which, as a consequence, inhibits insulin production. This suggests a potential relationship with an increased risk of developing diabetes.
Effects on reproductive system and fetal health
Mediated by the effect of endocrine disruption derived from exposure to BPA associated with plastics, in addition to an increase in estrogenic activity, high incidences of uterine, ovarian, prostate, and testicular cancer have been described.
The most solid evidence is found in its condition on the female reproductive system, specifically a dysfunction in the ovaries, related to the alteration of the meiosis process and low quality of the oocytes.
Exposure to BPA during the gestational period affects the neurological development of fetuses and is associated with behavioral problems in neonates and children.
https://www.sanidad.gob.es/gl/ciudadanos/saludAmbLaboral/docs/SALUD_Y_RESIDUOS_ACCESIBLE.pdf
Plastic bowel
Detection of microplastics in the intestine of patients with colorectal adenocarcinoma
The presence of nanoplastics has been reported in non-tumor colon tissues and in patients diagnosed with colorectal adenocarcinoma. Comparing with the results obtained from colon tissue samples collected from subjects not diagnosed with colorectal cancer, it was determined that the amount of microplastics extracted from the cancer group was significantly higher than the amount of microplastics extracted from the non-tumor groups.
https://onlinelibrary.wiley.com/doi/full/10.1002/jgh3.12457
Faced with high doses of polystyrene nanoparticles (PNP), the HCT116 colorectal cell line undergoes significant oxidative stress with the consequent reduction in cell viability and an increase in the biosynthesis of detoxifying enzymes.
The concentration that causes the most significant reduction in viability, probably due to the high production of Reactive Oxygen Species (ROS), is 800 μg/mL; These data have been confirmed by the Cytokinesis-Block Micronucleus cytome (CBMN cyt) assay, where nuclear damage is more significantly detectable at the concentration of 800 μg/mL, both with formation of Micronuclei (MN) and Nuclear Buds (NBUDs) as well as genotoxicity biomarker.
Genotoxicity tests could be used to understand the mutagenic effects that are present after exposure to PNP.
Several studies have suggested that the ingestion of plastic particles through food and/or drinking water may be a sufficient source for the absorption of plastic nanoparticles.
The effects of nanoplastics are mainly chronic and therefore in the long term, inflammatory, cytotoxic and genotoxic phenomena increase, due to the bioaccumulation process.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8301662/
https://www.sciencedirect.com/science/article/abs/pii/S1385894721034185