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. 2024 Sep 3;7(9):e2440018.
doi: 10.1001/jamanetworkopen.2024.40018.

Microplastics in the Olfactory Bulb of the Human Brain

Luís Fernando Amato-Lourenço  1   2 , Katia Cristina Dantas  2 , Gabriel Ribeiro Júnior  2 , Vitor Ribeiro Paes  2 , Rômulo Augusto Ando  3 , Raul de Oliveira Freitas  4 , Ohanna Maria Menezes M da Costa  4 , Renata S Rabelo  4 , Kelly Cristina Soares Bispo  2 , Regiani Carvalho-Oliveira  2 , Thais Mauad  2
Affiliations

Microplastics in the Olfactory Bulb of the Human Brain

Luís Fernando Amato-Lourenço et al. JAMA Netw Open. .

Abstract

Importance: Microplastic (MP) pollution is an emerging environmental and health concern. While MPs have been detected in various human tissues, their presence in the human brain has not been documented, raising important questions about potential neurotoxic effects and the mechanisms by which MPs might reach brain tissues.

Objective: To determine the presence of MPs in the human olfactory bulb and to analyze their characteristics such as size, morphology, color, and polymeric composition.

Design, setting, and participants: This case series study used a cross-sectional design involving the analysis of olfactory bulb tissues obtained from deceased individuals during routine coroner autopsies. The sampling procedures were conducted at São Paulo City Death Verification Service, with laboratory analysis carried out at the Brazilian Synchrotron Light Laboratory (LNLS). Participants included 15 adult individuals who had been residents of São Paulo for more than 5 years and underwent coroner autopsies. Exclusion criteria included previous neurosurgical interventions. Data analysis was performed in April 2024.

Exposure: The primary exposure assessed was the presence of MPs in the olfactory bulb, analyzed through direct tissue examination and digested tissue filtration followed by micro-Fourier transform infrared spectroscopy.

Main outcomes and measures: The main outcomes were the identification and characterization of MPs within the olfactory bulb, including their size, morphology, color, and polymeric composition.

Results: The median age of the 15 deceased individuals was 69.5 years, ranging from 33 to 100 years, with 12 males and 3 females. MPs were detected in the olfactory bulbs of 8 out of 15 individuals. A total of 16 synthetic polymer particles and fibers were identified, with 75% being particles and 25% being fibers. The most common polymer detected was polypropylene (43.8%). Sizes of MPs ranged from 5.5 μm to 26.4 μm for particles, and the mean fiber length was 21.4 μm. Polymeric materials were absent in procedural blank and negative control filters, indicating minimal contamination risk.

Conclusions and relevance: This case series provides evidence of MPs found in the human olfactory bulb, suggesting a potential pathway for the translocation of MPs to the brain. The findings underscore the need for further research on the health implications of MP exposure, particularly concerning neurotoxicity and the potential for MPs to bypass the blood-brain barrier.

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Conflict of interest statement

Conflict of Interest Disclosures: None reported.

Figures

Figure 1.
Figure 1.. Microphotographs and Micro-Fourier Transform Infrared (μFTIR) Spectra of the Microplastics Found in the Olfactory Bulb Tissue
HQI indicates hit quality index.
Figure 2.
Figure 2.. Microphotographs and Micro-Fourier Transform Infrared (μFTIR) Spectra of the Main Microplastics Found in the Digested Olfactory Bulb
HQI indicates hit quality index.
See this image and copyright information in PMC

References

    1. Li Y, Tao L, Wang Q, Wang F, Li G, Song M. Potential health impact of microplastics: a review of environmental distribution, human exposure, and toxic effects. Environ Health. 2023;1(4):249-257. doi: 10.1021/envhealth.3c00052 - DOI
    1. Marfella R, Prattichizzo F, Sardu C, et al. Microplastics and nanoplastics in atheromas and cardiovascular events. N Engl J Med. 2024;390(10):900-910. doi: 10.1056/NEJMoa2309822 - DOI - PMC - PubMed
    1. Jenner LC, Rotchell JM, Bennett RT, Cowen M, Tentzeris V, Sadofsky LR. Detection of microplastics in human lung tissue using μFTIR spectroscopy. Sci Total Environ. 2022;831:154907. doi: 10.1016/j.scitotenv.2022.154907 - DOI - PubMed
    1. Amato-Lourenço LF, Carvalho-Oliveira R, Júnior GR, Dos Santos Galvão L, Ando RA, Mauad T. Presence of airborne microplastics in human lung tissue. J Hazard Mater. 2021;416:126124. doi: 10.1016/j.jhazmat.2021.126124 - DOI - PubMed
    1. Zhu L, Kang Y, Ma M, et al. Tissue accumulation of microplastics and potential health risks in human. Sci Total Environ. 2024;915:170004. doi: 10.1016/j.scitotenv.2024.170004 - DOI - PubMed

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