Microplastics: challenges of assessment in biological samples and their implication for in vitro and in vivo effects.

Microplastics (MPs) have attracted global interest because they have been recognized as emerging pollutants that require urgent attention. MPs are plastic particles with a size between 1 micron and 5 mm (1 µm-5mm); those measuring less than 1 µm are known as nanoplastics (NPs). MP is distributed in the environment in various physical forms that depend on the degradation process, the erosion factors to which it was subjected, or the original form in which it was intentionally manufactured. Humans may be exposed to these pollutants mainly by ingestion or inhalation, which could adversely affect human health with effects that are still unknown due to limitations that are often dependent on their analytical determination and lack of studies over time, as it is a relatively new topic. Therefore, this review focuses on the challenges currently faced by laboratories for determining MPs in different matrices. We highlight the application of methods and techniques to assess the precise levels of exposure to MPs in biological samples. In addition, exposure pathways, sources, and evidence of adverse effects reported in vitro and in vivo studies are described to generate knowledge about their potential threat to human health.

Circulating exosomal MicroRNAs: New non-invasive biomarkers of non-communicable disease.

Exosomes are vesicles, ranging of 30-150 nm in diameter, which are released by different cell types into the extracellular space. Exosomes are capable of transporting several biomolecules such as proteins, lipids, DNA, mRNA, and non-coding RNA, including microRNAs (miRs). miRs signatures have been linked to the development of non-communicable diseases and their classification into various subtypes and/or stages. Interestingly, the miRs contained in exosomes (exomiRs) are suitable candidates as non-invasive biomarkers due to their stability in body fluids and harsh conditions, as well as they are considered critical players involved in intercellular communication; so that they can be a promising diagnostic tool for several diseases. Besides, exomiRs allow discrimination between different stages of the disease and could be a valuable strategy for the early detection of several pathologies in a non-invasive approach. This review aims to describe exomiRs present in biologic fluids that can be used as a tool for the diagnosis and prognosis of non-communicable diseases such as cancer, cardiovascular, kidney, and neurodegenerative disease.

Respiratory health assessment and exposure to polycyclic aromatic hydrocarbons in Mexican indigenous population.

Indoor air pollution is an important risk factor for the generation of lung diseases in developing countries. The indigenous population is particularly susceptible to be exposed to the mixture of pollutants from the biomass burning, among them, polycyclic aromatic hydrocarbons (PAHs). The objective of this study was to assess respiratory health and exposure to PAHs in indigenous populations of the Huasteca Potosina in Mexico. The urinary metabolite 1-hydroxypyrene (1-OHP) was evaluated by HPLC with fluorescence detector, the forced expiratory volume in one second (FEV1) and the FEV1/FVC ratio (forced vital capacity) by spirometry in the Teenek indigenous adult population of the communities from Tocoy (TOC), Xolol (XOL), and Tanjajnec (TAN). A total of 134 subjects participated in the study: 64 from TOC, 30 from XOL, and 40 from TAN; in all the communities, high percentages of overweight and obesity were presented (from 50 to 73%). The average hours of firewood usage per year were 281.06, 284.6, and 206.6 in TOC, XOL, and TAN, respectively. The average of the three communities of the % FEV1 post-bronchodilator was 86.1%. There were identified from 4.5 to 6.6% and from 12.5 to 15.5% of spirometric obstructive and restrictive patterns respectively, in all communities. The highest exposure levels reported as median were found in TOC (1.15 µmol/mol of creatinine) followed by TAN (0.94 µmol/mol of creatinine) and XOL (0.65 µmol/mol of creatinine). Considering the magnitude of the indigenous population exposed to pollutants from the biomass burning and the possible effects on respiratory health, it is important to design strategies that mitigate exposure and evaluate the effectiveness through biological monitoring and effects.