Microplastics (MP) are plastic particles with dimension up to 5 mm. Due to their persistence, global spread across different ecosystems and potential human health effects, they have gained increasing attention during the last decade. However, the extent of human exposure to MP through different pathways and their intake have not been elucidated. The objective of this review is to provide an overview on the pathways of exposure to MP through inhalation, ingestion, and dermal contact considering data from the open bibliography on MP in air, dust, food, water and drinks. A bibliographic search on Scopus and PubMed was conducted using keywords on MP in outdoor and indoor air, indoor dust, food including beverages and water and human intake (n = 521). Articles were sorted by their title and abstract (n = 213), and only studies reporting MP identification and quantification techniques were further considered (n = 168). A total of 115 articles that include quality assurance and quality control (QA/QC) procedures are finally discussed in the present review. Based on MP concentration data available in literature, we estimated the potential inhaled dose (ID), dust intake (DI), the estimated daily intake (EDI) via food and beverages. Finally, the total daily intake (TDI) considering both inhalation and ingestion routes are provided for adults, infants and newborns. The concentrations of MP in outdoor and indoor air, dust, and in food and water are provided according to the bibliography. Human exposure to MP through dust ingestion, inhalation of air and food/drinks consumption revealed that indoor air and drinking waters were the main sources of MP. This study reveals that humans are constantly exposed to MP, and that the indoor environment and the food and water we ingest decisively contribute to MP intake. Additionally, we highlight that infants and newborns are exposed to high MP concentrations and further studies are needed to evaluate the presence and risk of MP in this vulnerable age-population.

Microplastics (MPs) are plastic particles (<5 mm) ubiquitous in water, soil, and air, indicating that humans can be exposed to MPs through ingestion of water and food, and inhalation. This review provides an overview of the current human biomonitoring data available to evaluate human exposure and health impact of MPs. We compiled 91 relevant studies on MPs in human matrices and MPs toxicological endpoints to provide evidence on MPs distribution in the different tissues and the implications this can have from a health perspective. Human exposure to MPs has been corroborated by the detection of MPs in different human biological samples including blood, urine, stool, lung tissue, breast milk, semen and placenta. Although humans have clearance mechanisms protecting them from potentially harmful substances, health risks associated to MPs exposure include the onset of inflammation, oxidative stress, and DNA damage, potentially leading to cardiovascular and respiratory diseases, as well as cancer, as suggested by in vitro and in vivo studies. Based on compiled data, MPs have been recurrently identified in different human tissues and fluids, suggesting that humans are exposed to MPs through inhalation and ingestion. Despite differences in MPs concentrations appear in exposed and non-exposed people, accumulation and distribution pathways and potential human health hazards is still at an infant stage. Human biomonitoring data enables the assessment of human exposure to MPs and associated risks, and this information can contribute to draw management actions and guidelines to minimize MP release to the environment, and thus, reduce human uptake.

Pyrolysis-gas chromatography coupled to Orbitrap-mass spectrometry is a novel technique that allows the low level and precise determination of microplastics in environmental samples. In this paper, we develop and assess the target and untargeted performance of Pyr-GC-Orbitrap-MS. The method was optimized for 10 plastic polymers: polymethyl methacrylate, nylon-6,6, polypropylene, nitrile butadiene rubber, polyvinyl chloride, polyethylene terephthalate, acrylonitrile butadiene styrene, polyethylene, polycarbonate, and polystyrene. Standards were home-made using a diamond driller to attain mean sizes within the range of 45-382 µm. A step-by-step optimization of the analytical procedure was carried out. First, accurate mass measurement of each polymer at 60,000 resolution was studied to select the 3 most intense and selective quantification and confirmation ions. Second, internal standard quantification was optimized, and good linearity, repeatability, and reproducibility were obtained. Blank contribution and instrumental detection limit were evaluated for each polymer. Finally, the combined and expanded uncertainty of the Pyr-GC-Orbitrap-MS method was calculated to determine the sources of variation, considering that home-made standards were used. To evaluate method performance, targeted and non-targeted analysis of indoor air samples collected from gyms and department stores were carried out. The Pyr-GC-Orbitrap-MS methodology herein described can be applied for the quantitative assessment of MPs and other substances in different matrices.

The reaction of the cyclometalated rollover complex [Pt(bpy-H)(Me)(DMSO)] (bpy-H = cyclometalated 2,2′-bipyridine) with two diphosphines, dppm (1,1-bis(diphenylphosphino)methane) and dppe (1,2-bis(diphenylphosphino)ethane), was investigated. According to the reaction conditions, dppm behaves as a monodentate, bridging or chelated ligand, whereas dppe gave only chelated species. Some aspects of the reactivity of the isolated species were studied, including protonation with [H₃O·18-crown-6][BF₄] and coordination reactions of mononuclear complexes, obtaining, inter alia, rare examples of unsymmetrical organometallic species with bridging dppm.