Pathways of human exposure to microplastics, and estimation of the total burden

Altres ajuts: Acord transformatiu CRUE-CSICJ. Domenech was supported by a Predoctoral Fellowship (PIF) from the Universitat Autònoma de Barcelona.Plastic production is continuously growing and their wastes contaminate practically all environmental niches. In the environment, large plastics undergo continuous degradation processes generating a broad amount of microplastics and nanoplastics (MNPLs) that spread through air, land, and seas. Thus, humans suffer chronic exposures to MNPLs through different pathways: ingestion, inhalation, and dermal contact. Here, we have reviewed the recently published data regarding human exposure to MNPLs. The total load of plastic particles that humans are exposed to has been estimated based on these newly reported studies. This analysis of novel literature shows that despite ingestion is the most studied route of exposure, other routes of contact with MNPLs should not be underestimated. At the same time, gaps regarding the investigation of human exposures to environmental MNPLs have been detected, as well as the lack of robust and standardized protocols, operating procedures, and methodologies to detect/quantify MNPL in human/biological matrices

Insights into the potential carcinogenicity of micro- and nano-plastics

There is a growing concern regarding the potential health effects that continuous exposure to environmental micro- and nano-plastics (MNPLs) may cause on humans. Due to their persistent nature, MNPLs may accumulate in different organs and tissues and may induce in the long term the development of cancer. The present study aimed to review the existing literature on the carcinogenic potential of MNPLs. As studies directly assessing carcinogenicity were expected to be scarce, studies dealing with indirect outcomes associated with the carcinogenic process were considered in the literature search. Of the 126 studies screened, 19 satisfied the inclusion criteria. Besides, 7 additional cross-referenced articles, identified through a careful reading of the previously selected papers, also met the inclusion criteria and, consequently, were included in the review. Most of the selected studies were performed using in vitro models whereas about 40% of the studies were done in rodents, although none of them included a 2-year carcinogenicity assay. Most of the reviewed studies pointed out the potential of MNPLs to induce inflammation and genotoxicity, the latter being recognized as a strong predictor of carcinogenicity. These, along with other important findings such as the MNPLs’ ability to accumulate into cells and tissues, or their capacity to induce fibrosis, may suggest an association between MNPLs exposures and the carcinogenic potential. Nevertheless, the limited number of available studies precludes reaching clear conclusions. Therefore, this review also provides several recommendations to cover the current knowledge gaps and address the future evaluation of the MNPLs’ carcinogenic risk

Hazard assessment of ingested polystyrene nanoplastics in Drosophila larvae

Micro- and nanoplastics (MNPLs) are intentionally produced for commercial uses (primary MNPLs) or are formed from environmentally aged plastics (secondary MNPLs). Independent of their origin, all of them will finally end up in the environment constituting some of the known emergent pollutants. Despite the inert nature of plastics, questions about their potential biological effects on human health need to find sound answers. In addition, the association between the potentially induced effects and the MNPL size is also required to be known. In this context, we have used our in vivo model of Drosophila larvae and three nanopolystyrene plastics (PSNPLs) sized 50, 200, and 500 nm (PS-50, PS-200, and PS-500) to add new data to better understand the potential health risks of MNPLs. Our model has permitted us to visualize (via transmission electron microscopy, TEM) the journey of the PSNPLs administered via ingestion, their interaction with gut lumen components (including symbiotic microbiota), their uptake by gut enterocytes, their translocation through the intestinal barrier to the hemolymph, and their uptake by hemocytes. This behavior was observed for the three analyzed sizes and, for the largest sizes, changes in size/shape were observed in ingested PSNPLs. Although no relevant toxicity, as measured by the egg-to-adult viability, was observed, exposure induced a wide molecular response altering the expression of genes involved in the general stress response, in the antioxidant response and even in the genotoxicity response, as well as in genes related to the intestinal damage response. Furthermore, a general induction of ROS production and DNA damage was also detected. Interestingly, these types of responses were size-dependent with the small PSNPL size inducing a higher response

Nanoplastics and arsenic co-exposures exacerbate oncogenic biomarkers under an in vitro long-term exposure scenario

The increasing accumulation of plastic waste and the widespread presence of its derivatives, micro- and nanoplastics (MNPLs), call for an urgent evaluation of their potential health risks. In the environment, MNPLs coexist with other known hazardous contaminants and, thus, an interesting question arises as to whether MNPLs can act as carriers of such pollutants, modulating their uptake and their harmful effects. In this context, we have examined the interaction and joint effects of two relevant water contaminants: arsenic and polystyrene nanoplastics (PSNPLs), the latter being a model of nanoplastics. Since both agents are persistent pollutants, their potential effects have been evaluated under a chronic exposure scenario and measuring different effect biomarkers involved in the cell transformation process. Mouse embryonic fibroblasts deficient for oxidative DNA damage repair mechanisms, and showing a cell transformation status, were used as a sensitive cell model. Such cells were exposed to PSNPLs, arsenic, and a combination PSNPLs/arsenic for 12 weeks. Interestingly, a physical interaction between both pollutants was demonstrated by using TEM/EDX methodologies. Results also indicate that the continuous co-exposure enhances the DNA damage and the aggressive features of the initially transformed phenotype. Remarkably, co-exposed cells present a higher proportion of spindle-like cells within the population, an increased capacity to grow independently of anchorage, as well as enhanced migrating and invading potential when compared to cells exposed to arsenic or PSNPLs alone. This study highlights the need for further studies exploring the long-term effects of contaminants of emerging concern, such as MNPLs, and the importance of considering the behavior of mixtures as part of the hazard and human risk assessment approaches

Long-term exposure to nanoplastics alters molecular and functional traits related to the carcinogenic process

Acord transformatiu CRUE-CSICMicro/nanoplastics (MNPLs) are considered emergent pollutants widely spread over all environmental compartments. Although their potential biological effects are being intensively evaluated, many doubts remain about their potential health effects in humans. One of the most underdeveloped fields is the determination of the potential tumorigenic risk of MNPLs exposure. To shed light on this topic, we have designed a wide battery of different hallmarks of cancer applied to prone-to-transformed progress MEF cells exposed to polystyrene nanoplastics (PSNPLs) in the long term (6 months). Interestingly, most of the evaluated hallmarks of cancer are exacerbated after exposure, independently if they are associated with an early tumoral phenotype (changes in stress-related genes, or microRNA deregulation), advanced tumoral phenotype (growing independently of anchorage ability, and migration capacity), or an aggressive tumoral phenotype (invasion potential, changes in pluripotency markers, and ability to grow to form tumorspheres). This set of obtained data constitutes a relevant warning on the potential carcinogenic risk associated with long-term exposures to MNPLs, specifically that induced by the PSNPLs evaluated in this study

Long-term effects of polystyrene nanoplastics in human intestinal Caco-2 cells

The increasing presence of micro- and nanoplastics (MNPLs) in the environment, and their consequent accumulation in trophic niches, could pose a potential health threat to humans, especially due to their chronic ingestion. In vitro studies using human cells are considered pertinent approaches to determine potential health risks to humans. Nevertheless, most of such studies have been conducted using short exposure times and high concentrations. Since human exposure to MNPLs is supposed to be chronic, there is a lack of information regarding the potential in vitro MNPLs effects under chronic exposure conditions. To this aim, we assessed the accumulation and potential outcomes of polystyrene nanoparticles (PSNPs), as a model of MNPLs, in undifferentiated Caco-2 cells (as models of cell target in ingestion exposures) under a relevant long-term exposure scenario, consisting of eight weeks of exposure to sub-toxic PSNPs concentrations. In such exposure conditions, culture-media was changed every 2-3 days to maintain constant exposure. The different analyzed endpoints were cytotoxicity, dysregulation of stress-related genes, genotoxicity, oxidative DNA damage, and intracellular ROS levels. These are endpoints that showed to be sensitive enough in different studies. The obtained results attest that PSNPs accumulate in the cells through time, inducing changes at the ultrastructural and molecular levels. Nevertheless, minor changes in the different evaluated genotoxicity-related biomarkers were observed. This would indicate that no DNA damage or oxidative stress is observed in the human intestinal Caco-2 cells after long-term exposure to PSNPs. This is the first study dealing with the long-term effects of PSNPs on human cultured cells

Hazard characterization of graphene-based nanomaterials in energy production and storage (GrapHazard)

This publication is the final report of the research project “Hazard characterization of graphene-based nanomaterials in energy production and storage (GrapHazard)”, funded by the Finnish Work Environmental Fund, the Italian National Institute for Insurance against Accidents at Work (INAIL), the Finnish Institute of Occupational Health, and the University of Trieste in the frame of the SAF€RA 2020 program. The report summarizes the findings of the toxicological assessment of different types of graphene-based materials by using an in vitro lung system to investigate the involved mechanisms of action and how different key physicochemical properties of the materials can modulate the toxic response. In addition, recommendations for a safe use of graphene-based materials in occupational settings are provided

Resultados de una intervención motivacional con niños obesos o con sobrepeso y sus familias: Estudio Piloto

Introducción: el objetivo fue analizar los resultados de una intervención motivacional con modificación de los hábitos alimentarios, los estilos de vida y los trastornos emocionales en niños obesos de 6 a 12 años y sus familias. Material y métodos: Estudio de intervención con evaluación pre- y posintervención del programa Familias en Movimiento. Se incluyeron 11 niños (10 niñas y 1 niño) de 6 a 12 años tratados con otros programas para la pérdida de peso sin éxito. Se evaluaron al inicio y al final los parámetros: Índice de Masa Corporal (IMC), los resultados de los cuestionarios: de Dieta Mediterránea y ansiedad en niños y el peso y la ansiedad de los adultos tras la intervención. Resultados: El IMC disminuyó de una mediana de 25,2 (Rango intercuartílico de 23,3–28,0) a 23,9 y (22,9–27,6) tras la intervención, cambio no estadísticamente significativo (p<0,086). La mediana de adherencia a la Dieta Mediterránea aumentó significativamente en 2,2 puntos (7,1 a 9,3), debido principalmente a que un mayor número de niños tomaban desayuno (44%) y hubo una disminución del consumo de golosinas y bollería industrial en el desayuno (22,2%). La intervención redujo significativamente en 8,7 puntos la ansiedad en los niños. De los adultos, 9 de ellos participaron en la evaluación inicial, la media de disminución de peso fue de 3,6kg y la disminución de la ansiedad pasó de 45,6 a 27,3 (p=0,02). Conclusiones: La aplicación del programa Familias en Movimiento disminuyó el IMC, aumentó la puntuación en la adherencia a Dieta Mediterránea y disminuyó la ansiedad en los niños, además se redujo el peso y la ansiedad en los adultos que acompañaron en el programa a los niños

Resultados de una intervención motivacional con niños obesos o con sobrepeso y sus familias: Estudio Piloto

Introduction: The objective was to analyze the modification of eating habits, lifestyles and emotional disorders in obese children (6 to 12 years of age) and their families through a motivational intervention.Material and Methods: Intervention study with pre- and post-intervention evaluation through Familias en Movimiento program. This program included 11 children (10 girls and 1 boy) aged 6 to 12 years who had been unsuccessfully treated with other weight loss programs. The following parameters were evaluated at the beginning and at the end: Body Mass Index (BMI), the results of the questionnaires: Mediterranean Diet and anxiety in children, and the weight and anxiety of adults after the intervention.Results: The BMI decreased from a median of 25.2 (interquartile range of 23.3–28.0) to 23.9 and (22.9–27.6) after the intervention, a change not statistically significant (p&lt;0.086). Median adherence to the Mediterranean Diet increased significantly by 2.2 points (7.1 to 9.3), mainly due to the fact that more children ate breakfast (44%) and there was a decrease in the consumption of sweets and pastries industrial breakfast (22.2%). The intervention significantly reduced anxiety in children by 8.7 points. 9 of the adults participated in the initial assessment, the average weight loss was 3.6kg and the decrease in anxiety step from 45.6 to 27.3 (p=0.02). Conclusions: The application of the “Families in movement” program decreased the BMI, increased the score in adherence to the Mediterranean Diet and decreased the anxiety in the children. In addition the weight and anxiety were reduced in the adults who accompanied the program to the children.Introducción: el objetivo fue analizar los resultados de una intervención motivacional con modificación de los hábitos alimentarios, los estilos de vida y los trastornos emocionales en niños obesos de 6 a 12 años y sus familias. Material y métodos: Estudio de intervención con evaluación pre- y posintervención del programa Familias en Movimiento. Se incluyeron 11 niños (10 niñas y 1 niño) de 6 a 12 años tratados con otros programas para la pérdida de peso sin éxito. Se evaluaron al inicio y al final los parámetros: Índice de Masa Corporal (IMC), los resultados de los cuestionarios: de Dieta Mediterránea y ansiedad en niños y el peso y la ansiedad de los adultos tras la intervención.Resultados: El IMC disminuyó de una mediana de 25,2 (Rango intercuartílico de 23,3–28,0) a 23,9 y (22,9–27,6) tras la intervención, cambio no estadísticamente significativo (p&lt;0,086). La mediana de adherencia a la Dieta Mediterránea aumentó significativamente en 2,2 puntos (7,1 a 9,3), debido principalmente a que un mayor número de niños tomaban desayuno (44%) y hubo una disminución del consumo de golosinas y bollería industrial en el desayuno (22,2%). La intervención redujo significativamente en 8,7 puntos la ansiedad en los niños. De los adultos, 9 de ellos participaron en la evaluación inicial, la media de disminución de peso fue de 3,6kg y la disminución de la ansiedad pasó de 45,6 a 27,3 (p=0,02).Conclusiones: La aplicación del programa Familias en Movimiento disminuyó el IMC, aumentó la puntuación en la adherencia a Dieta Mediterránea y disminuyó la ansiedad en los niños, además se redujo el peso y la ansiedad en los adultos que acompañaron en el programa a los niños