The endocrine disrupting effects of nanoplastic exposure: A systematic review.

Good mechanical properties and low costs have led to a global expansion of plastic production and use. Unfortunately, much of this material can be released into the environment as a waste product and cleaved into micro- and nanoplastics (NPs) whose impact on the environment and human health is still largely unknown. Considering the growing worldwide awareness on exposure to chemicals that can act as endocrine disruptors, a systematic review was performed to assess the impact of NPs on the endocrine function of in vitro and in vivo models. Although a limited number of investigations is currently available, retrieved findings showed that NPs may induce changes in endocrine system functionality, with evident alterations in reproductive and thyroid hormones and gene expression patterns, also with a trans-generational impact. Nanoplastic size, concentration, and the co-exposure to other endocrine disrupting pollutants may have an influencing role on these effects. Overall, although it is still too early to draw conclusions regarding the human health risks derived from NPs, these preliminary results support the need for further studies employing a wider range of plastic polymer types, concentrations, and time points as well as species and life stages to address a great variety of endocrine outcomes and to achieve a broader and shared consensus on the role of NPs as endocrine disruptors.

The Impact of Thyroid Diseases on Patients' Work Functioning: A Pilot Study.

OBJECTIVE: This study aimed to investigate the impact of thyroid diseases (TDs) on patients' work ability (WA) and related influencing factors. METHODS: A total of 150 TD workers and matched healthy controls were enrolled from May 2020 to November 2021. The Work Ability Index was used to assess the workers' perception of WA. RESULTS: Overall, TD workers reported a good WA, although with a significantly lower mean score compared with controls (39 ± 6 vs 43 ± 4, P < 0.001). Subjects with Graves disease and follicular carcinoma showed the worst WA perception. Suffering from a TD ( ß = -0.396, P < 0.001) and job duration ( ß = -0.173, P < 0.001) were associated with poorer WA. CONCLUSIONS: Better understanding the impact that TD may have on work functioning can inform an interdisciplinary management of TD workers to support their personal, social, and professional lives.

Hormetic dose responses induced by antibiotics in bacteria: A phantom menace to be thoroughly evaluated to address the environmental risk and tackle the antibiotic resistance phenomenon.

The environmental contamination of antibiotics caused by their over or inappropriate use is a major issue for environmental and human health since it can adversely impact the ecosystems and promote the antimicrobial resistance. Indeed, considering that in the environmental matrices these drugs are present at low levels, the possibility that bacteria exhibit a hormetic response to increase their resilience when exposed to antibiotic subinhibitory concentrations might represent a serious threat. Information reported in this review showed that exposure to different types of antibiotics, either administered individually or in mixtures, is capable of exerting hormetic effects on bacteria at environmentally relevant concentrations. These responses have been reported regardless of the type of bacterium or antibiotic, thus suggesting that hormesis would be a generalized adaptive mechanism implemented by bacteria to strengthen their resistance to antibiotics. Hormetic effects included growth, bioluminescence and motility of bacteria, their ability to produce biofilm, but also the frequency of mutation and plasmid conjugative transfer. The evaluation of quantitative features of antibiotic-induced hormesis showed that these responses have both maximum stimulation and dose width characteristics similar to those already reported in the literature for other stressors. Notably, mixtures comprising individual antibiotic inducing stimulatory responses might have distinct combined effects based on antagonistic, synergistic or additive interactions between components. Regarding the molecular mechanisms of action underlying the aforementioned effects, we put forward the hypothesis that the adoption of adaptive/defensive responses would be driven by the ability of antibiotic low doses to modulate the transcriptional activity of bacteria. Overall, our findings suggest that hormesis plays a pivotal role in affecting the bacterial behavior in order to acquire a survival advantage. Therefore, a proactive and effective risk assessment should necessarily take due account of the hormesis concept to adequately evaluate the risks to ecosystems and human health posed by antibiotic environmental contamination.

Impact of Shift Work and Long Working Hours on Worker Cognitive Functions: Current Evidence and Future Research Needs.

Particular working conditions and/or organization of working time may cause important sleep disturbances that have been proposed to be predictive of cognitive decline. In this regard, circadian rhythm misalignment induced by exposure to night work or long working hours would be responsible for cognitive impairment. Nevertheless, evidence supporting this correlation is limited and several issues still need to be elucidated. In this regard, we conducted a systematic review to evaluate the association between shift/night work and cognitive impairment and address its main determinants. Information provided by the reviewed studies suggested that night work might have serious immediate negative effects especially on cognitive domains related to attention, memory and response inhibition. Furthermore, cognitive performance would progressively worsen over consecutive night shifts or following exposure to very long work shifts. Otherwise, conflicting results emerged regarding the possible etiological role that night work chronic exposure would have on cognitive impairment. Therefore, circadian rhythm desynchronization, lack of sleep and fatigue resulting from night work may negatively impact worker's cognitive efficiency. However, in light of the considerable methodological variability of the reviewed studies, we proposed to develop a standardized research and evaluation strategy in order to obtain a better and comprehensive understanding of this topic.

Low dose ionizing radiation exposure and risk of thyroid functional alterations in healthcare workers.

PURPOSE: To evaluate the possible role of occupational low dose ionizing radiation exposure in increasing the healthcare workers' risk of thyroid functional alterations. METHODS: 120 healthcare workers exposed to ionizing radiation (60 belonging to category A with a potential exposure to an annual dose between 6 and 20 mSv and 60 to category B potentially exposed to an annual dose between 1 and 6 mSv) were compared with a control group consisting of 60 unexposed healthcare subjects assessing serum levels of different thyroid function parameters as free triiodothyronine, free thyroxine, thyroid stimulating hormone and thyroid autoantibodies. Age, gender, history of thyroid diseases, job task, dosimetric values were analysed as possible influencing factors using linear and multiple logistic regression analysis. RESULTS: Exposed workers showed significantly higher average levels of thyroid stimulating hormone, and lower average levels of free triiodothyronine and free thyroxine than non-exposed workers, although nonsignificant differences were observed between the two different exposure categories. According to the values of the thyroid hormones a condition of hypothyroidism has been considered in 11 exposed workers (9.2 %) and interestingly this clinical condition was significantly associated with ionizing radiation exposure. CONCLUSIONS: Low dose ionizing radiation exposure would seem to significantly influence levels of free triiodothyronine, free thyroxine, thyroid stimulating hormone, then suggesting a possible increased risk of hypothyroidism in healthcare workers although no relationship could be determined with exposure category. However, further studies are necessary to confirm such association on greater number of workers in order also to define a possible dose-response relationship.

The Impact of Thyroid Diseases on the Working Life of Patients: A Systematic Review.

Thyroid diseases are characterized by a wide range of physical and mental symptoms that can affect biological function, emotional and social life of patients. However, their impact on work functioning is not yet fully understood. Therefore, this review aims to address the way in which thyroid diseases can affect occupational outcomes, i.e., the employment rate, sick leave, working capacity and work income of patients. A systematic review of Pubmed, Scopus and ISI Web of Knowledge databases has been performed. Although it is not possible to extrapolate precise data for benign pathologies, about a third of the survivors of thyroid cancer could be unemployed. Hyperthyroid and hypothyroid patients presented a greater risk of long-term sick leave than controls, depending on the severity of the disease. Hyperthyroidism impaired working ability in about a third of affected patients, particularly in cases complicated by orbitopathy with diplopia. A possible influence of thyroid diseases on various occupational outcomes emerged from our review, however further research seems necessary to understand the relationship between work problems, specific pathological characteristics over time and risk factors in the workplace. This may support a comprehensive, interdisciplinary management of thyroid disorders, with benefits for patients' personal, social and professional life.

The Impact of Shift-Work and Night Shift-Work on Thyroid: A Systematic Review.

Thyroid hormones are regulated by the pituitary thyroid stimulating hormone (TSH), whose secretion presents a circadian rhythmicity. Indeed, it is conceivable that shift- and night shift-work, affecting sleep-wake rhythms, may impact thyroid functionality. Therefore, the aim of the present review was to provide an overview on the association between shift- and night shift-work and thyroid hormonal changes and disease development. A systematic review of studies available in PubMed, Scopus, and ISI Web of Science databases was performed. A positive association between night shift-work and increased TSH concentrations was reported by most of the reviewed investigations. Inconclusive evidence was available on thyroid diseases. However, the limited number of studies, the noticeable heterogeneity in the shift-work scheduling, in terms of amount, duration, type of shift- or night shift-work, prevents easily integrating findings and extrapolating definite conclusions. Further investigation seems necessary to better define the relationship between shift schedules and different thyroid outcomes, and possible long-term implications of early functional changes. Overall, this may support the adoption of advanced risk assessment and management strategies aimed to achieve a safer workplace organization and a timely, responsible realization of all the benefits of a 24-h economy.

Welding Fume Exposure and Epigenetic Alterations: A Systematic Review.

Epigenetics are heritable changes in gene expression not coded in the DNA sequence, which stand at the interface between the genome, environmental exposure and development. From an occupational health perspective, epigenetic variants may link workplace exposures and health effects. Therefore, this review aimed to overview possible epigenetic effects induced by welding fumes on exposed workers and health implications. A systematic search was performed on Pubmed, Scopus, and ISI Web of Knowledge databases. DNA methylation changes have been reported in genes responsible for the cardiac autonomic function and coagulation, i.e., LINE-1, GPR133 and F2RL3, in mitochondrial-DNA-sequences involved in the regulation of energy-generation/redox-signaling, as well as in inflammatory activated genes, i.e., iNOS. However, the limited number of retrieved articles, their cross-sectional nature, the lack of a suitable qualitative-quantitative exposure assessment, and the heterogeneity of biological-outcomes investigated, prevent the extrapolation of a definite causal relationship between welding fumes and epigenetic phenomena. Future studies should clarify the function of such epigenetic alterations as possible markers of occupational exposure and early effect, dose-response relationships, and underlying molecular mechanisms. Overall, this may be helpful to guide suitable risk assessment and management strategies to protect the health of workers exposed to welding fumes.

Altered Thyroid Function and Structure in Children and Adolescents Who Are Overweight and Obese: Reversal After Weight Loss.

CONTEXT: Obesity is associated with hypothyroidism and goiter. OBJECTIVE: The aim of the study was to verify whether thyroid structure and function would improve after weight loss. DESIGN AND PATIENTS: We evaluated 96 children who were overweight/obese who showed an altered parenchymal pattern at thyroid ultrasound without circulating antithyroid antibodies. At phase 1, body mass index (BMI), SD score (SDS), body composition, free T4 (fT4), TSH, high-sensitivity C reactive protein (CRPhs), white blood cells, metabolic profile, and a thyroid ultrasound were assessed. Thyroid volume was expressed as SDS on the basis of the references values for age. Alterations in echogenicity and homogeneity were graded from 0 to 5 (thyroid score). The same parameters were re-examined after a weight loss program (phase 2). RESULTS: After a mean period of treatment of 0.8 ± 0.3 years, there was a significant decrease of BMI SDS, percentage fat mass, CRPhs, TSH, and thyroid volume SDS (all P < 0.0001), whereas fT4 remained unchanged. The thyroid score significantly improved (z = -9088; P < 0.0001) [i.e., it decreased in 82 individuals, was tied in 12, and worsened only in two subjects; the score completely normalized in 48 (50%) individuals]. BMI SDS reduction was a unique predictor of the decrease of TSH, thyroid volume, and structure, whereas CRPhs reduction was an independent predictor only for the TSH change. Moreover, CRPhs variations mediated the association between BMI SDS and TSH. CONCLUSION: The alterations of thyroid function and structure in children with obesity are reversible after weight loss.