scholarly journals An Overview of Per- and Polyfluoroalkyl Substances (PFAS) in the Environment: Source, Fate, Risk and Regulations

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3590
Author(s):  
Ziyad Abunada ◽  
Motasem Y. D. Alazaiza ◽  
Mohammed J. K. Bashir

The current article reviews the state of art of the perfluoroalkyl and polyfluoroalkyl substances (PFASs) compounds and provides an overview of PFASs occurrence in the environment, wildlife, and humans. This study reviews the issues concerning PFASs exposure and potential risks generated with a focus on PFAS occurrence and transformation in various media, discusses their physicochemical characterization and treatment technologies, before discussing the potential human exposure routes. The various toxicological impacts to human health are also discussed. The article pays particular attention to the complexity and challenging issue of regulating PFAS compounds due to the arising uncertainty and lack of epidemiological evidence encountered. The variation in PFAS regulatory values across the globe can be easily addressed due to the influence of multiple scientific, technical, and social factors. The varied toxicology and the insufficient definition of PFAS exposure rate are among the main factors contributing to this discrepancy. The lack of proven standard approaches for examining PFAS in surface water, groundwater, wastewater, or solids adds more technical complexity. Although it is agreed that PFASs pose potential health risks in various media, the link between the extent of PFAS exposure and the significance of PFAS risk remain among the evolving research areas. There is a growing need to address the correlation between the frequency and the likelihood of human exposure to PFAS and the possible health risks encountered. Although USEPA (United States Environmental Protection Agency) recommends the 70 ng/L lifetime health advisory in drinking water for both perfluorooctane sulfonate (PFO) perfluorooctanoic acid (PFOA), which is similar to the Australian regulations, the German Ministry of Health proposed a health-based guidance of maximum of 300 ng/L for the combination of PFOA and PFOS. Moreover, there are significant discrepancies among the US states where the water guideline levels for the different states ranged from 13 to 1000 ng L−1 for PFOA and/or PFOS. The current review highlighted the significance of the future research required to fill in the knowledge gap in PFAS toxicology and to better understand this through real field data and long-term monitoring programs.

2021 ◽  
Author(s):  
Jingshu Wang ◽  
Jinhui Jeanne Huang ◽  
Catherine Mulligan

Abstract Human exposure to metals on road dust might have potential health risks through touching, ingesting, and inhaling. There were limited studies to link seasonal emission sources to health risks from metals on road dust. In this study, metals on road dust from different functional areas were seasonally monitored. The pollutant sources in study city varied slightly with the seasons, but the major pollutant source in the particular study site were significantly affected by the seasons. By combining the source apportionment model (PMF), line sources model and health risk models (HI: Hazard index and ILCR: Incremental Lifetime Carcinogenic risk), industrial and construction activity was identified as the crucial source of both the pollutants on road dust (29% - 47%), and the HI for adults (27% - 45%) and children (41% - 50%) in different seasons. The traffic non-exhaust emission dominated in the carcinogenic risks for children in spring (45%) and summer (36%). Factors such as seasons, particle size, metal bioavailability, human exposure time, and exposure area were all taken into consideration to avoid overestimating or underestimating health risks. The carcinogenic risks for children (1.6 E-06) and adults (2.8 E-06) exposed to Cr both exceed the minimum threshold (10-6). Measured metals mainly posed hazard to human health through ingestion route. Pb and Mn, Fe and Mn were the main harmful elements that induced non-carcinogenic risks for adults and children, respectively. Effectively identifying the source-specific health risks in different seasons will help in the formulation of adaptive strategies to diminish the potential risks.


Toxics ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 224
Author(s):  
Concetta Pironti ◽  
Maria Ricciardi ◽  
Oriana Motta ◽  
Ylenia Miele ◽  
Antonio Proto ◽  
...  

Recently, studies on microplastics (MPs) have increased rapidly due to the growing awareness of the potential health risks related to their occurrence. The first part of this review is devoted to MP occurrence, distribution, and quantification. MPs can be transferred from the environment to humans mainly through inhalation, secondly from ingestion, and, to a lesser extent, through dermal contact. As regards food web contamination, we discuss the microplastic presence not only in the most investigated sources, such as seafood, drinking water, and salts, but also in other foods such as honey, sugar, milk, fruit, and meat (chickens, cows, and pigs). All literature data suggest not-negligible human exposure to MPs through the above-mentioned routes. Consequently, several research efforts have been devoted to assessing potential human health risks. Initially, toxicological studies were conducted with aquatic organisms and then with experimental mammal animal models and human cell cultures. In the latter case, toxicological effects were observed at high concentrations of MPs (polystyrene is the most common MP benchmark) for a short time. Further studies must be performed to assess the real consequences of MP contamination at low concentrations and prolonged exposure.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Louis G. Lategan ◽  
Shayne Erasmus ◽  
Markus Zietsman ◽  
Elizelle J. Cilliers ◽  
Mario Wolf ◽  
...  

Informal backyard rentals (IBRs) constitute South Africa’s fastest growing housing subsector, flourishing within a relative research vacuum and without national policy intervention to address the vulnerabilities of stakeholders to the health risks potentially presented. This article reviewed the literature on IBRs, focussing on past policies and interventions, general characteristics, infrastructure and service access to inform an analysis of potential health risks from the existing literature to guide future research and policy-making. Research followed a qualitative approach to review IBR literature dating after 2004. Relevant publications were identified from bibliographic databases using Boolean search logic and by reviewing citations in and later citations of these publications. Relevant secondary sources were also included. The review evidenced that IBRs have received increasing policy, but limited research attention, and that health hazards have been particularly neglected. Although issues such as shared water and sanitation, inappropriate waste disposal, poor hygiene practices, high densities and poor quality structures have been referenced extensively – alluding to risks and health concerns – few studies have focussed directly on health, risk and vulnerability. The risk analysis completed based on the literature made potential risks explicit, exemplified by references to specific conditions, such as HIV/AIDS, tuberculosis and the coronavirus pandemic, demonstrating pathogenic pathways, contamination and transmission risks conducive to poor health, infection and potential disaster. The review captured and updated the contemporary literature on IBRs, with the subsequent analysis providing a platform for future empirical research on health, infrastructure and IBRs to address potential risks towards positive change in future policies.


2020 ◽  
Vol 266 ◽  
pp. 115240
Author(s):  
Naga Raju Maddela ◽  
Kadiyala Venkateswarlu ◽  
Dhatri Kakarla ◽  
Mallavarapu Megharaj

2020 ◽  
Vol 13 ◽  
Author(s):  
Gaurav Gaurav ◽  
Abhay Sharma ◽  
G S Dangayach ◽  
M L Meena

Background: Minimum quantity lubrication (MQL) is one of the most promising machining techniques that can yield a reduction in consumption of cutting fluid more than 90 % while ensuring the surface quality and tool life. The significance of the MQL in machining makes it imperative to consolidate and analyse the current direction and status of research in MQL. Objective: This study aims to assess global research publication trends and hot topics in the field of MQL among machining process. The bibliometric and descriptive analysis are the tools that the investigation aims to use for the data analysis of related literature collected from Scopus databases. Methods: Various performance parameters are extracted, such as document types and languages of publication, annual scientific production, total documents, total citations, and citations per article. The top 20 of the most relevant and productive sources, authors, affiliations, countries, word cloud, and word dynamics are assessed. The graphical visualisation of the bibliometric data is presented in terms of bibliographic coupling, citation, and co-citation network. Results: The investigation reveals that the International Journal of Machine Tools and Manufacture (2611 citations, 31 hindex) is the most productive journal that publishes on MQL. The most productive institution is the University of Michigan (32 publications), the most cited country is Germany (1879 citations), and the most productive country in MQL is China (124 publications). The study shows that ‘Cryogenic Machining’, ‘Sustainable Machining’, ‘Sustainability’, ‘Nanofluid’ and ‘Titanium alloy’ are the most recent keywords and indications of the hot topics and future research directions in the MQL field. Conclusion: The analysis finds that MQL is progressing in publications and the emerging with issues that are strongly associated with the research. This study is expected to help the researchers to find the most current research areas through the author’s keywords and future research directions in MQL and thereby expand their research interests.


Author(s):  
Ronald E. Rice ◽  
Simeon J. Yates ◽  
Jordana Blejmar

We conclude the Handbook of Digital Technology and Society by identifying topics that appear in multiple chapters, are more unique to some chapters, and that represent general themes across the material. Each of these is considered separately for the ESRC theme chapters and the non-ESRC chapters. In the ESRC theme chapters, cross-cutting research topics include digital divides and inequalities; data and digital literacy; governance, regulation, and legislation; and the roles and impacts of major platforms. Cross-cutting challenges include methods; theory development, testing, and evaluation; ethics; big data; and multi-platform/holistic studies. Gaps include policy implications, and digital culture. In the non-ESRC chapters, more cross-cutting themes include future research and methods; technology venues; relationships; content and creation; culture and everyday life; theory; and societal effects. More unique, these were digitization of self; managing digital experience; names for the digital/social era; ethics; user groups; civic issues; health, and positive effects. The chapter also shows how the non-ESRC chapters may be clustered together based on their shared themes and subthemes, identifying two general themes of more micro and more macro topics. The identification of both more and less common topics and themes can provide the basis for understanding the landscape of prior research, what areas need to be included in ongoing research, and what research areas might benefit from more attention. The chapter ends with some recommendations for such ongoing and future research in the rich, important, and challenging area of digital technology and society.


Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 940
Author(s):  
Linda Rubinstein ◽  
Amber M. Paul ◽  
Charles Houseman ◽  
Metadel Abegaz ◽  
Steffy Tabares Ruiz ◽  
...  

Long duration spaceflight poses potential health risks to astronauts during flight and re-adaptation after return to Earth. There is an emerging need for NASA to provide successful and reliable therapeutics for long duration missions when capability for medical intervention will be limited. Clinically relevant, human placenta-derived therapeutic stromal cells (PLX-PAD) are a promising therapeutic alternative. We found that treatment of adult female mice with PLX-PAD near the onset of simulated weightlessness by hindlimb unloading (HU, 30 d) was well-tolerated and partially mitigated decrements caused by HU. Specifically, PLX-PAD treatment rescued HU-induced thymic atrophy, and mitigated HU-induced changes in percentages of circulating neutrophils, but did not rescue changes in the percentages of lymphocytes, monocytes, natural killer (NK) cells, T-cells and splenic atrophy. Further, PLX-PAD partially mitigated HU effects on the expression of select cytokines in the hippocampus. In contrast, PLX-PAD failed to protect bone and muscle from HU-induced effects, suggesting that the mechanisms which regulate the structure of these mechanosensitive tissues in response to disuse are discrete from those that regulate the immune- and central nervous system (CNS). These findings support the therapeutic potential of placenta-derived stromal cells for select physiological deficits during simulated spaceflight. Multiple countermeasures are likely needed for comprehensive protection from the deleterious effects of prolonged spaceflight.


2021 ◽  
Author(s):  
Polona Caserman ◽  
Augusto Garcia-Agundez ◽  
Alvar Gámez Zerban ◽  
Stefan Göbel

AbstractCybersickness (CS) is a term used to refer to symptoms, such as nausea, headache, and dizziness that users experience during or after virtual reality immersion. Initially discovered in flight simulators, commercial virtual reality (VR) head-mounted displays (HMD) of the current generation also seem to cause CS, albeit in a different manner and severity. The goal of this work is to summarize recent literature on CS with modern HMDs, to determine the specificities and profile of immersive VR-caused CS, and to provide an outlook for future research areas. A systematic review was performed on the databases IEEE Xplore, PubMed, ACM, and Scopus from 2013 to 2019 and 49 publications were selected. A summarized text states how different VR HMDs impact CS, how the nature of movement in VR HMDs contributes to CS, and how we can use biosensors to detect CS. The results of the meta-analysis show that although current-generation VR HMDs cause significantly less CS ($$p<0.001$$ p < 0.001 ), some symptoms remain as intense. Further results show that the nature of movement and, in particular, sensory mismatch as well as perceived motion have been the leading cause of CS. We suggest an outlook on future research, including the use of galvanic skin response to evaluate CS in combination with the golden standard (Simulator Sickness Questionnaire, SSQ) as well as an update on the subjective evaluation scores of the SSQ.


Sign in / Sign up

Export Citation Format

Share Document