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Uncertainty factors (UFs) are used to account for uncertainties and variability when setting exposure limits or guidance values. Starting from a proposal of a single UF of 100 to extrapolate from an animal NOAEL to a human acceptable exposure, the aspects of uncertainty and number of UFs have diversified and today there are several risk assessment guidelines that contain schemes of default UFs of varying complexity. In the present work, we scoped the scientific literature on default UFs to map developments regarding recommendations and evaluations of these. We identified 91 publications making recommendations for one or several UFs and 55 publications evaluating UFs without making explicit recommendations about numerical values; these were published between 1954 and 2021. The 2000s was the decade with the largest number of publications, interspecies differences and intraspecies variability being the most frequent topics. The academic sector has been the most active (76 out of 146 publications). Authors from the private sector more often presented UF recommendations, but differences between sectors regarding size of recommendations were not statistically significant. The empirical underpinning of the reviewed recommendations ranges from four to 462 chemicals, that is, relatively low numbers compared with the range of chemicals these default UFs are expected to cover. The recommended UFs have remained remarkably constant, with merely a slight decrease over time. Although chemical specific UFs are preferable, the widespread use of default UFs warrants further attention regarding their empirical and normative basis., QC 20230524

Gold nanoparticles (AuNPs) are readily functionalized and considered biocompatible making them useful in a wide range of applications. Upon human exposure, AuNPs will to a high extent reside in macrophages, cells that are designed to digest foreign materials. To better understand the fate of AuNPs in the human body, their possible dissolution needs to be explored. In this study, we tested the hypothesis that macrophages, and especially stimulated macrophages, can impact the dissolution of AuNPs in a size-dependent manner. We developed an in vitro method to compare the dissolution of citrate coated 5 and 50 nm-sized AuNPs, in terms of released gold ions as measured by inductive coupled mass spectrometry (ICP-MS), in (i) cell medium (alone) (ii) in medium with macrophages present and (iii) in medium with lipopolysaccharide (LPS) triggered macrophages (simulating inflammatory conditions). We found an evident, time-dependent dissolution of AuNPs in cell medium, corresponding to 3% and 0.6% of the added amounts of 5 and 50 nm AuNPs, respectively, after 1 week (168 h) of incubation. The dissolution of 5 nm AuNPs was further increased to 4% in the presence of macrophages and, most strikingly, 14% was dissolved in case of LPS-triggering. In contrast, only a minor increase was observed for 50 nm AuNPs after 1 week in the presence of LPS-triggered macrophages compared to medium alone. Dissolution experiments in the absence of cells highlighted the importance of biomolecules. Our findings thus show dissolution of citrate coated AuNPs that is dependent on size, presence of macrophages, and their inflammatory state. These findings have implications for understanding the transformation/dissolution and fate of AuNPs., QC 20200916

The secondary alcohol 3-methyl-1-butanol (3MB, isoamyl alcohol) is used, for example, as a solvent in a variety of applications and as a fragrance ingredient. It is also one of the microbial volatile organic compounds (MVOCs) found in indoor air. There are little data on acute effects. The aim of the study was to assess the acute effects of 3MB in humans. Thirty healthy volunteers (16 men and 14 women) were exposed in random order to 1 mg/m3 3MB or clean air for 2 h at controlled conditions. Ratings with visual analogue scales revealed slightly increased perceptions of eye irritation (P = 0.048, Wilcoxon) and smell (P < 0.0001) compared with control exposure. The other ratings were not significantly affected (irritation in nose and throat, dyspnea, headache, fatigue, dizziness, nausea, and intoxication). No significant exposure-related effects were found in blinking frequency, tear film break-up time, vital staining of the eye, nasal lavage biomarkers, lung function, and nasal swelling. In conclusion, this study suggests that 3MB is not a causative factor for health effects in damp and moldy buildings.

The new European Union (EU) REACH legislation requires Derived No-Effect Levels (DNEL) to be calculated for substances produced in quantities above 10 tonnes/year. Workers are one population that these DNELs are to protect. Meanwhile, the setting of occupational exposure limits (OEL) continues both at the member state and the EU level. Health-based OELs are proposed by the Commission's Scientific Committee on OELs (SCOEL) and eventually result in Indicative OEL Values (IOELV) in EU Directives. According to REACH, IOELVs may under some circumstances be used as worker-DNELs. On the other hand, worker-DNELs will be derived for several thousand substances, far more than the roughly 100 substances for which IOELVs have been established. Thus, the procedure to set health-based OELs may become influential on that of DNELs and vice versa. This study presents a comparison of the safety margins of 88 SCOEL recommendations with those of the corresponding worker-DNELs, derived according to the REACH guidance document. Overall, the REACH safety margins were approximately six times higher than those derived from the SCOEL documentation but varied widely with REACH/SCOEL ratios ranging by two orders of magnitude, from 0.3 to 58. It was also found that the REACH guidance document, although encompassing detailed advice on many issues, including default assessment factors for species and route extrapolation, gives no quantitative guidance on when and how to depart from defaults.

The objective was to assess acute effects from controlled exposure of volunteers to 2-ethyl-1-hexanol, a volatile organic compound that is often found in indoor air. Sixteen males and fourteen females were in random order exposed to 1 mg/m3 of vapors of 2-ethyl-1-hexanol or to clean air (control exposure) in an exposure chamber during 2 h at rest. The subjects performed symptom ratings on Visual Analog Scales. During exposure to 2-ethyl-1-hexanol subjective ratings of smell and eye discomfort were minimally but significantly increased. Ratings of nasal irritation, throat irritation, headache, dyspnoea, fatigue, dizziness, nausea, and intoxication were not significantly affected. No exposure-related effects on measurement of blinking frequency by electromyography, measurement of the eye break-up time, vital staining of the eye, nasal lavage biomarkers, transfer tests, spirometric and rhinometric measures were seen. No differences in response were seen between sexes or between atopics and non-atopics

This chapter outlines the conceptual framework, methodology and initial interpretations of a pilot study undertaken by a state government agency and coordinated by the Human Services Network (HSNet). The study, conducted in a rural community in NSW, Australia, approaches the communication between the service delivery and consumer as a dialogue. A dialogue between two parties can be positioned to trace and reflect on: (1) the governmental planning model of service delivery and (2) the community that experiences these services as individuals. Such experiential knowledge can be gained from understandings from a range of client stories that reflect the community interaction with service delivery. The design problem focuses on how to increase the bandwidth for such interactions so that all parties can derive meaning. The long term goal is to position the health service network in a role where such mediation between parties can: (1) be explicitly and implicitly linked to action that affects service planning and community delivery, and (2) that the experience of the individual in the community can be incorporated actively into the process of such planning. The chapter concludes with summary of preliminary insights from the project and a brief overview of future developments.

Educational applications of Information and Communications Technologies offer opportunities for social inclusion at the school level and beyond. Many studies note enhanced engagement with learning and improved cognitive outcomes when digital technologies are used to support communication and learning, particularly for students who are socially and academically ‘at risk’. Appropriate and innovative ICT applications improve engagement and connectedness with learning that in turn leads to improved social interaction, good school retention and completion rates, employability and entry into higher education and robust mental health. Today, the positive effects of ICTs as scaffolding devices for literacy, higher order thinking and problem-solving support equity and inclusion in an educational sense. ICT inequalities are linked to differential learning outcomes in schools and classrooms and are powerful drivers of employment opportunities and income differentiation. Unfortunately, many Australian students, especially from poorer or remote communities, have limited opportunities to engage with ICTs at school. Equity and inclusion issues are prominent in discussions about optimizing school learning and are central to continuing government initiatives to improve ICT opportunities in schools. This presentation highlights some issues involved in using digital technologies for building ‘knowledge ready’ skills and the interplay between knowledge-ready skills, academic outcomes and social inclusion more broadly. With pedagogy at the centre of effective ICT use in schools, today’s educators face significant challenges to be both effective users of new technologies and promoters of real-world thinking and doing skills (such as reasoning, enquiry, planning, analysis, and self-regulation) that can be applied within and across educational domains.

The West End suburb of Brisbane is an example of a socially, culturally and economically diverse community in Australia. The suburb has traditionally been home to Indigenous and migrant populations as well as being a refuge for many of Brisbane’s homeless people. The demographics of this suburb, however, are being significantly altered by new property developments with wealthier residents choosing to move close to the city. West End is rapidly becoming a digitally divided community. In 2004/05, academics from the Queensland University of Technology, worked with staff from the State Library of Queensland and the Ethnics Community Council of Queensland, and members of two West End community groups – the Women’s Ethnic Network and the African Women’s Network on a community Information and Communication Technology (ICT) project. Twelve community members from the groups participated in a ten month project that began with focus groups to discuss how ICT was used in the daily life of participants and what they perceived were their personal training needs and the training needs of the larger community group they represent. Training sessions (i.e. Beginning Email) were delivered based on these focus groups. Three months after the sessions, participants were interviewed about their ongoing feelings with ICT; whether they had shared their training experiences with other community members and what impact they felt the training had on their life. All participants reported that the training had a positive impact on their lives and their community. This paper presents the results of a focus group with the participants one year after their initial training experience to determine what ongoing impact, if any, the training had on their life and their community. The study is limited by its small sample size. Nonetheless, three observations can be noted: Firstly, ICT and ICT training does empower and change people’s lives. Secondly, ICT training for community groups should be provided