The presence of selected UV filters in a freshwater recreational reservoir and fate in controlled experiments

UV filters present in sunscreen and other cosmetics are directly released into the environment during aquatic recreational activities. The extent to which the wide range of UV filters pose a risk to the environment remains unclear. This study investigated the occurrence and dissipation of selected organic UV filters at a recreational site (Enoggera Reservoir, Queensland, Australia) over 12 h. Furthermore, different possible degradation processes were investigated in a controlled off-site experiment with surface water exposed to natural light. Half-lives were estimated for ten UV filters. In Enoggera Reservoir, seven UV filters were detected, of which the most prevalent were octocrylene, avobenzone (BMDBM) and enzacamene (4-MBC). Summed concentrations of the seven UV filters ranged from 7330 ng L at 13:00 h to 2550 ng L at 21:00 h. In the degradation experiment, four UV filters showed no significant change over time. The fate of these compounds in the environment is likely to be mainly influenced by dispersion. Half-lives of the remaining UV filters were 6.6 h for amiloxate (IMC), 20 h for benzophenone 1, 23 h for octinoxate (EHMC), 30 h for 3-benzylidene camphor, 34 h for 4-MBC and 140 h for dioxybenzone (BP8). The degree of susceptibility to photodegradation and biodegradation was generally consistent within a structural class. The fate and half-lives of UV filters are variable and should be considered on a per site basis when assessing environmental risk

Why safety knowledge cannot be transferred directly to expected safety outcomes in construction workers: the moderating effect of physiological perceived control and mediating effect of safety behavior

The construction industry is notorious for its high accident and workplace injury rates. High rates of construction workplace injuries, including fatalities, occur worldwide in both developed and developing nations. Our study examines the effects of safety behavior and physiological perceived control (PPC) on the relationship between safety knowledge and outcomes. We examined this relationship by focusing on the mediating role of safety behavior and the moderating role of PPC. We employed a time-lagged design to collect data. Field survey results from 385 site workers from construction sites in the Yangtze region of China show that safety behavior mediated the positive relationship between safety knowledge and outcomes. Furthermore, PPC strengthens the relationship between safety knowledge and safety behavior. The results indicate that workers’ safety knowledge may not transform into expected safety behavior and performance if they experience low levels of PPC. These findings provide new insights into levels of PPC as a boundary condition for understanding the relationships among safety knowledge, safety behavior, and safety outcomes. We discuss the theoretical and practical implications of our findings

An investigation into the long-term binding and uptake of PFOS, PFOA and PFHxS in soil – plant systems

This study investigated the potential aging and plant bioaccumulation of three perfluoroalkyl acids (PFAAs), perfluorosulphonic acid (PFOS), perfluorooctanoic acid (PFOA) and perfluorohexanesulphonic acid (PFHxS) in 20 soils over a six-month period. Sorption coefficients (Log Kd) ranged from 0.13–1.28 for PFHxS, 0.17–1.06 for PFOA and 0.98–2.03 for PFOS, respectively, and bioaccumulation factors (Log BAFs) ranged from 0.29–1.24, 0.22–1.46 and 0.05–0.65 for PFHxS, PFOA and PFOS, respectively. Over the six-month period, Kd values significantly increased for PFHxS and PFOA but the magnitude of the increase was very small and did not translate into differences in plant PFAA-concentrations between aged and freshly spiked treatments. The Kd and BAF values were modelled by multiple linear regression (MLR) to soil physico-chemical properties and by partial least squares regression to soil spectra acquired by mid-infrared spectroscopy (DRIFT−PLSR). Modelling of each PFAA was influenced by different soil properties, including organic carbon, pH, CEC, exchangeable cations (Ca2+, Mg2+, Na+ and K+) and oxalate extractable Al. BAF values were not strongly correlated to any soil property but were inversely correlated to Kd values. Our results indicate that limited aging occurred in these soils over the six-month period

Hydrophobic behavior of fluorite surface in strongly alkaline solution and its application in flotation

Normally fluorite was collected by fatty acid collectors at pH 5–11, rendering the surface to be hydrophobic. In this study, we found that fluorite surfaces are naturally hydrophobic at high pH without any surfactant, which is beneficial for the selective flotation separation of fluorite from calcite. In a flotation test, fluorite recovery showed a decreasing trend at alkalescent pH but increased at high pH. Sum-frequency generation spectroscopy spectrum confirmed that the orientation and hydrogen bonding structure of the water molecules are dramatically changed at fluorite/water interface. Moreover, a new signal peak, wavenumber of 3657 cm, appeared under strongly alkaline conditions; this peak is normally attributed to free OH stretching region and indicates a hydrophobic surface. Meanwhile, the results of contact angle and atomic force microscopy measurements show that the hydrophobicity obviously increases at pH 13. Therefore, the surface structure of fluorite must undergo some significant changes, which will play an important role in the flotation of fluorite

Comparison of the structure and properties of hydroxypropylated acid-hydrolysed maize starches with different amylose/amylopectin contents

Dually modified regular maize starch (RMS) and high-amylose maize starch (HAMS) were successfully prepared by first acid hydrolysis and subsequently hydroxypropylation. The effects of hydrolysis time (0–24 h) and propylene oxide (PO) content (10–30%) on the structure and physicochemical properties were investigated. The molar substitution (MS) of HAMS samples (up to 0.163) was generally higher than that of RMS samples (up to 0.149), suggesting the higher reactivity of amylose for hydroxypropylation. Besides, PO content had a greater influence on MS whereas the effect of acid hydrolysis time was minor. For both starches, the dual modifications did not cause apparent changes to the granule morphology but reduced gelatinisation temperatures and enthalpy; and a higher PO content led to higher relative crystallinity. These results suggest that hydroxypropylation occurred mainly on the surface of HAMS granules and had little influence on the compact granular structure, whereas this reaction impacted the internal structure of RMS much more. The rheological study shows the introduced hydroxypropyl bulky groups weakened the entanglements between amylose chains or amylopectin chains with long branches. Thus, this work provides insights into the rational design of modified starch products containing different amylose/amylopectin contents with tailored properties

Conversion of agricultural waste into stable biocrude using spinel oxide catalysts

Biomass, the feedstock for biocrude and ultimately renewable diesel is a low energy density feedstock. The transport of this feedstock over long distance has been proven to be a major burden on the commercialisation of biorefining. Therefore, it has been generally accepted that biomass should be upgraded to biocrude (a relatively high energy density liquid) in close proximity to the biomass sources. The biocrude liquid would then be transported to a biorefinery. Biocrude contains large amounts of oxygen (generally up to 38 wt%) that is removed from the crude in the refining process. In this study, we have synthesised a range of spinel oxide based catalysts to remove oxygen from the biocrude during the catalytic fast pyrolysis. The activity of spinel oxide (MgB2O4 where B = Fe, Al, Cr, Ga, La, Y, In) catalysts were screened for the pyrolysis reaction. While all the tested spinel oxides deoxygenated the pyrolysis vapour, MgCr2O4 was found to be effective in terms of oxygen removal efficiency relative to the quantity of bio oil produced

Alternative entry points for adaptation: examples from Vanuatu

As climate change accelerates, effective adaptation is an urgent and unavoidable priority. Bottom-up approaches such as community-based adaptation have been portrayed as the panacea. Recent studies are, however, highlighting the ongoing and inherent issues with normative “community” conceptualizations that assume a geographically bound, temporally fixed, and harmonious unit. Despite documentation on the negative impact these problematic assumptions can have on adaptation outcomes, adaptation at the community scale remains the preferred option for project delivery in highly exposed places such as the Pacific Islands region. More creative entry points that are less charged with problematic assumptions are needed at the local scale. This paper draws from three examples in Vanuatu to offer compelling alternative entry points for adaptation: 1) a rural technical college embedded within an Anglican mission village, 2) a whole-of-island approach, and 3) the “collective of vendors” at marketplaces. We offer hope by identifying ways to expand on and complement existing, restricted notions of community and, through this, to improve adaptation outcomes

Does exposure to product market competition influence insider trading profitability?

We examine whether and how product market competition affects insider trading profitability. We empirically show that the insiders of firms in highly competitive industries make higher abnormal profits. Our identification strategy includes both a quasi-natural experiment setting and an instrumental variable approach to address endogeneity concerns. We also run an extensive array of robustness checks and find that our baseline results remain substantially unchanged. Our cross-sectional analyses show that insider trading profitability is more pronounced for firms with: a higher level of trade secrecy, a higher level of R&D, a lower level of management voluntary disclosures, less readable 10-K reports and highly tone-ambiguous financial disclosures. We also find that our results are robust to the inclusion of corporate governance mechanisms. Overall, this study is consistent with the theoretical predictions that support the information asymmetry and proprietary cost channels of competition and that increases in competition lead insiders to undertake more rent-seeking activity