Disrupting COVID-19 by Improving Environmental Performance

This paper provides evidence that increasing environmental quality can mitigate the spread of COVID-19 by producing natural antibodies. Using recent data from the 2020 Environmental Performance Index for more than 70 countries, our findings validate the effectiveness of lockdown policies in preventing outbreaks. The results are robust across econometric techniques as well as across the environmental proxy variables adopted. We also suggest implementing specific reforms to strengthen ecological performance.

Technical note: Lithium isotopes in dolostone as a palaeo-environmental proxy – an experimental approach

Lithium (Li) isotopes in marine carbonates have considerable potential as a proxy to constrain past changes in silicate weathering fluxes and improve our understanding of Earth's climate. To date the majority of Li isotope studies on marine carbonates have focussed on calcium carbonates. The determination of the Li isotope fractionation between dolomite and a dolomitizing fluid would allow us to extend investigations to deep times (i.e. Precambrian) when dolostones were the most abundant marine carbonate archives. Dolostones often contain a significant proportion of detrital silicate material, which dominates the Li budget; thus, pretreatment needs to be designed so that only the isotope composition of the carbonate-associated Li is measured. This study aims to serve two main goals: (1) to determine the Li isotope fractionation between Ca–Mg carbonates and solution, and (2) to develop a method for leaching the carbonate-associated Li out of dolostone while not affecting the Li contained within the detrital portion of the rock. We synthesized Ca–Mg carbonates at high temperatures (150 to 220 ∘C) and measured the Li isotope composition (δ7Li) of the precipitated solids and their respective reactive solutions. The relationship of the Li isotope fractionation factor with temperature was obtained: 103ln⁡αprec-sol=-(2.56±0.27)106(1)/T2+(5.8±1.3) Competitive nucleation and growth between dolomite and magnesite were observed during the experiments; however, there was no notable effect of their relative proportion on the apparent Li isotope fractionation. We found that Li isotope fractionation between the precipitated solid and solution is higher for Ca–Mg carbonates than for Ca carbonates. If the temperature of a precipitating solution is known or can be estimated independently, the above equation could be used in conjunction with the Li isotope composition of dolostones to derive the composition of the solution and hence make inferences about the past Li cycle. In addition, we also conducted leaching experiments on a Neoproterozoic dolostone and a Holocene coral. Results show that leaching with 0.05 M hydrochloric acid (HCl) or 0.5 % acetic acid (HAc) at room temperature for 60 min releases Li from the carbonate fraction without a significant contribution of Li from the siliciclastic detrital component. These experimental and analytical developments provide a basis for the use of Li isotopes in dolostones as a palaeo-environmental proxy, which will contribute to further advance our understanding of the evolution of Earth's surface environments.

Potential of shells of three species of eastern Australian freshwater mussels (Bivalvia: Hyriidae) as environmental proxy archives

Freshwater mussels in Australia are rarely studied for their life history and potential as palaeoclimate proxy archives. Therefore, we studied three freshwater mussel species from the Williams River, Hunter Valley, Australia, namely Alathyria profuga, Cucumerunio novaehollandiae and Hyridella drapeta, to identify their potential as new environmental proxy archives from Australian freshwater bodies. Growth analysis revealed that A. profuga and C. novaehollandiae produce distinctive growth lines, which allow the first identification of age and growth structure of these species. The oxygen isotope ratio in A. profuga shells and high-resolution element concentrations in all three species show cyclic, annual variations. A high correlation between growth rates and the combined winter air temperature and annual rainfall, as well as accurate temperature reconstruction using oxygen isotope values in the shells suggest that A. profuga has good potential as an environmental proxy archive. However, the low correlation observed between the Sr:Ca ratio and temperature limited the usefulness of the Sr:Ca ratio in A. profuga shells as a water temperate proxy. In contrast, growth rates and element ratios of C. novaehollandiae do not indicate a significant relationship with environmental variables, suggesting that this species, together with H. drapeta, is probably not suitable for palaeoclimatic studies.

Lithium isotopes in dolostone as a palaeo-environmental proxy – An experimental approach

Lithium (Li) isotopes in marine carbonates have considerable potential as a proxy to constrain past changes in silicate weathering fluxes and improve our understanding of Earth’s climate. To date the majority of Li isotope studies on marine carbonates have focussed on calcium carbonates. Determination of the Li isotope fractionation between dolomite and a dolomitizing fluid, would allow us to extend investigations to deep times (i.e., Precambrian) when dolostones were the most abundant marine carbonate archives. Dolostones often contain a significant proportion of detrital silicate material, which dominates the Li budget, thus pre-treatment needs to be designed so that only the isotope composition of the carbonate-associated Li is measured. This study aims to serve two main goals: (1) determining the Li isotope fractionation between Ca-Mg carbonates and solution and (2) to develop a method for leaching the carbonate-associated Li out of dolostone while not affecting that contained within the detrital portion of the rock. We synthesized Ca-Mg carbonates at high temperature (150 to 220 °C) and measured the Li isotope composition (δ7Li) of precipitated solids and their respective reactive solutions. The relationship of the Li isotope fractionation factor with temperature was obtained: 103lnαprec-sol = −(2.56 ± 0.27) × 106T2 + (5.8 ± 1.3) Competitive nucleation and growth between dolomite and magnesite were observed during the experiments, however, without notable effect of their relative proportion on the apparent Li isotope fractionation. We found that Li isotope fractionation between precipitated solid and solution is much greater for Ca-Mg carbonates than for Ca carbonates. If the seawater temperature can be estimated independently, the above equation could be used in conjunction with the Li isotope composition of dolostones to derive those of the precipitating solutions and hence make inferrals about the past oceanic Li cycle. In addition, we also conducted leaching experiments on a Neoproterozoic dolostone and a Holocene coral. Results show that leaching with 0.05M HCl or 0.5 % acetic acid at room temperature for 60 min releases Li from the carbonate fraction without significant contribution of Li from the siliciclastic detrital component. These experimental and analytical developments provide a basis for the use of Li isotopes in dolostones as a palaeo-environmental proxy, which will contribute to further advance our understanding of the evolution of Earth’s surface environments.

PROPOSAL OF A THERMAL DEGRADATION METHODOLOGY WITH SCRAPS OF LOGS FROM Araucaria columnaris

The reconstruction of past environments has been studied in several areas of science, aiming to help in understanding the several events that occurred on the planet. Plants are considered environmental markers and usually show structural adaptations that are characteristic of their habitat. Therefore, after passing through the charring process, they may not be completely consumed by the fire, being possible to find remnants of charcoal and other remaining materials. Based on this, the presence of charcoal is an evidence of the occurrence of current or past fires, contributing with a valuable source of (paleo) environmental proxy data. In this sense, the objective of this work is to assess the physical and chemical changes that occur on scraps of logs from Araucaria columnaris. It will be done during the charring process in muffle, at different temperatures, allowing us to assess important influences in relation to its forming process. The charring temperatures of the logs in natura were in a range of 50 to 1000 ° C, with ranging temperatures from 50 to 50 ° C, and heating ramp of 25 °C min-1. The analysis of this result seeks to allow the proposal of a methodology that assists in the characterization of the natural processes involved in the forming of this type of material, serving as a contribution to (paleo) environmental inferences.