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1. Habitat loss for black flying foxes and implications for Hendra virus

   https://doi.org/10.1007/s10980-023-01642-w  

   Baranowski, Kelsee ; Bharti, Nita ( April 2023 , Landscape Ecology)

   Environmental change impacts natural ecosystems and wildlife populations. In Australia, native forests have been heavily cleared and the local emergence of Hendra virus (HeV) has been linked to land-use change, winter habitat loss, and changing bat behavior.

   We quantified changes in landscape factors for black flying foxes (Pteropus alecto), a reservoir host of HeV, in sub-tropical Queensland, Australia from 2000–2020. We hypothesized that native winter habitat loss and native remnant forest loss were greatest in areas with the most human population growth.

   We measured the spatiotemporal change in human population size and native ‘remnant’ woody vegetation extent. We assessed changes in the observedP. alectopopulation and native winter habitats in bioregions whereP. alectoare observed roosting in winter. We assessed changes in the amount of remnant vegetation across bioregions and within 50 km foraging buffers around roosts.

   Human populations in these bioregions grew by 1.18 M people, mostly within 50 km foraging areas around roosts. Remnant forest extent decreased overall, but regrowth was observed when policy restricted vegetation clearing. Winter habitats were continuously lost across all spatial scales. Observed roost counts ofP. alectodeclined.

   Native remnant forest loss and winter habitat loss were not directly linked to spatial human population growth. Rather, most remnant vegetation was cleared for indirect human use. We observed forest loss and regrowth in response to state land clearing policies. Expanded flying fox population surveys will help better understand how land-use change has impactedP. alectodistribution and Hendra virus spillover.

    

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2. Assessment of the cytotoxic effects and chemical composition of the insoluble precipitate formed from sodium hypochlorite and chlorhexidine gluconate

   https://doi.org/10.1111/iej.13583  

   Jeong, Ji Wook ; Sarmast, Nima D. ; Terlier, Tanguy ; van der Hoeven, Ransome ; Holland, Julian N. ; Parikh, Neha ( July 2021 , International Endodontic Journal)

   To investigate (1) the cytotoxic potential of the brown precipitate (BP) formed with sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX), using both a small animal model ofCaenorhabditis elegans(C. elegans)and cultured human gingival fibroblasts; and (2) the chemical composition of BP using Time‐of‐Flight Secondary Ion Mass Spectrometry (ToF‐SIMS).

   Brown precipitate was obtained by mixing equal volumes of 6% NaOCl and 2% CHX and separating the BP from clear supernatant by centrifugation. The brown precipitate was weighed and solubilized in dimethyl sulfoxide for cytotoxicity experiments. The cytotoxic effect of BP was assessed usingC. eleganslarvae and primary immortalized human gingival fibroblasts‐hTERT (hTERT‐hNOF) cells. Various dilutions of BP (25 ng/µL–150 ng/µL), supernatant (0.15% v/v), NaOCl (1:100–1:1000 dilutions of 6% NaOCl) or CHX (1:500–1:1000 dilutions of 2% CHX) along with vehicle control (0.5% v/v ethanol and 0.15% v/v DMSO) or untreated control (growth medium) were tested onC. eleganslarvae and hTERT‐hNOF cells. Viability was assessed inC. eleganslarvae using stereomicroscopy and in hTERT‐hNOF cells using dehydrogenase‐based colorimetric assay. ToF‐SIMS was used to assess the chemical composition of BP in comparison with CHX and para‐chloroaniline (PCA). TheC. elegansand cell line data were analysed using Log‐Rank test and Student's t‐test, respectively (p < .05).

   BP‐75 ng/µL and BP‐150 ng/µL were significantly more toxic toC. eleganslarvae than the untreated, vehicle, supernatant or CHX treatment groups (p < .0001). Similarly, in hTERT‐hNOF cells, BP‐50 ng/µL, BP‐75 ng/µL and BP‐150 ng/µL induced significant cytotoxicity within 2 h compared with untreated, vehicle, supernatant and CHX treatments (p < .05). ToF‐SIMS analysis of BP revealed ion composition characteristic of both CHX and the carcinogen PCA.

   Brown precipitate was toxic in bothC. eleganslarvae and hTERT‐hNOF cells. The ToF‐SIMS analysis of BP revealed ions characteristic of CHX and PCA that could account for the toxicities observed inC. eleganslarvae and human gingival fibroblasts. Because of the insoluble and toxic nature of BP, consecutive use of CHX and NaOCl irrigants should be avoided in root canal treatment.

    

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3. Integrating dairy manure for enhanced resource recovery at a WRRF: Environmental life cycle and pilot‐scale analyses

   https://doi.org/10.1002/wer.1574  

   Bryant, Casey ; Coats, Erik R. ( April 2021 , Water Environment Research)

   The Twin Falls, Idaho wastewater treatment plant (WWTP), currently operates solely to achieve regulatory permit compliance. Research was conducted to evaluate conversion of the WWTP to a water resource recovery facility (WRRF) and to assess the WRRF environmental sustainability; process configurations were evaluated to produce five resources—reclaimed water, biosolids, struvite, biogas, and bioplastics (polyhydroxyalkanoates, PHA). PHA production occurred using fermented dairy manure. State‐of‐the‐art biokinetic modeling, performed using Dynamita's SUMO process model, was coupled with environmental life cycle assessment to quantify environmental sustainability. Results indicate that electricity production via combined heat and power (CHP) was most important in achieving environmental sustainability; energy offset ranged from 43% to 60%, thereby reducing demand for external fossil fuel‐based energy. While struvite production helps maintain a resilient enhanced biological phosphorus removal (EBPR) process, MgO₂production exhibits negative environmental impacts; integration with CHP negates the adverse consequences. Integrating dairy manure to produce bioplastics diversifies the resource recovery portfolio while maintaining WRRF environmental sustainability; pilot‐scale evaluations demonstrated that WRRF effluent quality was not affected by the addition of effluent from PHA production. Collectively, results show that a WRRF integrating dairy manure can yield a diverse portfolio of products while operating in an environmentally sustainable manner.

   Wastewater carbon recovery via anaerobic digestion with combined heat/power production significantly reduces water resource recovery facility (WRRF) environmental emissions.

   Wastewater phosphorus recovery is of value; however, struvite production exhibits negative environmental impacts due to MgO₂production emissions.

   Bioplastics production on imported organic‐rich agri‐food waste can diversify the WRRF portfolio.

   Dairy manure can be successfully integrated into a WRRF for bioplastics production without compromising WRRF performance.

   Diversifying the WRRF products portfolio is a strategy to maximize resource recovery from wastewater while concurrently achieving environmental sustainability.

    

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4. Life cycle assessment of green–grey coastal flood protection infrastructure: a case study from New Orleans

   https://doi.org/10.1088/2634-4505/ad3578  

   Hasan, Rahaf ; McPhillips, Lauren ; Warn, Gordon ; Bilec, Melissa ( April 2024 , Environmental Research: Infrastructure and Sustainability)

   The study compared the life cycle environmental impacts of three coastal flood management strategies: grey infrastructure (levee), green–grey infrastructure (levee and oyster reef), and a do-nothing scenario, considering the flood damage of a single flooding event in the absence of protection infrastructure. A case study was adopted from a New Orleans, Louisiana residential area to facilitate the comparison. Hazus software, design guidelines, reports, existing projects, and literature were utilized as foreground data for modelling materials. A process-based life cycle assessment was used to assess environmental impacts. The life cycle environmental impacts included global warming, ozone depletion, acidification, eutrophication, smog formation, resource depletion, ecotoxicity, and various human health effects. The ecoinvent database was used for the selected life cycle unit processes. The mean results show green–grey infrastructure as the most promising strategy across most impact categories, reducing 47% of the greenhouse gas (GHG) emissions compared to the do-nothing strategy. Compared to grey infrastructure, green–grey infrastructure mitigates 13%–15% of the environmental impacts while providing equivalent flood protection. A flooding event with a 100-year recurrence interval in the study area is estimated at 34 million kg of CO₂equivalent per kilometre of shoreline, while grey and green–grey infrastructure mitigating such flooding is estimated to be 21 and 18 million kg, respectively. This study reinforced that coastal flooding environmental impacts are primarily caused by rebuilding damaged houses, especially concrete and structural timber replacement, accounting for 90% of GHG emissions, with only 10% associated with flood debris waste treatment. The asphalt cover of the levee was identified as the primary contributor to environmental impacts in grey infrastructure, accounting for over 75% of GHG emissions during construction. We found that there is an important interplay between grey and green infrastructure and optimizing their designs can offer solutions to sustainable coastal flood protection.

    

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5. Extreme Ozone Loss Following Nuclear War Results in Enhanced Surface Ultraviolet Radiation

   https://doi.org/10.1029/2021JD035079  

   Bardeen, Charles G. ; Kinnison, Douglas E. ; Toon, Owen B. ; Mills, Michael J. ; Vitt, Francis ; Xia, Lili ; Jägermeyr, Jonas ; Lovenduski, Nicole S. ; Scherrer, Kim J. N. ; Clyne, Margot ; et al ( September 2021 , Journal of Geophysical Research: Atmospheres)

   For the first time, we use a modern climate model with interactive chemistry including the effects of aerosols on photolysis rates to simulate the consequences of regional and global scale nuclear wars (injecting 5 and 150 Tg of soot respectively) for the ozone layer and surface ultraviolet (UV) light. For a global nuclear war, heating in the stratosphere, reduced photolysis, and an increase in catalytic loss from the HO_xcycle cause a 15 year‐long reduction in the ozone column, with a peak loss of 75% globally and 65% in the tropics. This is larger than predictions from the 1980s, which assumed large injections of nitrogen oxides (NO_x), but did not include the effects of smoke. NO_xfrom the fireball and the fires provide a small (5%) increase to the global average ozone loss for the first few years. Initially, soot would shield the surface from UV‐B, but UV Index values would become extreme: greater than 35 in the tropics for 4 years, and greater than 45 during the summer in the southern polar regions for 3 years. For a regional war, global column ozone would be reduced by 25% with recovery taking 12 years. This is similar to previous simulations, but with a faster recovery time due to a shorter lifetime for soot in our simulations. In‐line photolysis provides process specific action spectra enabling future integration with biogeochemistry models and allows output that quantifies the potential health impacts from changes in surface UV for this and other larger aerosol injections.

    

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