Arsenic is a major environmental toxicant of concern, affecting both female and male reproductive systems. The present study was conducted to investigate the toxic effects of arsenic on semen quality and reproductive hormones of Teddy bucks, an important domestic species in regions of Pakistan. In addition to arsenic, vitamin C was fed to a subset of animals to determine if there were ameliorative effects on reproductive parameters. Sixteen adult Teddy bucks were randomly divided into four experimental groups: A (control), B (arsenic 5 mg/kg BW/day orally), and C (arsenic 5 mg/kg BW/day plus vitamin C of an oral dose of 200 mg/kg BW/day). The animals in experimental group D were given only vitamin C (oral dose of 200 mg/kg BW/day). Animals were fed treated food once a day for 12 weeks. Semen quality parameters (volume, motility, count, sperm morphology, live dead ratio, sperm membrane integrity, and sperm DNA integrity) of bucks from each experimental group were evaluated on a weekly basis. Hematology and the level of arsenic in the blood were assessed every 2 weeks. Serum was collected fortnightly to measure reproductive and stress hormones (testosterone, luteinizing hormone, follicle-stimulating hormones, and cortisol). At the end of the study, all the animals were slaughtered, and the testes of all the animals were collected and evaluated for histopathology. Semen parameters in arsenic-treated bucks were significantly reduced (p < 0.05) compared with controls. Moreover, the levels of male hormones (testosterone, luteinizing hormone, and follicle-stimulating hormone) were significantly decreased in arsenic-treated animals, while cortisol was significantly increased with arsenic exposure. The histopathological lesions in the testes were present in the form of the loss of germinal epithelium and atrophy of Leydig cells. Supplementation of vitamin C however ameliorated the adverse effects of arsenic on semen quality and hormones. The histopathological lesions were also ameliorated due to vitamin C treatment. This study demonstrates that arsenic can adversely affect reproductive endpoints in Teddy goat bucks and supports the hypothesis that vitamin C is an effective treatment in arsenic-induced toxicosis. This study has high significance for Pakistan, as water contaminated with arsenic is a top health concern and is a recurring issue for both domestic animals and humans.

This paper seeks to answer an empirical question of whether clean biomass energy consumption lowers CO₂ emissions while controlling for technical innovation in eight selected countries from Africa for the 1980–2015 period. The countries which are chosen based on availability of data on biomass energy and technological innovation include Egypt, Algeria, South Africa, Mauritius, Kenya, Morocco, Tunisia, and Zambia. Applying pooled mean group, mean group, and dynamic fixed effect panel estimators, the results indicate that clean biomass energy use decreases CO₂ emission in the long run. But the effect of biomass energy consumption on CO₂ emission is insignificant in the short run. The findings imply that CO₂ emission can be reduced by increasing clean biomass energy in the energy mix of these countries. Similarly, environmental quality and economic growth can be achieved simultaneously by increasing the share of biomass energy in large-scale production process. Furthermore, the environmental Kuznets curve (EKC), which hypothesizes an inverted U-shaped relationship between CO₂ emission and economic growth, was validated in the long run. This suggests that the EKC pattern is only observed in the long run. Thus, as part of recommendation from this study, policy makers in these countries should formulate more policies that will enhance clean biomass energy production and its usage to substitute significant percentage of fossil fuel use in production process.

The environmental health of Buenaventura Bay, a highly impacted tropical estuary, is influenced by numerous human activities, including mining upstream. Large- and small-scale fishing plays an important role in the local economy, so we investigated the dynamic processes of bioaccumulation of mercury at basal trophic levels. Four samples were taken at each of the four locations in Buenaventura Bay during each of the four seasons of 2015. We measured the total mercury content (T-Hg, dry weight) in sediments and in muscle tissue across 17 macroinvertebrate species. The most abundant were the blue crab (C. arcuatus) and the mantis shrimp (S. aculeata aculeata). Blue crab showed an average muscle T-Hg value ​​exceeding the limit of 0.2 g·g⁻¹, which is the maximum T-Hg level suggested for food consumption by vulnerable humans and populations: pregnant women, children, and the community that feeds from this source of protein on a daily basis. It was found that, 6.22% of individuals exceeded the 0.5 g·g⁻¹ level, which is the maximum T-Hg level suggested for food consumption by the general population: the population that consumes it sporadically. Significantly high values ​​of T-Hg in blue crab and mantis shrimp occurred during low salinity conditions in the estuary, suggesting that Hg mainly originates from river runoff during the rainy season. Nevertheless, the biota-sediment accumulation factor (BSAF) was favored in high salinity, which could mean greater availability of Hg for higher levels of the estuarine food web in the dry season and in marine waters. In general, the T-Hg levels in some samples exceeded 0.2 g·g⁻¹. Therefore this pollutant must be monitored due to its biomagnification potential and as a threat to human health, especially that for the local population of fishermen and their families.

Lipases are hydrolytic enzymes owing much importance in industrial applications. These enzyme-based detergents are ecofriendly and produce a wastewater with low level of COD (chemical oxygen demand). In the present work, a novel halophilous, thermoalkaline, and detergent-tolerant lipase produced by a newly isolated Aeribacillus pallidus strain VP3 was studied. Considerable interest has been given to this lipase by the improvement of its catalytic activity through the optimization of the pH, the (C/N) ratio, and the inoculum size, using the response surface methodology based on the Box-Behnken design of experiments. A total of 16 experiments were conducted, and the optimized pH, (C/N) ratio, and inoculum size were 10, 1, and 0.3, respectively. The results of the analysis of variance (ANOVA) test indicated that the established model was significant (p value < 0.05). The optimization of the production conditions leads to 2.83-fold of increase in the catalytic activity calculated as the ratio of the activity obtained after optimization (68 U) and the initial activity before optimization (24 U). All in all, the lipase of Aeribacillus pallidus could be considered as a potential candidate to be incorporated in detergent formulations since it shows a good stability towards detergents and wash performance.

The purpose of this work was to produce iron nanoparticles (Fe-NP) by microbial pathway from anaerobic bacteria grown in anaerobic fluidized bed reactors (AnFBRs) that constitute a new stage of a waste-based biorefinery. Bioparticles from biological fluidized bed reactors from a biorefinery of organic fraction of municipal solid wastes (that produces hydrolysates rich in reducing sugars) were nanodecorated (embedded nanobioparticle or nanodecorated bioparticle, ENBP) by biological reduction of iron salts. Factors “origin of bioparticles” (either from hydrogenogenic or methanogenic fluidized bed reactor) and “type of iron precursor salt” (iron chloride or iron citrate) were explored. SEM and high-resolution transmission electron microscopy (HRTEM) showed amorphous distribution of nanoparticles (NP) on the bioparticles surface, although small structures that are nanoparticle-like could be seen in the SEM micrographs. Some agglomeration of NPs was confirmed by DLS. Average NP size was lower in general for NP in ENBP-M than ENBP-H according to HRTEM. The factors did not have a significant influence on the specific surface area of NPs, which was high and in the range 490 to 650 m² g⁻¹. Analysis by EDS displayed consistent iron concentration 60–65% iron in nanoparticles present in ENBP-M (bioparticles previously grown in methanogenic bioreactor), whereas the iron concentration in NPs present in ENBP-H (bioparticles previously grown in hydrogenogenic bioreactor) was more variable in a range from 8.5 to 62%, depending on the iron salt. X-ray diffraction patterns showed the typical peaks for magnetite at 35° (3 1 1), 43° (4 0 0), and 62° (4 0 0); moreover, siderite diffraction pattern was found at 26° (0 1 2), 38° (1 1 0), and 42° (1 1 3). Results of infrared analysis of ENBP in our work were congruent with presence of magnetite and occasionally siderite determined by XRD analysis as well as presence of both Fe⁺² and F⁺³ (and selected satellite signal peaks) observed by XPS. Our results on the ENBPs hold promise for water treatment, since iron NPs are commonly used in wastewater technologies that treat a wide variety of pollutants. Finally, the biological production of ENBP coupled to a biorefinery could become an environmentally friendly platform for nanomaterial biosynthesis as well as an additional source of revenues for a waste-based biorefinery.

Bisphenol A (BPA) and di(2-ethylhexyl) phthalate (DEHP) are endocrine-disrupting chemicals (EDCs) used in a wide variety of industrial products as plasticizers. Exposure to EDCs, particularly in mixtures, in prenatal and early postnatal periods may lead to unwanted effects and can cause both developmental and reproductive problems. In this study, we aimed to determine the individual and combined effects of prenatal and lactational exposure to BPA and/or DEHP on testicular histology, apoptosis, and autophagic proteins. Pregnant Sprague-Dawley rats (n = 3) were divided into four groups (control, BPA (50 mg/kg/day), DEHP (30 mg/kg/day), and BPA (50 mg/kg/day) + DEHP (30 mg/kg/day)) and dosed by oral gavage during pregnancy and lactation. The male offspring (n = 6) from each group were chosen randomly, and their testicular examinations were performed on the twelfth week. The results showed that fetal and neonatal exposure to BPA and DEHP could lead to significant testicular histopathological alterations and cause increases in apoptosis markers (as evidenced by increases in caspase 3 and caspase 8 levels; increased TUNEL-positive spermatogonia and TUNEL-positive testicular apoptotic cells) and autophagic proteins (as evidenced by increased LC3 and Beclin levels and decreased p62 levels) in testicular tissue. We can suggest that EDCs cause more dramatic changes in both testicular structure and cell death when there is combined exposure.

After the success of the Toxics Release Inventory (TRI) in the United States (US), Canada created the National Pollutant Release Inventory (NPRI). Both NPRI and TRI focus on public opinion to coerce facilities to reduce quantities of emissions, through market pressure, although early reductions in Canada may be attributed to traditional command-and-control mechanisms. NPRI uses a quantity-based approach to report atmospheric and effluent releases of pollutants to air and water, but does not account for relative toxicity of releases, which could lead to harmful chemicals being overlooked. A toxicity-based approach using characterization factors from the USEtox® environmental impact assessment tool was used for this study. Releases of organic and inorganic pollutants to both air and water in Nova Scotia for 2015 were analyzed. Using an ecotoxicity analysis found that the highest priority chemicals identified using the NPRI’s quantity-based approach differed markedly from those identified using the toxicity-based approach. Many of the high-priority chemicals identified using toxicity-based analysis are detrimental to ecosystem health and warrant regulatory attention. The Office of the Auditor General of Canada recently suggested that the Canadian federal government needs to improve control risks of toxic substances. Using a toxicity-based approach may help decision makers in the Canadian federal government effectively control risks of toxic substances and help to inform decision makers, regulators, and Canadians about those risks.

A large number of iron ore tailings (IOTs) are produced in steel industry, posing threat to the environment during its storage and disposal. To effectively reutilize Fe in IOTs, we propose a comprehensive utilization scheme: (1) most Fe in IOTs is extracted by concentrated hydrochloric acid to form FeCl₃ flocculants; (2) after separation from the FeCl₃ flocculants, a small amount of Fe is absorbed on the residue solids, which is further washed out to synthesize micron Fe₃O₄ as magnetic seeds. Results show that the as-synthetic FeCl₃ flocculants meet the product standard for FeCl₃ flocculants in China (GB/T 4482-2018) after a series of treatments including rotary evaporation, neutralization, and dilution and have comparable performance with commercial polyaluminum chloride (PAC) and polyaluminum ferric chloride (PAFC). Moreover, the addition of synthetic superparamagnetic Fe₃O₄ (as magnetic seeds) doubled the flocculation rate compared with as-synthetic FeCl₃ flocculants alone. Finally, the reutilization of Fe in IOTs can create a direct economic value of ¥ 1.27/kg IOTs, and produce 745 g high-silicon residues for further reutilization, which indicates that our comprehensive utilization scheme is of great application potential.

This study investigates the relationship between environmental performance and the comparative advantage of crude oil by incorporating the role of institutional quality in 28 oil-producing countries from 2002 to 2014. Using dynamic panel data analysis, the results show that environmental performance and institutional quality along with the conventional factors for comparative advantage are key determinants of the comparative advantage of crude oil. Specifically, while environmental performance negatively affects the comparative advantage of crude oil, it is also negatively associated with the comparative advantage of crude oil. These results are in support of the pollution haven hypothesis in resource-based industry, and it shows a bidirectional relationship between environmental performance and comparative advantage of producing crude oil. Further, the results revealed a vital role played by institutional quality in enhancing the comparative advantage of crude oil and environmental performance. More so, the environmental Kuznets curve (EKC) hypothesis is validated in our result. Finally, a substantial difference in the results between OPEC and non-OPEC countries is confirmed by a set of dummy variables.

Designated as the most harmful for health, PM₂.₅ aerosol fraction was a subject of our study. It was collected for all four seasons during 2014/15 in the suburban area of Belgrade (Serbia) and analysed for Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Br, As, Ba and Pb elements and for NH₄⁺, NO₃⁻ and SO₄²⁻ ions by particle-induced X-ray emission and ion chromatography techniques, respectively. Obtained concentrations have been treated by a combination of several receptor-oriented models to reveal source contributions to the suburban PM₂.₅ at different spatial scales. Applied positive matrix factorization analysis indicated five main groups of emission sources: biomass burning (14.5%), traffic (3.9%), regional combustion/secondary sulphates (28.8%), local combustion/secondary nitrates (29.7%) and soil (5.4%). Local heating units had been pointed out as dominant contributors by long-range transport and ground-wind circulation analyses. Air masses circulating over the Balkan Peninsula denoted regional emissions as responsible for the high concentrations of secondary sulphates. Local and long-range transport analyses combined suggested that the BB and the LC/NO₃ originated from the wider urban area. Several Saharan dust episodes were detected as well. Presented results might be a basis for the development of air pollution mitigation strategies in the continental Balkan area, considered one of the most polluted and under-investigated European regions.