Restoration and conservation potential of destroyed Qinghai spruce (<Emphasis Type="Italic">Picea crassifolia</Emphasis>) forests in the Qilian Mountains of northwest China

Each of the last three decades has seen the Earth’s surface get progressively warmer more than any preceding decade since the 1850s. Greenhouse gas emissions from human activities have been scientifically demonstrated as the primary cause of the observed global climate change. The reduction of greenhouse gas levels in the atmosphere has deserved international attention. Aside from strategies to reduce emissions, increasing carbon storage by restoring and protecting destroyed forests has become an alternative method to lower carbon dioxide (CO₂) levels. Therefore, effective restoration/conservation plans for deforested lands are urgently needed. The current work focuses on the restoration and conservation potential of destroyed Qinghai spruce (Picea crassifolia) forests in the Qilian Mountains of northwest China and provides a reasonable approach for drafting effective restoration/conservation plans for deforested lands. We first estimated habitat suitability of the Qinghai spruce using a habitat suitability model based on the relationships among the three most influential/significant environmental variables: average annual precipitation (P), average air temperature in July (T), and solar radiation (R) and the corresponding occurrence frequency of Qinghai spruce in the niche space. We then calculated the index of habitat suitability (IHS) for Qinghai spruce by applying a model in the study area. We finally used field data to classify the IHS map and identified the prior restoration and conservation areas for Qinghai spruce. The results show that (1) the optimal combination of T, P, and R for Qinghai spruce is 11.5 °C, 380 mm, and 2?×?10³ kWh/m², respectively; (2) these forests have potential for restoration; (3) areas with priority restoration and conservation potential are about 43 and 56.65 km². The results of this study will help decision-makers develop and implement effective restoration/conservation strategies in the Qilian Mountains. This study presents a useful approach for helping decision-makers in other regions of the world draft effective restoration/conservation plans for deforested lands. The implementation of these plans will reduce CO₂ concentration in the atmosphere, in turn, may retard global warming.     

Mathematical modeling of sustainable development goals of India agenda 2030: a Neutrosophic programming approach

Environment, Development and Sustainability - Since 2015, the United Nations sustainable development goals (SDGs) agenda 2030 has been designed with 17 goals, 169 targets, and 232 unique indicators...     

Nexus between corruption and regional Environmental Kuznets Curve: the case of South Asian countries

This study attempts to investigate the presence of a regional Environmental Kuznets Curve (EKC) in selected South Asian countries, namely, Pakistan, India, Bangladesh, and Sri Lanka for the period 1984–2008. In addition, it also intends to inspect the impact of corruption on environmental degradation in this region. The Fixed Effect results confirm the existence of the regional EKC in these countries. Furthermore, the results indicate that corruption do affect environment in the manner that it delays the turning point in EKC. It is found that, in the presence of corruption, the per capita GDP at the turning point is USD 998, which is USD 128 higher from the value that would have been in the absence of corruption. Based on these results, the study suggests appropriate policy measures.     

Characterization of municipal solid waste temporary storage sites: Risks posed to surrounding areas as a consequence of fire incidents

In this study temporary storage sites of municipal solid waste were characterized based on their potential social, health and environmental impacts as a consequence of spontaneous fires, by employing Boolean as well as weighted-linear-combination approaches in connection with various fuzzy set functions of population density around the storage sites. Sweden was used as the case study and data from 105 storage sites were analysed; of these, 38 were identified to be posing high risk for downwind residing population. Furthermore, during the past 10 years, the fire frequency and the average population residing within a radius of 1, 2, and 3 km were found to be comparatively higher for storage sites owned by private companies than for those owned by municipalities. The study provided first-cut information of poorly sited temporary storage sites and can help in formalizing the comprehensive risk analysis in the future.     

Economic valuation of Shadegan International Wetland,Iran: notes for conservation

Wetlands are among the most productive ecosystems on the earth. They produce various market and non-market goods and services, which have a significant role in human welfare. Despite the great opportunities from sustainable development, wetlands all over the world are under serious threat from a diverse range of non-sustainable activities. One of the major reasons for excessive depletion and the conversion of wetland resources is due to underestimating the non-market values of wetlands during development decisions. Shadegan International Wetland (SIW) in southern Iran is one of these wetland areas that is threatened by undervaluation and overexploitation from commercial activities. This study utilizes the contingent valuation method to estimate the economic benefits of SIW from the view point of peoples’ willingness to pay (WTP). The logit model was defined based on dichotomous choice to measure individuals’ WTP. The estimated mean WTP was US$ 1.74 per household as a onetime donation. This study concludes that the benefits of SIW to society could encourage managers to set priorities to ensure that the health of the ecosystem, its integrity, and its uniqueness would be conserved in a proper manner.     

Synthesis and biological activities of new azacrown ether Schiff bases and spectrophotometric studies of their complexation with [60]fullerene

A series of novel azacrown ether Schiff bases 1–3 have been synthesized in good yield and in a simple way. Their host–guest interaction with [60]fullerene has been studied in toluene by absorption spectroscopic method. All the complexes are found to be stable with 1:1 stoichiometry. Because of their potential applications in industry, agriculture and medicine, they were investigated for their mutagenic and antimutagenic activities using the spot test and the plate incorporation assay of Ames. Compounds 1, 2 and 3 were found to be nonmutagenic in the Ames test using strains TA 1535, TA100 and TA97a of Salmonella typhimurium. However, using strain TA102 revealed that, although both compounds 1 and 2 were nonmutagenic, compound 2 gave a positive response indicating that it acts as an oxidative mutagen. The structure-activity relationship may throw some light on the biological activity of such series of compounds.     

Foliar uptake of arsenic nanoparticles by spinach: an assessment of physiological and human health risk implications

Atmospheric contamination by heavy metal(loid)–enriched particulate matter (metal-PM) is highly topical these days because of its high persistence, toxic nature, and health risks. Globally, foliar uptake of metal(loid)s occurs for vegetables/crops grown in the vicinity of industrial or urban areas with a metal-PM-contaminated atmosphere. The current study evaluated the foliar uptake of arsenic (As), accumulation of As in different plant organs, its toxicity (in terms of ROS generation, chlorophyll degradation, and lipid peroxidation), and its defensive mechanism (antioxidant enzymes) in spinach (Spinacia oleracea) after foliar application of As in the form of nanoparticles (As-NPs). The As-NPs were prepared using a chemical method. Results indicate that spinach can absorb As via foliar pathways (0.50 to 0.73 mg/kg in leaves) and can translocate it towards root tissues (0.35 to 0.68 mg/kg). However, health risk assessment parameters showed that the As level in the edible parts of spinach was below the critical limit (hazard quotient <?1). Despite low tissue level, As-NP exposure caused phytotoxicity in terms of a decrease in plant dry biomass (up to 84%) and pigment contents (up to 38%). Furthermore, several-fold higher activities of antioxidant enzymes were observed under metal stress than control. However, no significant variation was observed in the level of hydrogen peroxide (H₂O₂), which can be its possible transformation to other forms of reactive oxygen species (ROS). It is proposed that As can be absorbed by spinach via foliar pathway and then disturbs the plant metabolism. Therefore, air quality needs to be considered and monitored continuously for the human health risk assessment and quality of vegetables cultivated on polluted soils (roadside and industrial vicinity).

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Residual effects of tobacco biochar along with different fixing agents on stabilization of trace elements in multi-metal contaminated soils

The residual effect of tobacco biochar(TB ≥ 500°C) mono and co-application with Cahydroxide(CH),Ca-bentonite(CB) and natural zeolite(NZ) on the bio-availability of trace elements TE(s) in alkaline soils has not been deeply studied yet.A pot study that had earlier been investigated TB mono and blended with CH,CB and NZ on the immobilization of Pb,Cu Cd,and Zn by Chinese cabbage.Maize crop in the rotation was selected as test plant to assess the residual impact of amendments on stabilization of Pb,Cu Cd,and Zn in mine polluted(M-P),smelter heavily and low polluted(S-HP and S-LP,respectively) soils.The obtained results showed that stabilization of Pb,Cd,Cu and Zn reached 63.84% with TB + CB,61.19% with TB + CH,83.31% with TB + CH and 35.27% with TB + CH for M-P soil,36.46% with TB + NZ,38.46% with TB + NZ,19.40% with TB + CH and 62.43% with TB + CH for S-LP soil,52.94% TB + NZ,57.65% with TB + NZ,52.94% with TB + NZ,and 28.44% with TB + CH for S-LP soil.Conversely,TB + CH and TB alone had mobilized Pb and Zn up to19.29% and 34.96% in M-P soil.The mobility of Zn reached 8.38% with TB + CB and 66.03%with TB for S-HP and S-LP soils.The uptake and accumulation of Pb,Cd,Cu and Zn in shoot and root were reduced in three polluted soils.Overall,the combination of TB along with CH,CB and NZ has been proven to be effective in Pb,Cd,Cu and Zn polluted mine/smelter soils restoration.     

Qualitatively and quantitatively assessing the aggregation ability of sludge during aerobic granulation process combined XDLVO theory with physicochemical properties

Inexact mechanism of aerobic granulation still impedes optimization and application of aerobic granules. In this study, the extended Derjaguin, Landau, Verwey, and Overbeek(XDLVO) theory and physicochemical properties were combined to assess the aggregation ability of sludge during aerobic granulation process qualitatively and quantitatively. Results show that relative hydrophobicity of sludge and polysaccharide content of extracellular polymeric substances(EPS) increased, while electronegativity of sludge decreased during acclimation phase. After 20 days' acclimation, small granules began to form due to high aggregation ability of sludge. Since then, coexisted flocs and granules possessed distinct physicochemical properties during granulation and maturation phase. The relative hydrophobicity decreased while electronegativity increased for flocs, whereas that for granules presented reverse trend. Through analyzing the interaction energy using the XDLVO theory, small granules tended to self-grow rather than self-aggregate or attach of flocs due to poor aggregation ability between flocs and granules during the granulation phase. Besides, remaining flocs were unlikely to self-aggregate owing to poor aggregation ability, low hydrophobicity and high electronegativity.     

RETRACTED ARTICLE: Consequences of health risk assessment of wastewater irrigation in Pakistan

Statement of Retraction

We, the Editors and Publisher of Toxicological & Environmental Chemistry, have retracted the following article:

Maria Sabeen, Qaisar Mahmood, Abdol Ghaffar Ebadi, Zulfiqar Ahmad Bhatti, Faridullah, Muhammad Irshad, Allauddin Kakar, Muhammad Bilal, Hafiz Muhammad Arshad and Naeem Shahid, ‘Consequences of health risk assessment of wastewater irrigation in Pakistan Israel Affairs’, Toxicological & Environmental Chemistry, 2019, DOI: 10.1080/02772248.2019.1619335

The article is retracted due to the oversights that were made during peer review process that resulted in the article being published online in error. Further review from independent reviewers was sought. This confirmed that the central findings and methodology of the study in question are unreliable and therefore unsuitable for publication.

We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions.

The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as “Retracted”.