Impact of economic growth, nonrenewable and renewable energy consumption, and urbanization on carbon emissions in Sub-Saharan Africa

Abstract

The present study explores the impact of economic growth; urban expansion; and consumption of fossil fuels, solid fuels, and renewable energy on environmental degradation in developing economies of Sub-Saharan Africa. To demonstrate its findings in detail, the study adopts a system generalized method of moment (GMM) on a panel of 34 emerging economies for the period from 1995 to 2015. The results describe that the consumption of fossil and solid fuels for cooking and expansion of urban areas are significantly contributing to carbon dioxide emissions, on one end, and stimulating air pollution, on the other. The results also exhibit an inverted U-shape relationship between per capita economic growth and carbon emissions. This relation confirms the existence of an environmental Kuznets curve (EKC) in middle- and low-income economies of Sub-Saharan Africa. Furthermore, the findings reveal that the use of renewable energy alternatives improves air quality by controlling carbon emissions and lowering the direct interaction of households with toxic gases. Thus, the use of renewable energy alternatives helps the economies to achieve sustainable development targets.

Heavy metal bioaccessibility and health risks in the contaminated soil of an abandoned, small-scale lead and zinc mine

Abstract

The lack of management in small-scale mining operations has the potential for negative repercussions, e.g., mine collapses, compared with well-regulated large-scale mines. Here, we used an in vitro model to investigate heavy metal soil pollution characteristics and their attendant health risks in an abandoned, small-scale lead (Pb) and zinc (Zn) mine located in southwestern China that had suffered from collapse. Our results showed the following: (1) Even the mine had been closed for many years, the soil was still heavily polluted by Pb, cadmium (Cd), and Zn, and there is a risk of secondary pollution. Pb, Zn, and Cd concentrations in the mining areas were all approximately 22–42 times higher than the background soil levels of Guangxi Province. (2) Cd had the largest bioaccessibility, and mining areas tend to have soils containing more bioaccessible metals (78 ± 14%, 27 ± 4%, and 38 ± 12% for Cd, Pb, and Zn in gastric phase and 40 ± 12%, 10 ± 5%, and 19 ± 8% in intestinal phase correspondingly). (3) Results of a stepwise, multiple regression analysis revealed that the total soil content of the three metals (Pb, Zn, and Cd), TOC (total organic carbon), soil composition, and Mn content were the main impact factors for the Pb, Cd, and Zn soil bioaccessibility in study area (R² = 0.37~0.93). (4) A health risk assessment based on Pb, Cd, and Zn bioaccessibility indicated that the health risk for people in mine area is not high (HI is 1.07 at most and CR 2.40E−6 at most for children).

Investigating the role of urban development in the conventional environmental Kuznets curve: evidence from the globe

Abstract

We investigated the role of urbanization in the conventional environmental Kuznets curve (EKC) of the globe. The overall population and rural population were also considered for control purposes. Based on our findings, we suggest that the conventional EKC of the globe is not an inverted U-shape but becomes downward sloping when urban development is added and inverted U-shapes when the overall population and rural population volumes are added.

Risk assessment by percolation leaching tests of extensive green roofs with fine fraction of mixed recycled aggregates from construction and demolition waste

Abstract

Extensive green roofs are urban construction systems that provide thermal regulation and sound proofing for the buildings involved, in addition to providing an urban heat island mitigation or water retention. On the other hand, policies towards reduction of energy consumption, a circular economy and sustainability are core in the European Union. Motivated by this, an experimental study was carried out to evaluate the environmental risk assessment according to release levels of polluting elements on leachates of different green roof substrate mixtures based on recycled aggregates from construction and demolition waste through (i) the performance in laboratory of two procedures: compliance and percolation tests and (ii) an upscaled experimental leaching test for long-term on-site prediction. Four plots were built on a building roof and covered with autochthonous Mediterranean plants in Córdoba, South of Spain. As growing substrate, four mixtures were used of a commercial growing substrate with different proportions of a fine mixed recycled aggregate ranging from 0 to 75% by volume. The results show that these mixtures were classified as non-hazardous materials according to legal limits of the Landfill Directive 2003/33/CE. The release levels registered in extensive green roofs were lower compared to the laboratory test data. This shows how laboratory conditions can overestimate the potential pollutant effect of these materials compared to actual conditions.

Contribution of root uptake to cadmium accumulation in two peanut cultivars: evidence from a split-column soil experiment

Abstract

Cadmium (Cd) accumulation and internal Cd translocation in the peanut (Arachis hypogaea L.) are highly related to root uptake, which may largely depend on the cultivar variation and the depth of the Cd-contaminated soil. A split-column soil experiment was conducted using two common Chinese peanut cultivars (Huayu-20 and Huayu-23) known to relocate Cd to different tissues. The growth medium was separated into four layers and Cd solution was solely applied to one layer to determine the key depth affecting the Cd accumulation in a plant via root uptakes. The results showed that the biomass of Huayu-23 was significantly higher biomass (3.28–94.0%) than that of Huayu-20, especially in the aerial parts (stems and leaves) and kernels, implying the dilution of Cd. Following the addition of Cd to the soil, the Cd concentrations in peanut tissues increased on average by 28.9–172 and 28.3–111% in Huayu-20 and Huayu-23, respectively. The largest presence of Cd in a peanut plant was observed in the aerial parts, followed by the kernels. Huayu-20 accumulated more Cd in plant tissues than did Huayu-23 due to the former's high Cd translocation. These findings imply that peanut cultivars vary widely in biomass, Cd accumulation, and the percentage distribution of Cd among various plant tissues, especially kernels. Different Cd treatments in the full depth of the root zone induced significant alterations in Cd accumulation of peanut tissues, especially kernels, for both cultivars. The percentage distribution of Cd accumulation by kernels was significantly higher in the deeper layer than in the top layer of the root zone for both peanut cultivars. This study suggests that soil modifications performed during agronomic activities should take into account the full depth of root exploration as well as the peanut cultivars to manage plant Cd uptake.

European cancer mortality predictions for the year 2018 with focus on colorectal cancer

Abstract

Background

We projected cancer mortality statistics for 2018 for the European Union (EU) and its six more populous countries, using the most recent available data. We focused on colorectal cancer.

Materials and methods

We obtained cancer death certification data from stomach, colorectum, pancreas, lung, breast, uterus, ovary, prostate, bladder, leukaemia, and total cancers from the World Health Organisation database and projected population data from Eurostat. We derived figures for France, Germany, Italy, Poland, Spain, the UK, and the EU in 1970–2012. We predicted death numbers by age group and age-standardized (world population) rates for 2018 through joinpoint regression models.

Results

EU total cancer mortality rates are predicted to decline by 10.3% in men between 2012 and 2018, reaching a predicted rate of 128.9/100 000, and by 5.0% in women with a rate of 83.6. The predicted total number of cancer deaths is 1 382 000 when compared with 1 333 362 in 2012 (+3.6%). We confirmed a further fall in male lung cancer, but an unfavourable trend in females, with a rate of 14.7/100 000 for 2018 (13.9 in 2012, +5.8%) and 94 500 expected deaths, higher than the rate of 13.7 and 92 700 deaths from breast cancer. Colorectal cancer predicted rates are 15.8/100 000 men (−6.7%) and 9.2 in women (−7.5%); declines are expected in all age groups. Pancreatic cancer is stable in men, but in women it rose +2.8% since 2012. Ovarian, uterine and bladder cancer rates are predicted to decline further. In 2018 alone, about 392 300 cancer deaths were avoided compared with peak rates in the late 1980s.

Conclusion

We predicted continuing falls in mortality rates from major cancer sites in the EU and its major countries to 2018. Exceptions are pancreatic cancer and lung cancer in women. Improved treatment and—above age 50 years—organized screening may account for recent favourable colorectal cancer trends.

Impaired spirometry may predict bronchial hyperresponsiveness

Publication date: Available online 17 March 2018
Source:The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Ignazio Cirillo, Fabio Gallo, Giorgio Ciprandi

Anaphylaxis after first exposure to gadoterate meglumine: a case report and literature review

Publication date: Available online 17 March 2018
Source:The Journal of Allergy and Clinical Immunology: In Practice
Author(s): Leonardo Bianchi, Katharina Hansel, Rossella Marietti, Marta Tramontana, Luca Stingeni