Although growing vegetables in urban gardens has several benefits, some questions in relation with the safety of foods remain when the self-production is carried out on highly contaminated garden soils. To better assess the local population’s exposure to Cd and Pb induced by the past activities of a lead smelter, a participatory program was initiated in 115 private kitchen gardens located in northern France to assist gardeners in understanding their soil environment. The challenge included contributing to the database of urban garden soils with the collection of a large number of samples: 1525 crops grouped into 12 types (leaf, fruiting, root, stem and bulbous vegetables, tubers, cabbages, leguminous plants, celeriac, fresh herbs, fruits, and berries), 708 topsoils, and 52 samples of self-produced compost. The main results were as follows: (i) topsoils were strongly contaminated by Cd and Pb compared to regional reference values; (ii) great variability in physicochemical parameters and metal concentrations in topsoils; (iii) the highest concentrations of Cd and Pb for celeriac and fresh herbs and the lowest for fruits and fruiting vegetables; (iv) a high percentage of vegetables that did not comply with the European foodstuff legislation; and (v) most self-produced compost samples were strongly contaminated. This study aimed to raise awareness and generate functional recommendations to reduce human exposure and to provide useful data that could be considered in other environmental contexts.

Environmental, biological, and ecosystem-specific properties may influence the transfer of chemical elements (CEs) from soils to plants, including the variation in the chemical elements’ concentration, their types, and physiological parameters, such as biotransformation ability in the plants. The interface between the soil and a plant, or the concentration of a particular chemical element in a plant with respect to its concentration in the soil, is the basis for a widely used biological absorption coefficient, also known as the transfer factor, bioaccumulation factor, mobility ratio, or plant-soil coefficient, which is expressed in terms of the chemical element’s concentration in the plant and soil. However, from the biogeochemical perspective, these coefficients/factors can provide a comparison of the chemical element (CE) concentration in different media (plants and soil), but only in a particular place (under typical environmental conditions) and at a particular time. However, factors that highlight the variation in the processes, rather than the variation in the chemical element quantity under the conditions of the environmental variation, are required. The second-level or dynamic factors can be used for this purpose. A quantitative method, using the dynamic factors of bioaccumulation, biophilicity, translocation, bioavailability, and phytoremediation, is offered to assess the variation in the process of the uptake of chemical elements by different plants, to evaluate the influence of soil modification on their participation in the plants’ metabolism and to perform quantitative evaluation of phytoremediation efficiency over a particular period of time. The use of dynamic factors for describing the chemical elements’ uptake by plants in various cases, representing aerogenic and edaphic chemical elements’ transfer, is discussed.

Suspended solids (SS) and phosphorus (P) losses in rainfall generated runoff can lead to the deterioration of surface water quality. Simulated rainfall experiments were conducted to investigate the effects of rainfall intensity (30, 50, 65, and 100 mm h⁻¹) and land slope (0°, 5°, and 10°) on SS and P losses in runoff from experimental rigs containing bare land soil and soil planted with grass (tall fescue). In addition, total phosphorus (TP), particulate phosphorus (PP), and dissolved phosphorus (DP) losses in runoff were also measured. Results showed that tall fescue could reduce loads of SS by 86–99.5%, PP by 92–98.5%, and TP by 55–89.8% in runoff compared with losses from bare soil; this is due to a combination reduced raindrop kinetic energy at the soil surface, reduced soil erodibility in the presence of plant roots and shoots, and an increase in roughness and consequently reduced overland flow velocity resulting in the trapping of particles. Linear relationships between losses of SS and TP and between TP and PP in runoff were significant (R² > 0.93) in both bare soil and grass. In addition, SS and TP losses increased greatly significantly with rainfall intensity and slope. The influence of rainfall intensity on SS and P losses was greater than the influence of slope. Simple linear regressions were constructed between losses of SS and P, the rainfall intensity (30 to 100 mm h⁻¹), and land slope (0° to 10°). The multiple regression equations of SS and P losses in runoff established in this study can provide a simple predicting approach for estimating the non-point source pollution load of SS and P arising from rainfall.

Lead (Pb) exposure is reported to be unsafe for humans. There have been several studies documenting acute and chronic Pb toxicity on the organ systems. New studies suggest that early-life exposure to such environmental toxins may increase the susceptibility to late-onset degenerative disorders. We aimed to examine the long-term effects of early-life postnatal exposure of Pb on retinal degeneration. Pb exposure (200 ppm) was provided either at postnatal day 1 through lactation (early-life exposure) or at 7th week of age (adulthood exposure) directly through drinking water for 20 days. The Pb-treated mice were followed till 20 weeks of age. At 20th week, ischemia/reperfusion (I/R) injury was induced in these mice by pterygopalatine artery ligation. Further, alpha lipoic acid (ALA) was administered to examine its neuroprotective effects against retinal damage. Histological and molecular analysis revealed that Pb-treated mice had greater retinal damage after I/R injury as compared to untreated or ALA treated mice, suggesting that ALA protects the early-life Pb exposure and its consequent impact on later life. The elevated levels of glial derived neurotrophic factor (GDNF) and ciliary neurotrophic factor (CNTF) and reduced levels of glial fibrillary acidic protein (GFAP) upon ALA pre-treatment suggest that it probably exerts anti-inflammatory effects via upregulation of neurotrophic factors.

At the mouth of the Odiel River, within the Natural Area “Marismas del Odiel”, there has been for years a collection of waste from different mining sites. In the present work, an approach has been made to the problem that this supposes, quantifying the pollutants that are poured into the estuary from the mineral collection located on the banks of the river. The study carried out has been able to determine high metal concentrations, comparable with any rubble from the upstream mines, with pH value of 1.66, lower than many other areas affected by acid mine drainage in the same river, and even with concentrations of Fe and As higher than those provided by the rest of the mining facilities of the Odiel basin. This can make us understand the serious situation of the Natural Park, where a great variety of birds and plants of special ecological interest are located.

The linkage between high concentration of greenhouse gases (GHGs) and climate change is well recognized as there is severe influence of climate change on public health. Carbon dioxide is most prominent GHG which deteriorates the environment and impacts human health. On the parallel, economic growth also affects health conditions sometimes positively or vice versa. The objective of this research work is to examine the dynamic linkages among CO₂ emissions, health expenditures, and economic growth in the presence of gross fixed capital formation and per capita trade by using auto regressive distributive lag (ARDL) model for Pakistan covering annual data from the year 1995–2017. Our empirical results show that there is significant long run as well as short-term causal relationship between health expenditure, CO₂ emissions, and economic growth in Pakistan. Bidirectional relationship of Granger causality is found between health expenditures and CO₂ emissions, and further between health expenditures and economic growth. Short-run unidirectional causality is running from carbon emissions to health-related expenditures. The bidirectional causal relationship is also investigated between carbon emissions and growth as well as gross fixed capital formation and growth. Then, policy recommendations towards controlling pollution, particularly CO₂ emissions and health expenditures without compromising economic growth are suggested. Graphical abstract .

In recent years, the photocatalytic process by using TiO₂ nanoparticles (NPs) has produced a great interest in wastewater treatment due to its interesting features such as low-cost, environmental compatibility, and especially capacity to eliminate persistent organic compounds as well as microorganisms in water. In the present work, the photocatalytic activity of Gd-doped TiO₂ nanopowders, with different doping amount 0.1, 1, and 5 mol% synthesized by the sol-gel method, was studied under UV/Visible irradiation for water treatment application. The Gd-doped TiO₂ nanoparticles were investigated for their photocatalytic degradation of methylene blue (MB) dye and antibacterial activities against two bacterial strains namely Stenotrophomonas maltophilia (S. maltophilia) and Micrococcus luteus (M. luteus). MB dye was used as a pollutant model to estimate reactive oxygen species (ROS) generation and to correlate killing action of nanoparticles with the generation of ROS. Scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and Raman spectroscopy were used to characterize the as-synthesized nanomaterials. Photocatalytic, as well as antibacterial tests, showed that doping with an appropriate amount of Gd could reduce the radiative recombination process of photogenerated electron-hole pairs in TiO₂ and induce a significant enhancement in photocatalytic and consequently antibacterial activity. The experimental sequence of bactericidal activity and photocatalytic degradation efficiency exhibited by the different gadolinium-doped nanoparticles was the following: 0.1 mol% Gd-doped TiO₂ > 1 mol% Gd-doped TiO₂ > 5 mol% Gd-doped TiO₂ > pure titania.

Heavy metal contamination, one of the greatest global problems, not only endangers humans and animals but also negatively affects plants. New trends, the production and industrial applications of metals in nanoforms, lead to release of large amounts of nanoparticles into the environment. However, the influence of nanoparticles on living organisms is not well understood. Cadmium is a heavy metal not essential for plants, and to its phytotoxicity also contributes its chemical similarity to zinc. It has been recorded that zinc at low concentrations reduces the toxicity of cadmium, but our results with ZnO nanoparticles did not proved it. In contrast, ZnO nanoparticles significantly increased the negative effect of cadmium, which was reflected mainly in changes in the content of photosynthetic pigments.

Arsenic exposure by groundwater contamination is a menace which threatens more than 26 million individuals of West Bengal. Interestingly, with similar levels of arsenic exposure, only 15–20% of the population show arsenic-induced skin lesions, the hallmarks of chronic arsenic toxicity, but the rest do not. In this study, our aim was to identify whether microRNAs (miRNA) have any role to play in causing such arsenic susceptibility. Global plasma miRNA profiling was done in 12 arsenic-exposed individuals with skin lesions and 12 exposed individuals without skin lesions. Two hundred two miRNAs were found to be differentially regulated between the two study groups. Results were validated by quantitative real-time PCR in 30 exposed subjects from each of the groups, which showed that among others miR-21, miR-23a, miR-27a, miR-122, miR-124, miR-126, miR-619, and miR-3613 were significantly upregulated and miR-1282 and miR-4530 were downregulated in the skin lesion group compared with the no skin lesion group. Bioinformatic analyses predicted that these altered miRNAs have targets in 7 different biochemical pathways, including glycerophospholipid metabolism, colorectal cancer, glycosphingolipid biosynthesis, T cell receptor signaling, and neurotrophin signaling pathways; glycerophospholipid metabolism pathway being the most enriched pathway. Association study show that these microRNAs contribute significantly to the increased prevalence of other non-dermatological health effects like conjunctival irritations of the eyes and respiratory distress in the study subjects. To our knowledge, this is the first study of its kind involving miRNA expressions contributing to arsenic susceptibility in the exposed population of West Bengal.

Composting is an attractive way to recycle organic wastes because the product (compost) can be used as an organic fertilizer or a culture substrate. This study assessed coal fly ash (CFA; at 0, 15, and 35%) and/or vinegar residue (VR; at 0, 35, and 55%) as additives in the green waste (GW) composting process. Compost maturity was assessed based on the following indicators: water-holding capacity, pH, total organic carbon, electrical conductivity, total Kjeldahl nitrogen, and germination index. Other important compost properties that were determined included germination percentage and root length of seeds in a germination assay, crude fiber degradation, specific UV absorption, E₄/E₆ ratio, microbial numbers (culturable bacteria and volatile fatty acid-degrading bacteria), enzyme activities (dehydrogenase, β-glucosidase, acid-phosphatase, urease, and ortho-diphenol oxidase), and available nutrients. When added together, CFA and VR improved all of these properties. As indicated by the maturity indicators and other properties, the best treatment (the combined addition of 15% CFA and 55% VR) required only 23 days to produce a mature and high quality compost.