Plants were sampled from four different types of chlordecone-contaminated land in Guadeloupe (West Indies). The objective was to investigate the importance of biological and agri-environmental parameters in the ability of plants to bioaccumulate chlordecone. Among the plant traits studied, only the growth habit significantly affected chlordecone transfer, since prostrate plants concentrated more chlordecone than erect plants. In addition, intensification of land use has led to a significant increase in the amount of chlordecone absorbed by plants. The use of Bayesian networks uncovers some hypothesis and identifies paths for reflection and possible studies to identify and quantify relationships that explain our data. Graphical abstract

Chlordecone (kepone or CLD) was formerly used in French West Indies as an insecticide. Despite its formal ban in 1993, high levels of this pesticide are still found in soils. As such, sequestering matrices like biochars or activated carbons (ACs) may successfully decrease the bioavailability of halogenated compounds like CLD when added to contaminated soils. The present study intends (i) to produce contrasted sequestering matrices in order to (ii) assess their respective efficiency to reduce CLD environmental availability. Hence, the work was designed following two experimental steps. The first one consisted at producing different sequestering media (biochars and ACs) via pyrolysis and distinct activation processes, using two lignocellulosic precursors (raw biomass): oak wood (Quercus ilex) and coconut shell (Cocos nucifera). The chemical activation was carried out with phosphoric acid while physical activation was done with carbon dioxide and steam. In the second step, the CLD environmental availability was assessed either in an OECD artificial soil or in an Antillean contaminated nitisol (i.e., 2.1⁻¹μg CLD per g of soil dry matter, DM), both amended with 5 wt% of biochar or 5 wt% of AC. These both steps aim to determine CLD environmental availability reduction efficiency of these media when added (i) to a standard soil material or (ii) to a soil representative of the Antillean CLD contamination context. Textural characteristics of the derived coconut and oak biochars and ACs were determined by nitrogen adsorption at 77 K. Mixed microporous and mesoporous textures consisting of high pore volume (ranging from 0.38 cm³.g⁻¹ to 2.00 cm³.g⁻¹) and specific (BET) surface areas from 299.9 m².g⁻¹ to 1285.1 m².g⁻¹ were obtained. Overall, soil amendment with biochars did not limit CLD environmental availability (environmental availability assay ISO/DIS 16751 Part B). When soil was amended with ACs, a significant reduction of the environmental availability in both artificial and natural soils was observed. AC soil amendment resulted in a reduced CLD transfer by at least 65% (P < 0.001) for all lignocellulosic matrices (excepted for coconut sample activated with steam, which displayed a 47% reduction). These features confirm that both pore structure and extent of porosity are of particular importance in the retention process of CLD in aged soil. Owing to its adsorptive properties, AC amendment of CLD-contaminated soils appears as a promising approach to reduce the pollutant transfer to fauna and biota.

The endocrine system of crustaceans regulates the molt cycle with ecdysteroid hormones, mainly the 20-hydroxyecdysone (20-HE). Moreover, the molt process requires the action of chitinolytic enzymes (e.g., chitinase, chitobiase) to break down the old cuticle. However, endocrine disrupting compounds (EDC) are capable of altering their normal functioning. Glyphosate-based herbicides (GBH), such as Roundup®, the most widely used herbicides, are found in freshwater environments and have been considered EDC for many aquatic organisms. Therefore, this study examined the effects of environmentally relevant GBH concentrations (0.0065, 0.065, and 0.28 mg L⁻¹) on the 20-HE concentration and chitobiase activity in the decapod prawn Macrobrachium potiuna exposed for 14 days. Additionally, lipid peroxidation, a biomarker of membrane lipid degradation, was evaluated in hepatopancreas to assess cellular damage. Results showed that GBH decreased the 20-HE concentration in females at the two highest concentrations tested, while an increase was observed in males exposed to the highest GBH concentration. In addition, GBH also decreased chitobiase activity in males (all concentrations) and females (the two highest concentrations). Finally, GBH caused increased lipid peroxidation in males, indicating cellular damage in the hepatopancreas. In conclusion, this work suggests that GBH is an EDC for crustaceans by disrupting molting, which could lead to altered reproduction and thus population dynamics. Graphical abstract Decrease in the 20-HE concentration and chitobiase activity in muscle of males and females of the freshwater prawn Macrobrachium potiuna exposed to the herbicide Roundup® for 14 days

This paper focuses on long-term evidence on economic growth, international tourism, globalization, energy consumption and carbon dioxide (CO₂) emissions in OECD countries for the period of 1994–2014. The empirical analysis reveals that climate change is magnified by energy use, tourism and economic growth. An inverted U-shaped relationship is also found between international tourism and CO₂ emissions. The contribution of international tourism to climate change in the early stages of development is thus diminished by globalization in the later stages. In other words, globalization appears to reduce carbon emissions from international tourism. The empirical results provide additional arguments for shaping regulatory frameworks aimed at reversing the current energy mix in OECD countries by facilitating energy efficiency and promoting renewable sources.

Capping water body sediments with a thin layer of sand is an effective technique to decrease nutrient concentrations in the water column and accelerate ecological restoration of eutrophic water bodies. However, long-term effects of thin-layer sand capping in shallow lakes are reported less often. Using clean fine sand and geotextile mats as capping materials for sediments collected from Wuhan Donghu Lake in China, we designed a 290-day tank experiment with 3 cm of sand capping at four percentages of sediment coverage from 25 to 100% and a control (no capping). We monitored total nitrogen (TN), total phosphorus (TP), nitrate (NO₃⁻), ammonia (NH₄⁺), and soluble reactive phosphorus (SRP) in the overlying water every 7 days. Mean TN and NO₃⁻ concentrations were significantly the lowest (P < 0.05) at 50% coverage. Further increase in coverage kept them slightly fluctuating. NH₄⁺ concentration was significantly lowest (P < 0.05) at 75% coverage. The relation between coverage and mean TP and SRP concentrations indicated that 75% coverage significantly decreased (P < 0.05) them, and increasing coverage to 100% decreased them even more. The fluxes of TN and TP estimated between sediments and overlying water showed that the thin fine-sand layer significantly increased the function of sediments as a sink of TN from overlying water and the potential of a sand layer to block release of TP from sediments (P < 0.05). Our results suggested that if thin-layer sand capping were applied to Wuhan Donghu Lake, more than 50% coverage is required to decrease nutrients in the lake’s water.

Composting has been recommended as a suitable alternative for recycling wastes and could improve tannery sludge (TS) before its use. However, the long-term application of composted tannery sludge (CTS) may bring concerns about its effects on soil properties and, consequently, on plants and environment, mainly when considering Cr contamination. In this study, we summarize the responses of soil chemical and biological parameters in a 10-year study with yearly applications of CTS. Chemical and biological parameters were assessed in soil samples, and the multivariate analysis method principal response curve (PRC) was used to show the temporal changes in all the biological and chemical properties caused by CTS. The PRC analysis showed different long-term response patterns of chemical and biological parameters according to the rates of CTS. Interestingly, Cr content increased strongly in the first 5 years and only increased slightly in the following 5 years. The yearly applications of CTS changed the biological and chemical parameters of the soil, negatively and positively, respectively. Organic matter, K and P, increased during the 10 years of application, while soil pH and Cr concentration increased, and soil microbial biomass and enzymes activity decreased.

Fishponds are man-made shallow water bodies that are still little studied because of their small size. They represent high value ecosystems, both environmentally (biodiversity hotspot) and economically (fish production). They can have a high place on the hydrographic network, so their influence on water quality is of first importance for rivers and water bodies located downstream and monitored under the Water Framework Directive. These small water bodies can be a source of contaminants during draining period or an efficient buffer for pesticides. We wanted to evaluate whether these ponds could also be a remediation tool against metals by following the annual evolution of upstream/downstream flows. Cadmium, copper, lead and zinc concentrations were quantified in the dissolved phase upstream and downstream of three ponds, each one having a specific agricultural environment (traditional or organic). Metal concentration was quantified in sediments and water. For the dissolved phase, the predictive non-effect concentration was often exceeded, suggesting an environmental risk. Results highlighted also greater quantity of metals at the downstream of the pond compared to the upstream, suggesting remobilization into the ponds or direct cross-sectional contributions from the watershed (e.g. runoff from crops) or even remobilization. Regarding sediments, minimal contamination was shown but a high mineralogical variability. No buffer effect of ponds, which could reduce the risk of acute or chronic toxicity, was detected.

The use antimicrobials for therapeutic and metaphylactic purpose in humans and agriculture exerts selective pressure on animal and environmental microbiota resulting in the survival and spread of antimicrobial resistance genes among bacteria and subsequent development of resistance in bacteria. Previous studies have shown that honey bees’ microbiota (Apis mellifera) can accumulate antimicrobial resistance genes in their microbiome and act as collectors and disseminators of resistance genes. The aim of this study was to investigate to what extent honey bees act as reservoir of select antimicrobial resistance genes. This study was conducted on 35 groups of bees. Bees were collected from 35 sites in Umbria, Italy. PCR was used to screen pooled ground bees’ specimens for genes that code for resistance against antimicrobials that are commonly used in humans and in veterinary medicine including aminoglycosides (aph), beta-lactams (blaZ), tetracycline (tetM) and sulphonamides (sul1 and sul2). Twenty-four samples out of 35 (68.57%) were positive for at least one antimicrobial resistance gene. Two samples were positive for the aph, 5.71%; eight for blaZ, 22.86%; three for tetM, 8.57%; ten for sul1, 28.57% and eighteen for sul2, 51.43%. Positivity to more than one antimicrobial resistance gene was observed in nine samples, 25.71%. The multivariate analysis identified “presence of farms nearby” as the factor most closely related to PCR positivity. Honey bees (Apis mellifera) from Umbria, Italy, carry antimicrobial resistance genes and can be used as indicators of the presence of resistance genes in the environment.

Selection of plant species with a great remediating capacity and a high biomass production is an important step for depolluting soils especially mine soils. Hyperaccumulators are used in phytoextraction for extracting metals from soil to roots and to translocate them to aerial parts. While in phytostabilization that usually requires amendment, metals are accumulated in the plant roots. The purpose of this study is to investigate Oxalis pes-caprae L. tolerance to Pb and As from Pontgibaud mine soil in France amended with compost and/or biochar. Oxalis bulbils were harvested in three sites located around Algiers: (1) an agricultural land in Reghaïa, (2) an area planted with Pines at the USTHB university campus, and (3) the polluted bank of the El Harrach river. The small and medium bulbil sizes were selected from each locality. Concerning the experimental soil, five mixtures of Pontgibaud technosol (P) with amendments compost (C) and biochar (Bc) were prepared: PC, PBc5, PBc10, PBc5 C, PBcC (w/w). The results indicate that amendments alter the soil physico-chemical characteristics and the mobility of metal(loid)s. They also reveal that As and Pb are differently distributed in plant organs. Medium bulbils especially from El Harrach river and the university campus have shown a better growth. Seedlings growth rate has been the highest in Pontgibaud amended with PC and the lowest in PBc10.

Chemical contaminants are released from mining, domestic and industrial effluents into an aquatic environment. Sediments (n = 10) were collected with an Eckman grab at ten stations in the Densu Estuary for ecological risk assessment. The spatial distribution of organic characteristics and ecological risk of metals—zinc, lead, copper, mercury, iron, and manganese in sediment—were analyzed using standard methods. The organic parameters occurred in the ranges, as follows: % C, 0.76 to 2.05, % TN, 0.06 to 0.015; % TP, 0.44 to 1.38; and C/N, 12.31 to 34.81. The ranges of metal concentrations (mg/kg) were as follows: Fe, 201.10 to 720.90; Mn, 40.10 to 152.70; Zn, 7.3 to 158.3; Pb, 1.9 to 84.7; Cu 3.4 to 23.0; and Hg, 0.01 to 0.05. The mean concentration of metals in the sediment were Fe > Mn > Pb > Zn > Cu > Hg. The highest mean concentration of Fe suggested redox conditions in the Densu Estuary. There is a low contamination factor (CF) for five metals (Zn, Hg, Fe, Cu, and Mn) (CF < 1) to high contamination of Pb (3 < CF ≤ 6). The average Pb concentration was above local and geological backgrounds, suggesting an anthropogenic source of pollution from industrial and domestic effluents and agrochemicals. The sediment was extremely enriched by Pb (EF > 50) with a positive index of geoaccumulation (0 < Igeo ≤ 2) than other metals. There is considerable to a very high degree of contamination (DC) (3 ≤ DC ≥ 6) of metals in the sediment of Densu Estuary. The potential ecological risk index (≤ 40 PERI < 80) suggested a very low to moderate ecological risk of metal pollution. The study provides baseline knowledge on geochemical contamination in tropical estuarine systems for the development of effective chemical control strategies towards sustainable management of coastal waters.