One of the main environmental issues affecting coastal marine environments is the accumulation of contaminants in sediments and their potential mobility. In situ benthic chamber experiments were conducted at two tourist ports (marinas) located in the Gulf of Trieste, one in Slovenia and one in Italy. The aim was to understand if and where recycling at the sediment-water interface (SWI) may affect metal(loid)s. Short sediment cores were also collected near the chamber to investigate the solid (sediments) and dissolved phases (porewaters). Both diffusive and benthic fluxes were estimated to elucidate the release of metal(loid)s at the SWI. Total element concentrations and their labile fractions were determined in sediments to quantify their potential mobility. The total element contents were found to be two orders of magnitude higher in the Italian marina than in the Slovenian one, especially for Hg (up to 1000 mg kg⁻¹), whereas the labile fraction was scarce or null. The opposite occurred in the Slovenian marina. Metal(loid)s in porewaters showed a clear diagenetic sequence and a close dependence upon the suboxic/anoxic conditions of sediments. The results suggest that although the sediments of the Italian marina exhibit the highest total metal(loid) concentration, these elements are scarcely remobilisable. Conversely, in the Slovenian marina, sediments seem to be comparatively more prone to release metal(loid)s at the SWI.

High levels of heavy metals in soils may impose serious impacts on terrestrial organisms. In Brazil, the prevention values for evaluating the ecological risk of these elements are based only on soil chemical analyses and/or on data from ecotoxicological assays performed in soils of temperate regions. However, the attributes of the Brazilian highly-weathered tropical soils can influence the availability of heavy metals for soil fauna, resulting in different toxic values. To provide more accurate ecotoxicological risk values for arsenic (As) in tropical soils, we assessed the impacts of sodium arsenate (Na₂HAsO₄·7H₂O) on the reproduction of earthworms (Eisenia andrei) and collembolans (Folsomia candida), as well as on As bioaccumulation and growth (weight loss) of E. andrei in a tropical artificial soil (TAS) and in an Oxisol. In TAS, As doses reduced the reproduction of the species and promoted weight loss of earthworms. On the other hand, the reproductions of the species as well as the earthworm growth were not altered by As in the Oxisol. The effective concentrations that reduce the reproduction of E. andrei and F. candida by 50 % (EC₅₀) obtained in TAS (22.7 and 26.1 mg of As kg⁻¹ of dry soil, respectively) were lower than those in the Oxisol (>135 mg kg⁻¹, for both species). Although there was As bioaccumulation in earthworms in both soils, the internal concentrations in the earthworms were much higher in the oligochaetes exposed to arsenic in TAS. All these differences were attributed to the higher availability of As in the TAS, compared to the Oxisol, which increased the exposure of the species to the metal. The lower availability in the Oxisol was related to higher contents of type 1:1 silicate minerals and Fe and Al oxides and hydroxides, which strongly bind to As. These results highlight the importance of using tropical soils of humid regions to derive the Brazilian ecological risk prevention values for heavy metals, since the toxicity values are specific for these soils.

Microcapsulses can be designed to effectively encapsulate, protect, and control the release of pesticides. In this study, emulsion-solvent evaporation method was used to fabricate microcapsules using dichloromethane as the solvent, polylactic acid (PLA) as the carrier materials, poly(vinyl alcohol) as the emulsifier, and β-cypermethrin as the entrapped pesticide. The effects of process parameters on the microcapsules characteristics (size, loading content, and encapsulation efficiency) were investigated. Also, the release behavior of the β-cypermethrin was measured experimentally and modeled mathematically. Kinetic analysis indicated that release mechanism of β-cypermethrin was compatible to Fickian diffusion. By optimizing the process parameters, β-cypermethrin-loaded microcapsules were successfully produced with spherical shape, smooth surface, high encapsulation efficiency (> 80%), and a range of pesticide contents. These parameters could be adjusted to achieve delivery systems with desirable release profiles. The results are beneficial to develop delivery systems for rational and effective usage of pesticides.

The application of mineral fertilizers which have contaminants of trace elements may impose concern regarding the entry and toxic accumulation of these elements in agro-ecosystems. In this study, 57 mineral fertilizers (nitrogen, potassium, phosphate, and compound fertilizers) distributed in Iran were analyzed for their contents of Cd, Co, Cr, Cu, Mn, Ni, Pb, Zn, and Fe. The results revealed that the contents of these trace elements varied considerably depending on the type of the element and the fertilizer. Among these elements, Fe displayed the highest average content, whereas Cd showed the lowest. Generally, the trace element contents in P-containing fertilizers were higher than those in nitrogen and potassium fertilizers. The mean values of trace elements (mg kg⁻¹) in P-containing fertilizers were 4.0 (Cd), 5.5 (Co), 35.7 (Cr), 24.4 (Cu), 272 (Mn), 14.3 (Ni), 6.0 (Pb), 226 (Zn), and 2532 (Fe). Comparing trace element contents to limit values set by the German Fertilizer Ordinance showed that the mean contents of potentially toxic trace elements, such as Cd and Pb, were lower than their limit values in all groups of fertilizers. On the other hand, while a number of fertilizers contained a high content of some essential trace elements, particularly Fe, they were not labeled as such.

Metal wet deposition has become an environmental concern because of its threats to soil or water quality and human health. This study was to collect rainfall waters in 2016 from seven sites, representing urban, town, rural, and wetland, within the Three Gorges Reservoir (TGR) region of Southwest China, determine the metal concentration and flux (Zn, Mn, Cu, As, Cd, Pb), and identify their possible sources. Results indicated that Zn was the most abundant metal with a concentration of 16.92 μg L⁻¹ in fall and 19.91 μg L⁻¹ in winter and flux of 4.71 mg m⁻² in fall, while Cd was the least with a monthly mean concentration of 0.02–0.37 μg L⁻¹. Among the seven sites, urban (FL) had the highest values of both concentrations of metals (Zn, Cu, Pb) and fluxes of metals (Mn, As), which significantly differed from the other sites. Component and redundancy analysis suggested that fossil fuel and biomass combustion be a potential metal source. Enrichment factors, box model, and potential ecological risk index showed that the TGR water quality could face a high risk due to wet metal deposition, especially Cd. Data could provide a valuable aid in mitigating metal pollution, developing the best watershed management practices, as well as safeguarding water quality and human health in the TGR region or other reservoir regions.

Spatial interpolation method is the basis of soil heavy metal pollution assessment and remediation. The existing evaluation index for interpolation accuracy did not combine with actual situation. The selection of interpolation methods needs to be based on specific research purposes and research object characteristics. In this paper, As pollution in soils of Beijing was taken as an example. The prediction accuracy of ordinary kriging (OK) and inverse distance weighted (IDW) were evaluated based on the cross validation results and spatial distribution characteristics of influencing factors. The results showed that, under the condition of specific spatial correlation, the cross validation results of OK and IDW for every soil point and the prediction accuracy of spatial distribution trend are similar. But the prediction accuracy of OK for the maximum and minimum is less than IDW, while the number of high pollution areas identified by OK are less than IDW. It is difficult to identify the high pollution areas fully by OK, which shows that the smoothing effect of OK is obvious. In addition, with increasing of the spatial correlation of As concentration, the cross validation error of OK and IDW decreases, and the high pollution area identified by OK is approaching the result of IDW, which can identify the high pollution areas more comprehensively. However, because the semivariogram constructed by OK interpolation method is more subjective and requires larger number of soil samples, IDW is more suitable for spatial prediction of heavy metal pollution in soils.

Uptake of lead from soil was examined in order to establish a site-specific ecological protective concentration level for the Texas Horned Lizard (Phrynosoma cornutum) at the Former Humble Refinery in San Antonio, Texas. Soils, harvester ants, and rinse water from the ants were analyzed at 11 Texas Harvester Ant (Pogonomyrmex barbatus) mounds. Soil concentrations at the harvester ant mounds ranged from 13 to 7474 mg/kg of lead dry weight. Ant tissue sample concentrations ranged from < 0.82 to 21.17 mg/kg dry weight. Rinse water concentrations were below the reporting limit in the majority of samples. Two uptake models were developed for the ants. A bioaccumulation factor model did not fit the data, as there was a strong decay in the calculated value with rising soil concentrations. A univariate natural log-transformed regression model produced a significant regression (p < .0001) with a high coefficient of determination (0.82), indicating a good fit to the data. Other diagnostic regression statistics indicated that the regression model could be reliably used to predict concentrations of lead in harvester ants from soil concentrations. Estimates of protective levels for P. cornutum were developed using published sub-chronic toxicological findings for the Western Fence Lizard that were allometricly adapted and compared to the Doseₒᵣₐₗ equation, which estimated lead consumed through ants plus incidental soil ingestion. The no observed adverse effect level toxicological limit for P. cornutum was estimated to be 5500 mg/kg.

In the tropical region, the greatest challenge of the biomonitoring approach is to establish linear relationships between biomarkers measured in plants and pollutant concentrations, since the bioindicator responses can be intensified or restricted by climatic variations. In southeastern Brazil, there are two regions affected by air pollution, where the Atlantic Forest remains and should be preserved. Consequently, both areas have been monitored by biomonitoring procedures using standardized and tropical plants. The industrial complex settled in Cubatão is one of the world’s most famous examples of environmental pollution and degradation, with consequent decline of the Atlantic Forest. An oil refinery is among the most polluting industries in the Cubatão region. The other region is located in the Metropolitan Region of Campinas (MRC). The MRC has been affected by high levels of air pollutants originated from road traffic and is responsible for over 80% of CO, NOx, and hydrocarbon emissions and develops industrial activities that emit about 70% of the particulate matter present in the region. Both regions are distinguished by the climate, despite the fact that they are only about 130 km far from each other. Several studies carried out by our group in these regions aimed to establish the best native tree species and respective potential biomarkers for future assessment of pollution effects on tropical Forests. We present a critical review about the efficiency of native species compared to standardized bioindicator plants considering antioxidant defense system, nutrient accumulation, and microscopic aspects when exposed to atmospheric pollutants and climate.

A novel adsorbent, three-dimensional porous graphene/lignin/sodium alginate nanocomposite (denoted as 3D PG/L/SA) was fabricated by hydrothermal polymerization of lignin and sodium alginate in the presence of graphene oxide (GO) in an aqueous system. Fourier transform infrared spectra, thermo-gravimetric analysis, scanning electron microscopy, and X-ray photoelectron spectroscopy were employed to characterize the morphology and structure of this novel functional PG/L/SA nanocomposite. A series of adsorption experiments for cleanup of Cd(II) and Pb(II) were conducted to investigate the effects of lignin and sodium alginate on the graphene structure. It was found that PG/L/SA showed a significant increase in adsorption capacity contrast to porous graphene (PG). The as-prepared material achieved the adsorption capacity for Cd(II) and Pb(II) of 79.88 and 226.24 mg/g, respectively. Meanwhile, the adsorption process matched well with the Langmuir isotherm model and the pseudo-second-order kinetic model. Studies were also conducted to demonstrate the applicability of the sorbent to the removal of heavy metal ions from metal smelting wastewater.

The occurrence of cyanobacteria in freshwaters attracts much attention due to its associated health threats and ecological implications. Yet data on the composition of cyanobacteria taxa and toxigenicity in some regions is still scarce. Here, we explored the occurrence of cyanobacteria and cyanotoxins in three locations in Ukraine (reservoir for Kasperivtsi Hydrothermal Power Plant and outflowing River Seret, and cooling pond of Khmelnytsky Atomic Power Plant) in summer 2017. Cyanobacteria were a dominant fraction at all stations. A number of potent-toxin producers were identified including Cylindrospermopsis raciborskii, Aphanizomenon gracile, Dolichospermum flos-aquae, and Planktothrix agardhii. Screening for the presence of dissolved and particulate content of microcystins (-LR, -YR, and -RR), cylindrospermopsin, and anatoxin-a yielded negative results. The studied waters displayed no toxicity in human platelets in vitro. Further toxicological and ecological studies are necessary to evaluate the potential presence of cyanotoxin producers in Ukraine.