The use of mercury in small-scale gold mining is globally the largest anthropogenic source of mercury in the environment. In countries like Ghana, where small-scale gold mining is a highly important economic sector, the activity is also expected to cause local pollution. This study is based on a hypothesis that the mining activity in Ghana is causing more widespread soil pollution also outside active mining sites, and that the main part of regional differences in soil concentrations of mercury might come from pollution. Little systematic and dependable data has been collected to assess the extent of mercury contamination of soils in areas outside active mining areas. The regional aspect of mercury pollution from mining has not been studied in Ghana or other countries with a large small-scale gold mining sector. Systematic collection of soil samples on a 25 × 25 km² net covering the entire country was carried out to ensure the representativeness of data and to allow calculation of spatial trends. The soil concentrations found in one-third of the country, where most intensive mining takes place, are three times higher than concentrations in the rest of the country. This difference cannot be explained by sources of natural variation in mercury concentrations but can be explained by decades of atmospheric deposition. It is therefore likely that the mining activity has caused a more widespread increase in soil concentrations, also outside active mining sites. The mercury concentrations found are on average 0.024 mg kg⁻¹, which is low compared to published studies from other countries and regions and estimated world averages. All measured concentrations are well below soil quality criteria for human health. The build-up of soil concentrations in the mining area is still problematic because mercury is a hazardous substance in the environment.

Concerns about the environmental and human health implications of TiO₂ nanoparticles (nTiO₂) are growing with their increased use in consumer and industrial products. Investigations of the underlying molecular mechanisms of nTiO₂ tolerance in organisms will assist in countering nTiO₂ toxicity. In this study, the countermeasures exhibited by the slime mold Physarum polycephalum macroplasmodium against nTiO₂ toxicity were investigated from a physiological, transcriptional, and metabolic perspective. The results suggested that the countermeasures against nTiO₂ exposure include gene-associated metabolic rearrangements in cellular pathways involved in amino acid, carbohydrate, and nucleic acid metabolism. Gene-associated nonmetabolic rearrangements involve processes such as DNA repair, DNA replication, and the cell cycle, and occur mainly when macroplasmodia are exposed to inhibitory doses of nTiO₂. Interestingly, the growth of macroplasmodia and mammal cells was significantly restored by supplementation with a combination of responsive metabolites identified by metabolome analysis. Taken together, we report a novel model organism for the study of nTiO₂ tolerance and provide insights into countermeasures taken by macroplasmodia in response to nTiO₂ toxicity. Furthermore, we also present an approach to mitigate the effects of nTiO₂ toxicity in cells by metabolic intervention.

The presence of polycyclic aromatic hydrocarbons (PAHs) in the fetal environment is a high-priority concern due to the fetus being more sensitive than adults to these ubiquitous xenobiotics. The aim of the present study was to compare the maternal and fetal serum levels of ΣPAHs and their effects on fetal growth in an industrial and an urban area in Southwest Iran. The industrial area was the petrochemical and gas area (PGA) of the Central District of Asaluyeh County and the urban area (UA) was the Central District of Bushehr County, Ninety-nine maternal serum (MS) and 99 cord serum (CS) samples from the PGA and 100 MS and 100 CS samples from the UA were collected during May 2018 to February 2019. The mean concentrations of ΣPAHs were significantly (p < 0.05) higher in the PGA than the UA in both MS (157.71 vs. 93.56 μg/L) and CS (155.28 vs. 93.19 μg/L) samples. Naphthalene (NAP) was the predominant PAH detected in all the studied samples. Significant negative associations were found between birth weight and anthracene (ANT) level in MS (β = −22.917, p = 0.032; weight decrement = 22.917 g for a 1 μg/L increase in ANT); head circumference and chrysene (CHR) level in MS (β = −0.206, p = 0.023; head circumference decrement = 0.206 cm for a 1 μg/L increase in CHR); and birth height and NAP level in CS (β = −0.20, p = 0.005; height decrement = 0.20 cm for a 1 μg/L increase in NAP). Maternal diet had a significant effect on the serum levels of PAHs. The results of this study showed that transmission of PAHs from mother to fetus through the cord blood is an important issue and mothers who live in industrial areas and consume PAH-containing foodstuffs, and their fetuses, are more at risk than those living in a non-industrial urban area.

China produces and consumes large quantities of brominated flame retardants (BFRs) as well as several other unregulated electronic waste recycling activities, causing high BFR concentrations in the natural environment. Thus, Traditional Chinese Medicines (TCMs) may be contaminated by legacy BFRs (e.g. polybrominated diphenyl ethers (PBDEs)) and emerging BFRs (eBFRs, such as decabromodiphenyl ethane (DBDPE)) during growth, processing, packaging, and transportation. Pheretima, which is a typical animal drug recorded in Chinese Pharmacopoeia, was used as an example to evaluate human exposure to BFRs through TCM intake. This study is the first to determine 25 PBDEs and 5 eBFRs in Pheretima and estimate the daily BFR intake via Pheretima-containing TCMs. Twenty-seven Shanghai Pheretima and fifty-one Guang Pheretima samples were collected between March and June 2019 in southeast China. High BFR detection frequencies were found in Pheretima, of which BDE-209 and DBDPE were the most predominant analytes. The total PBDE contents ranged from 73 pg/g to 8,725 pg/g, while that of the eBFRs varied between 115 pg/g and 2,824 pg/g. The profiles and abundances were found to be species- and origin-dependent. However, the traditional processing of Pheretima may reduce BFR residues. Based on the usual clinical doses of Pheretima and the available chronic oral reference doses of BDE-47, 99, 153, and 209, the mean (95th percentile) of the total hazard quotient was estimated to be 9.1 × 10⁻⁵ (2.7 × 10⁻⁴). Therefore, there is little risk related to BFR exposure for patients taking formulated Pheretima-containing TCMs. However, it is necessary to establish routine monitoring programs for the co-existence of pollutants in TCMs to perform a systematic and comprehensive risk assessment.

Children in urban environments are exposed to potential harmful elements (PHEs) through variable exposure media. Playing activities in outdoor playgrounds have been considered of high concern due to children's exposure to sand-bound PHEs through unintentional or intentional sand ingestion. Furthermore, the affinity of magnetic particles with dust-bound PHEs in playgrounds has been reported. In this study, playground sands (PG sands) from public playgrounds in the city of Thessaloniki, N. Greece were sampled and the levels, the contamination degree, oral bioaccessibility and exposure assessment of PHEs were evaluated. In addition, low-cost and fast magnetic measurements (i.e. mass specific magnetic susceptibility, χₗf) were explored as potential pollution and health risk proxies. Mineralogically, siliceous PG sands dominated, while morphologically angular magnetic particles and Fe-rich “spherules” of anthropogenic origin were revealed and verified by enhanced χₗf values. The average total elemental contents exhibited a descending order of Mn > Ba > Cr > Zn > Ni > Pb > Cu > Co > As > Sn > Bi > Cd, however only Cd, Bi, Pb, Cr, As and Zn were presented anthropogenically enhanced. Notable increase on PHEs levels and finer sand fractions were observed with continuous sand use. Anthropogenically derived elements (i.e. Cd and Pb with high Igₑₒ values) exhibited higher bioaccessible fractions in PG sands and considered easily soluble in gastric fluids through ingestion. However, increased risks were found for specific PHEs (especially Pb) only in a worst case exposure scenario of an intentional sand ingestion (pica disorder). Statistical analysis results revealed a linkage of anthropogenic components with sand-bound magnetic particles. Moreover, the recorded high affinity of Pb contents (in an enhanced magnetized sub-set of PG sands) and bioaccessible Cd fractions with χₗf provide a preliminary indication on the successful applicability of low-cost and fast magnetic measurements in high impacted playground environments.

Microplastics pollution in marine environments is concerning. Microplastics persist and accumulate in various sections of the ocean where they present opportunity for micropollutant accumulation and microbial colonisation. Even though biofilm formation on plastics was first reported in the 1970's, it is only in recent years were plastic associated biofilms have gained research attention. Plastic surfaces pose a problem as they are a niche ready for colonisation by diverse biofilm assemblages, composed of specific bacterial communities and putative pathogens prone to acquiring ARGs and resistance in the biofilm. However, the nature of antibiotic resistance on aquatic plastic debris is not yet fully understood and remains a concern. Given the inevitable increase of plastic production and waste generation, microplastics released into the environment may prove to be problematic. This review explores microplastic waste in the ocean and possible concerns that may arise from the presence of microplastics in conjunction with favourable conditions for the development and dispersal of antibiotic resistance in the ocean and food web.

Anthropogenic noise in the oceans is disturbing marine life. Among other groups, pelagic fish are likely to be affected by sound from human activities, but so far have received relatively little attention. Offshore wind farms have become numerous and will become even more abundant in the next decades. Wind farms can be interesting to pelagic fish due to food abundance or fisheries restrictions. At the same time, construction of wind farms involves high levels of anthropogenic noise, likely disturbing and/or deterring pelagic fish. Here, we investigated whether bottom-moored echosounders are a suitable tool for studying the effects of impulsive – intermittent, high-intensity – anthropogenic noise on pelagic fish around wind farms and we explored the possible nature of their responses. Three different wind farms along the Dutch and Belgian coast were examined, one with exposure to the passing by of an experimental seismic survey with a full-scale airgun array, one with pile driving activity in an adjacent wind farm construction site and one control site without exposure. Two bottom-moored echosounders were placed in each wind farm and recorded fish presence and behaviour before, during and after the exposures. The echosounders were successful in detecting variation in the number of fish schools and their behaviour. During the seismic survey exposure there were significantly fewer, but more cohesive, schools than before, whereas during pile driving fish swam shallower with more cohesive schools. However, the types and magnitudes of response patterns were also observed at the control site with no impulsive sound exposure. We therefore stress the need for thorough replication beyond single case studies, before we can conclude that impulsive sounds, from either seismic surveys or pile driving, are a disturbing factor for pelagic fish in otherwise attractive habitat around wind farms.

The on-going and extensive use of neonicotinoids occur in orchards. However, it is still unknown whether and how orchard management affects soil properties, especially the contents and structure of soil organic matter during orchard development, and their further influences on neonicotinoid persistence. Here, surface soil samples were collected from the citrus orchards with different cultivation ages (1, 10, 14, and 20 years), and their physicochemical properties were determined. Changes in the chemical structure of soil organic matter (SOM) were furtherly examined using solid-state CP/TOSS ¹³C NMR. Then, the sorption isotherms of imidacloprid in these soils were investigated. The sorption coefficient (Kd) of imidacloprid at Cₑ of 0.05 mg/L in the orchard soils increased by 19.4–23.3%, along a 20-year chronosequence of cultivation, which should be mainly ascribed to the increase of SOM. However, the organic carbon-normalized sorption coefficient (Kₒc, sorption per unit mass of OM) of imidacloprid declined with increasing cultivation ages. Moreover, the polar and aliphatic domains of SOM had a significantly positive relation to the Kₒc of imidacloprid, suggesting its key role in governing imidacloprid sorption. The results highlighted that reasonable management measures could be adopted to control the occurrence and fate of neonicotinoids in soils, mainly by affecting the content and quality of SOM.

In this study, water and sediment samples from the Jiaozhou Bay and surrounding rivers were collected to analyze the seasonal occurrence and allocation of 12 organophosphate esters (OPEs) and the associated ecological risk. The higher contamination of OPEs in the adjacent rivers indicated the impact of terrestrial input. Tris(1-chloropropan-2-yl) phosphate (TCIPP) was the predominant OPE in the four environmental sample groups investigated. The spatial distribution of OPEs in seawater varied greatly seasonally and was mainly affected by terrestrial input, with OPEs being redistributed under the influence of tidal currents. The partition coefficients (log Kₒc) of the OPEs were calculated, and their strong correlation with the log Kₒw (octanol-water) values suggested that the water-sediment allocation was significantly affected by hydrophobicity. The homologous relationships among the 7 OPEs with detection frequencies greater than 40% were identified by principal component analysis (PCA). The partial least squares regression (PLSR) model explicated that ∑OPEs cycling dynamics and principal controlling factors were dissimilar in the bay versus surrounding rivers. The risk quotient (RQ) faced by typical organisms in seawater and river water indicated that short-term OPEs exposure was safe for green algae, daphnia and fish. The organisms in rivers faced the higher ecological risk of OPEs in spring than in summer and winter. Therefore, the terrestrial transport of OPEs in spring should be controlled.

Because the pollutants produced by human activities have destroyed the ecological balance of natural water environment, and caused severe impact on human life safety and environmental security. Hence the task of water environment restoration is imminent. Metal-organic frameworks (MOFs), structured from organic ligands and inorganic metal ions, are notable for their outstanding crystallinity, diverse structures, large surface areas, adsorption performance, and excellent component tunability. The water stability of MOFs is a key requisite for their possible actual applications in separation, catalysis, adsorption, and other water environment remediation areas because it is necessary to safeguard the integrity of the material structure during utilization. In this article, we comprehensively review state-of-the-art research progress on the promising potential of MOFs as excellent nanomaterials to remove contaminants from the water environment. Firstly, the fundamental characteristics and preparation methods of several typical water-stable MOFs include UiO, MIL, and ZIF are introduced. Then, the removal property and mechanism of heavy metal ions, radionuclide contaminants, drugs, and organic dyes by different MOFs were compared. Finally, the application prospect of MOFs in pollutant remediation prospected. In this review, the synthesis methods and application in water pollutant removal are explored, which provide ways toward the effective use of water-stable MOFs in materials design and environmental remediation.