In this study, 24 surface water samples were collected from Dongting Lake, China, in the wet and dry seasons, then the concentrations, composition profiles and spatio-seasonal variations of nine organophosphate triesters (OPEs) and five organophosphate diesters (Di-OPs) were determined. Significantly higher total OPE concentrations (∑OPEs) were observed in the wet season (49.5–148 ng L⁻¹) than in the dry season (5.00–45.7 ng L⁻¹) suggesting higher input via tributaries discharge as well as wet deposition in the studied region. Whereas lower levels of TnBP and (triphenyl phosphate (TPHP) in wet season reflected their possible degradation under solar irradiation. Comparable levels of total Di-OPs (∑Di-OPs) were found in the wet season (3.41–13.9 ng L⁻¹) and dry season (1.01–12.3 ng L⁻¹). Tri(2-chloroethyl) phosphate and tris(2-chloroisopropyl) phosphate were the main OPE components, while diphenyl phosphate, di-n-butyl phosphate and bis(1,3-dichloro-2-propyl) phosphate were the main Di-OP components. High levels of OPEs and Di-OPs were found in Datong Lake suggesting possible local emissions potentially related to fishery activity in the land-locked lake. Samples at river mouths to the lake also have higher levels of target OPEs and Di-OPs, the results disclosed obvious discharges from tributaries in Hunan Province. Negligible non-carcinogenic and carcinogenic risks were determined based on the measured concentrations in source waters. A limited ecological risk aquatic organisms in the Dongting Lake was identified, with most risk from TPHP.

One of the strategies to realize a nitrogen cycle society, we attempted to recover ammonium ions from industrial wastewater, especially sewage water with adsorbent materials. We have developed an adsorbent with high ammonium selectivity based on copper hexacyanoferrate and granulated it as pellets. Using a compact column system filled with this granule adsorbent, ammonium ions were recovered from sewage containing 1000–1500 mg-NH₄⁺/L ammonium ions. Despite the coexistence of many metal ions, the adsorbent selectively and stably adsorbed ammonium ions. Furthermore, it was shown that the saturated adsorbent can be regenerated by flowing a potassium ion solution through a column adsorbent to desorb ammonium ions. In other words, the column can be used repeatedly, and there was almost little deterioration in adsorption even after 250 cycles. In addition, it was shown that by increasing the number of stages of this column, it is possible to sufficiently reduce the ammonium in the adsorbent solution and recover the concentrated ammonium solution.

The existing limitations in analytical techniques for characterization and quantification of nanoscale plastic debris (NPD) in organisms hinder understanding of the parental and trophic transfer of NPD in organisms. Herein, we used iron oxide-doped polystyrene (PS) NPD (Fe-PS-NPD) of 270 nm and Europium (Eu)-doped PS-NPD (Eu-PS-NPD) of 640 nm to circumvent these limitations and to evaluate the influence of particle size on the trophic transfer of NPD along an algae-daphnids food chain and on the reproduction of daphnids fed with NPD-exposed algae. We used Fe and Eu as proxies for the Fe-PS-NPD and Eu-Ps-NPD, respectively. The algae cells (Pseudokirchinella subcapitata) were exposed to 4.8 × 10¹⁰ particles/L of Fe-PS-NPD or Eu-PS-NPD for 72 h. A high percentage (>60%) of the NPD was associated with algal cells. Only a small fraction (<11%) of the NPD, however, was transferred to daphnids fed for 21 days on the NPD-exposed algae. The uptake and trophic transfer of the 270 nm Fe-PS-NPD were higher than those for the 640 nm Eu-PS-NPD, indicating that smaller NPD are more likely to transfer along food chains. After exposure to Fe-PS-NPD, the time to first brood was prolonged and the number of neonates per adult significantly decreased compared to the control without any exposure and compared to daphnids exposed to the Eu-Ps-NPD. The offspring of daphnids exposed to Eu-PS-NPD through algae, showed a traceable concentration of Eu, suggesting that NPD are transferred from parents to offspring. We conclude that NPD can be transferred in food chains and caused reproductive toxicity as a function of NPD size. Studies with prolonged exposure and weathered NPD are endeavored to increase environmental realism of the impacts determined.

Titanium dioxide nanoparticles (TiO₂NPs) application in variety of commercial products would likely release these NPs into the environment. The interaction of TiO₂NPs with terrestrial plants upon uptake can disturb plants functional traits and can also transfer to the food chain members. In this study, we investigated the impact of TiO₂NPs on wheat (Triticum aestivum L.) plants functional traits, primary macronutrients assimilation, and change in the profile of bio-macromolecule. Moreover, the mechanism of biochar-TiO₂NPs interaction, immobilization, and tissue accumulation to cell translocation of NPs in plants was also explored. The results indicated that the contents of Ti in wheat tissues was reduced about 3-fold and the Ti transfer rate (per day) was reduced about 2 fold at the 1000 mg L⁻¹ exposure level of TiO₂NPs in biochar amended exposure medium. Transmission electron microscopy (TEM) with elemental mapping confirmed that Ti concentrated in plant tissues in nano-form. The interactive effect of TiO₂NPs + biochar amendment on photosynthesis related and gas exchange traits was observed at relatively low TiO₂NPs exposure level (200 mg L⁻¹), which induced the positive impact on wheat plants proliferation. TiO₂NPs alone exposure to wheat also modified the plant’s bio-macromolecules profile with the reduction in the assimilation of primary macronutrients, which could affect the food crop nutritional value and quality. X-ray photoelectron spectroscopy (XPS) chemical analysis of biochar + TiO₂NPs showed an additional peak, which indicated the binding interaction of NPs with biochar. Moreover, Fourier-transform infrared (FTIR) spectroscopy confirmed that the biochar carboxyl group is the main functionality involved in the bonding process with TiO₂NPs. These findings will help for a mechanistic understanding of the role of biochar in the reduction of NPs bioavailability to primary producers of the terrestrial environment.

This study investigated the polycyclic aromatic hydrocarbons (PAHs) occurrence, and their impact on the microbial community and PAH-degrading genera and genes in the Knysna Estuary of South Africa. The results reveal that the estuary exhibits low PAH levels (114.1–356.0 ng g⁻¹). Ignavibacteriae and Deferribacteres, as well as Proteobacteria and Bacteroidetes, are keystone phyla. Among measured environmental factors, total organic carbon (TOC), nutrients such as nitrite and nitrate, metals as Al, Cr, Cu, Ni, Pb and Zn, and environmental properties (pH and salinity) are primary contributors to structuring the bacterial community assemblage. The abundance of alpha subunit genes of the PAH-ring hydroxylating dioxygenases (PAH-RHDα) of Gram-negative bacteria lies in the range of (2.0–4.2) × 10⁵ copies g⁻¹, while that of Gram-positive bacteria ranges from 3.0 × 10⁵ to 1.3 × 10⁷ copies g⁻¹. The PAH-degrading bacteria account for up to 0.1% of the bacterial community and respond mainly to nitrate, TOC and salinity, while PAHs at low concentration are not significant influencing factors. PAH degraders such as Xanthomonadales, Pseudomonas, and Mycobacterium, which play a central role in PAH-metabolization coupled with other biogeochemical processes (e.g. iron cycling), may contribute to maintaining a healthy estuarine ecosystem. These results are important for developing appropriate utilization and protection strategies for pristine estuaries worldwide.

Cetaceans accumulate persistent and toxic substances such as polybrominated diphenyl ethers in their tissue. PBDEs are ubiquitous in marine environments, and their exposure to mammals is linked to numerous health effects such as endocrine disruption, neurotoxicity, carcinogenicity, and fetal toxicity. However, the toxicological effects and mechanism of toxicity in cetaceans remains poorly understood. The effects of BDE-47 (0.1–0.5 μg mL⁻¹), BDE-100 (0.1–0.5 μg mL⁻¹), and BDE-209 (0.25–1.0 μg mL⁻¹) exposure on cell viability, oxidative stress, mitochondrial structure, and apoptosis were evaluated using a recently established pantropical spotted dolphin (Stenella attenuata) skin fibroblast cell line (PSD-LWHT) as an in vitro model. However, the production of reactive oxygen species (ROS) increased following exposure to 1.0 μg mL⁻¹ PBDE while superoxide anion, hydroxyl radicals, and inducible nitric oxide increased in a dose-dependent manner. At 0.5–1.0 μg mL⁻¹, PBDEs significantly reduced the mitochondrial membrane potential. In addition, exposure to BDE-47 and -209 significantly affected mitochondrial structure as well as cell signaling and transduction compared to BDE-100. Although PBDE exposure did not affect cell viability, a significant increase in cell apoptosis markers (Bcl2 and caspase-9) was observed. This study demonstrated that BDE-47, -100, and −209 congeners might cause cytotoxic and genotoxic effects as they play a crucial role in the dysregulation of oxidative stress and alteration of mitochondrial and cell membrane structure and activity in the fibroblast cells. Hence, these results suggest that PBDEs might have adverse health effects on cetaceans inhabiting contaminated marine environments.

Polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/F) emission is one of main concerns for the secondary pollution of municipal solid waste incinerators (MSWI). For timely response to emission, 1,2,4-trichlorobenzene (1,2,4-TrClBz) as dioxin indicator can be monitored via online measurement techniques. In this study, multi-walled carbon nanotubes (MWCNTs) were investigated for their suitability as a 1,2,4-TrClBz sorbent for MSWI stack gas analysis. The tests include, batch adsorption, continuous adsorption-desorption of 1,2,4-TrClBz via thermal desorption coupled with gas chromatography (TD-GC-ECD), temperature and concentration stability of MWCNTs, and adsorption performance of the system. Thermogravimetric/derivative thermogravimetric (TGA/DTG) analysis reveals that MWCNTs has higher capacity in terms of weight loss (14.34%) to adsorb 1,2,4-TrClBz compared to Tenax TA (9.46%) and also shows fast desorption of adsorbate at temperature of 87 °C compared to Tenax TA (130 °C). Interestingly, carbon nanotubes and Tenax TA gave almost similar adsorption-desorption response, and from TD-GC-ECD analysis it was found that with increasing mass flow of 1,2,4-TrClBz (7.42 × 10⁻⁶ - 44.52 × 10⁻⁶ mg ml⁻¹) through sorbent traps, average peak areas increased from 2.86 ± 0.02 to 13.54 ± 0.26 for MWCNTs and 2.89 ± 0.02 to 13.38 ± 0.12 for Tenax TA, respectively. The stability of MWCNTs for temperature was 400 °C and for concentration of 1,2,4-TrClBz was 50 ppbv. However, regeneration of sorbent at 100 ppbv (1,2,4-TrClBz) was not possible. TD-GC-ECD system showed high adsorption performance with 3.86% and 3.59% relative standard deviation at 250 °C and 300 °C, respectively. Further Fourier Transform Infrared Spectroscopy (FTIR) analysis confirmed that adsorbate can be fully desorbed at 300 °C.

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.

Volatile Organic Compound (VOC) analysis is usually applied in pollution assessment by checking for toxic or harmful volatile compounds in air, water and soil samples. In this study, exogenous VOCs and their derivatives, metabolized by cells, were valued into specific body fluids. In particular, the VOC profiles of blood, urine and human semen samples collected from young men living in two high pollution areas in Italy, i.e. Land of Fires and Valley of Sacco River, were fingerprinted. The analysis is based on Headspace Solid Phase MicroExtraction (HS-SPME) followed by Gas Chromatography-Mass Spectrometric detection (GC-MS). The volatile composition of the three body fluids showed that some VOCs are in common between blood, urine and human semen samples, whereas others are present only in a body fluid. Some compounds, as well as also some chemical classes show a higher affinity for a specific body fluid. Statistical analysis allowed to discriminate the two contaminated areas and identify those compounds which significantly contribute to the two areas classification. Some of these compounds are toxic and found prevalently in Valley of Sacco River samples, correspondingly to sperm analysis results for young men living in this zona worse than those living in Land of Fires.

The present study is a literature-based analysis investigating occurrence and the possible consequences of polycyclic aromatic hydrocarbons (PAH) in marine protected areas (MPAs) of Latin America and Caribbean. The approach using overlapping of georeferenced MPA polygons with data compiled from peer-reviewed literature, published during the last 15 years, showed 341 records of PAH in 9 countries. PAH was reported to occur within the boundaries of 36 MPAs located in Argentina, Brazil, Colombia, Mexico, Nicaragua and Uruguay. According to quality guidelines, low to moderate impacts are expected in MPAs categorized in different management classes. Considering sediment samples, 13% of the records presented concentrations enough to cause occasional toxicity. Such level of risk was also seen in Ramsar sites and in Amazonian MPAs. In addition, based on concentrations reported in biota, occasional deleterious effects on organisms from Biosphere Reserves might occur. Diagnostic ratios pointed out petrogenic and pyrolytic processes as PAH predominant sources, and were mainly attributed to the proximity to ports, industries and urban areas. MPAs located in the vicinity of impact-generating areas may be under threat and require government attention and action, mainly through implementation of contamination monitoring programs.