To explore the utility of artificial sweeteners (Acesulfame: ACE; sucralose: SUC; saccharin: SAC; cyclamate: CYC) as molecular markers and to establish a historical benchmark of the water pollution status in the 2010 decade, 272 surface water samples, including river water, sewage, and livestock wastewater, were collected from African (Ghana, Kenya, Mozambique, South Africa), Asian (Vietnam, Indonesia, Thailand, Philippines, Cambodia, Malaysia, India, and Japan) and Middle Eastern (Iran and Lebanon) countries during 2010–2019 and were analyzed for the artificial sweeteners by high performance liquid chromatograph with tandem mass spectrometer coupled with online solid-phase extractor. ACE was most frequently detected (87% of the samples) due to its widespread use and lower detection limit (2 ng/L). SUC was less frequently detected (51%) because of its lower sensitivity and detection limit of 100 ng/L, and less widespread use in some low-income countries, probably due to its higher price. SAC and/or CYC were abundant in surface waters of most countries, despite their biodegradable nature. This was ascribed to intensive usage of SAC and CYC and extensive inputs of untreated sewage to rivers due to limited installation of sewage treatment systems. Concentrations of the sweeteners were higher in urbanized rivers (~1 μg/L to ~100 μg/L) than those in corresponding suburban and rural sites, reflecting spatial patterns of sewage inputs. Furthermore, concentrations of the sweeteners were positively correlated with those of linear alkylbenzenes (LABs) for all countries except Malaysia. These results confirm the utility of artificial sweeteners as indicators of sewage inputs. SAC and CYC could be indicators of untreated sewage inputs. ACE has proved to be the most sensitive and reliable marker to assess inputs of sewage, i.e., both treated and untreated, to surface waters. However, ACE concentrations in secondary effluents and receiving waters in Tokyo decreased two orders of magnitude from 2011 to 2019, while sucralose did not show such a marked decrease. This is probably due to the upgrading of activated sludge treatment, i.e., introducing anaerobic-anoxic-oxic (A2O) treatment and resultant higher removal of ACE. Therefore, the measurement of multiple markers, including SUC, is recommended for long-term monitoring.

There has been little research on the pollution of drifted debris in terrestrial ecosystems in coastal areas compared to research focusing on aquatic environment and aquatic organisms. In this study, two species of terrestrial hermit crabs and three species of coastal plants were collected from a polluted site (Nita) and a control site (Furuzamami) in Zamami Island, Okinawa, and analysed to evaluate element contamination in order to evaluate the risk of drifted debris as a source of trace element pollution in terrestrial ecosystems. In both species of terrestrial hermit crabs, Cd was detected at significantly higher concentrations in both the muscle and hepatopancreas of individuals collected from the polluted site. In addition, Pb, often contained in polyvinyl chloride products along with Cd, had higher concentrations in the hepatopancreas of terrestrial hermit crabs in the contaminated site than in the control site. Among the three coastal plants, Pandanus tectorius was the most sensitive to trace element pollution via drifted debris. In general, plants tended to accumulate elements in accordance with their leachability from plastics. This result suggested that trace elements, leaching from drifted debris to soils, accumulated in the plants. These results indicate that leaching rates from drifted plastics have a greater effect on element accumulation in plants than in terrestrial hermit crabs. The degree of influence of the leaching rate of elements from drifting debris differed between the hermit crabs and plants. In addition, the accumulation of elements that were easily adsorbed by plastics was observed in each species. In the environment, drifted debris is potentially hazardous as a medium of contamination to organisms, as it adsorbs various elements during their transport in the ocean.

Organohalogen compounds (OHCs) are persistent environmental contaminants that can pose health risks to both humans and animals. This study aimed to assess the contamination levels of OHCs in dry and wet pet foods sold in Japan and evaluate their potential health implications for companion animals.

Results indicated that OHCs were widely present in all types of pet foods analyzed, with dry foods generally exhibiting higher contamination levels than wet foods. Polychlorinated biphenyls (PCBs), dichlorodiphenyltrichloroethanes (DDTs), chlordanes (CHLs), hexachlorocyclohexanes (HCHs), polybrominated diphenyl ethers (PBDEs), and decabromodiphenyl ethane (DBDPE) were detected in varying concentrations across different pet food types. The contamination profiles differed based on the raw materials and country of origin. Estimations of OHC concentrations from raw materials highlighted potential contamination sources beyond ingredient-related contributions, including the manufacturing process.

Moreover, risk assessments were conducted to evaluate the potential health risks posed by OHCs exposure through pet food consumption. While PBDEs, CHLs, and DDTs generally posed low risks, PCBs were found to be of concern, particularly in pet foods containing salmon as a primary ingredient. The results underscored the importance of considering the type of pet food and its raw materials when assessing exposure risks.

Three monitoring methods, including manual monitoring methods based on active and passive samplings and an automatic active monitoring method, for atmospheric mercury (Hg) concentrations are recommended in the guidance on monitoring Hg based on Article 22 of the Minamata Convention on Mercury, which entered into force in 2017. However, among these methods, the dataset obtained by manual monitoring based on active sampling and automatic active monitoring has not yet been verified. Parallel observations using these two methods were conducted in one month for each season from May 2021 to February 2022 at urban and rural sites in Japan. The main objective of this study was to evaluate the comparability of the observations obtained using the two methods. Because the sampling duration of the manual monitoring method based on active sampling using the Japanese monitoring network was 24 h, the data on the daily mean concentrations of atmospheric Hg obtained by both methods were compared, and their consistency was evaluated using t-test, correlation analysis, and Bland–Altman analysis.

The observation values obtained by the two methods were consistent (correlation coefficients=0.99 or higher) in all seasons, despite the large seasonal variation in meteorological conditions, and the unpaired t-test indicated that there were no differences between them in each season. Moreover, the Bland–Altman analysis showed that more than 96% of the data points were found to be within the 95% limit of agreement. Therefore, the manual monitoring method based on active sampling used in this study was in better agreement with the automatic active monitoring method. These results indicate that the data obtained by both methods are comparable. Additionally, manual monitoring based on active sampling can be used to build mercury monitoring networks at a lower cost than automatic active monitoring. Overall, the data obtained by both methods were proven to be beneficial for the effectiveness evaluation of the Minamata Convention.

The Karnaphuli River in Bangladesh, a lifeline for socio-economic activities, plays a crucial role by providing a considerable water supply. However, the aquatic environment is under threat from contamination originating from several sources such as industrial wastewater discharge, maritime operations, wastages from garments and leather industries, fertilizers industries, and the discharge of urban runoff. This study revealed the total petroleum hydrocarbon contamination of the Karnaphuli River. This study delves into the total petroleum hydrocarbon concentrations at several key points along the Karnaphuli River. Near the Amanat Shah Bridge, the total petroleum hydrocarbon level is at 29.70 mg/L, whereas it spikes to 84.67 mg/L in Chaktai Khal, indicating substantial variability across different locations. Mahesh Khal registers a total petroleum hydrocarbon concentration of 52.07 mg/L, followed by 31.09 mg/L in Sadar Ghat, 70.04 mg/L in Khal No 10, and 31.87 mg/L in the KAFCO outfall. These findings illustrate the pervasive nature of total petroleum hydrocarbon contamination throughout the river, thereby posing a grave threat to its ecological integrity and the well-being of communities reliant on it. Comparative analysis with a previous study spanning an 18-year interval unveils a decline in total petroleum hydrocarbon concentrations, hinting at potential improvement in environmental conditions. Although this trend offers a glimmer of hope, it underscores the persistent need for vigilant monitoring and concerted efforts to curtail pollution sources. By elucidating the evolving landscape of total petroleum hydrocarbon contamination in the Karnaphuli River, this study furnishes invaluable insights into its environmental implications and paves a way for informed decision-making in environmental management.

In this paper, literature from the last decade concerning the environmental levels of polychlorinated biphenyls (PCBs) in Africa is reviewed. Although data to determine general trends of PCBs across African countries were insufficient, high levels were observed in environmental and biological samples from some urban and industrial areas near electronic waste (e-waste) sites in Ghana, South Africa and Nigeria, in comparison to those in rural settings. Notably, atmospheric PCB concentrations showed a slow rate of decrease, particularly in a 10-year monitoring program (2008–2019), in which PCB levels ranged from 0.5 to 37.7 pg/m³, whereas more rapid decreases were observed in other areas globally. PCB levels in plastic resin pellets, which reflect pollution in coastal waters, in some African countries, namely, Tunisia and Senegal (554–3,384 ng/g-pellet, respectively), were comparable with, or slightly higher than, those in developed countries, i.e., the United States and France (178 and 2,230 ng/g-pellet, respectively). Nevertheless, due to inconsistent monitoring methods and limited data availability, temporal trends were still unclear. Improperly disposed PCB-containing equipment, like electrical transformers and capacitors, informal recycling and open burning of e-waste are significant contributors of PCBs in Africa. Even though there is no known PCB production in the region, the contamination levels mirror those in historically heavy-use areas, largely due to electrical equipment and inadequate e-waste handling practices. The understanding of temporal trends is hindered by the current gaps in data, which highlights that comprehensive monitoring and effective enforcement of global treaties such as the Stockholm Convention and the Basel Convention are urgently needed. To understand better and address the pervasive impact of PCBs in Africa, this review calls for sustained monitoring with follow-up intervals.

We measured Cs-137 concentrations in persimmon and yuzu (citron) fruits within a non-decontaminated biotope in Saitama Prefecture, which was affected by the Fukushima Daiichi Nuclear Power Plant (FDNPP) incident in 2011, spanning from 2011 to 2019. In 2011, the Cs-137 concentration in yuzus was five times higher than that in persimmons. In 2019, the Cs-137 concentrations in the two fruits were almost the same. Additionally, these values were nearly equal to the yuzus collected in Fukushima Prefecture before the FDNPP accident occurred. The effective half-lives of Cs-137 calculated based on the survey results were 380 days and 310 days for persimmons and yuzus, respectively.

The findings indicated that the Cs-137 concentration in fruits in non-decontaminated areas decreased faster than predicted by the physical half-life of Cs-137, which is 30 years.

Crude oil is a cornerstone of the American energy sector, particularly vital for transportation and plastic manufacturing industries. This study investigates the environmental impacts of the oil industry, focusing on carcinogenic emissions from oil refineries. Using data from the Environmental Protection Agency’s Toxic Release Inventory and the Energy Information Administration’s refinery capacity reports, Kendall rank correlation and regression analyses examine the relationship between refinery capacity and emissions of benzene, ethylbenzene, naphthalene and polycyclic aromatic compounds from 2010 to 2022. The analysis revealed significant findings: benzene emissions in Wyoming showed a statistically significant negative correlation with refinery capacity (τ=−0.49, p<0.05), suggesting that increased capacity correlates with lower benzene emissions. Ethylbenzene emissions in Alaska (τ=0.61, p<0.05) and Texas (τ=0.46, p<0.05) were positively correlated with capacity, indicating that higher production is associated with increased emissions. Naphthalene emissions display mixed results, with a significant positive correlation in Alaska (τ=0.63, p<0.05) and a significant negative correlation in California (τ=−0.50, p<0.05). R-squared values for these relationships suggest moderate explanatory power, such as 0.25 for benzene in Wyoming and 0.19 for ethylbenzene in Alaska. These findings indicate that although regulatory measures and technological advancements have reduced emissions over time, certain carcinogens still pose challenges as production capacity increases. The study underscores the need for stronger regulations and sustainable practices in oil refining to address the ongoing risks to public health and environmental sustainability.

The suppression effect of fertilizers on heavy metal (HM) stress in aquatic plants was studied using the probe beam deflection/fluorescence quenching method. Egeria densa Planchon, Cu²⁺, and HYPONEX were used as model aquatic plants, HM ions, and fertilizers, respectively. The model aquatic plant was cultured in mixture solutions of 10⁻⁶ M Cu²⁺ and HYPONEX with different dilution ratios containing a fluorescent probe of 10⁻⁶ M Ru (II) complex (Tris (2,2’-bipyridyl) ruthenium (II) chloride). Change trends in both DO concentration and probe beam deflection with time at vicinities of within micrometers from the aquatic plant leaf surface were monitored in real time during both respiration and photosynthesis processes. The experimental results showed that the fertilizer HYPONEX suppressed the HM stress in aquatic plants caused by 10⁻⁶ M Cu²⁺. The lower the dilution ratio or the higher the concentration of the fertilizer, the greater the suppression of HM stress in aquatic plants. Additionally, the suppression of HM stress by the fertilizer during respiration appears to be more remarkable than that during photosynthesis.

The peak separation of all 136 tetra- to octa-chlorinated dibenzo-p-dioxins and dibenzofurans on two types of 50% phenyl methyl siloxane gas chromatography columns, DB-17ms and VF-17ms, is presented. Four congeners of the seventeen 2,3,7,8-congeners, 2,3,7,8-TeCDD, 1,2,3,7,8-PeCDD, 2,3,7,8-TeCDF, and 1,2,3,4,7,8-HxCDF, were not separated clearly on DB-17ms. On VF-17ms, 2,3,7,8-TeCDD, 2,3,7,8-TeCDF, 1,2,3,7,8-PeCDF, and 1,2,3,6,7,8-HxCDF were not clearly separated. The other 2,3,7,8-congeners showed good separation on both columns. Therefore, the concentrations of all seventeen 2,3,7,8-congeners can be obtained by combining the measurement results from DB-17ms or VF-17ms with those from DB-5ms or similar columns.

The use of pesticides in modern agriculture became inevitable owing to improvements in crop protection and yield, whereas their residues in crops and other non-target environmental matrices remain matters of health concern. Therefore, this study is conducted to estimate pesticide contamination in food crops cultivated on floodplains of some rivers in Ekiti State, Southwest Nigeria, and their possible health risk. Soil samples were collected from the farms at 5, 25 and 45 m perpendicular to the river at upper, middle and lower courses of the river while crops sample appropriates were taken randomly from the farms. Samples of soil and food crops taken were subjected to laboratory treatments before they were analysed for organochlorine pesticides using standard procedures. The total soil OCPs range (μg/kg) at Irintan, Omi-Eye and Egbigbu floodplains were 7.50–9.28, 8.72–9.94 and 7.33–9.21, respectively, whereas total crops OCPs range (μg/kg) at Irintan, Omi-Eye and Egbigbu were 21.35–41.75, 12.05–51.89 and 19.42–107.48, respectively. The risk estimate of food crops consumption from the floodplains indicated that there may not be health risk associated with their consumption because the estimated daily intake was relatively lower than the standard reference dose and hazard index was less than one. However, the recent use of banned organochlorine pesticides was given by the ratio of β/α+γ benzene hexachloride residues values, which were greater than 0.5 in soil samples at the studied farms. Consequently, this should be a concern to the international community; this underscores the need for a stricter government regulation in line with United Nations’ safeguard for environment.