Identifying contamination sources of environmental media and revealing their changing trends over time is useful for regional contamination control and environmental improvements. Four sediment cores (S1−S4) were collected from the Shima River to determine lead (Pb) concentrations, geochemical fractions and isotopic compositions, as well as the geochronology of core S3. The results show that Pb concentrations decreased from the upper and middle reach sites (means: 57.6, 95.9, and 97.6 mg kg⁻¹, respectively) to the lower reach site (43.8 mg kg⁻¹), resulting in a minimal to moderate enrichment in the sediments; enrichment increased due to anthropogenic Pb inputs at the river middle reach site since the 1990s. Sediment Pb in the geochemical fractions followed a decreasing order of reducible (47.3%) > residual (37.8%) > oxidizable (11.2%) > acid-soluble fraction (3.68%), exhibiting high mobility, further verifying the anthropogenic inputs. A descending trend in the ²⁰⁶Pb/²⁰⁷Pb ratio of the top sediments was the result of anthropogenic activities. In the present study, coal combustion, which was the major anthropogenic Pb source determined by its isotopic composition, contributed significantly (means: 18.4–60.6%) to sediment Pb based on a three end-members model. Less of a contribution (0–10.6%) was derived from vehicle exhaust. The increasing trend in the coal contribution was in accordance with that of the coal consumption in the study area. These results suggest that Pb contamination resulting from coal combustion has grown to become a major environmental issue in the study area.

Five Descriptors (D) of Marine Strategy Framework Directive (MSFD): marine litter (D10), non-indigenous species (D2) and organic and inorganic pollutants (D8), were estimated in a coastal area of GSA 16 (Augusta harbour, Central Mediterranean Sea) in order to study their effects on the biodiversity (D1) of the benthic community D6) and to improve data for the MSFD. Investigation of plastic debris had led to the identification of 38 fragments divided into four categories, among which microplastics resulted as the most abundant. Six non-indigenous species, belonging to Polychaeta (Kirkegaardia dorsobranchialis, Notomastus aberans, Pista unibranchia, Pseudonereis anomala, Branchiomma bairdi) and Mollusca (Brachidontes pharaonis) were found. Biodiversity and benthic indices suggested a generalised, slightly disturbed ecological status. Anthracene, Zinc and Chrome were the most abundant chemical compounds in analysed sediments. Significant correlations were found between the abundance of trace elements vs biotic indices and between plastic debris vs biodiversity and benthic indices. This study represents the first report about the abundance of plastic debris and its relationship to contaminants and infauna in Augusta harbour. Our results can provide useful information for national and international laws and directives.

Herein, we utilize sequential extraction and high-throughput sequencing to investigate the effects of nanomaterial additives on As volatilization from flooded soils. We reveal that maximum volatilization is achieved in the fourth week and is followed by stabilization. The extent of volatilization decreased in the order of control > nano-zerovalent iron >40-nm hydroxyapatite > nano-Fe₃O₄ > 20-nm hydroxyapatite > multilayer graphene oxide > high-quality graphene oxide. The most abundant forms of As in soil corresponded to As-Fe and Al oxides. In soil with low levels of As pollution, the contents of these species increased after treatment with graphene oxides but decreased after treatment with other nanomaterials, with an opposite trend observed for soil with high levels of As pollution. The addition of nanomaterials influenced the activity of soil enzymes, e.g., hydroxyapatites affected the activities of urease and alkaline phosphatase, whereas graphene oxides significantly impacted that of peroxidase (P < 0.05). The addition of nanomaterials (which can potentially inhibit microbial growth) affected As levels by influencing the amount of As volatilized from polluted soil. Moreover, As volatilization, enzyme activity, and As speciation were observed to be mutually correlated (e.g., volatilization was negatively correlated to peroxidase activity and the contents of amorphous crystalline hydrous oxides of As-Fe and Al).

On-board emissions measurements were performed on a Handysize-class bulk carrier operating under real-world conditions. Emission factors (EFs) were determined for criteria pollutants such as NOₓ, CO, total hydrocarbons (THC), and PM; PM composition, including organic and elemental carbon (OC and EC), inorganic species, and a variety of organic compounds and VOC species (including alkanes, alkenes, single-ring aromatics, and oxygenated VOCs) were also analyzed. To investigate the impacts of engine type, fuel, and operating conditions on emissions, measurements were conducted on one main and one auxiliary engines using low- and high-sulfur fuels (LSF and HSF) under actual operating conditions, including at-berth, maneuvering, and cruising at different engine loads. OC was the most abundant PM component (contributing 45–65%), followed by sulfate (2–15%) and EC (1–20%). Compounds with 3 or 4 aromatic rings, including phenanthrene, fluoranthene, pyrene, and benzo[b+k]fluoranthene, dominated the particulate polycyclic aromatic hydrocarbons (PAHs) emitted from the ship, accounting for 69–89% of the total PAHs. Single-ring aromatics constituted 50–78% of the emitted VOCs and were dominated by toluene. In this study, switching from HSF (1.12% S) to LSF (0.38% S) reduced emitted PM by 12%, OC by 20%, sulfate by 71%, and particulate PAHs by 94%, but caused an increase in single-ring aromatics. The power-based EFs generally decreased with increasing engine loads. However, decreasing the ship engine load also reduced the vessel speed and, thus, decreased emissions over a given voyage distance. Herein, a Vessel Speed Reduction (VSR) from 11 to 8–9 knots decreased NOₓ and PM emissions by approximately 33% and 36%, respectively, and OC, EC, sulfate, and particulate PAHs in PM emissions by 34%, 83%, 29%, and 11%. These data can be used to minimize uncertainty in the emission factors used in ship emissions calculations.

Accurate measuring n-octanol/water partition coefficients (log Kₒw) of perfluoroalkyl carboxylic acids (PFCAs) using experimental approach has been proven to be very difficult due to their special properties. The ionizable carboxyl groups in PFCAs make their log Kₒw dependent on pH. In this study, the log Kₒw values of neutral species of PFCAs (C₄≤ₙ≤₁₄) were measured based on reversed-phase high-performance liquid chromatography (RP-HPLC) with the mobile phase pH varying in the range of 1.09–5.00. The relationship between log Kₒw and retention times was established using some reference compounds (including agrochemicals, polycyclic aromatic hydrocarbons) with known log Kₒw values, and then validated with alkyl fatty acids, which have similar chemical structures as PFCAs. The apparent log Kₒw (i.e., log Dₒw) of the C₄–₁₄ PFCAs were calculated based on their retention times using the established model, and they displayed a negative linear relationship with the mobile phase pH in the range of 1.09–4.00. Consequently, the log Dₒw values were converted to the corresponding log Kₒw values (1.05–7.19) based on the relationship of log Dₒw = log Kₒw + pKₐ – pH. The log Kₒw increased with perfluorinated carbon chain length with a greater rate for C₄ to C₅ PFCAs than for C₅–₁₄ PFCAs.

Coastal areas provide important ecosystem services and affect local tourism. However, these areas are also sensitive to coastal erosion. The purpose of this study was to simulate a landscape plan scenario to improve the value of ecosystem services. The Shinduri coastal area in South Korea which has important natural resources, such as coastal sand dunes and coastal forests. To simulate landscape changes, this study was conducted using system dynamics. The study progressed in three stages: first, an analysis of the landscape change behavior model of Shinduri in its current state and an evaluation of the value of ecosystem services was conducted. Second, a simulation was carried out by applying a coastal erosion scenario. Third, a simulation of landscape change was run, and the value of ecosystem services was estimated, with regard to afforestation, thinning, weeding and coastal sand dune restoration plan scenarios. The results were as follows: in the absence of disturbances, current landscape change models are stable, and the value of ecosystem services, which was $859,259 in 2014, has increased over time. However, the value of ecosystem services decreased when subjected to a coastal erosion scenario. The evaluation of value of ecosystem services under afforestation, thinning, weeding and coastal sand dune plan scenarios revealed an optimal landscape plan that focuses on a coastal sand dune restoration plan suggesting restoration of these dunes at a rate of 27.05 ha per year. When the coastal sand dune restoration plan is applied, the value of ecosystem services increases to $ 895,474 by 2054. The coastal sand dune restoration plan should prioritize the protection of the coastal sand dune area as component of the restoration of coastal ecological resources in the area. These findings could contribute to the ecological management and improvement of coastal ecosystem services.

Intermittent, fluctuating and pulsed contaminant discharges may result in organisms receiving highly variable toxicant exposures. This study investigated the toxicity of continuous and pulsed exposures of a complex, neutralised drainage water (NDW) and dissolved copper-spiked dilute NDW to the green alga, Pseudokirchneriella subcapitata. The effects of single pulses of between 1 and 48 h duration and continuous exposures (72 h) on algal growth rate inhibition were compared on a time-averaged concentration (TAC) basis. Algal growth rates generally recovered to control levels within 24–48 h of the pulse removal. Continuous exposures to NDW resulted in similar or marginally higher toxicity to the algae when compared to pulsed exposures of equivalent TAC (% NDW). The toxicity of the NDW was attributed mostly to the metals, with the major cations potentially causing effects that are both additive (direct toxicity) and antagonistic (lower bioavailability of trace metals). For dissolved copper in dilute NDW, the pulsed exposures caused slightly higher toxicity than continuous exposures of equivalent dissolved copper TAC, with much of the difference explained by differences in labile copper concentrations between treatments. The results indicate that water quality guideline values for toxicants derived from continuous chronic exposures may be relaxed for pulsed exposures by a factor related to the TAC with the intent to provide an adequately protective but not overly-conservative outcome. The study highlights the influence that natural water quality parameters such as water hardness and DOC can have metal speciation and toxicity, and indicates that these parameters are particularly important for site-specific water quality guideline value derivation where, on a TAC basis, pulsed exposures may be more toxic than continuous exposures typically used in guideline value derivation.

Cs-137 is considered to be the most significant anthropogenic contributor to human dose and presents a particularly difficult remediation challenge after a dispersal following nuclear incident. The Chernobyl Nuclear Power Plant meltdown in April 1986 represents the largest nuclear accident in history and released over 80 PBq of 137Cs into the environment. As a result, much of the land in close proximity to Chernobyl, which includes the Polessie State Radioecology Reserve in Belarus, remains highly contaminated with 137Cs to such an extent they remain uninhabitable. Whilst there is a broad scale understanding of the depositional patterns within and beyond the exclusion zone, detailed mapping of the distribution is often limited. New developments in mobile gamma spectrometry provide the opportunity to map the fallout of 137Cs and begin to reconstruct the depositional environment and the long-term behaviour of 137Cs in the environment. Here, full gamma spectrum analysis using algorithms based on the peak-valley ratio derived from Monte Carlo simulations are used to estimate the total 137Cs deposition and its depth distribution in the soil. The results revealed a pattern of 137Cs distribution consistent with the deposition occurring at a time of flooding, which is validated by review of satellite imagery acquired at similar times of the year. The results were also consistent with systematic burial of the fallout 137Cs by annual flooding events. These results were validated by sediment cores collected along a transect across the flood plain. The true merit of the approach was confirmed by exposing new insights into the spatial distribution and long term fate of 137Cs across the floodplain. Such systematic patterns of behaviour are likely to be fundamental to the understanding of the radioecological behaviour of 137Cs whilst also providing a tracer for quantifying the ecological controls on sediment movement and deposition at a landscape scale.

In order to study the distribution of pesticide residues in beekeeping matrices, samples of live in-hive worker honey bees (Apis mellifera), fresh stored pollen and beeswax were collected during 2016–2017 from 45 apiaries located in different landscape contexts in Spain. A total of 133 samples were screened for 63 pesticides or their degradation products to estimate the pesticide exposure to honey bee health through the calculation of the hazard quotient (HQ). The influence of the surrounding environment on the content of pesticides in pollen was assessed by comparing the concentrations of pesticide residues found in apiaries from intensive farming landscapes to those found in apiaries located in mountainous, grassland and urban contexts. Beeswax revealed high levels of miticides used in beekeeping such as coumaphos, chlorfenvinphos, fluvalinate and acrinathrin, which were detected in more than 75% of samples. Pollen was predominantly contaminated by miticides but also by insecticides used in agriculture such as chlorpyrifos and acetamiprid, which showed concentrations significantly higher in apiaries located in intensive farming contexts. Pesticides residues were less frequent and at lower concentrations in live honey bees. Beeswax showed the highest average hazard scores (HQ > 5000) to honey bees. Pollen samples contained the largest number of pesticide residues and relevant hazard (HQ > 50) to bees. Acrinathrin was the most important contributor to the hazard quotient scores in wax and pollen samples. The contributions of the pesticides dimethoate and chlorpyrifos to HQ were considered relevant in samples.

Millimetre-sized fragments have been documented in many fish species, but their transfer through food webs is still poorly understood. Here we quantified and described plastic fragments in the digestive tracts of 43 Easter Island flying fish (Cheilopogon rapanouiensis) and 50 yellowfin tunas (Thunnus albacares) from coastal waters around Rapa Nui (Easter Island) in the South Pacific subtropical gyre, and of fish preyed upon by T. albacares. Overall, seven C. rapanouiensis (16%) individuals had ingested microplastics, most of which resembled the common planktonic prey of the fish. One microplastic was found in the gut of a fish ingested by a tuna, which indicates that trophic transfer may occur between tuna and prey. A single T. albacares (2%) had ingested five mesoplastics (15.2–26.3 mm) that were probably not mistaken for prey items, but rather accidentally ingested during foraging on fish prey. The absence of microplastics in T. albacares suggests that such small particles, if transferred from the prey, do not accumulate in the relatively large digestive tract of large predators. On the other hand, larger plastic items may accumulate in the gut of tunas, to which they may induce deleterious effects that still need to be examined. However, only a small portion of the fish had ingested mesoplastics. The results of this study suggest that microplastic contamination is not an immediate threat to large predatory fish, such as T. albacares, along the coast of Easter Island within the South Pacific subtropical gyre.