Climate change and environmental concentrations of POPs: A review

Spatiotemporal distribution and inter-media transfer of polycyclic aromatic hydrocarbons in Shanghai, China: Historical patterns and future trends

Polycyclic Aromatic Hydrocarbons (PAHs) represent pervasive pollutants, posing health risks in urban environments. It is essential to comprehend the spatiotemporal distributions, composition profiles, and inter-media transfer processes of PAHs in various environmental compartments, influenced by both natural changes and anthropogenic activities. This study integrates historical and future spatiotemporally changing environmental parameters, including climate data, GDP, population data, land-use types, and hydrological variables, into the Multimedia Urban Model (MUM). This integration enables the simulation of spatiotemporal distributions and inter-media transfer fluxes of PAHs among six different media from the 2010s to the 2100s under two distinct Shared Socio-economic Pathways (SSP) scenarios in the megacity of Shanghai, China. The MUM model, featuring diverse gridded parameters, effectively captures PAH concentrations and movement across environmental compartments. Results indicate a decreasing trend in PAHs concentrations in the 2100s compared to the 2010s, with PAH concentrations in water, sediment, vegetation, and organic film covering impermeable surfaces under the SSP3-7.0 scenario higher than those of the SSP1-2.6 scenario. Low molecular weight PAHs dominate in the sediment, water, and air, whereas high molecular weight PAHs prevail in the organic film, vegetation, and soil. Sediment and soil serve as the predominant sinks for PAHs. The primary transport processes for PAH movement include air-film, air-soil, film-water, soil-air, and water-air. Almost all transfer fluxes exhibit a declining trend in future periods except for the air-film transport pathway. The principal input and removal routes for PAHs in Shanghai involve the advection of air and water. The study provides essential insights into the environmental behavior of PAHs and informs targeted pollution control in Shanghai. Additionally, it serves as a technical reference for similar pollution prediction research.

Environmental contaminants in Arctic human populations: Trends over 30 years

INTRODUCTION

Arctic Monitoring and Assessment Programme (AMAP) monitors persistent organic pollutant (POP) levels in the Arctic populations and assesses health effects related to exposure to them. Many internationally regulated POPs persist in humans and biota, while new Emerging Contaminants of Arctic Concern (ECAC), many of which are unregulated, present additional challenges. Biomonitoring offers valuable insights into temporal trends within human matrices, revealing critical information not only about the efficacy of international regulations but also serving as an early warning system for exposure and risks for human health.

METHODS

Data analyzed in this study is aggregated data presented in the AMAP Human Health in the Arctic assessments, which provide data on contaminant concentrations measured in human matrices from adults, and children across various population studies conducted in the Arctic since the 1980 s. Linear regression analyses were used to assess trends of various POPs including organochlorine (OCPs), polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and per- and polyfluoroalkyl substances (PFAS), measured over time from the Arctic populations in Finland, Norway, Sweden, Denmark, Iceland, Canada and Alaska (USA).

RESULTS

Overall, decreasing trends were observed for PCBs and OCPs. Regulated PFAS showed decreasing trends, but increasing trends were observed for unregulated PFAS in certain populations. PBDEs showed decreasing or inconsistent trends in certain Arctic populations.

CONCLUSIONS

Decreasing trends are observed for legacy POPs, but the trends for new emerging contaminants are inconsistent. More focus is needed on biomonitoring the new emerging contaminants of concern in the Arctic and their implications on human health.

Temperature influence on the sensitivity of Artemia franciscana to globally used pesticides - Oxyfluorfen and copper

Climate change further the world's human population increase is a mainstream political issue, and it's critical to search for solutions to produce enough food to feed everyone. Pesticides and fertilizers have been used as an easy solution to prevent pests and increase food production. Nevertheless, their overuse has dangerous effects on the ecosystems and communities. Oxyfluorfen (Oxy) and copper (Cu) based formulations are used as pesticides and widely applied on agricultural fields for crop protection. However, they have shown negative effects on non-target species. So, this work proposes to: a)determine the lethal concentration of Oxy and Cu to the zooplankton, Artemia franciscana, at different temperatures (15 °C, 20 °C and 25 °C); b)understand the biochemical impacts of these chemicals at the different temperatures scenarios, on A. franciscana and c)evaluate the impact of the climate changes, particularly the temperature increase, on this species sensitivity to the tested pesticides. Acute and sub-lethal bioassays with Oxy and Cu were performed at different temperatures to determine the lethal concentration of each chemical and to understand the effects of the compounds at different temperatures on the biochemical profiles of A. franciscana. Results showed an increase in chemicals toxicity with the temperature, and Oxy was revealed to be more noxious to A. franciscana than Cu; at a biochemical level, significant differences were observed among temperatures, with the biggest differences between the organisms exposed to 15 °C and 25 °C. Overall, a decrease in fatty acids (FA) and sugars was observed with the increase in Cu and oxyfluorfen concentrations. Different trends were observed with temperature increase, with FA increase in the organisms exposed to Cu and the opposite was observed in the ones exposed to oxyfluorfen. Sugar content decreases in the organisms exposed to oxyfluorfen with temperature increase and showed a non-linear behaviour in the ones exposed to Control and Cu treatments.

Contamination of aquatic ecosystems by persistent organic pollutants (POPs) originating from landfills in Canada and the United States: A rapid scoping review

Persistent organic pollutants (POPs) are organic chemical substances that threaten human health and the planet's ecosystems due to their toxicity and their ability to remain intact for a long time, wide distribution throughout the environment, and accumulation and magnification in living organisms through the food chain. Discarded products from landfills and dumpsites are potential sources of POPs due to their persistence for several decades and constant release to surrounding environment. POPs in aquatic systems signal input predominantly from landfills, wastewater treatment plants, sewage, and urban runoff, suggesting a research gap to guide policies to address these unabated releases. This scoping review aims to rapidly identify the key concepts underpinning the containment, translation, and migration of POPs in Canadian and US landfill leachate. The review targeted multidisciplinary perspectives on the topic and spanned forensic biology, environmental sciences, chemistry, and geology. Contaminated municipal solid waste (MSW) landfill characteristics, as reported by government agencies in Canada and the US, were synthesized and harmonized to illustrate the geographical scope of MSW landfills releasing POPs into the surrounding environment. The knowledge and data gaps summarized in this study highlight the need to address the inadvertent release of POPs from Canadian and US landfills, particularly in consideration of dated and degrading landfill infrastructure, the proximity of marginalized people, and the implications of climate change on the countries' more vulnerable landscapes. This review is applicable to the development of future studies that aim to guide environmental protective policies.

Models for predicting vehicle emissions: A comprehensive review

Air pollution is a primary concern, causing around 7 million premature deaths annually, with traffic-related sources contributing 23 %-45 % of emissions. While several studies have surveyed vehicle emission models, they are either outdated or focus on specific data-driven models. This paper systematically reviews vehicle emission prediction models, comparing traditional approaches with data-driven emission models. The traditional emission models can be divided into average-speed, modal, and other models, noting their reliance on empirical assumptions and parameters that may not be universally applicable. In contrast, we delve into data-driven models utilizing dynamometer and on-road test data for time-series and spatial-temporal predictions. The application of these models is discussed across various scenarios, highlighting the progress and gap. We observed that traditional models, primarily estimating total traffic emissions in study regions, lack micro-level detail crucial for tailored decisions. The direct link between road emission model accuracy and input data quality poses challenges in disaggregating on-road vehicle emission inventories. Due to unique transportation instruments, traffic fleet components, and patterns, exploring the effects of emission-reduction policies in specific cities or regions is urgent. Vehicle characteristics, environmental conditions, traffic scenarios, and prediction scales are common effect factors, while instantaneous driving profiles prove effective in model calibration. In data-driven models, ANN outperforms in estimating emissions and performance of low-power diesel engines with errors not exceeding 5 %. However, no single data-driven method performed excellently in predicting all pollutants. Besides, integrated methods utilizing LSTM, GRU, and RNN outperform individual models. To enhance prediction accuracy considering the inherent connectivity of road networks and spatiotemporal variation patterns of vehicle emissions, GCN is an emerging approach for capturing spatial-temporal relationships based on remote sensing data. Moreover, limited data-driven studies have been performed to forecast particle matter emissions, the main contributors to urban pollution, calling for more attention for future research.

Temporal Trends of Great Lakes Legacy Contaminants: Ecological and Biological Considerations Applying the Age-Trend Model

The USEPA Great Lakes Fish Monitoring and Surveillance Program (GLFMSP) has been monitoring top predator lake trout and walleye contaminant concentrations since the early 1970s. Our research revealed that select legacy contaminant groups (∑PCBs, ∑DDTs, ∑chlordanes, and ∑5PBDEs) have similar t1/2 and k2 values across the Great Lakes, with the exception of both Lake Erie sites and the Lake Superior─Keweenaw Point site. The slower halving times determined at both Lake Erie sites are consistent with legacy contaminant remobilization due to extreme weather climate effects and past remedial actions on the Detroit River, whereas the Lake Superior─Keweenaw Point site demonstrates contaminant halving times approaching the exponential minimum. Overall, Great Lakes select contaminant groupings have decreased between 25.8 and 97.9% since 2004. An age-normalized Great Lakes Contaminant Index (GLCI) was devised, indicating both Lake Michigan sites as the most highly impacted. The mean absolute deviation statistic was applied, documenting the need to age-correct contaminant trends due to highly variable age profiles. With the noted exceptions, the uniformity of age-corrected trend modeling suggests that a combination of the fundamental biological and physicochemical mechanisms of natural contaminant sequestration, declining dissolved water concentrations, accumulation/metabolism/depuration, and the overall reduction of legacy contaminant loading are driving the generally consistent rates of declines in the Great Lakes. Many of the biological and ecological stressors currently associated with climate change appear to be accounted for by the age-trend model.

Impacts of climate change on the fate of contaminants through extreme weather events

The direct impacts of climate change involve a multitude of phenomena, including rising sea levels, intensified severe weather events such as droughts and flooding, increased temperatures leading to wildfires, and unpredictable fluctuations in rainfall. This comprehensive review intends to examine firstly the probable consequences of climate change on extreme weather events such as drought, flood and wildfire. This review subsequently examines the release and transformation of contaminants in terrestrial, aquatic, and atmospheric environments in response to extreme weather events driven by climate change. While drought and flood influence the dynamics of inorganic and organic contaminants in terrestrial and aquatic environments, thereby influencing their mobility and transport, wildfire results in the release and spread of organic contaminants in the atmosphere. There is a nascent awareness of climate change's influence of climate change-induced extreme weather events on the dynamics of environmental contaminants in the scientific community and decision-making processes. The remediation industry, in particular, lags behind in adopting adaptive measures for managing contaminated environments affected by climate change-induced extreme weather events. However, recognizing the need for assessment measures represents a pivotal first step towards fostering more adaptive practices in the management of contaminated environments. We highlight the urgency of collaboration between environmental chemists and climate change experts, emphasizing the importance of jointly assessing the fate of contaminants and rigorous action to augment risk assessment and remediation strategies to safeguard the health of our environment.

When aerobic granular sludge faces emerging contaminants: A review

The evolution of emerging contaminants (ECs) has caused greater requirements and challenges to the current biological wastewater treatment technology. As one of the most promising biological treatment technologies, the aerobic granular sludge (AGS) process also faces the challenge of ECs. This study summarizes the recent progress and characteristics of several representative ECs (persistent organic pollutants, endocrine disrupting chemicals, antibiotics, and microplastics) in AGS systems that have garnered widespread attention. Additionally, the biodegradation and adsorption mechanisms of ECs were discussed, and the interactions between various ECs and AGS was elucidated. The importance of extracellular polymeric substances for the stabilization of AGS and the removal of ECs is also discussed. Knowledge gaps and future research directions that may enable the practical application of AGS are highlighted. Overall, AGS processes show great application potential and this review provides guidance for the future implementation of AGS technology as well as elucidating the mechanism of its interaction with ECs.

China's public health initiatives for climate change adaptation

China's health gains over the past decades face potential reversals if climate change adaptation is not prioritized. China's temperature rise surpasses the global average due to urban heat islands and ecological changes, and demands urgent actions to safeguard public health. Effective adaptation need to consider China's urbanization trends, underlying non-communicable diseases, an aging population, and future pandemic threats. Climate change adaptation initiatives and strategies include urban green space, healthy indoor environments, spatial planning for cities, advance location-specific early warning systems for extreme weather events, and a holistic approach for linking carbon neutrality to health co-benefits. Innovation and technology uptake is a crucial opportunity. China's successful climate adaptation can foster international collaboration regionally and beyond.

Study of the presence and environmental risk of organic contaminants policed by the European Union and other organic compounds in the water resources of a region overlapping protected areas: The Guadiaro River basin (southern Spain)

The study presented here is a first qualitative assessment of the occurrence of organic contaminants contemplated and not yet contemplated in European Union environmental legislation in water resources in the little anthropized Guadiaro River basin (70% of its area is covered by natural vegetation), in southern Spain. Water samples were collected from four carbonate aquifers, two detrital aquifers and four surface water courses and were analyzed for (i) 171 organic contaminants, (ii) major ions and (iii) stable isotopes (δ18OH2O, δ2HH2O, δ13CDIC). An environmental risk assessment was conducted through calculation of risk quotients comparing measured concentrations with ecotoxicological data found in the literature. Twenty-five organic contaminants were detected, at least once, including pesticides, pharmaceuticals, drugs of abuse and polycyclic aromatic hydrocarbons (PAHs). Cocaine and its main metabolite were detected in 85% and 95% of water samples, respectively (0.001-0.18 μg/L and 0.004-0.6 μg/L, respectively). Pyrene (PAH) was found in all water samples (0.001-0.015 μg/L) and forest fires were pointed out as a potential diffuse source. Relationship between rivers and aquifers is reflected by the distribution of organic contaminants, essentially the drugs of abuse. Concentration of contaminants were generally higher in groundwater samples, especially from detrital aquifers, potentially due to an accumulation process promoted by irrigation-return flows and by its slow dynamic compared to that of karstic systems. Pyrene concentration was also higher in some springs from karstic aquifers. Hence, calculated risk quotients were in general higher in groundwater, meaning that the threat to surface aquatic systems can grow as aquifers increase their influence on the water courses as the dry season progresses. The relationship between δ13CDIC and most organic contaminants (especially pyrene) reveal the role of the soil as storage media.

Impact of chemical pollution on threatened marine mammals: A systematic review

Marine mammals, due to their long life span, key position in the food web, and large lipid deposits, often face significant health risks from accumulating contaminants. This systematic review examines published literature on pollutant-induced adverse health effects in the International Union for Conservation of Nature (IUCN) red-listed marine mammal species. Thereby, identifying gaps in literature across different extinction risk categories, spatial distribution and climatic zones of studied habitats, commonly used methodologies, researched pollutants, and mechanisms from cellular to population levels. Our findings reveal a lower availability of exposure-effect data for higher extinction risk species (critically endangered 16%, endangered 15%, vulnerable 66%), highlighting the need for more research. For many threatened species in the Southern Hemisphere pollutant-effect relationships are not established. Non-destructively sampled tissues, like blood or skin, are commonly measured for exposure assessment. The most studied pollutants are POPs (31%), metals (30%), and pesticides (17%). Research on mixture toxicity is scarce while pollution-effect studies primarily focus on molecular and cellular levels. Bridging the gap between molecular data and higher-level effects is crucial, with computational approaches offering a high potential through in vitro to in vivo extrapolation using (toxico-)kinetic modelling. This could aid in population-level risk assessment for threatened marine mammals.

Generation and application of a novel transgenic zebrafish line Tg(GAcyp1a:eGFP/Luc) as an in vivo assay to sensitive and specific monitoring of DLCs in the environment

CYP1A is the most commonly used biomarker and transgenic fish which carrying a cyp1a promoter to drive a reporter gene can be used as reliable way to monitor dioxin/dioxin-like compounds (DLCs) in the environment. Here, we cloned the cyp1a promoter of Gambusia affinis and this promoter showed stronger transcriptional activity than that of zebrafish. Then, a Tg(GAcyp1a:eGFP/Luc) transgenic zebrafish line was first constructed with the G. affinis cyp1a promoter driving eGFP expression using meganuclease I-SceI mediated transgenesis technology. The Tg(GAcyp1a:eGFP/Luc) larvae at 72 h post-fertilization (hpf) were tested by exposing to TCDD for 72 h, and induced GFP was mainly expressed in the liver with low background. The Tg(GAcyp1a:eGFP/Luc) zebrafish showed high sensitivity (limit of detection of 0.322 ng/L TCDD and 0.7 TEQ-ng/L PCDD/Fs) and specificity (insensitive to responses to PAHs and PCBs). In addition, the transgenic line showed a low detection concentration of the DLCs contaminated environmental samples (as low as 1.8 TEQ-ng/L), and the eGFP fluorescence intensity and the chemical-TEQ values were closely correlated. In conclusion, a sensitively and specifically transgenic zebrafish line was established to convenient and effective to detect DLCs in the environment.

Characterization and expression of heat shock and immune genes in natural populations of Prodiamesa olivacea (Diptera) exposed to thermal stress

This paper characterizes the heat stress response (HSR) and explores the impact of temperatures on the immune response of larvae from two chironomid species, Prodiamesa olivacea and Chironomus riparius. Genes involved in crucial metabolic pathways were de novo identified in P. olivacea: Hsp27, Hsp60, Hsp70, Hsc70, Cdc37, and HSF for the heat stress response (HSR) and TOLL, PGRP, C-type lectin, and JAK/hopscotch for the immune system response (ISR). Quantitative real-time PCR was used to evaluate the expression levels of the selected genes in short-term treatments (up to 120') at high temperatures (35 °C and 39 °C). Exposing P. olivacea to elevated temperatures resulted in HSR induction with increased expression of specific heat shock genes, suggesting the potential of HSPs as early indicators of acute thermal stress. Surprisingly, we found that heat shock represses multiple immune genes, revealing the antagonist relation between the heat shock response and the innate immune response in P. olivacea. Our results also showed species-dependent gene responses, with more significant effects in P. olivacea, for most of the biomarkers studied, demonstrating a higher sensitivity in this species to environmental stress conditions than that of C. riparius. This work shows a multi-species approach that enables a deeper understanding of the effects of heat stress at the molecular level in aquatic dipterans.

Effects of Dichlorodiphenyltrichloroethane on the Female Reproductive Tract Leading to Infertility and Cancer: Systematic Search and Review

Persistent Organic Pollutants (POPs) such as dichlorodimethyltrichloroethane (DDT) are present and ubiquitous in the environment due to their resilient nature. DDT is a prevalent endocrine disruptor still found in detectable amounts in organisms and the environment even after its use was banned in the 1970s. Medline and Google Scholar were systematically searched to detect all relevant animal and human studies published in the last 20 years (January 2003 to February 2023) in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. In total, 38 studies were included for qualitative synthesis. This systematic search and review indicated that exposure to DDT is associated with female reproductive health issues, such as reduced fecundability; increased risk of preterm/premature deliveries; increased periods of gestation; alterations in the synthesis of crucial reproductive hormones (Progesterone and Oxytocin) through ion imbalances and changes in prostaglandin synthesis, myometrial and stromal hypertrophy, and edema; and variations in uterine contractions through increased uterine wet weight. There was also limited evidence indicating DDT as a carcinogen sufficient to instigate reproductive cancers. However, this review only takes into account the in vitro studies that have established a possible pathway to understand how DDT impacts female infertility and leads to reproductive cancers. Links between the pathways described in various studies have been developed in this review to produce a summarized picture of how one event might lead to another. Additionally, epidemiological studies that specifically targeted the exposure to DDT of females belonging to various ethnicities have been reviewed to develop an overall picture of prevailing female reproductive health concerns in different nations.

Influence of temperature and precipitation on the fate of polycyclic aromatic hydrocarbons: simulation experiments on peat cores from a typical alpine peatland in Central China

The corresponding relationships between temperature, precipitation, and polycyclic aromatic hydrocarbon (PAH) concentration in a typical ombrotrophic peatland in Dajiuhu, Shennongjia, were quantitatively characterized by field sampling tests validated with simulation experiments. The PAH concentrations of peat cores in Dajiuhu peatland ranged from 262 to 977 ng·g^-1, with a mean value of 536 ± 284 ng·g^-1. PAHs were mainly composed of 2-3 ring PAHs, accounting for 31.7% ± 2.00% and 31.7% ± 5.00%, respectively. The concentration of PAHs in peat cores showed a significant decrease with increasing temperature, while the low molecular weight PAHs (LMW-PAHs) were more sensitive to temperature changes compared to the high molecular weight PAHs (HMW-PAHs). Besides, with the increase of quantity and velocity of leaching liquid, PAHs in peat were first transferred in the form of attached large-size particles and then gradually entered the aqueous phase. According to the IPCC projections of global warming, Dajiuhu peatland will release 956 ± 26.3 kg·°C^-1 PAHs into gas phase during 2030-2052, and a conservative projection based on local temperature trends showed that 459 ± 12.6 kg·°C^-1 PAHs will be released into gas phase by 2047 in Dajiuhu peatland. The projected release fluxes of PAHs in Dajiuhu peatland with precipitation volume and precipitation velocity are 381 ± 201 kg·100 mm^-1 and 1052 ± 167 kg·min·mL^-1, respectively, which are primarily from peat into particulate and aqueous phase.

Analysis of the multi-media environmental behavior of polycyclic aromatic hydrocarbons (PAHs) within Haizhou Bay using a fugacity model

In this study, we aimed to quantify the transport and fate of PAHs in different environmental phases (air, seawater, soil, sediment and fish), verify application of the Level III fugacity model in a bay simulation, and understand the transport and fate of PAHs in the bay environment on a macroscopic scale. The simulated average concentrations of ∑₁₆PAH in the air and soil (23.8 ng/m³ and 1080.91 ng/g, respectively), which is as a background reference data for the Haizhou Bay. In addition, the soil (307 t), fish (29.4 t), and sediment (9.72 t) phases were found to be important reservoirs in the Haizhou Bay. Emissions from road vehicles (658 t) accounted for the largest share of PAH emissions in the area, and atmospheric deposition contributed most to the input of PAHs to the polluted area in the region. Whereas the contribution of river runoff input was small, and degradation loss was the main output pathway.

Persistent Organic Pollutants (POPs) in Sardine (Sardinella brasiliensis): Biomonitoring and Potential Human Health Effects

Organochloride (OC) and polychlorinated biphenyl (PCB) concentrations were determined in the muscle tissue of fifty sardine samples (Sardinella brasiliensis) sampled off the south-east Brazilian shelf. The aim herein was to investigate OCs and PCBs composition profile, bioaccumulation potential and human risks. The concentrations of 18 organochlorine pesticides (OCPs) were below the method limit of quantification in most samples (ca. 94%), with few detected, namely δ-HCH, γ-HCH, Endosulfan I and II, Endosulfan Sulphate, DDE, Dieldrin, Endrin, Endrin Aldeide, Endrin Cetone and Metoxyclor. The median concentration for the Σ41 PCBs was 2.32 ng g^-1, ranging from values below the limit of quantification (<LOQ) to 37.2 ng g^-1. Based on the analyzed samples, the concentrations reported herein do not represent a risk for human consumption according to both national and international guidelines, nor do OC and PCB bioaccumulation in sardines appear to be a concern at the moment. These findings, although preliminary, represent a baseline for future comparisons of the quality of an important source of protein available to the poorest Brazilian population strata.

Recent advances in application of metal-organic frameworks (MOFs) as adsorbent and catalyst in removal of persistent organic pollutants (POPs)

The presence of persistent organic pollutants (POPs) in the aquatic environment is causing widespread concern due to their bioaccumulation, toxicity, and possible environmental risk. These contaminants are produced daily in large quantities and released into water bodies. Traditional wastewater treatment plants are ineffective at degrading these pollutants. As a result, the development of long-term and effective POP removal techniques is critical. In water, adsorption removal and photocatalytic degradation of POPs have been identified as energy and cost-efficient solutions. Both technologies have received a lot of attention for their efforts to treat the world's wastewater. Photocatalytic removal of POPs is a promising, effective, and long-lasting method, while adsorption removal of persistent POPs represents a simple, practical method, particularly in decentralized systems and isolated areas. It is critical to develop new adsorbents/photocatalysts with the desired structure, tunable chemistry, and maximum adsorption sites for highly efficient removal of POPs. As a class of recently created multifunctional porous materials, Metal-organic frameworks (MOFs) offer tremendous prospects in adsorptive removal and photocatalytic degradation of POPs for water remediation. This review defines POPs and discusses current research on adsorptive and photocatalytic POP removal using emerging MOFs for each type of POPs.

Pollution characteristics and health risk assessment of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons during heating season in Beijing

Polycyclic aromatic hydrocarbons (PAHs) and their nitrated derivatives (NPAHs) attract continuous attention due to their outstanding carcinogenicity and mutagenicity. In order to investigate the diurnal variations, sources, formation mechanism, and health risk assessment of them in heating season, particulate matter (PM) were collected in Beijing urban area from December 26, 2017 to January 17, 2018. PAHs and NPAHs in PM were quantitatively analyzed via gas chromatography-mass spectrometry (GC-MS) . Average daily concentrations of PAHs and NPAHs were (78 ± 54) ng/m³ and (783 ± 684) pg/m³, respectively. The concentrations of them were significantly higher at nighttime than at daytime, and NPAHs concentrations were 1-2 orders of magnitude lower than PAHs concentrations. In the heating season, the dominant species of PAHs include benzo[b]fluoranthene, fluoranthene, pyrene, and chrysene, while 9-nitroanthracene, 2+3-nitrofluoranthene, and 2-nitropyrene were dominant species for NPAHs. NPAHs were found to have a single peak during heating and to be primarily distributed in the 0.4-0.7 µm particle size. Primary emissions such as biomass burning, coal combustion, and traffic emissions were the major sources of PAHs. NPAHs were produced by the primary source of vehicle emissions and the secondary reaction triggered by OH radicals, as well as biomass burning during daytime. According to the health risk assessment, the total carcinogenic risk was higher in adults than in children. While upon oral ingestion, the carcinogenic risk in children was higher than that of adults, but the risk of adults was higher than children through skin contact and respiratory inhalation.

The Influence of Daily Temperature Fluctuation on the Efficacy of Bioinsecticides on Spotted Wing Drosophila Larvae

Global climate change is allowing the invasion of insect pests into new areas without natural competitors and/or predators. The dipteran Drosophila suzukii has invaded both the Americas and Europe, becoming a serious problem for fruit crops. Control methods for this pest are still based on the use of pesticides, but less invasive and more sustainable methods, such as biocontrol, are needed. Variations in environmental conditions can affect the efficacy of bioinsecticides influencing their behavior and physiology besides that of the target insects. In this work, we developed a system that simulates the daily temperature fluctuations (DTFs) detected in the environment, with the aim of studying the influence of temperature on biocontrol processes. We investigated the effects of DTFs on the efficacy of four bioinsecticides. Results showed that DTFs modify the efficacy of some entomopathogens while they are ineffective on others. Specifically, the bacterium Bacillus thuringiensis is the most effective bioinsecticide under all conditions tested, i.e., low DTF (11−22 °C) and high DTF (17−33 °C) compared to constant temperature (25 °C). In contrast, nematodes are more sensitive to changes in temperature: Steinernema carpocapsae loses efficacy at low DTF, while Steinernema feltiae and Heterorhabditis bacteriophora are not effective in controlling the target dipteran. This work provides a basis for reviewing biological control methods against invasive species in the current context of climate change.

A bibliometric analysis of pre- and post-Stockholm Convention research publications on the Dirty Dozen Chemicals (DDCs) in the African environment

Persistent organic pollutants (POPs) are toxic chemicals that stay in the environment for a long time. To address the toxicity issues, global nations, including 53 African countries, ratified the Stockholm Convention to minimize or eliminate the production of 12 POPs known as the "Dirty Dozen". However, these Dirty Dozen Chemicals (DDCs) still exist in significant concentration in the African environment, prompting numerous research to investigate the level of their occurrences. Here, we conducted a bibliometric analysis to examine the publication trends in DDCs-related research in Africa using articles published between 1949 and 2021 from the Web of Science and Scopus databases. A total of 884 articles were published within the survey period, with a publication/author and author/publication ratio of 0.36 and 2.76, respectively. South Africa ranked first in terms of number of publications (n = 133, 15.05%), and total citations (n = 3115), followed by Egypt (n = 117), Nigeria (n = 77), USA (n = 40), and Ghana (n = 38). Research collaboration was relatively high (collaboration index = 2.88). The insignificant difference between the theoretical and observed Lotka's distribution indicates Lotka's law does not fit the DDC literature. An annual growth rate of 0.57% implies that a substantial increase of articles in years to come is not expected. More research programs should be established in other African countries to measure up to South Africa's supremacy. This is critical in order to provide a basis for effective compliance to the Stockholm Convention on POPs in Africa.

Legacy and emerging pollutants in Latin America: A critical review of occurrence and levels in environmental and food samples

The increase and indiscriminate use of personal care products, food products, fertilizers, pesticides, and health products, among others, have resulted/are resulting in extensive environmental contamination. Most of these products contain traces of widespread chemicals, usually known as emerging pollutants (EPs) or pollutants of emerging concern (PEC). The Latin American (LA) region comprises 20 countries with different social and cultural aspects, with 81 % of the population living in urban areas. The LA region has some countries on the top list of users/consumers of EPs, from pesticides and fertilizers to personal care products. However, there is a gap in information related to the distribution of EPs in the environment of this region, with very few existing review texts exploring this issue. Therefore, this present paper advances this approach. An exhaustive literature review, with the selection of 176 documents, provided unique up-to-date information on the presence/distribution of 17 classes of legacy or emerging pollutants in different food and environmental matrices (soil, sediment, water, and air). The study shows that the wide distribution and recorded levels of these pollutants in the continental environment are potential risks to human health, mainly through food and drinking water ingestion. Polycyclic aromatic hydrocarbons are pollutants of deep public concern since they show carcinogenic properties. Several classes of pollutants, like endocrine disruptors, have caused harmful effects on humans and the environment. Besides that, pharmaceutical products and pesticides are compounds of high consumption worldwide, being environmental contamination a real and ongoing possibility. Finally, gaps and future research needs are deeply pointed out.

Promotional effect of Ca doping on Bi2Fe4O9 as peroxymonosulfate activator for gatifloxacin removal

A series of Ca-doped bismuth ferrite was prepared at various %w/w of Ca via a facile hydrothermal method to obtain Bi_2XCa_2(1-X)Fe₄O₉ (denoted as BFOCa-X, where X = 1, 0.95, 0.90, 0.80, 0.50). The BFOCa-X catalysts were characterized, and the results showed that they consist of pure phase BFO with nanosheet-like morphology. The as-prepared BFOCa-X catalysts were used as peroxymonosulfate (PMS) activator for gatifloxacin (GAT) removal. It was found that the catalytic activity decreased in the following order: BFOCa-0.8 (90.2% GAT removal efficiency in 45 min, k_app = 0.084 min^-1)>BFOCa-0.95 > BFOCa-0.9 > BFOCa-0.5 > BFO indicating that BFOCa-0.8 has the optimized active sites for catalysis. The Ca dopant contributed to the increased oxygen vacancies and surface hydroxyl groups, promoting the catalytic PMS activation process. The k_app value increased gradually with increasing catalyst loading and PMS dosage while pH 9 presented the highest GAT removal rate. The GAT degradation rate was inhibited by PO₄³-, humic acid and NH₄⁺ but promoted in the presence of Cl-, NO₃- and HCO₃-. It was also found that the GAT can undergo several degradation pathways in the catalytic PMS system, which eventually mineralized into innocuous compounds. The dominant reactive oxygen species (ROS) were identified using chemical scavengers, revealing that SO₄^•-, ¹O₂ and ^•OH contributed significantly to GAT degradation. Based on the XPS study, PMS was activated by the Fe²⁺/Fe³⁺ redox cycling and oxygen vacancies to produce SO₄^•-/^•OH and ¹O₂, respectively. Overall, the BFOCa-0.8 also showed excellent reusability up to at least 4 cycles with low Bi and Fe leaching (<7 and 62 μg L^-1, respectively), indicating that it has promising potential for application as PMS activator for antibiotics removal.

Impact of global warming on regional cycling of mercury and persistent organic pollutants on the Tibetan Plateau: current progress and future prospects

Global warming profoundly affects not only mountainous and polar environments, but also the global and regional cycling of pollutants. Mercury (Hg) and persistent organic pollutants (POPs) have global transport capacity and are regulated by the Minamata Convention and Stockholm Convention, respectively. Since the beginning of this century, understanding of the origin and fate of Hg and POPs on the Tibetan Plateau (TP, also known as the third pole) has been deepening. In this paper, the existing literature is reviewed to comprehensively understand the atmospheric transport, atmospheric deposition, cumulative transformation and accumulation of Hg and POPs on the TP region under the background of global warming. The biogeochemical cycle of both Hg and POPs has the following environmental characteristics: (1) the Indian summer monsoon and westerly winds carry Hg and POPs inland to the TP; (2) the cold trapping effect causes Hg and POPs to be deposited on the TP by dry and wet deposition, making glaciers, permafrost, and snow the key sinks of Hg and POPs; (3) Hg and POPs can subsequently be released due to the melting of glaciers and permafrost; (4) bioaccumulation and biomagnification of Hg and POPs have been examined in the aquatic food chain; (5) ice cores and lake cores preserve the impacts of both regional emissions and glacial melting on Hg and POP migration. This implies that comprehensive models will be needed to evaluate the fate and toxicity of Hg and POPs on larger spatial and longer temporal scales to forecast their projected tendencies under diverse climate scenarios. Future policies and regulations should address the disrupted repercussions of inclusive CC such as weather extremes, floods and storms, and soil sustainable desertification on the fate of Hg and POPs. The present findings advocate the strengthening of the cross-national programs aimed at the elimination of Hg and POPs in polar (Arctic, Antarctic and TP) and certain mountainous (the Himalaya, Rocky Mountains, and Alps) ecosystems for better understanding the impacts of global warming on the accumulation of Hg/POPs in cold and remote areas.

POPs in Antarctic ecosystems: is climate change affecting their temporal trends?

Climate change is affecting Antarctica and the Southern Ocean and effects have been already reported for the abiotic compartments of the ecosystems, e.g. ice loss and iceberg calving. Global warming can alter also the distribution of persistent organic pollutant (POPs) both at a global scale and in the Antarctic Region, due to their physical-chemical characteristics. Effects of climate changes have been already reported on feeding behaviour and reproductive process of organisms. Another consequence for organisms includes the POP bioaccumulation. Here we review the literature reporting the linkage between recorded effects of climate changes and POP bioaccumulation in resident marine Antarctic species (fish and penguins). Notwithstanding Antarctica is a final sink for persistent contaminants due to the extreme cold climate, a general decreasing POP trend has been observed for some POPs. Their concentrations in biota are reported to be linked to ice melting and large iceberg calving; the peculiar marine Antarctic ecosystems and the pelagic-benthic coupling may also contribute to alterations in the bioaccumulation processes. These effects are similar in polar regions, although the comparison with the Arctic biota is not possible due to the lack of data in the Antarctic Region. It remains an open question if the POP amount accumulated in the Antarctic ecosystems is decreasing or not.

Accumulative levels, temporal and spatial distribution of common chemical pollutants in the blood of Chinese adults

China has been in a rapid development period in recent decades, the mass production and use of chemical industrial products and pesticides have resulted in a large amount of pollutants in the environment. These pollutants enter the human body through environmental exposure and dietary intake, causing adverse health effects. Although many of them have been banned and restricted in the production and use in China, these pollutants still remain in the human body due to their high persistence and strong bioaccumulation. In this review, we aim to reveal the accumulation levels and profiles, as well as the temporal and spatial distribution of common chemical pollutants including chlorinated paraffins (CPs), polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers, organophosphorus flame retardants (OPFRs), new halogenated flame retardants (NHFRs), polychlorinated biphenyls, phthalic acid esters, perfluorinated compounds, bisphenols, organophosphorus pesticides and pyrethroid insecticides in the blood (including whole blood, serum and plasma) of Chinese adults by extracting 93 related studies published from 1990 to 2021. Results have shown that CPs, OCPs and PAHs were the main pollutants in China, the levels of short-chain chlorinated paraffin, p,p'-DDE and phenanthrene in blood even reached 11,060.58, 740.41 and 498.28 ng/g lipid respectively. Under the strict control of pollutants in China, the levels of most pollutants have been on a downward trend except for perfluoro octanoate and perfluoro nonanoate. Besides, OPFRs, NHFRs and PAHs may have a potential upward trend, requiring further research and observation. As for spatial distribution, East China (Bohai Bay and Yangtze River Delta) and South China (Pearl River Delta) were the major polluted regions due to their fast development of industry and agriculture.

Global PBDE contamination in cetaceans. A critical review

This review summarizes the most relevant information on PBDEs' occurrence and their impacts in cetaceans at global scale, with special attention on the species with the highest reported levels and therefore the most potentially impacted by the current and continuous release of these substances. This review also emphasizes the anthropogenic and environmental factors that could increase concentrations and associated risks for these species in the next future. High PBDE concentrations above the toxicity threshold and stationary trends have been related to continuous import of PBDE-containing products in cetaceans of Brazil and Australia, where PBDEs have never been produced. Non-decreasing levels documented in cetaceans from the Northwest Pacific Ocean might be linked to the increased e-waste import and ongoing production and use of deca-BDE that is still allowed in China. Moreover, high levels of PBDEs in some endangered species such as beluga whales (Delphinapterus leucas) in St. Lawrence Estuary and Southern Resident killer whales (Orcinus Orca) are influenced by the discharge of contaminated waters deriving from wastewater treatment plants. Climate change related processes such as enhanced long-range transport, re-emissions from secondary sources and shifts in migration habits could lead to greater exposure and accumulation of PBDEs in cetaceans, above all in those species living in the Arctic. In addition, increased rainfall could carry greater amount of contaminants to the marine environment, thereby, enhancing the exposure and accumulation especially for coastal species. Synergic effects of all these factors and ongoing emissions of PBDEs, expected to continue at least until 2050, could increase the degree of exposure and menace for cetacean populations. In this regard, it is necessary to improve current regulations on PBDEs and broader the knowledge about their toxicological effects, in order to assess health risks and support regulatory protection for cetacean species.

Legacy and emerging organic contaminants in the polar regions

The presence of numerous emerging organic contaminants (EOCs) and remobilization of legacy persistent organic pollutants (POPs) in polar regions have become significant concerns of the scientific communities, public groups and stakeholders. This work reviews the occurrences of EOCs and POPs and their long-range environmental transport (LRET) processes via atmosphere and ocean currents from continental sources to polar regions. Concentrations of classic POPs have been systematically monitored in air at several Arctic stations and showed seasonal variations and declining trends. These chemicals were also the major POPs reported in the Antarctica, while their concentrations were lower than those in the Arctic, illustrating the combination of remoteness and lack of potential local sources for the Antarctica. EOCs were investigated in air, water, snow, ice and organisms in the Arctic. Data in the Antarctica are rare. Reemission of legacy POPs and EOCs accumulated in glaciers, sea ice and snow may alter the concentrations and amplify their effects in polar regions. Thus, future research will need to understand the various biogeochemical and geophysical processes under climate change and anthropogenic pressures.

Occurrence of persistent organic pollutants (POPs) in the atmosphere of South Korea: A review

Numerous studies found the presence of persistent organic pollutants (POPs) in various environmental compartments, including air, water, and soil. POPs have been discovered in various industrial and agricultural products with severe environmental and human health consequences. According to the data, South Korea is a hotspot for POP pollution in the southern part of Asia; hence, South Korea has implemented the Stockholm Convention's National Implementation Plan (NIP) to address this worldwide issue. The purpose of this review is to assess the distribution pattern of POPs pollution in South Korea's atmosphere. According to findings, PAHs, PCBs, BFRs, and PBDEs significantly polluted the atmosphere of South Korea; however, assessing their exposure nationwide is difficult due to a shortage of data. The POPs temporal trend and meta-analysis disclosed no proof of a decrease in PAHs and BFRs residues in the atmosphere. However, POP pollution in South Korea tends to decrease compared to contamination levels in neighboring countries like Japan and China.

Influence of edaphic conditions and persistent organic pollutants on earthworms in an infiltration basin

In recent decades, stormwater management has developed to allow stormwater to infiltrate directly into the soils instead of being collected and routed to sewer systems. However, during infiltration, stormwater creates a sediment deposit at the soil surface as the result of high loads of suspended particles (including pollutants), leading to the settlement of sedimentary layers prone to colonization by plants and earthworms. This study aims to investigate the earthworm communities of a peculiar infiltration basin and investigate the influence of edaphic conditions (water content, organic matter content, pH, height of sediment) and of persistent organic pollutants (POPs: PCBs, PCDDs and PCDFs) on these earthworms. Attention was paid to their age (juveniles or adults) and their functional group (epigeic, endogeic, anecic). We found that the earthworm abundance was mostly driven by edaphic conditions, with only a slight impact of POPs, with a significant negative impact of PCBDLno for juveniles and endogeic, and PCDDs for epigeic. On the contrary, the height of the sediment and the water content are beneficial for their presence and reproduction. Furthermore, POPs contents are also linked to physicochemical parameters of the sediment. Bioaccumulation was clearly revealed in the studied site but does not differ between juveniles and adults, except for PCDDs. Conversely, BAF values seemed to vary between functional groups, except for PCBDL non-ortho. It strongly varies with the family types (PCBs versus PCCD/Fs) and between congeners within the same family, with specific strong bioaccumulation for a few congeners.

Organochlorine pesticides and polychlorinated biphenyls in high mountain lakes, Mexico

Pollution levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) were investigated in the El Sol and the La Luna alpine lakes. The lakes are located in central Mexico, in the crater of the Nevado de Toluca volcano. The El Sol and the La Luna lakes are extremely relevant in Mexico and in the world because they are recognized as pristine regions and environmental reservoirs. Samples of atmospheric aerosol, sediment, plankton, and Tubifex tubifex (sludge worm) were collected at three different sample locations for three years (2017, 2018, and 2019) at three different times of year, meaning that the weather conditions at the time of sampling were different. Pollutants were analysed by gas chromatography-mass spectrometry with negative chemical ionisation (GC-MS/NCI). Endosulfan was the most frequent and abundant pollutant, showing the highest peaks of all. Atmospheric aerosol revealed Σ₂ = 45 pg/m³, including α and β, while sediment lakes displayed α, β and endosulfan sulfate as Σ₃ = 1963 pg/g, whereas plankton and Tubifex tubifex showed Σ₂ = 576 pg/g and 540 pg/g for α and β respectively. Results of endosulfan ratios (α/β) and (α-β/endosulfan sulfate) suggest that both fresh and old discharges continue to arrive at the lakes. This study shows for the first time the pollution levels of OCP and PCB in high mountain lakes in Mexico. These results that must be considered by policy makers to mitigate their use in the various productive activities of the region.

Interactive effects of high temperature and pesticide exposure on oxidative status, apoptosis, and renin expression in kidney of goldfish: Molecular and cellular mechanisms of widespread kidney damage and renin attenuation

One of many noteworthy consequences of increasing societal reliance on pesticides is their predominance in aquatic environments. These pernicious chemicals interact with high temperatures from global climate change, heat waves, and natural variations to create unstable environments that negatively impact organisms' health. To understand these conditions, we examined the dose-dependent effects of environmentally relevant pesticide mixtures (metolachlor, linuron, isoproturon, tebuconazole, aclonifen, atrazine, pendimethalin, and azinphos-methyl) combined with elevated temperatures (22 control vs. 32°C for 4-week exposure) on renin, dinitrophenyl protein (DNP, an indicator of reactive oxygen species, ROS), 3-nitrotyrosine protein (NTP, an indicator of reactive nitrogen species, RNS), superoxidase dismutase (SOD, an antioxidant), and catalase (CAT, an antioxidant) expressions in the kidneys of goldfish (Carassius auratus). Histopathological analysis showed widespread damage to kidney tissues in high temperature and pesticide co-exposure groups, including rupture of the epithelial layer, hemorrhaging, and degeneration of tubular epithelium. Quantitative real-time polymerase chain reaction (qRT-PCR) and immunohistochemical analyses demonstrated significant declines in renin receptor-like mRNA and protein expressions in kidney tissues under combined exposure to high temperature and pesticides compared with controls; conversely, expression of DNP, NTP, SOD, and CAT increased in kidney tissues under the same conditions. Apoptotic cells were also increased in co-exposure groups as assessed by in situ terminal deoxynucleotidyl transferase dUTP nick labeling (TUNEL) assay. The enhanced apoptosis in kidneys of heat and pesticides co-exposed fish was associated with increased caspase-3 (a protease enzyme) mRNA levels. Our results demonstrated that high temperature and pesticides induced oxidative/nitrative stress (i.e., ROS/RNS), damaged tissues, increased cellular apoptosis, and suppressed renin expression in kidneys of goldfish.

Toxicity evaluation and oxidative stress response of fumaronitrile, a persistent organic pollutant (POP) of industrial waste water on tilapia fish (Oreochromis mossambicus)

The study was designed to determine the impact of acute toxicity of fumaronitrile exposure through tissue damaging, oxidative stress enzymes and histopathological studies in gills, liver and muscle cells of freshwater tilapia fish (Oreochromis mossambicus). In gill, liver, and muscle cells, biochemical indicators such as tissue damage enzymes (Acid Phosphatase (ACP), Alkaline Phosphatase (ALP), and Lactate Dehydrogenase (LDH)) and antioxidative enzymes (Superoxide Dismutase (SOD); Catalase (CAT); Glutathione-S-transferase (GST); Reduced Glutathione (GSH); Glutamate oxaloacetate transaminase (GOT) and Glutamate pyruvate transaminase (GPT) were quantified in the time interval of 30, 60 and 90 days exposure to the fumaronitrile. After 90 days, under 6 ppb exposure conditions, the acid phosphatase (ACP) levels of fish increased significantly in the gills (3.439 μmol/mg protein/min), liver (1.743 μmol/mg protein/min), and muscles (2.158 μmol/mg protein/min). After 90 days of exposure to the same concentration and days, ALP activity increased significantly in gills (4.354 μmol/mg protein/min) and liver (1.754 μmol/mg protein/min), but muscle cells had a little decrease in ALP activity (2.158 μmol/mg protein/min). The LDH concentration in gills following treatment with fumaronitrile over a period of 0-90 days was 3.573 > 3.521 > 2.245 μmol/mg protein/min over 30 > 60 > 90 days. However, at the same dose and treatment duration, a greater LDH level of 0.499 μmol/mg protein/min was found in liver and muscle cells. Histopathological abnormalities in the gills, liver, and muscle cells of treated fish were also examined, indicating that fumaronitrile treatment generated the most severe histological changes. The current study reveals that fumaronitrile exposure has an effect on Oreochromis mossambicus survival, explaining and emphasising the risk associated with this POP exposure to ecosystems and human populations.

Biofilm on microplastics in aqueous environment: Physicochemical properties and environmental implications

The excellent properties of plastics make them widely used all over the world. However, when plastics enter the environmental medium, microplastics will inevitably be produced due to physical, chemical and biological factors. Studies have shown that microplastics have been detected in terrestrial, aquatic and atmospheric environments. In addition, the presence of microplastics will provide a new artificial adhesion substrate for biofilms. It has been proved that the formation of biofilms could significantly change some properties of microplastics. Some studies have found that microplastics attached with biofilms have higher environmental risks and eco-toxicity. Therefore, considering the widespread existence of microplastics and the ecological risks of microplastic biofilms, the physical and chemical properties of biofilms on microplastics and their impact on microplastics in aqueous environment are worth reviewing. In this paper, we comprehensively reviewed representative studies in this area. Firstly, this study reviews that the existence of biofilms could change the transport and deposition of microplastics. Subsequently, the presence of biofilms would enhance the ability of microplastics to accumulate pollutant, such as persistent organic pollutants, heavy metals and antibiotics. Moreover, the effect of biofilms on microplastics enrichment of harmful microorganisms is summarized. Finally, some future research needs and strategies are proposed to better understand the problem of biofilms on microplastics.

Soil degradation in the European Mediterranean region: Processes, status and consequences

Soil, a non-renewable resource, sustains life on Earth by supporting around 95% of global food production and providing ecosystem services such as biomass production, filtration of contaminants and transfer of mass and energy between spheres. Unsustainable management practices and climate change are threatening the natural capital of soils, particularly in the Mediterranean region, where increasing population, rapid land-use changes, associated socio-economic activities and climate change are imposing high pressures on the region's shallow soils. Despite evidence of high soil susceptibility to degradation and desertification, the true extent of soil degradation in the region is unknown. This paper reviews and summarises the scientific literature and relevant official reports, with the aim to advance this knowledge by synthesizing, mapping, and identifying gaps regarding the status, causes, and consequences of soil degradation processes in the European Mediterranean region. This is needed as scientific underpinning of efforts to counteract soil degradation in the region. Three main degradation categories are then considered: physical (soil sealing, compaction, erosion), chemical (soil organic matter, contamination, salinisation), and biological. We find some degradation processes to be relatively well-documented (e.g. soil erosion), while others, such as loss of biodiversity, remain poorly addressed, with limited data availability. We suggest establishment of a continuous, harmonised soil monitoring system at national and regional scale in the Mediterranean region to provide comparable datasets and chart the spatial extent and temporal changes in soil degradation, and corresponding economic implications. This is critical to support decision-making and fulfilment of related sustainable development goals.

Seasonal variability in multimedia transport and fate of benzo[a]pyrene (BaP) affected by climatic factors

The impact of meteorological factors on the transport behavior and distribution of volatile and semi-volatile organic pollutants has become an area of increasing concern. Here, we analyzed seasonal variation in climatic variables including wind, temperature, and precipitation to quantitatively assess the impact of these factors on the multimedia transport and fate of BaP in the continental region of China using a Berkeley-Trent (BETR) model. The advective rates of air exhibited an increasing trend of autumn (1.830 mol/h) < summer (1.975 mol/h) < winter (2.053 mol/h) < spring (2.405 mol/h) in association with increasing wind speed, indicating that lower atmospheric BaP concentrations are present in regions with high wind speeds and advective rates. The air-soil transport rates (0.08-45.55 mol/h) in winter were higher than in summer (0.07-32.41 mol/h), while low winter temperatures accelerate BaP accumulation in terrestrial ecosystems due to cold deposition. Cold deposition effects were more evident in northern regions than in southern regions. Further, increasing precipitation enhanced air-soil and soil-freshwater transport rates with the correlation coefficients of r = 0.445 and r = 0.598 respectively, while decreasing the air-vegetation transport rates (r = 0.475), thereby contributing to the accumulation of BaP in soils and freshwaters. In the light of the potential dispersion of BaP pollution at regional and global scales affected by these key climatic factors, this indirectly indicated the impact of future climate change on the BaP transport. Thus, flexible policy interventions should be enacted to slow future climate change.

Modern lake sedimentary record of PAHs and OCPs in a typical karst wetland, south China: Response to human activities and environmental changes

The sedimentary history of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) over the past 140 years in a lake sediment core from Huixian karst wetland was reconstructed. The total PAHs and OCPs concentrations ranged from 40.0 to 210 ng g^-1 and 0.98 to 31.4 ng g^-1, respectively. The vertical distribution of PAHs and OCPs in different stages was great consistent with the history of regional socio-economic development and the usage of OCPs. As the indicators of socio-economic development, gross domestic product (GDP), population, energy consumption, highway mileage, and private vehicles correlated with the PAHs concentrations, indicating the impact of human activities on PAHs levels. The PAHs and OCPs concentrations were also affected by environmental changes in the wetland, as reconstructed by total organic carbon (TOC), sand, silt, clay, quartz, and calcite in sediments. Redundancy analysis (RDA) results showed TOC was the dominant factor to explain the concentrations of PAHs and OCPs with the explanation of 86.7% and 43.5%, respectively. In addition, TOC content had significantly positive correlation with PAHs (0.96, p < 0.01) and OCPs (0.78, p < 0.01). In particular, the significantly positive correlation (p < 0.05) between calcite and PAHs and OCPs inferred that karstification might play an important role in the migration of PAHs and OCPs in the karst area. Therefore, the lake in Huixian wetland tended to be a sink more than a source of PAHs and OCPs influenced by the increasing TOC content and karstification under climate warming.

Emerging materials and technologies for landfill leachate treatment: A critical review

Sanitary landfill is the most popular way to dispose solid wastes with one major drawback: the generation of landfill leachate resulting from percolation of rainfall through exposed landfill areas or infiltration of groundwater into the landfill. The landfill leachate impacts on the environment has forced authorities to stipulate more stringent requirements for pollution control, generating the need for innovative technologies to eliminate waste degradation by-products incorporated in the leachate. Natural attenuation has no effect while conventional treatment processes are not capable of removing some the pollutants contained in the leachate which are reported to reach the natural environment, the aquatic food web, and the anthroposphere. This review critically evaluates the state-of-the-art engineered materials and technologies for the treatment of landfill leachate with the potential for real-scale application. The study outcomes confirmed that only a limited number of studies are available for providing new information about novel materials or technologies suitable for application in the removal of pollutants from landfill leachate. This paper focuses on the type of pollutants being removed, the process conditions and the outcomes reported in the literature. The emerging trends are also highlighted as well as the identification of current knowledge gaps and future research directions along with recommendations related to the application of available technologies for landfill leachate treatment.

Spatial distribution and source identification of persistent organic pollutants in the sediments of the Yeşilırmak River and coastal area in the Black Sea

Surface sediments from the Yeşilırmak River and the near coastal area in the Black Sea were collected using sediment traps to assess the spatial distributions of persistent organic pollutants and find their potential sources. Analyses were carried out to determine the concentrations of the persistent organic pollutants of seventeen polychlorinated dibenzo-p-dioxins and dibenzofurans, sixteen polycyclic aromatic hydrocarbons, seven polychlorinated biphenyls, and eight organochlorine pesticides using high-resolution gas chromatography-mass spectrometry and gas chromatography-tandem mass spectrometry systems. Analysis showed that the three main components of persistent organic pollutants (polychlorinated dibenzo-p-dioxins and dibenzofurans, polycyclic aromatic hydrocarbons, and organochlorine pesticides) primary sources are industrial activities. In addition, the widespread occurrence of persistent organic pollutants in the watershed surface sediments taken from the Yeşilırmak River basin showed that agricultural and urban areas are also diffuse persistent organic pollutants sources.

Multiresidues of environmental contaminants in bats from Turkey

Bat populations have been steadily declining, most likely because of anthropogenic factors. Identification and classification of these risks have crucial importance in ensuring the survival of this species. Bats often coexist with humans in urban, industrial, and agricultural areas and are potentially exposed to a range of environmental pollutants. Two bat species widely distributed in Turkey were selected, and the residues of pesticides and organic contaminants in their carcasses were analyzed using: gas chromatography-mass spectrometry, gas chromatography-tandem mass spectrometry, and liquid chromatography-tandem mass spectrometry. Species and sex specific differences were evaluated along with their potential to be used as bioindicators. During the rigor mortis period, 23 adult Pipistrellus pipistrellus (11 female and 12 male) and 19 adult Myotis myotis (9 female and 10 male) were collected and 322 contaminants (pesticides and organic contaminants) were analyzed in whole carcasses of bats by using a validated method. Multiple pesticides and organic contaminants were detected in all collected 42 bats. The most frequent contamination was detected as 4,4-DDE, followed by ethoprophos, quinalphos, methidation, paraoxon-methyl, phosalone and tetramethrin. The least common compounds were as follows: 2,4-DDD, endrin, HCH-alpha, fenamiphos sulfoxide, parathion ethyl, bitertanol, oxycarboxin, procymidone, fluazifop-butyl, trifluralin, bifenazate, DMF, fenpyroximate, PBDE-47, benzo(a)anthracene, benzo(b)fluoranthene, and benzo(g,h,i) perylene; of these only one was found in each bat. In terms of frequency and concentration, there was no significant difference between species and sex. An average of 26.1 pollutants was found in each bat. Thus, it was concluded that bats can be used as potential bioindicators in determining environmental pollution.

Extraction of Chlorobenzenes and PCBs from Water by ZnO Nanoparticles

Metal oxide nanoparticles have great potential for selective adsorption and catalytic degradation of contaminants from aqueous solutions. In this study, we employ mass spectrometry and molecular dynamics simulations to better understand the chemical and physical mechanisms determining the affinity of chlorobenzenes and polychlorinated biphenyls (PCBs) for zinc oxide nanoparticles (ZnO NPs). The experiments and simulations both demonstrate that the adsorption coefficients for chlorobenzenes increase steadily with the number of chlorine atoms, while, for PCBs, the relation is more complex. The simulations link this complexity to chlorine atoms at ortho positions hindering coplanar conformations. For a given number of chlorine atoms, the simulations predict decreasing adsorption affinity with increasing numbers of ortho substitutions. Consequently, the simulations predict that some of the highest adsorption affinities for ZnO NPs are exhibited by dioxin-like PCBs, suggesting the possibility of selective sequestration of these most acutely toxic PCBs. Remarkably, the experiments show that the PCB adsorption coefficients of ZnO NPs with diameters ≤ 80 nm exceed those of a soil sample by 5–7 orders of magnitude, meaning that a single gram of ZnO NPs could sequester low levels of PCB contamination from as much as a ton of soil.

Environmental impact and human health risks of air pollutants near a large chemical/petrochemical complex: Case study in Tarragona, Spain

Chemical industries and oil refineries are known emission sources of environmental contaminants, such as metals/metalloids, polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), among others. Based on the toxicological potential of these pollutants, harmful health effects can be expected for the population living near these facilities. One of the largest chemical/petrochemical complexes in Europe is located in Tarragona County (Catalonia, Spain). In the last two decades, a number of investigations aimed at assessing the environmental impact of air pollutants potentially emitted by this industrial complex have been carried out. The present paper is a review of the available scientific information on the levels of air pollutants related with the activities of this chemical/petrochemical complex. Although there are currently some data on the environmental burdens of metals/metalloids, PAHs, VOCs and PCDD/Fs, there is an evident lack of specific biological monitoring studies on human health. Taking into account the amount of chemicals released to air and their toxicity, it is essential to perform an in-depth analysis of the current health status of the population living in Tarragona County.

Do dissipation and transformation of γ-HCH and p,p'-DDT in soil respond to a proxy for climate change? Insights from a field study on the eastern Tibetan Plateau

While the influence of climate change on the fate of persistent organic pollutants (POPs) is becoming a topic of global concern, it has yet to be demonstrated how POPs and their transformation products in soil respond to a changing climate at the local scale. We conducted a year-long field experiment with spiked soils to investigate the impact of climate on the dissipation of γ-hexachlorocyclohexane (γ-HCH) and p,p'-dichlorodiphenyltrichloroethane (p,p'-DDT) as well as the formation of their products. Four sites along an elevational gradient on the eastern Tibetan Plateau were selected to represent four scenarios ranging from a dry and cold to a warm and humid climate. Based on the measured concentrations of the two pesticides and their transformation products, we calculated the dissipation rates of γ-HCH and p,p'-DDT in soil using two biphasic kinetic models, and the formation rates of transformation products using a mid-point rectangular approximation method. The spiked γ-HCH generally showed the expected decrease in dissipation from soils with increasing altitudes, and therefore decreasing temperature and precipitation, whereas dissipation of p,p'-DDT was influenced more by photolysis and sequestration in soil. The formation rates of the primary products of γ-HCH (i.e. γ-HCH→PeCCH and γ-HCH→TeCCH) and p,p'-DDT (i.e. p,p'-DDT→p,p'-DDE and p,p'-DDT→p,p'-DDD) indicate that a warmer and wetter climate favors dechloroelimination (anaerobic biodegradation) over dehydrochlorination (aerobic biodegradation). The significantly longer dissipation half-lives of γ-HCH at the coldest site suggests that the fate of POPs in frozen regions (e.g. polar regions) needs more attention. Overall, the fate of more volatile chemicals (e.g. γ-HCH) might be more responsive to the climate change.

National Hazards Vulnerability and the Remediation, Restoration and Revitalization of Contaminated Sites-1. Superfund

Natural hazards can be prominent and powerful mechanisms that impact the remediation and restoration of contaminated sites and the revitalization of communities associated with these sites. The potential for hazardous material releases following a natural disaster can exacerbate the impact of contaminated sites by causing the release of toxic or hazardous materials and inhibiting the restoration of the site as well as altering the long-term sustainable revitalization of adjacent communities. Disaster-related hazardous releases, particularly in population-dense areas, can create problems as difficult as the original site clean-up. Similarly, exposure of contaminated sites to natural hazards can enhance the probability of future issues associated with the site. This manuscript addresses the co-occurrence of 12 natural hazards (singly and in combination) and individual Superfund sites.

Biodegradation of trichlorobiphenyls and their hydroxylated derivatives by Rhodococcus-strains

A possibility of using a complex approach is considered to explain features of biodestruction of polychlorinated biphenyls (PCBs), which are known to be persistent organic pollutants. The approach comprises the following main stages: (i) chemical modification of chloroarenes by hydroxylation and (ii) bacterial degradation of the hydroxylated derivatives. This approach is applicable to individual trichlorobiphenyls (PCB 29, PCB 30) and to a widespread mixture Trikhlorbifenil (analog of Aroclor 1242 and Delor 103). As bacterial strain destructors, the Rhodococcus-strains (КТ112-7, СН628, P25) were used. It was established that the main metabolites of microbial biodegradation of both polychlorobiphenyls and their hydroxy derivatives are polychloro- and hydroxy(polychloro)benzoic acids, which allows an assumption to be made about possible further biodegradation of these compounds down to the products of the base exchange reaction in a cell: water, carbon dioxide and chlorine compounds. The study discusses the effect that the structure of PCBs congeners causes on the conversion by hydroxylation, on the biodegradation rate of both PCBs and their hydroxy derivatives, and on the metabolite formation levels.

A critical review on the formation, fate and degradation of the persistent organic pollutant hexachlorocyclohexane in water systems and waste streams

The environmental impacts of persistent organic pollutants (POPs) is an increasingly prominent topic in the scientific community. POPs are stable chemicals that are accumulated in living beings and can act as endocrine disruptors or carcinogens on prolonged exposure. Although efforts have been taken to minimize or ban the use of certain POPs, their use is still widespread due to their importance in several industries. As a result, it is imperative that POPs in the ecosystem are degraded efficiently and safely in order to avoid long-lasting environmental damage. This review focuses on the degradation techniques of hexachlorocyclohexane (HCH), a pollutant that has strong adverse effects on a variety of organisms. Different technologies such as adsorption, bioremediation and advanced oxidation process have been critically analyzed in this study. All 3 techniques have exhibited near complete removal of HCH under ideal conditions, and the median removal efficiency values for adsorption, bioremediation and advanced oxidation process were found to be 80%, 93% and 82% respectively. However, it must be noted that there is no ideal HCH removal technique and the selection of removal method depends on several factors. Furthermore, the fates of HCH in the environment and challenges faced by HCH degradation have also been explained in this study. The future scope for research in this field has also received attention.

Hexachlorocyclohexane toxicity in water bodies of Pakistan: challenges and possible reclamation technologies

Pakistan is an agro-economy country where hexachlorocyclohexane (HCH) pesticides are being used to improve crop productivity, as a result the risk of contamination of soil and sediment has been increased. HCH exhibits all the characteristics of persistent organic pollutants (POP), and was therefore added to the list of 'new POPs' in 2009. This review report revealed that the major rivers of Pakistan such as the Indus Basin, River Ravi, River Chenab and their tributaries all are contaminated with HCH and the highest residual concentration (4,090 ng/g) was detected in a pesticide burial ground in Hyderabad city. Major sources of HCH contamination were identified as agricultural runoff, discharge of untreated industrial effluents and surface runoff. In order to manage HCH pollution, various ex-situ and in-situ remediation techniques along with their merits and demerits are thoroughly reviewed. Among these, microbial bioremediation is a low cost, environment friendly, effective in-situ remediation technique for remediation of HCH. Overall, the information provided in this manuscript will provide a future reference to the scientific community and bridge the knowledge gap between HCH release in the environment and their mitigation through proper treatment methods.

Levels of Polychlorinated Dibenzo-p-Dioxins/Furans (PCDD/Fs) and Dioxin-Like Polychlorinated Biphenyls (DL-PCBs) in Human Breast Milk in Chile: A Pilot Study

Persistent organic pollutants (POPs) are organic compounds that resist biochemical degradation, moving long distances across the atmosphere before deposition occurs. Our goal was to provide up-to-date data on the levels of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in breast milk from Chilean women and to estimate the exposure of infants due to breast milk consumption. In Chile, we conducted a cross-sectional study based on methodologies proposed by the WHO, with a sample of 30 women recruited from three defined areas: 10 from the Arica Region (urban; Arica and Parinacota Region), 10 from Coltauco (rural; O'Higgins Region), and 10 from Molina (40% rural; Maule Region). High-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC/HRMS) was performed on pooled samples from each area. We calculated equivalent toxic concentrations (WHO-TEQ) based on the current WHO Toxic Equivalency Factors (TEF). The minimum and maximum values of ∑ PCDDs/Fs + DL-PCBs-TEQ were 4.317 pg TEQ/g fat in Coltauco and 6.31 pg TEQ/g fat in Arica. Molina had a total TEQ of 5.50 pg TEQ/g fat. The contribution of PCDD/Fs was approximately five-fold higher than that of DL-PCBs. The Estimated Daily Intake (EDI) of ∑ PCDDs/Fs + DL-PCBs based on the three pooled samples ranged between 6.71 and 26.28 pg TEQ/kg body weight (bw)/day, with a mean intake of 16.11 (±6.71) pg TEQ/kg bw/day in breastfed children from 0 to 24 months old. These levels were lower than those reported in international studies. Despite the fact that the observed levels were low compared to those in most industrialized countries, the detection of a variety of POPs in breast milk from Chilean women indicates the need for follow-up studies to determine whether such exposures during childhood could represent a health risk in adulthood.

Interspecific and intraspecific variation in organochlorine pesticides and polychlorinated biphenyls using non-destructive samples from Pygoscelis penguins

As humans are present in Antarctica only for scientific and tourism-related purposes, it is often described as a pristine region. However, studies have identified measurable levels of Persistent Organic Pollutants (POPs), such as organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs), in the Antarctic region. These are highly toxic anthropogenic compounds with tendency to travel long distances and reach remote environments, where they can bioaccumulate in the biota. Penguins are exposed to POPs mainly through their diet, which they partially eliminate via feathers. Species of the genus Pygoscelis occur around Antarctic continent and its surrounding regions, and can act as indicators of contaminants that reach the continent. Here, we report OCP and PCB levels in feathers of male and female penguins of P. adeliae, P. antarcticus and P. papua from King George Island, South Shetland Islands, Antarctica. Interspecific, sex- and body-size-related differences were investigated in the contamination profiles of PCBs and OCPs. Feather samples were collected from adult penguins (n = 41). Quantification of compounds was performed by gas chromatography-tandem mass spectrometry. The three Pygoscelis species presented similar contamination profiles, with higher concentrations of dichlorodiphenyltrichloroethane (∑DDT; 1.56-3.82 ng g^-1 dw), lighter PCB congeners (∑PCB: 11.81-18.65 ng g^-1 dw) and HCB (hexachlorobenzene: 1.65-4.06 ng g^-1 dw). Amongst the three penguin species, P. antarcticus had lower and P. papua higher concentrations of most of the compounds identified. We found interspecific differences in POPs accumulation as well as sex differences in POP concentrations. Our data indicate a small but significant positive correlation between body size and the concentrations of some compounds. Despite the overall low concentrations found, this study increases knowledge of the occurrence of POPs in Antarctic penguins, thereby reinforcing concerns that Antarctica, although remote and perceived to be protected, is not free from the impact of anthropogenic pollutants.

Occurrence, Human Exposure, and Risk Assessment of Polybrominated Dibenzo-p-Dioxins and Dibenzofurans, Polychlorinated Naphthalenes, and Metals in Atmosphere Around Industrial Parks in Jiangsu, China

Air samples were collected around industrial parks in Jiangsu, China, to allow the concentrations, profiles, and risk assessment of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), polychlorinated naphthalenes (PCNs), and metals to be investigated. The concentrations of ΣPBDD/Fs and ΣPCNs were 1324.26-2080.98 fg/m³ (11.35-42.57 fg I-TEQ/m³) and 10,404.9-29,322.9 fg/m³ (1.32-7.19 fg I-TEQ/ m³), respectively. The highest concentration of ΣPBDD/Fs and ΣPCNs were observed at site C. PBDD/Fs were mainly dominated by PBDFs. The main contributor to the ΣPBDD/Fs in all samples was 1,2,3,4,6,7,8-HpBDF, which accounted for 25.75%-39.4%. For PCNs, the predominating homologues were tetra-, tri- and penta-CNs, which contributed 30.7%-43.3%, 24.7%-31.0%, and 10.6%-21.6%, respectively. As for metals, the pollution of As, Mn, Cr, and Ni in most samples exceeded National Ambient Air Quality Standards of China. Assessing the risk of inhalation exposure showed that there were potential carcinogenic risks to local residents.