Prediction of the bioaccumulation of PAHs in surface sediments of Bohai Sea, China and quantitative assessment of the related toxicity and health risk to humans

Organic matter sources and distribution along land-use gradient in a Himalayan foothills River: Insights from molecular markers

The analysis of hydrocarbon biomarkers in surface sediments along the Markanda River in the foothills of the Indian Himalayas was conducted to gain insights into the distribution and composition of organic matter (OM) within the sediments. This investigation is essential for comprehending how anthropogenic changes are influencing the OM dynamics in river systems. The study involved identification and quantification of various compound groups such as n-alkanes, hopanes, steranes, polycyclic aromatic hydrocarbons (PAHs), linear alkyl benzenes (LABs) and phthalate esters along with their respective parametric ratios. The variation in distribution of n-alkanes and associated indices (odd-even carbon number predominance (OEP), average chain length (ACL), terrigenous to aquatic ratio (TAR), carbon preference index (CPI), and natural n-alkanes ratio (NAR)) were used to distinguish the natural source of organic content from those influenced by anthropogenic contamination. The detection of petroleum contamination was indicated by the presence of prominent unresolved complex mixtures (UCM) as well as specific petroleum biomarkers such as hopanes, diasteranes, and steranes. The study revealed varying concentrations of the analyzed organic pollutants, with the average of PAHs at 24.6 ng/g dw, LABs at 18.1 ng/g dw, and phthalates at 8.3 μg/g dw. The variability in concentration of the investigated compound groups across different locations indicated spatial heterogeneity, and the land use patterns appears to modulate the sources of OM in surface sediments. The source contribution of PAHs and phthalates determined by positive matrix factorization (PMF) shows the predominant sources of the anthropogenic hydrocarbons were linked primarily to petroleum/petroleum-derived products emissions, industrial discharges, cultural practices and common household waste/sewage disposal. This analysis provides insights for developing mitigation strategies and informing relevant policy changes globally, thereby contributing to the broader understanding of anthropogenic impacts on water ecosystems.

Probabilistic Risk Assessment of Heavy Metals in Mining Soils Based on Fractions: A Case Study in Southern Shaanxi, China

With rapid economic development, soil heavy metal (HM) pollution has emerged as a global environmental concern. Because the toxicity of HMs differs dramatically among various fractions, risk assessments based on these fractions are of great significance for environmental management. This study employed a modified Hakanson index approach to evaluate the possible ecological impacts of soil HMs in a gold mine tailings pond in Shaanxi Province, China. A modified Hakanson-Monte Carlo model was built to perform a probabilistic risk assessment. The results showed that: (1) the exceedance rates of chromium (Cr) and zinc (Zn) were 68.75% and 93.75%, respectively. Moreover, the overall concentrations of nickel (Ni), copper (Cu), arsenic (As), and lead (Pb) were higher than the background soil environmental values in China. (2) HMs with the lowest oxidizable fraction were mostly present in the residual fraction. The oxidizable portions of Cr, Cu, and Pb and the reducible and residual fractions of As were notably distinct. (3) The risk degrees of Cr, Ni, Cu, and Zn were low; those of As and Pb were very high and moderate; and the comprehensive ecological hazard index was very high. This study offers a solid scientific foundation for ecological risk notification and environmental management.

The ban on the sale of new petrol and diesel cars: Can it help control prospective marine pollution of polycyclic aromatic hydrocarbons (PAHs) in Shandong Province, China?

The constantly increasing amount of road vehicles causes massive exhaust emissions of pollutants, including polycyclic aromatic hydrocarbons (PAHs), necessitating a global responsibility to implement the policy of the ban on the sale of new petrol and diesel cars. Here, we assessed the policy control efficiency on marine pollution of PAHs in China through scenario modeling and prediction models, based on pollution monitoring, risk assessment, and source apportionment of PAHs in typical bays of Shandong Province. The results showed that in 2021, the pollution risk levels were relatively low (HI: 0.008-0.068, M-ERM-Q: 0.001-0.016, IBR: 1.23-2.69, ILCR: 8.11 ×10-6-1.99 ×10-5), and PAHs were mainly derived from traffic emissions (24.9%-35.2%), coal combustion (25.2%-32.9%), petroleum (17.2%-28.9%), and biomass combustion (17.6%-22.8%). In 2050, the predicted decrease of pollution risk values after the implementation of the policy was significant (12%-26%), and the gap between 2021 and 2050 was also significantly huge (18%-85%) without considering possible substitution of conventional energy. Collectively, this study built systematic approaches for assessing prospective marine pollution of PAHs. However, due to the particularity of Shandong Province, i.e., its national predominance of conventional energy consumption, the policy may be more effective when it comes to other coastal areas worldwide, calling for a larger scale research.

Spatiotemporal distribution and particle-water partitioning of polycyclic aromatic hydrocarbons in Bohai Sea, China

The Bohai Sea is one of the most polluted marine areas in China with polycyclic aromatic hydrocarbons (PAHs) due to its unique hydrological and geographical environment. To investigate differences in PAH concentrations, composition, and particle-water partitioning before and after the rainy reason, water samples were collected during two surveying voyages covering most of the area of the Bohai Sea. Total and dissolved PAH concentrations were higher during the June voyage (total PAHs: 32.29 ± 15.18 ng/L, dissolved PAHs: 31.25 ± 15.26 ng/L) than the August voyage (total PAHs: 15.98 ± 6.39 ng/L, dissolved PAHs: 11.21 ± 5.59 ng/L). The opposite trend was observed for particulate PAHs (June: 1.04 ± 1.01 ng/L, August: 4.78 ± 2.96 ng/L). Among particulate PAHs, an unusually high proportion (65.07%) of low-molecular-weight (LMW) PAHs was observed during the August voyage, which was significantly higher than the proportion during the June voyage (21.86%). This high proportion was inconsistent with the general distribution of PAHs in the aquatic environment according to their physicochemical properties. The excess LMW PAHs adsorbed on suspended particulate matter arose mainly from soil affected by the petrochemical industry of the Bohai Economic Rim, and were carried with particles on runoff into the Bohai Sea during the rainy season. An estimated 5.49 t of LMW PAHs transitioned from the particulate phase to the dissolved phase during the rainy season. This transfer of LMW PAHs from coastal soil to the water column may be an important source of PAHs in the Bohai Sea.

Pollution characteristics, distribution, and source analysis of carbazole and polyhalogenated carbazoles in coastal areas of Bohai Bay, China

Polyhalogenated carbazoles (PHCZs) are a class of emerging environmental contaminants formed by the substitution of hydrogen on carbazole (CZ) benzene rings with halogens (Cl, Br, I) with potential dioxin-like toxicity, and they have been frequently detected in various environmental media and organisms recently. Nevertheless, co-research of CZ/PHCZs with PAHs is very limited. In addition, I-PHCZs, which are believed to be much more toxic than CZ, Cl-PHCZs and Br-PHCZs, have a few data in sediments previously. The concentration and distribution of CZ/PHCZs and PAHs were analyzed in 18 surface sediments of Bohai Bay, China. There is a significant correlation (R = 0.64, P＜0.05) between PHCZs and PAHs, and principal component analysis (PCA) also indicating that they may have a certain similarity in origin. Additionally, total CZ and PHCZs was up to 230.57 ng/g dw in the studied samples, which was approximately 1-2 orders of magnitude lower than PAHs and other common persistent organic pollutants (POPs). The compositions of the CZ/PHCZs in our study were dominated by CZ (2.74-18.28, median 2.92 ng/g dw), 3,6-dichlorocarbazole (n.d-6.78, median 0.97 ng/g dw) and 3,6-iodocarbazole (n.d-12.68, median 1.65 ng/g dw). Results of this study discovered the varying origins of CZ and PHCZs and/or a complexity of anthropogenic influences and natural sources processes, and revealed a wide distribution of CZ/PHCZs across the studied. Moreover, more attention should be paid by comparing CZ/PHCZs with other widely distributed POPs.

Advancements in Clay Materials for Trace Level Determination and Remediation of Phenols from Wastewater: A Review

The wide spread of phenols and their toxicity in the environment pose a severe threat to the existence and sustainability of living organisms. Rapid detection of these pollutants in wastewaters has attracted the attention of researchers from various fields of environmental science and engineering. Discoveries regarding materials and method developments are deemed necessary for the effective detection and remediation of wastewater. Although various advanced materials such as organic and inorganic materials have been developed, secondary pollution due to material leaching has become a major concern. Therefore, a natural-based material is preferable. Clay is one of the potential natural-based sorbents for the detection and remediation of phenols. It has a high porosity and polarity, good mechanical strength, moisture resistance, chemical and thermal stability, and cation exchange capacity, which will benefit the detection and adsorptive removal of phenols. Several attempts have been made to improve the capabilities of natural clay as sorbent. This manuscript will discuss the potential of clays as sorbents for the remediation of phenols. The activation, modification, and application of clays have been discussed. The achievements, challenges, and concluding remarks were provided.

Prediction of the impact of benzo[a]pyrene on shallow groundwater during natural infiltration of reclaimed water-receiving rivers: A case study of Liangshui, China

The quality of groundwater along rivers is greatly affected by long-term infiltration from surface water, especially reclaimed water-receiving rivers. To predict the degree of influence of contaminated river water on groundwater quality, the spatiotemporal distribution and migration evolution prediction of benzo[a]pyrene (B(a)P) was monitored and simulated by Hydrus-coupled Groundwater Modeling Systems (GMS) model in terms of reclaimed water-receiving Liangshui River. The prediction results indicated the goodness-of-fit of this coupled model, according to the model efficiency (E: 0.78-0.93), the mean absolute error (MAE: 0.01-0.32 m) and the root-mean-square error (RMSE: 0.06-0.35 m). The vertical infiltration rate of B(a)P in the vadose zone was 0.102 m^-1, which was only 0.73% that of water. B(a)P penetrated the 16 m depth vadose zone for 63 years owing to the attenuation function of adsorption and biodegradation, with contribution ratios of 78.4% and 19.3%, respectively. However, once B(a)P intersects with groundwater, the migration of B(a)P is dominated by horizontal migration due to downward movement along the groundwater flow direction. The migration rate of B(a)P in groundwater was 6.65 m/y in the horizontal direction, which was 2.42 and 16.22 times higher than the dispersion rate in the longitudinal and vertical directions, respectively. The spatiotemporal distribution indicated that the B(a)P concentration decreased with the crow-fly distance from river with attenuation rate constants of 1.19 × 10^-4, 3.05 × 10^-4, and 3.67 × 10^-3 m^-1 over horizontal, longitudinal, and vertical direction, respectively, which were negatively correlated with migration rate. However, the B(a)P content increased over the extension of infiltration time with an accumulation rate of 7.3 × 10^-2 d^-1. The migration and accumulation of B(a)P induced potential health risks to groundwater-based drinking water safety, which resulted in the groundwater safety utilization range decreasing from 450 m, 283 m, and 20.1 m-583 m, 338 m, and 28.2 m far from the river over the horizontal, longitudinal, and vertical directions, respectively, 20 years later. This study provides a numerical modeling solution for the viable spatiotemporal evolution of B(a)P in groundwater and an effective decision-making tool for the safe utilization of groundwater as drinking water.

Polycyclic aromatic hydrocarbons (PAHs) in the Bohai Sea: A review of their distribution, sources, and risks

The distribution, risks, and sources of polycyclic aromatic hydrocarbons (PAHs) observed in seawater and sediments in the Bohai Sea were reviewed. The ecological risk of total PAHs in seawater was low, but the ecological risks of several individual PAHs (Pyr, BbF, and IcdP) were high. Detected PAHs in sediments rarely had adverse biological effects. High PAH concentrations were identified in Bohai Bay, in the sea area near Qinhuangdao, in Jinzhou Bay, and in Bohai Strait. Low PAH concentrations were found in the central Bohai, in Laizhou Bay, and in the sea area with more intensive ocean currents near Caofeidian. PAH concentrations in the Bohai Sea present a seaward-decreasing trend. Their spatial distribution could be attributed to the influence of human activities (population, industrial activities, and shipping activities), which determined PAH emissions. The PAHs were characterized by local sources, indicating that coal consumption and vehicle emissions were important sources of PAHs. Integr Environ Assess Manag 2022;18:1705-1721. © 2022 SETAC.

Evolution of polycyclic aromatic hydrocarbons in the surface sediment of southern Jiaozhou Bay in northern China after an accident of oil pipeline explosion

The 2013 "Qingdao oil pipeline explosion" contaminated about 2.5 km of shoreline in the Jiaozhou Bay area and aroused widespread concern because of the serious casualties even though it was not the most severe oil-spill contamination in China. To evaluate the long-term impact, we collected thirty-three surface sediment samples after 3 years of the accident, with sixteen polycyclic aromatic hydrocarbons (PAHs) detected. Spatial-temporal variation in PAHs revealed that a minimal impact might still be present after 3 years. Source analysis combined with a one-way ANOVA showed that pyrolytic sources were consistently predominant. The environmental impact was already minimal 3 years later and negligible thereafter. Although the cancer risk has decreased over the years, there has always been a potential hazard to human for specific occupation, with all of the risk values exceeded 10^-6. This study offers a reference for assessing the long-term impact of oil spills in similar bay areas.

PAHs Source Identification in Sediments and Surrounding Soils of Poyang Lake in China Using Non-Negative Matrix Factorization Analysis

Identifying sources of soil and sediment PAHs and apportioning their contributions are key in building effective pollution abatement strategies, especially for Poyang Lake—the largest freshwater lake in China. PAHs were detected in all the monitored soil and sediment samples under three land use types, with the concentrations varying by area, ranging from moderate to relatively high. The order of PAHs content in different the land use types was as follows: industrial soil > grassland soil > agricultural soil. Although agricultural soil was dominated by LMW PAHs, industrial grassland soils were dominated by HMW PAHs. Based on factor analysis, non-negative matrix factorization analysis was effective in non-negative constrained skew rotation, especially for clear and interpretable source analysis of PAHs.

Ecological risk assessment for organophosphate esters in the surface water from the Bohai Sea of China using multimodal species sensitivity distributions

Organophosphate esters (OPEs) as the foremost substitutes of brominated flame retardants have been ubiquitously found in the aquatic environment around the world. However, the information on the community-level risks induced by OPEs to the marine ecosystem remains scarce. This study adopted ten commonly used species sensitivity distribution (SSD) parametric statistical approaches coupled with the acute-to-chronic transformation for the toxicity data to fit the sensitivity distributions of different species to four major OPE congeners including triethyl phosphate (TEP), tri-n-butyl phosphate (TnBP), tri(2-chloroethyl) phosphate (TCEP), and tris(1-chloro-2-propyl) phosphate (TCPP) in the surface water of the Bohai Sea. All SSD models except Exponential for TnBP, TCEP, and TCPP fitted well the chronic toxicity data for the four OPE congeners. Discrepancies appeared among the best fitting models for different congeners, which also happened to the fitting results from the multiple SSD models for each congener. Based on the best fitting models, the hazard concentrations corresponding to the cumulative probability of 5% were 3.58 mg/L, 0.116 mg/L, 1.30 mg/L, and 1.44 mg/L for TEP, TnBP, TCEP, and TCPP, respectively. The risks induced by the four OPE congeners to the Bohai Sea ecosystem were negligible during the monitoring period because of both the risk quotients and the hazard indexes far <0.1. This study drew a clear picture of the joint ecological risks of TEP, TnBP, TCEP, and TCPP to the Bohai Sea environment. The application of multimodal SSD statistical methods will benefit the accurate derivation of water quality criteria and the community-level ecological risk assessment for pollutants.

Distributions and potential sources of traditional and emerging polycyclic aromatic hydrocarbons in sediments from the lower reach of the Yangtze River, China

This study investigated the current contamination status and potential sources of traditional and emerging polycyclic aromatic hydrocarbons (t-PAHs and e-PAHs) in the sediments across a wide area of the Yangtze River, spanning nine cities. Fifty-seven sediment samples were collected in 2019, from which 15 t-PAHs and 11 e-PAHs were analyzed using GC-MSD. In addition, organic carbon (OC), total nitrogen (TN), and carbon and nitrogen stable isotope ratios (δ¹³C and δ¹⁵N) in sediments were measured to evaluate associations with PAHs contamination. OC, TN, and their stable isotope ratios showed a wide range of site-specific contents and values, indicating high variation in contamination and sources. Concentrations of t-PAHs and e-PAHs in sediments ranged from 0.6 to 200,000 ng g^-1 dry weight (dw) and 1.1 to 20,000 ng g^-1 dw, respectively. Hotspot sites located in Nanjing (PuKou), Taizhou (JingJiang), and Suzhou (ZhangJiaGang). PAHs contamination reflected land use type and human activity in the surrounding area. Positive matrix factorization (PMF) modeling showed that, on average (n = 57), vehicle emissions were the most dominant contribution (57%), followed by petroleum (28%) and fossil fuel combustion (15%). Sites with high PAHs contamination in sediments were of severe ecological risk. Contributions to the potential risks of PAHs were most significant in the order of dibenz[a,h]anthracene, benzo[b]fluoranthene, and benzo[a]pyrene. The primary origin of these compounds appeared to be fossil fuel combustion. The results of this study are expected to provide useful baseline data on the current contamination status and potential sources of traditional and emerging pollutants in the sediments of the Yangtze River, China.

Source apportionment and crop bioaccumulation of perfluoroalkyl acids and novel alternatives in an industrial-intensive region with fluorochemical production, China: Health implications for human exposure

Due to their great environmental hazards, the widely used legacy perfluoroalkyl acids (PFAAs) are gradually restricted, and novel alternatives are being developed and applied. For efficient control of emerging environmental risks in agricultural production, we systematically studied the source apportionment in field soils and bioaccumulation characteristics in multiple crops of 12 PFAAs and five novel alternatives in an industrial-intensive region of China, followed by human exposure estimation and health risk assessment. Compared with perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), shorter-chained PFAAs and novel alternatives have become the dominant components in local soils and crops, indicating their wide application. A positive matrix factorization (PMF) model coupled with multivariate analysis identified fluoropolymer manufacturing and textile treatment as the principal sources. The bioaccumulation factors (BAFs) of individual PFAAs and alternatives in crops decreased with increasing carbon chain lengths. As a novel alternative of PFOA, hexafluoropropylene oxide dimer acid (GenX) exhibited much higher BAFs; for the alternative of PFOS, 6:2 chlorinated polyfluorinated ether sulfonic acid (6:2 Cl-PFESA) showed lower BAFs. The bioaccumulation capacities of PFAAs and alternatives were also associated with soil organic matter and crop species. Through crop consumption, short-chained PFAAs and novel alternatives might pose emerging human health threats.

Legacy and emerging per- and polyfluoroalkyl substances (PFAS) in the Bohai Sea and its inflow rivers

In this study, the occurrence, distribution, sources, and risk of 29 legacy and emerging per- and polyfluoroalkyl substances (PFAS) in four kinds of environmental matrices in the Bohai Sea were investigated. The ∑PFAS concentrations were in the range of 0.40 ~ 61.4 ng/g dry weight (dw) in inflow river sediments, 0.48 ~ 61.4 ng/g dw in soil near river inflow, 0.37 ~ 4.18 ng/g dw in sea sediments, and 13.3 ~ 718 ng/L in seawater. PFAS with eight carbons accounted for > 62.2% by mass, in all samples. Perfluorooctanoic acid (PFOA) was the dominant PFAS both by mass and occurrence. Seawater from Laizhou Bay (south of the Bohai Sea) and sediments of Liaodong Bay (northeast of the Bohai Sea) had the highest levels of ∑PFAS. The sediment-water partition coefficient and organic carbon content normalized partition coefficient (log K_d and log K_oc) were calculated using measured PFAS concentrations to determine their distribution in seawater and sea sediments. The values of log K_d and log K_oc values increased with the increasing CF₂ units for perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkane sulfonic acids (PFSAs). Six primary sources were identified in this region, including aqueous film-forming foams (AFFF), metal plating, food packages, fluorine chemical industry, fluoropolymer manufacture, and domestic pollution. The risk quotient (RQ) values of PFAS were all < 1, indicating that organisms of the Bohai Sea were at low risk of PFAS exposure.

Pollution status of polycyclic aromatic hydrocarbons in surface sediments off the Jiangsu coastal zone, East China: A case study of Rudong

In the current study, 16 congeners of PAHs were measured in 32 surface sediment samples to determine their pollution status in the Jiangsu coastal zone, East China. The total concentrations of the 16 PAHs ranged from 2.2 to 46.6 ng g^-1 with an average of 8.36 ng g^-1 in surface sediments and were significantly lower than those of PAHs in other coastal areas of China. The spatial distribution of PAHs revealed an increasing trend from nearshore to offshore, controlled by the regional sedimentary dynamic environment. Diagnostic ratios and positive matrix factorization demonstrated that petroleum, industries, biomass and coal combustion, and marine and vehicular traffic sources contributed to 28.9%, 25.5%, 24.7%, and 20.9% of the total PAHs, respectively. Risk assessment suggested that the carcinogenic risks were <1 × 10^-4 for all age groups in the area, indicating that long-term seafood consumption does not pose a significant cancer risk in this area.

Perfluoroalkyl acids in rapidly developing coastal areas of China and South Korea: Spatiotemporal variation and source apportionment

Polyfluoroalkyl substances (PFASs) are recognized as emerging contaminants that have captured worldwide attention. They are primarily transported in environments and spread around the globe due to their persistent and bioaccumulative characteristics. In this study, 15 PFASs were detected in major rivers of the rapidly developing coastal areas of China and South Korea. The concentrations and compositions of these PFASs varied greatly between different regions along the coastline. The total concentrations ranged from 14.9 to 16,500 ng L^-1, and the mean concentrations of Σ₁₅PFASs in Liaodong Bay, Bohai Bay, Laizhou Bay, and the west coast of South Korea were 124 ng L^-1, 81.4 ng L^-1, 1550 ng L^-1, and 36.2 ng L^-1, respectively. In Laizhou Bay, the relatively high perfluorooctanoic acid (PFOA) was due to the high usage and manufacturing of PFOA-containing products and contributed 59% of the total compounds. In Liaodong Bay and Bohai Bay, PFBA and PFOA were the most abundant compounds, accounting for >55% of the total compounds. Along the west coast of South Korea, PFBA and PFPeA were the most prevalent compounds, contributing 28% and 24% of the total compounds, respectively. The data collected in the last decade were analyzed to investigate the temporal trends of selected PFASs. The total concentration of Σ₁₀ PFASs decreased in both China and South Korea, while the proportion of short-chain PFASs increased. The proportion of C₄-C₇ PFCAs in South Korea rapidly increased from 46% to 79% but decreased from 49% to 43% in China. The positive matrix factorization (PMF) model successfully addressed the site-specific source apportionment, which showed that 53% of the PFASs in Laizhou Bay were due to fluorine manufacturing. The results of this study provide novel insights into elucidating the spatiotemporal distribution and complicated sources of PFASs over a large area and provide a clear message for all stakeholders, water and coastal managers, and scientists.

An Overview and Evaluation of Highly Porous Adsorbent Materials for Polycyclic Aromatic Hydrocarbons and Phenols Removal from Wastewater

Polycyclic aromatic hydrocarbons (PAHs) and phenolic compounds had been widely recognized as priority organic pollutants in wastewater with toxic effects on both plants and animals. Thus, the remediation of these pollutants has been an active area of research in the field of environmental science and engineering. This review highlighted the advantage of adsorption technology in the removal of PAHs and phenols in wastewater. The literature presented on the applications of various porous carbon materials such as biochar, activated carbon (AC), carbon nanotubes (CNTs), and graphene as potential adsorbents for these pollutants has been critically reviewed and analyzed. Under similar conditions, the use of porous polymers such as Chitosan and molecularly imprinted polymers (MIPs) have been well presented. The high adsorption capacities of advanced porous materials such as mesoporous silica and metal-organic frameworks have been considered and evaluated. The preference of these materials, higher adsorption efficiencies, mechanism of adsorptions, and possible challenges have been discussed. Recommendations have been proposed for commercialization, pilot, and industrial-scale applications of the studied adsorbents towards persistent organic pollutants (POPs) removal from wastewater.

Overall comparison and source identification of PAHs in the sediments of European Baltic and North Seas, Chinese Bohai and Yellow Seas

An international sampling campaign was carried out to comprehensively investigate the occurrence of polycyclic aromatic hydrocarbons (PAHs) in the marine sediments from the European Baltic and North Seas, Chinese Bohai and Yellow Seas. The concentrations of ∑₁₈PAHs in the samples from these four seas were in the range of 0.91-5361 ng/g dry weight (dw), 0.46-227 ng/g dw, 25.0-308 ng/g dw and 4.3-659 ng/g dw, respectively. 4-rings PAHs, e.g., fluoranthene, pyrene and benzo(b)fluoranthene, were commonly the dominant compounds in all the samples. The PAH sources were identified via composition patterns, diagnostic ratios, principal component analysis (PCA) and positive matrix factorization (PMF). Coal combustion, vehicular emission, coke plant and petroleum residue were apportioned as the main sources in these marine sediments. However, through PMF modeling, different contributions of these sources were quantified to the deposited PAHs in the seas, suggesting distinct anthropogenic impacts on the adjacent marine system. It is note-worthy that biomass combustion may not be the main source of PAHs in the majority of sediments from these seas. This was evidenced by the ratios of naphthalene against its methylated derivatives (i.e. 1-,2-methylnaphthalenes) other than the composition pattern in the samples, of which the approach is in prospect of developing in future studies.

Spatiotemporal toxicity assessment of suspended particulate matter (SPM)-bound polycyclic aromatic hydrocarbons (PAHs) in Lake Chaohu, China: Application of a source-based quantitative method

The spatiotemporal associations between the emissions and environmental toxicities of polycyclic aromatic hydrocarbons (PAHs) in lake still remain an issue. Here, we focused on the suspended particulate matter (SPM)-bound PAHs in Lake Chaohu, China to quantitatively estimate their spatiotemporal toxicities from different sources. A source-based quantitative method, positive matrix factorization (PMF)-benzo[a]pyrene-based toxic equivalency (TEQ_BaP) model, was applied. Firstly, we investigated the spatiotemporal characteristics of SPM-bound PAHs. The concentrations of Σ₂₁ PAHs ranged from 1646 to 19267 ng·g^-1. Low-ring PAHs were found to have the highest fractions. T-distributed stochastic neighbor embedding (t-SNE)-partitioning around medoid (PAM) technic revealed significantly spatiotemporal variation characteristics of SPM-bound PAHs in Lake Chaohu. Season, location (west or east lake zone), and sample classification (estuary or lake) together governed the patterns. Then, their potential sources were apportioned. Our results found that diagnostic ratios did not work perfectly. However, 3 factors were separated by PMF model. Unburned petroleum (F1), biomass, coal and gasoline combustion (F2), and diesel, straw combustion (F3) were the main sources of PAHs, accounting for 36.16%, 48.96% and 14.88%, respectively. The patterns of the source profiles were season-dependent. Finally, the toxicity of SPM-bound PAHs from different sources were predicted by PMF-TEQ_BaP model, and the model predictions were satisfactorily acceptable. Overall, predicted Σ₁₉ TEQ_BaP of SPM-bound PAHs in Lake Chaohu ranged from 20.8 to 947.9 ng·g^-1. Benzo[e]pyrene (BeP), benzo[a]pyrene (BaP) and benzo[b]fluoranthene (BbF) were the main toxic species. Temporally, PAH toxicity posed significantly seasonal differences. F3 had primary contributions to Σ₁₉ TEQ_BaP. Cutting the diesel consumption and using cleaner energy substitutes were suggested to reduce the PAH toxicity in Lake Chaohu. Overall, we expected this study could give new insights into the spatiotemporal associations between the sources and toxicities of SPM-bound PAHs in lake ecosystem.

PAES and PAHs in the surface sediments of the East China Sea: Occurrence, distribution and influence factors

A total of 29 sediment samples were collected from the East China Sea (ECS), with the Yangtze River estuary and the Zhejiang costal area. These sediment samples were analyzed for 6 phthalate esters (PAEs) and 16 polycyclic aromatic hydrocarbons (PAHs): the ΣPAEs and ΣPAHs concentrations ranged between 1649.5 and 8451.5 ng g^-1 (mean = 3446.3 ng g^-1) and 57.5-364.5 ng g^-1 (mean = 166.2 ng g^-1), respectively. Overall, the PAEs and PAHs concentrations gradually decreasing in the offshore and southward directions: their compositions and distributions suggest they could have mainly derived from the Yangtze River. In particular, their distribution was influenced by the sources' proximity, hydrodynamics, and sediment geochemistry (i.e., TOC content and grain size). A classical two-end member model was utilized to estimate the fraction of terrestrial organic carbon in the sediments of the ECS. When the sediment was dominated by terrestrial-derived organic matter (OM), the concentrations of PAEs and PAHs were significantly correlated to the TOC content and gran size of the sediments. In contrast, the poor correlation of TOC content and grain size with PAEs in those sediments dominated by marine-derived OM, implied that the distribution of PAEs in the ECS was mainly related to land-based inputs, (especially to that of the Yangtze River). Regardless of the origin of most of the OM contained in the sediments, we observed positive correlations between the TOC content, and grain size of those containing PAHs. These results suggest that the distribution of PAHs in the ECS was not only related to the Yangtze River input, but also to the geochemical characteristics of the sediments.

Annual changes in concentrations and health risks of PCDD/Fs, DL-PCBs and organochlorine pesticides in ambient air based on the Global Monitoring Plan in São Paulo

Ambient air contains a number of persistent organic pollutants (POPs), to which inhalation exposure has drawn worldwide concern. However, information regarding annual changes in the concentrations and health risks of POPs in the ambient air of São Paulo, Brazil, are limited. This study provides comprehensive information on annual changes in polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), dioxin-like polychlorinated biphenyls (DL-PCBs), and 10 groups of organochlorine pesticides (OCPs) in the ambient air of São Paulo between 2010 and 2015 based on the Global Monitoring Plan. The mass concentrations of the studied POPs (PCDD/Fs, DL-PCBs, and OCPs) showed declining trends from 2010 to 2015 (from 2.65 × 10^-2 to 1.33 × 10^-2 pg m^-3, from 9.89 × 10^-2 to 3.12 × 10^-2 pg m^-3, and from 0.313 to 0.100 ng m^-3, respectively), which might be due to the decrease of non-intentional emissions. The carcinogenic risk (CR) and non-carcinogenic risk (Non-CR) of the studied POPs were 1.48 × 10^-11 to 6.08 × 10^-7 and 3.44 × 10^-8 to 3.34 × 10^-3, respectively, which are lower than the generally accepted threshold values (10^-6/10^-5 and 1 for CR and Non-CR, respectively), suggesting that the health risks posed by the studied POPs were acceptable. PCDD/Fs had the highest CR (6.08 × 10^-8-4.81 × 10^-7), whereas the 95th percentile CR of DL-PCBs and nine of the OCPs were lower than 10^-7, suggesting that among the studied POPs, PCDD/Fs in the ambient air warrant special attention. The 95th percentile CRs of dichlorodiphenyltrichloroethane (2.30 × 10^-8), dieldrin (1.30 × 10^-8), hexachlorocyclohexanes (1.05 × 10^-8), heptachlor (8.97 × 10^-9), hexachlorobenzene (6.47 × 10^-9), chlordane (5.89 × 10^-9), heptachlor epoxide (1.42 × 10^-9), aldrin (1.33 × 10^-9), and mirex (2.71 × 10^-10) in ambient air were relatively low, suggesting that their threats to human health were negligible. In general, PCDD/Fs, DL-PCBs, and OCPs in the ambient air of São Paulo did not pose serious threats to human health during 2010-2015.

Source apportionment and seasonal cancer risk of polycyclic aromatic hydrocarbons of sediments in a multi-use coastal environment containing a Ramsar wetland, for a Caribbean island

Although polycyclic aromatic hydrocarbons (PAHs) are toxic pollutants for which some are known carcinogens, there is limited information on the cancer risk such substances pose to the population via marine sediments, despite a significant part of the world's food supply being derived from the coastal environment. This study was conducted in a heavily industrialized and urbanized coastal area, in Trinidad. PAHs were quantified in sediments during the dry and wet seasons and were observed to be significantly higher in the wet season compared to the dry season. Also emerging from this study is that PAH levels were lower, in the areas where natural gas is the dominant energy source for industries, compared with those areas where crude oil-based fossil fuel is predominantly used. Perylene levels were demonstrated to be of biogenic origin near the protected wetland area. It was observed that nearshore sediment PAHs concentrations were higher than offshore levels. The sources of PAHs, identified by Positive Matrix Factorization (PMF) in the marine sediments, were vehicular combustion of gasoline and diesel, biomass burning, industrial combustion and oil spills. The mean Incremental Lifetime Cancer Risks (ILCR) due to fish consumption from this region during the dry and wet seasons was >1 × 10^-4, indicating a high cancer risk to the human population. The annual non-cancer risk (HQ) was high >1 at the 90th percentile level with an adverse risk to about 14% of the population. These results can be utilized for developing an effective environmental management policy for coastal areas in Trinidad and the wider Caribbean region, given that much of the islands' populations depend on the coastal regions for seafood. In addition, these results may assist in boosting current efforts of policymakers, towards phasing out crude oil-based fossil fuels for cleaner energy sources, such as compressed natural gas.

Distribution, partitioning behavior and positive matrix factorization-based source analysis of legacy and emerging polyfluorinated alkyl substances in the dissolved phase, surface sediment and suspended particulate matter around coastal areas of Bohai Bay, China

The concentrations and spatial occurrences of 17 legacy per- and polyfluoroalkyl substances (PFAS) and 4 emerging PFAS in the coastal water-dissolved phase, surface sediment phase and suspended particulate matter (SPM) in the coastal areas of Bohai Bay were investigated. In addition, the partition behaviors of PFAS in the water-SPM system and water-sediment system and the potential sources of PFAS in the marine environment were revealed. The total concentrations of PFAS (∑PFAS) in the water-dissolved phase, surface sediment and SPM were 20.5-684 ng/L, 2.69-25.0 ng/g dry weight (dw) and 4.39-527 ng/g dw, respectively. The level of PFAS contamination in the coastal areas of Shandong Province was higher than that in other areas. The average partition coefficients (log K_d) of PFAS in the water-SPM system and water-sediment system were 1.56-3.57 and 0.72-2.95, respectively. Long-chain PFAS and PFECHS (perfluoroethylcyclohexane sulfonate) have a higher log K_d than that of short-chain PFAS. PFAS with short carbon chains were mainly detected in the water-dissolved phase, but long-chain PFAS mainly occurred in the surface sediment and SPM phases. Source analysis based on the positive matrix factorization (PMF) model found that erosion inhibitor factories, aqueous film-forming foam factories, metal plating plants, fluoropolymer chemical manufacture and food contact materials were the main sources of PFAS in Bohai Bay. These results improved our understanding of the partitioning behavior and sources of PFAS in aquatic environments.

Investigation into Photoinduced Auto-Oxidation of Polycyclic Aromatic Hydrocarbons Resulting in Brown Carbon Production

Brown carbon (BrC) is a collection of oxidized atmospheric aromatic compounds detected worldwide with broad functionality. This multifunctional nature allows BrC to be water-soluble and bioavailable and demonstrate light absorption at multiple wavelengths. Polycyclic aromatic hydrocarbons (PAH) are major primary products of combustion emissions and have long been known to oxidize in the environment as components of secondary organic aerosols. In this study, we have exposed aqueous PAH suspensions to simulated sunlight to investigate oxidized PAH as BrC precursors. Illuminated samples of naphthalene and anthracene demonstrated growth of several new products with absorptions and oxidation consistent with humic-like substances (HULIS). Reactions of aqueous naphthalene, anthracene, and their oxidized derivatives were found to produce chromatographic and spectroscopic evidence of HULIS formation when exposed to sunlight. The association of oxyradicals with HULIS has implications on human health via lung tissue damage; and its absorption character may add to radiative forcing processes in the atmosphere. The overall product characterizations from naphthalene and anthracene indicate reaction mechanism pathways that use oxidized alcohol and quinone as intermediate species.

RETRACTED: Threats of indicator polychlorinated biphenyls (PCBs) in six molluscs from market to food safety: A case study in Haikou City, China

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the Editor-in-Chief and Authors. The article is a duplicate of a paper that has already been published in the Chinese language in the Journal of Ecology and Rural Environment, 34 (2018) 1091-1095. doi:10.11934/j.issn.1673-4831.2018.12.005). One of the conditions of submission of a paper for publication is that authors declare explicitly that the paper has not been previously published and is not under consideration for publication elsewhere. As such this article represents a misuse of the scientific publishing system. The scientific community takes a very strong view on this matter and apologies are offered to readers of the journal that this was not detected during the submission process.

Determination of 16 PAHs and 22 PCBs in honey samples originated from different region of Lebanon and used as environmental biomonitors sentinel

In order to assess the air quality in some Lebanese regions, a biomonitoring study based on honey as biomonitor candidate was conducted. For this, 18 samples of honey collected from four regions in Lebanon, were analyzed for their contamination by 16 polycyclic aromatic hydrocarbons (PAHs) and 22 polychlorinated biphenyls (PCBs). Samples were first extracted using a multi-residue extraction method based on the quick, easy, cheap, effective, rugged, and safe extraction method (QuEChERS) followed by a concentration step using Solid-phase microextraction (SPME) procedures. The extraction was then followed by chromatographic analysis by gas chromatography-ion-trap tandem mass spectrometry (GC-MS/MS). After PAHs samples assessment, different ratios of founded PAHs were calculated in order to estimate the sources of the pollution by these compounds. The obtained results showed that the four analyzed regions were contaminated with PAHs originated from both pyro and petro genic sources while none of them was found to be contaminated by any of the 22 assessed PCBs. The results of this study show that honey can be used as potential biomonitor candidate allowing the assessment of the pollution statement of a given environment.

Micropollutants removal and health risk reduction in a water reclamation and ecological reuse system

As reclaimed water use is increasing, its safety attracts growing attention, particularly with respect to the health risks associated with the wide range of micropollutants found in the reclaimed water. In this study, sophisticated analysis was conducted for water samples from a water reclamation and ecological reuse system where domestic wastewater was treated using an anaerobic-anoxic-oxic unit followed by a membrane bioreactor (A²O-MBR), and the reclaimed water was used for replenishing a landscape lake. A total of 58 organic micropollutants were detected in the system, consisting of 13 polycyclic aromatic hydrocarbons (PAHs), 16 phenols, 3 pesticides, and 26 pharmaceuticals and personal care products (PPCPs). After treatment by the A²O-MBR process, effective removal of pesticides and phenols was achieved, while when the reclaimed water entered the landscape lake, PPCPs were further removed. From the physicochemical properties of micropollutants, it could be inferred that phenols and dichlorphos (the only pesticide with considerable concentration in the influent) would have been mainly removed by biodegradation and/or volatilization in the biological treatment process. Additionally, it is probable that sludge adsorption also contributed to the removal of dichlorphos. For the predominant PPCP removal in the landscape lake, various actions, such as adsorption, biodegradation, photolysis, and ecologically mediated processes (via aquatic plants and animals), would have played significant roles. However, according to their logK_oc, logK_ow and logD (pH = 8) values, it could be concluded that adsorption by suspended solids might be an important action. Although carcinogenic and non-carcinogenic risks associated with all the detected micropollutants were at negligible levels, the hazard quotients (HQs) of PPCPs accounted for 92.03%-97.23% of the HQ_Total. With the significant removal of PPCPs through the ecological processes in the landscape lake, the safety of reclaimed water use could be improved. Therefore, the introduction of ecological unit into the water reclamation and reuse system could be an effective measure for health risk reduction posed by micropollutants.

Emission characteristics of PCDD/Fs in stack gas from municipal solid waste incineration plants in Northern China

Emission characteristics including congener's profile, gas emissions and toxic equivalent concentration (TEQ) indicators of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in 57 stack gas samples from 6 municipal solid waste incinerators (MSWIs) in Northern China were investigated by gas chromatography-high resolution mass spectrometry (HRGC-HRMS). Additionally, PCDD/Fs formation mechanisms from the MSWIs were briefly discussed. Results revealed that the concentrations and equivalent concentrations of PCDD/Fs emissions in stack gas from 6 MSWIs were in the range of 0.11-2.53 ng Nm^-3 and 0.007-0.059 ng TEQ Nm^-3, respectively. The emission factors of PCDD/Fs from 6 MSWIs varied from 0.027 to 0.225 μg I-TEQ tonne^-1, with a mean value of 0.17 μg I-TEQ tonne^-1 waste, which was estimated to an annual emission of 234.96 mg I-TEQ of PCDD/Fs from 6 MSWIs to the atmosphere. O8CDD, O8CDF and 1,2,3,4,6,7,8-H7CDD were the indicatory compounds of PCDD/Fs to apportion the sources of PCDD/Fs in environmental medium especially in ambient environment of MSWIs. 1,2,3,7,8,9-H6CDF and 1,2,3,4,7,8-H6CDF can be used as TEQ indicators for monitoring PCDD/Fs emission. Based on the positive matrix factorization (PMF) model, eight factors were extracted by the PMF analysis. Formation of low-chlorinated PCDDs (1,2,3,7,8-P5CDD, 1,2,3,4,7,8-H6CDD, 1,2,3,6,7,8-H6CDD and 1,2,3,7,8,9-H6CDD) possessed strong correlation, and the chlorophenols maybe the important precursors of low-chlorinated PCDDs, which were generated within the low chlorinated content. Penta- and hexa-PCDFs formation in stack gas from MSWI may block catalytic sites for PCDFs formation from carbon. Meanwhile, possible formation mechanisms of high-chlorinated PCDDs (hepta- and octa-PCDDs) and high-chlorinated PCDFs (hepta- and octa-PCDFs) were respectively dependent.

Source identification and ecological impact evaluation of PAHs in urban river sediments: A case study in Taiwan

The Love River and Ho-Jin River, two major urban rivers in Kaohsiung City, Taiwan, are moderately to heavily polluted because different types of improperly treated wastewaters are discharged into the rivers. In this study, sediment and river water samples were collected from two rivers to investigate the river water quality and accumulation of polycyclic aromatic hydrocarbons (PAHs) in sediments. The spatial distribution, composition, and source appointment of PAHs of the sediments were examined. The impacts of PAHs on ecological system were assessed using toxic equivalence quotient (TEQ) of potentially carcinogenic PAHs (TEQ^carc) and sediment quality guidelines. The average PAHs concentrations ranged from 2161 ng/g in Love River sediment to 160 ng/g in Ho-Jin River sediment. This could be due to the fact that Love River Basin had much higher population density and pyrolytic activities. High-ring PAHs (4-6 rings) contributed to 59-90% of the total PAHs concentrations. Benzo(a)pyrene (BaP) had the highest toxic equivalence quotient (up to 188 ng TEQ/g). Moreover, the downstream sediments contained higher TEQ of total TPHs than midstream and upstream sediment samples. The PAHs were adsorbed onto the fine particles with high organic content. Results from diagnostic ratio analyses indicate that the PAHs in two urban river sediments might originate from oil/coal combustion, traffic-related emissions, and waste combustion (pyrogenic activities). Future pollution prevention and management should target the various industries, incinerators, and transportation emission in this region to reduce the PAHs pollution.

Levels, sources and probabilistic health risks of polycyclic aromatic hydrocarbons in the agricultural soils from sites neighboring suburban industries in Shanghai

The levels, sources and quantitative probabilistic health risks for polycyclic aromatic hydrocarbons (PAHs) in agricultural soils in the vicinity of power, steel and petrochemical plants in the suburbs of Shanghai are discussed. The total concentration of 16 PAHs in the soils ranges from 223 to 8214ng g^-1. The sources of PAHs were analyzed by both isomeric ratios and a principal component analysis-multiple linear regression method. The results indicate that PAHs mainly originated from the incomplete combustion of coal and oil. The probabilistic risk assessments for both carcinogenic and non-carcinogenic risks posed by PAHs in soils with adult farmers as concerned receptors were quantitatively calculated by Monte Carlo simulation. The estimated total carcinogenic risks (TCR) for the agricultural soils has a 45% possibility of exceeding the acceptable threshold value (10^-6), indicating potential adverse health effects. However, all non-carcinogenic risks are below the threshold value. Oral intake is the dominant exposure pathway, accounting for 77.7% of TCR, while inhalation intake is negligible. The three PAHs with the highest contribution for TCR are BaP (64.35%), DBA (17.56%) and InP (9.06%). Sensitivity analyses indicate that exposure frequency has the greatest impact on the total risk uncertainty, followed by the exposure dose through oral intake and exposure duration. These results indicate that it is essential to manage the health risks of PAH-contaminated agricultural soils in the vicinity of typical industries in megacities.

Phthalates, heavy metals and PAHs in an overpopulated coastal region: Inferences from Abruzzo, central Italy

Phthalates are an emerging class of environmental pollutants whose distribution and effects in aquatic environments are not well characterized. We analyzed intertidal and emerged beach sediments from the Abruzzo coastline, along the Adriatic Sea, finding significant phthalate concentrations in marine sediments. Phthalate baseline levels in the intertidal environment, marked by substantial interplay of sediment, water and air, were determined. We used statistical rank methods to select representative phthalate compositions, for which we derived risk levels for ingestion, dermal absorption and inhalation. Our study shows that phthalates are a major cause of pollution along the Abruzzo coast, with river transport of sediments a continuous source of replenishment. Phthalate concentrations in two specific sites were determined to be of the same order of magnitude as the safety, remediation-warranting, threshold set by Italian law. Phthalates, heavy metals, PAHs appear to be correlated. We discuss possible intervention and mitigation strategies.

Chlorinated polycyclic aromatic hydrocarbons in surface sediment from Maowei Sea, Guangxi, China: occurrence, distribution, and source apportionment

Chlorinated polycyclic aromatic hydrocarbons (ClPAHs) with three to five aromatic rings have been documented to ubiquitously occur in environmental matrices. In this study, residual concentrations and profiles of 20 individual ClPAHs were determined in 35 surface sediment samples from Maowei Sea, a semi-enclosed shallow inland bay located in the northwestern part of South China Sea. The concentrations of ΣClPAHs in sediment ranged from 313 to 9650 pg/g dw with a detection rate of 43-100%. Of the individual ClPAH congeners, 9-ClPhe was the most abundant in Maowei Sea with the concentrations that ranged from 99.9 to 3610 pg/g dw (mean 1120 pg/g dw). High-molecular-weight ClPAH congeners (four to five rings) were predominant in sediments from sampling locations near a petrochemical industrial complex, whereas low-molecular-weight ClPAH congeners (three rings) were predominant in sediments from estuarine and mangrove locations. A positive matrix factorization (PMF) model in combination with dioxin-like toxic equivalency quotient (TEQ) results was used to apportion sources of ClPAHs. Vehicular emission, combustion/chemical industrial processes, and two other unknown sources accounted for 40.1, 25.5, 20.8, and 13.6%, respectively, of ClPAH sources in sediment; their contribution to TEQs in sediments were 24.2, 40.5, 19.3, and 16.0%, respectively. Further investigations are needed to elucidate potential sources and ecological risks of ClPAHs in sediments.

PCDD/Fs distribution characteristics and health risk assessment in fly ash discharged from MSWIs in China

This study provided distribution and health risk information of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in fly ash from 4 municipal solid waste incinerators (MSWIs) in four seasons from four sites, including Zhengzhou City in Henan Province, Chuzhou City in Anhui Province, Jilin City in Jilin Province and Zibo City in Shandong Province. The toxic equivalent concentration (I-TEQ) values of PCDD/Fs ranged from 0.0707 to 0.7742ng I-TEQ/g, and no identical sequence occurred during four seasons in different sampling sites. The stabilization process might efficiently reduce the content and toxicology of PCDD/Fs in fly ash. The value of PCDD/PCDF in fly ash ranged from 0.145 to 0.787 after solidification. The characteristic index (DCI) of 2,3,4,7,8-P₅CDF was 0.803 with 6.6% under 95% probability for fly ash samples discharged from MSWIs. The 95th percentile carcinogenic risks (CRs) for onsite workers were lower than the threshold value (10^-5), suggesting that the cancer risk levels of PCDD/Fs in fly ash for onsite workers were acceptable. The 95th percentile non-carcinogenic risks (non-CRs) for onsite workers were lower than 1, suggesting no obvious non-carcinogenic effect was developed for onsite workers. This paper provide an overview information on the distribution of PCDD/Fs in fly ash during four seasons, and it could be used as an important fingerprint to distinguish the fly ash sources. Thus, the research could provide basic information for fly ash management in environment.

Did municipal solid waste landfill have obvious influence on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in ambient air: A case study in East China

Municipal solid waste (MSW) landfill was a main way to disposal of MSW and almost 95% of MSW was disposed by landfills in the world. In order to understand the influence of MSW landfill on polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) in surrounding atmosphere, 42 ambient air samples were collected and analyzed from surrounding sites, background site, upwind site and downwind site of a MSW landfill in East China. The results of present study were summarized as follows. (1) The total concentrations of PCDD/Fs (∑PCDD/Fs) in ambient air from surrounding sites, background site, upwind site and downwind site were 2.215±1.004, 2.058±0.458, 2.617±1.092 and 1.822±0.566pgNm^-3, respectively. (2) The toxic equivalent concentrations (TEQ) of PCDD/Fs in ambient air from surrounding sites, background site, upwind site and downwind site were 0.103±0.017, 0.096±0.015, 0.120±0.024 and 0.108±0.014pg I-TEQNm^-3, respectively. (3) The congener profiles, ∑PCDD/Fs and TEQ between background atmosphere and surrounding atmosphere of landfill did not show statistically significant difference. (4) The ∑PCDD/Fs and TEQ in ambient air of downwind site were not higher than that of upwind site, suggesting that studied landfill did not have obvious influence on PCDD/Fs in ambient air from downwind site. (5) The 95th percentile carcinogenic risk (CR) of PCDD/Fs in ambient air from surrounding sites, background site, upwind site and downwind site were 8.03×10^-9, 7.57×10^-9, 9.69×10^-9 and 8.15×10^-9, respectively, which were much lower than the threshold value of CR (10^-6), suggesting that studied landfill did not influence the CR of PCDD/Fs in surrounding atmosphere and negligible cancer risk occurred. (6) The non-carcinogenic risk (non-CR) analysis indicated that landfill did not have influence on the non-CR of PCDD/Fs in surrounding atmosphere and no obvious non-carcinogenic effects developed.

Occurrences, composition profiles and source identifications of polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments

The aim of this study was to investigate the levels of persistent organic pollutants (POPs) including polycyclic aromatic hydrocarbons (PAHs), polybrominated diphenyl ethers (PBDEs) and polychlorinated biphenyls (PCBs) in ship ballast sediments. The ballast sediment samples were collected from six merchant ships docked in 2015 in Jiangyin City, China. Ballast sediments represent a potential vector for the transport of POPs and invasive species between marine environments. An attempt was also made to determine the sources of these compounds in the ballast sediment. The results indicated ballast sediments generally contain greater amounts of BDE-209 and comparable amounts of PAHs, PBDEs (exclusive of BDE-209) and PCBs compared to those in marine surface sediments. Based on the sediment quality guidelines, PAHs and PCBs in ballast sediments were estimated to have median or high potential of posing ecological risks, respectively, to marine life if ballast sediments were disposed without specific treatment. POPs in ballast sediments were derived from multiple sources with atmospheric deposition being an important origin. Ship activities including diesel exhaust and illegal oil sewage discharge were considerable contributors of certain individual POPs to ballast sediments. Our study is important because it represents the first report on levels, health risk assessment and source apportionments of POPs in ballast sediments and is a first step in the implementation of specific ballast sediment management measures.

Emission characteristic of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from medical waste incinerators (MWIs) in China in 2016: A comparison between higher emission levels of MWIs and lower emission levels of MWIs

Emission characteristic of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) from 12 medical waste incinerators (MWIs) which have a total yearly capacity of 523 440 ton medical waste and accounted for 8.1% of total yearly capacity of 246 MWIs in China were studied. The congeners profile, emissions and toxic equivalent concentrations (TEQ) indicators of PCDD/Fs in stack gas from two groups of MWIs were researched, and the possible formation mechanisms of PCDD/Fs from MWIs were preliminarily discussed. The results of present study were summarized as follows. (1) The total concentrations and TEQ of PCDD/Fs in stack gas from MWIs were 0.516-122.803 ng Nm^-3 and 0.031-3.463 ng I-TEQ Nm^-3, respectively. (2) 1,2,3,4,6,7,8-H7CDF, O8CDD, O8CDF and 1,2,3,4,6,7,8-H7CDD were the indicatory PCDD/Fs of MWI source, which could be used to apportion the sources of PCDD/Fs in environmental medium in China. (3) The emission factors of PCDD/Fs from MWIs ranged from 32.7 to 4900.0 ng I-TEQ ton^-1 with a mean of 1923.6 ng I-TEQ ton^-1. (4) The gas emissions of PCDD/Fs from researched 12 MWIs and all of MWIs in China in 2016 were 37.742 and 465.951 mg I-TEQ year^-1, respectively. (5) 1,2,3,7,8,9-H6CDF and 1,2,3,4,7,8-H6CDF were effective TEQ indicators for the real-time monitoring of the PCDD/Fs emission. (6) The congeners profile and factor composition of PCDD/Fs in stack gas from two groups of MWIs were researched based on positive matrix factorization (PMF) model, and the possible formation mechanisms of PCDD/Fs from MWIs were preliminarily discussed.

The use of conifer needles as biomonitor candidates for the study of temporal air pollution variation in the Strasbourg region

The continuous emission of polluting chemicals into the atmosphere requires the implementation of monitoring of ambient air quality. The use of vegetation for environmental monitoring can be considered as a simple monitoring technique by providing a cheap and accessible matrix. In this study, needles of two conifers (Pinus nigra and Cedrus atlantica), were used for the consecutive biomonitoring of multipollutants such as pesticides, polychlorinated biphenyls, and polyaromatic hydrocarbons (PAHs) in an urban area in Strasbourg (France). The extraction was performed by accelerated solvent extraction, solid-phase extraction, and solid-phase microextraction and was followed by gas chromatography coupled to tandem mass spectrometry and liquid chromatography coupled to tandem mass spectrometry analyses. The results obtained for conifer samples collected in 5 successive weeks (April 09-May 07, 2015) show a similar variation of the different types of pollutants. A pollution peak was observed during the second week of analysis, and the concentration of all pollutants then decreased to complete disappearance at the end of the sampling period. PAHs were the most concentrated with a total concentration of about 35.87 ng g^-1, and naphthalene was, among these pollutants, the most concentrated with a total concentration of about 15.1 ng g^-1. The analysis of meteorological data during this period suggests that the results correlated with climatic conditions that widely vary during this period of the year. The results show that the concentration peak was obtained when no precipitation was detected.

Comparative study of the intake of toxic persistent and semi persistent pollutants through the consumption of fish and seafood from two modes of production (wild-caught and farmed)

Adverse effects of chemical contaminants associated with seafood counteract the undoubted benefits for the health of its valuable nutrients. So much so that many dietary guidelines recommend no more than one serving a week of fish and seafood. Although is estimated that aquaculture provides more than 50% of the fish and seafood consumed globally, few research studies have focused in the assessment of the intake of pollutants through aquaculture products. In this study we determined the levels of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and toxic elements (Pb, Cd, Ni, Al, As, and Hg) in a large sample of farmed and wild-caught seafood, and we estimated the intake of these contaminants in two hypothetical models of consumers: those consuming only farmed fish, and those consuming only wild fish. Measured levels of most organic and many inorganic pollutants were higher in aquaculture products, and consequently intake levels if only such products were consumed would be also significantly higher. Thus, the intake of ∑PAHs in adults consuming aquaculture seafood would be 3.30ng/kg-bw/day, and consuming seafood from extractive fishing 2.41ng/kg-bw/day (p<0.05); ∑OCPs, 3.36 vs. 1.85ng/kg-bw/day, respectively (p<0.05); ∑PCBs, 2.35 vs. 2.11ng/kgbw/day, respectively; and the intake of Pb, Ni, As, and Al would be also significantly higher consuming farmed seafood. For children the estimations were very similar, but the difference of intake of PCBs reached statistical significance. The implementation of several decontamination practices in aquaculture would allow not only match the levels of pollution from wild-caught seafood, but also could provide products with much lower levels of pollutants than those, which in turn would allow to increase consumption over the "one serving per week", and so benefit the consumer of the enormous positive health effects of the valuable nutrients of seafood.

Composition profiles and health risk of PCDD/F in outdoor air and fly ash from municipal solid waste incineration and adjacent villages in East China

In present study, composition profiles and health risk of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in outdoor air and fly ash from domestic waste treatment center (DWTC) were studied. In addition, the composition profiles and health risk of PCDD/F in outdoor air from adjacent villages were researched and used to quantitatively analyze the difference between onsite workers and adjacent villagers. Moreover, the difference between old intake method and new inhalation dosimetry method in the process of assessing the health risk of PCDD/Fs in outdoor air was quantitatively compared and analyzed. The results of this study were summarized as follows. (1) The 95th percentile carcinogenic risk (CR) and non-carcinogenic risk (non-CR) for onsite workers and adjacent villagers were much lower than the threshold values of 10(-6) and 1.0, respectively, suggesting no potential health risk. (2) The 95th percentile CR for onsite workers was 1.27×10(-8) and was 64.8 times higher than that of adjacent villagers (1.99×10(-10)). (3) The 95th percentile non-CR for onsite workers and adjacent villagers were 1.37×10(-4) and 1.31×10(-7), respectively. (3) Accidental ingestion of fly ash was the largest contributor to CR and non-CR for onsite workers, contributing 62.98% and 64.04% to CR and non-CR, respectively. (4) The CR and non-CR of PCDD/Fs in outdoor air for onsite workers and adjacent villagers which calculated by old intake method was much higher than the results from new inhalation dosimetry method. The results quantitatively showed the levels and potential risks of PCDD/Fs posed by a DWTC site, which can be helpful to predict the influence from DWTC sites and promote the management of DWTC in China.

Composition profiles, monthly changes and health risk of PCDD/F in fly ash discharged from a municipal solid waste incinerator (MSWI) in Northeast China

Monthly changes and health risk of PCDD/Fs in fly ash which was one of hazardous wastes from municipal solid waste incinerator (MSWI) were studied.