Occurrence and partition of organochlorine pesticides (OCPs) in water, sediment, and organisms from the eastern sea area of Shandong Peninsula, Yellow Sea, China

Assessment of persistent and emerging pollutants levels in marine bivalves in the Gulf of Suez, Egypt

Bivalves possess important ecological and economic values. They have been extensively used as bioindicators for both emerging and classical pollutants in the aquatic environment. This study investigates the levels of trace metals, polycyclic aromatic hydrocarbons (PAHs), and organochlorine pesticides (OCPs), alongside microplastic (MPs), in Tridacna maxima, Paphia textile, and Paratapes undulatus, collected from the Gulf of Suez. This work represents the first investigation of MPs in marine bivalves from the Gulf of Suez. MPs were detected in 72% of the specimens examined and four types of MPs were identified. The metal pollution index indicated that bivalves may have long-term toxic effects on human consumers. The results showed minimal hydrocarbon pollution. Diagnostic ratios indicated a combination of pyrolytic and petrogenic sources, with a notable influence from pyrolytic origins. The risk assessment reflected that the levels of certain trace metals, PAHs, and OCP contaminants could present a low risk to human health.

Neonicotinoid insecticides in well-developed agricultural cultivation areas: Seawater occurrence, spatial-seasonal variability and ecological risks

Neonicotinoids (NEOs) are widely used insecticides and have been detected in aquatic environments globally. However, little is known about NEOs contamination in the coastal environments under the terrestrial pressure of multiple planting types simultaneously. This study investigated the occurrence, spatial-seasonal variability, and ecological risks of NEOs along the coast of the Shandong Peninsula during the dry and wet seasons, where located many largest fruit, vegetable, and grain production bases in China. The concentrations of ∑NEOs in seawater were higher in wet seasons (surface: 195.46 ng/L; bottom: 14.56 ng/L) than in dry seasons (surface: 10.07 ng/L; bottom: 8.45 ng/L). During the wet seasons, NEOs peaked in the northern and eastern areas of the Shandong Peninsula, where the inland fruit planting area is located. While dry seasons had higher concentrations in Laizhou Bay, influenced by rivers from vegetable-growing areas. Grain crops, fruit, and cotton planting were major NEOs sources during wet seasons, while wheat and vegetables dominated in dry seasons. Moderate or above ecological risks appeared at 53.8% of the monitoring sites. Generally, NEOs caused high risks in the wet seasons mainly caused by Imidacloprid, and medium risk in the dry seasons caused by Clothianidin, which should be prevented and controlled in advance.

Determination of pesticide residue in marginal lagoons of natural parks in Brazil using an improved calibrate passive sampler

Passive sampling is a sensitive and efficient method for analyzing pesticides in water. This article describes a hollow fiber liquid-phase microextraction (HF-LPME) device that was improved using polypropylene membranes grafted with nanocellulose for the passive sampling of pesticides in water. A comprehensive gas chromatography time-of-flight mass spectrometry (GCxGC/Q-TOFMS) system was used to separate, identify, and quantify pesticides. The sampling rates of 38 moderately hydrophobic to hydrophobic agricultural pesticides (2.18 < log Kow < 6.89) from different chemical classes, including the main triazine, organochlorine and organophosphate compounds, were calculated. A calibration process was applied to evaluate the role of flow velocity and select potential candidates for a possible performance reference compound (PRC). Sampling rates varied between 0.17 mL d-1 and 23.15 mL d-1. The accumulation curves identified linear periods ranging from 3 to 18 days. The new passive sampler device was applied for 8 days in rivers and marginal lagoons of natural parks of the São Francisco basin in Minas Gerais, Brazil and identified 10 target pesticides. Furthermore, 10 non-targeted pesticides were detected by the GCxGC/Q-TOFMS method.

Gross yield driving the mass fluxes of fishery drugs: Evidence of occurrence from full aquaculture cycle in lower Yangtze River Basin

Expanding aquaculture has generated pollutants like fishery drugs in wastewater, which affects the aquatic environments and hinders sustainable development of aquaculture. To evaluate the occurrence, mass fluxes and production factors of fishery drugs in aquaculture, full-aquaculture-cycle monitoring in finfish and crustacean wastewater was conducted in the lower Yangtze River Basin, and 28 pesticides and 15 antibiotics were detected. The results showed that individual fishery drugs varied from ppt to ppb levels. Among them, sulfonamides were dominant with a mean concentration of 105.95 ± 4.13 ng·L-1 in finfish aquacultural wastewater, and insecticides were prevailing in crustacean aquacultural wastewater with a content of 146.56 ± 0.66 ng·L-1. Since the susceptibility to finfish disease determined the aquaculture practice, there were significant differences between two types of aquacultural wastewater. Finfish aquacultural wastewater contained more drugs and reached peak earlier in rapid-growth period, yet crustacean aquacultural wastewater peaked at the harvest period, to prevent against disease. Meanwhile, higher ecological risk, especially for florfenicol, were found in finfish wastewater. With 6 production factors from Good Aquaculture Practice, the gross yield was the most influential factor of drug mass flux, explaining 98 % variance by stepwise regression. Apart from increasing concentrations of fishery drugs in wastewater, regional high-yield aquaculture also significantly impacted the corresponding mass flux. As estimated by linear regression, 1.63 tons of target drugs would be discharged by 1 Mt. aquatic products, and 7.77 tons were discharged from aquaculture in the lower Yangtze River Basin in 2021. This is the first report to quantify mass fluxes of fishery drugs and to highlight gross yield as the most influential factor, which provides guidance for the supervision and regulation of sustainable aquaculture.

Biodiversity in wetland+ system: a passive solution for HCH dump effluents

The hexachlorocyclohexane isomers (HCH) are long-banned pesticides. Even though their use has been prohibited for decades, their presence in the environment is still reported worldwide. Wetland + is a registered trademark of the remedial treatment technology consisting of an aerobic sedimentary tank, a permeable reactive barrier, a biosorption system, and an aerobic wetland. This proven method combines a reductive treatment known from PRBs with the natural wetland self-cleaning processes. The average efficiency of the system is 96.8% for chlorobenzenes (ClB) and 81.7% for HCH, during the first 12 months of the system operation. The presence of the genes encoding enzymes involved in the degradation of the HCH compounds indicates that the removal of HCH and ClB occurs not only by chemical removal but also through aerobic and anaerobic combining biodegradation. Changes in abundance and the composition of the diatom community were found to be suitable indicators of the water quality and of the impact of the Wetland + operation on the water ecosystem. The system's annual operation exhibited a markedly higher number of diatom species in the closing profiles of the Ostrovský Creek, the Wetland + effluent recipient.

Review of scientific literature on available methods of assessing organochlorine pesticides in the environment

Organochlorine pesticides (OCPs) are persistent organic pollutants (POPs) widely used in agriculture and industry, causing serious health and ecological consequences upon exposure. This review offers a thorough overview of OCPs analysis emphasizing the necessity of ongoing work to enhance the identification and monitoring of these POPs in environmental and human samples. The benefits and drawbacks of the various OCPs analysis techniques including gas chromatography-mass spectrometry (GC-MS), gas chromatography-electron capture detector (GC-ECD), and liquid chromatography-mass spectrometry (LC-MS) are discussed. Challenges associated with validation and optimization criteria, including accuracy, precision, limit of detection (LOD), and limit of quantitation (LOQ), must be met for a method to be regarded as accurate and reliable. Suitable quality control measures, such as method blanks and procedural blanks, are emphasized. The LOD and LOQ are critical quality control measure for efficient quantification of these compounds, and researchers have explored various techniques for their calculation. Matrix interference, solubility, volatility, and partition coefficient influence OCPs occurrences and are discussed in this review. Validation experiments, as stated by European Commission in document SANTE/11813/2017, showed that the acceptance criteria for method validation of OCP analytes include ≤20 % for high precision, and 70-120 % for recovery. This may ultimately be vital for determining the human health risk effects of exposure to OCP and for formulating sensible environmental and public health regulations.

Environmental assessment of oyster beds in the northern Arabian Gulf Coast of the United Arab Emirates

The United Arab of Emirates (UAE) hosts valuable coastal and marine biodiversity, and oysters are one of the habitants of its marine ecosystem. Oysters play an essential role in the nearshore coasts where they work as an active filter. They filter nutrients, phytoplankton, sediments, heavy metals, and toxins out of the water, which improves the water quality. This is the first study that characterizes oyster bed habitats in the UAE by analyzing water quality parameters, polycyclic aromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs)and heavy metals in water, sediments and oyster samples collected from five locations along the coasts of Sharjah, Ajman, and Umm al Quwain. Oyster bed areas supported a diverse assemblage of benthic life including oysters, scallops, pen shells, hard corals, and macroalgae. Mobile species in these habitats included groupers, emperors, snappers, sea snakes, among others. The phytoplankton assemblages were dominated by diatoms, dinoflagellates, and small cryptophytes. Harmful diatom Pseudonitzschia was found in all locations. No detectable concentrations of PAHs and OCPs were reported in this study, and water quality parameters were within the acceptable levels for the region. On the other hand, water quality index was reported marginal, mostly due to the presence of higher than acceptable concentrations of chromium and mercury in all sites studied. Bioconcentration factors concluded that oysters were able to bioconcentrate metals such as arsenic, cadmium, chromium, and zinc, when compared to water. No detectable concentrations of lead and mercury were reported in oysters, suggesting higher depuration rates for those metals.

Environmental profile, potential sources, and ecological risk of polycyclic aromatic hydrocarbons in a typical coastal bay and outer bay area

As a class of persistent organic pollutants, polycyclic aromatic hydrocarbons (PAHs) are widely present and accumulate in multimedia environments. The pollution characteristics, spatiotemporal distribution, potential sources, influencing factors, and ecological risks of 16 PAHs were investigated in the water-sediment system of the Hangzhou Bay and outer bay area (HZB and OBA, respectively). The total concentrations of 16 PAHs (∑_PAHs) were 220 ± 97.0 and 130 ± 36.0 ng/L in the seawater and 343 ± 179 and 505 ± 415 μg/kg (dry weight) in the sediments of the HZB and OBA, respectively. The pollution level of PAHs in the HZB seawater was higher than that in the OBA seawater, but the opposite result was found in the sediments. Moreover, ∑_PAHs exhibited high temporal variability in the HZB seawater (rainy season > dry season), whereas ∑_PAHs in the sediments showed no significant difference between seasons. The molecular diagnostic ratio method was used to identify pollution sources and showed that the PAHs in seawater came from different pollution sources (fuel combustion and petroleum), whereas the PAHs in the sediments originated from coincident sources (mixed combustion). Correlation analysis revealed that temperature was positively related to ∑_PAHs, whereas salinity was negatively related to seawater ∑_PAHs values. Ecological risk assessment demonstrated that the potential for adverse ecological effects was low to moderate in seawater but moderate to high in the sediments.

Evaluating the spatial and temporal distribution of emerging contaminants in the Pearl River Basin for regulating purposes

Little information is available on how the types, concentrations, and distribution of chemicals have evolved over the years. The objective of the present study is therefore to review the spatial and temporal distribution profile of emerging contaminants with limited toxicology data in the pearl river basin over the years to build up the emerging contaminants database in this region for risk assessment and regulatory purposes. The result revealed that seven groups of emerging contaminants were abundant in this region, and many emerging contaminants had been detected at much higher concentrations before 2011. Specifically, antibiotics, phenolic compounds, and acidic pharmaceuticals were the most abundant emerging contaminants detected in the aquatic compartment, while phenolic compounds were of the most profound concern in soil. Flame retardants and plastics were the most frequently studied chemicals in organisms. The abundance of the field concentrations and frequencies varied considerably over the years, and currently available data can hardly be used for regulation purposes. It is suggested that watershed management should establish a regular monitoring scheme and comprehensive database to monitor the distribution of emerging contaminants considering the highly condensed population in this region. The priority monitoring list should be formed in consideration of historical abundance, potential toxic effects of emerging contaminants as well as the distribution of heavily polluting industries in the region.

Quantification of insecticides in commercial seafood sold in East Asian markets: risk assessment for consumers

The extraction of 21 insecticides and 5 metabolites was performed using an optimized and validated QuEChERS protocol that was further used for the quantification (GC-MS/MS) in several seafood matrices (crustaceans, bivalves, and fish-mudskippers). Seven species, acquired from Hong Kong and Macao wet markets (a region so far poorly monitored), were selected based on their commercial importance in the Indo-Pacific region, market abundance, and affordable price. Among them, mussels from Hong Kong, together with mudskippers from Macao, presented the highest insecticide concentrations (median values of 30.33 and 23.90 ng/g WW, respectively). Residual levels of fenobucarb, DDTs, HCHs, and heptachlors were above the established threshold (10 ng/g WW) for human consumption according to the European and Chinese legislations: for example, in fish-mudskippers, DDTs, fenobucarb, and heptachlors (5-, 20- and tenfold, respectively), and in bivalves, HCHs (fourfold) had higher levels than the threshold. Risk assessment revealed potential human health effects (e.g., neurotoxicity), especially through fish and bivalve consumption (non-carcinogenic risk; ΣHQ_LT > 1), and a potential concern of lifetime cancer risk development through the consumption of fish, bivalves, and crustaceans collected from these markets (carcinogenic risk; ΣTCR > 10^-4). Since these results indicate polluted regions, where the seafood is collected/produced, a strict monitoring framework should be implemented in those areas to improve food quality and safety of seafood products.

Bioaccumulation of organochlorine pesticide residues (OCPs) at different growth stages of pacific white leg shrimp (Penaeus vannamei): First report on ecotoxicological and human health risk assessment

Pesticide residues (PRs) in farmed shrimps are concerning food safety risks. Globally, India is a major exporter of pacific white leg shrimp (P. vannamei). This study was undertaken to analyze PRs in the water, sediments, shrimps, and feed at different growth stages to evaluate the ecotoxicological and human health risks. PRs in the seawater and sediments ranged from not detected (ND) to 0.027 μg/L and 0.006-12.39 μg/kg, and the concentrations were within the maximum residual limits (MRLs) and sediment quality guidelines prescribed by the World Health Organization and Canadian Environment Guidelines, respectively. PRs in shrimps at three growth stages viz. Postlarvae, juvenile, and adults, ranged from ND to 0.522 μg/kg, below the MRLs set by Codex Alimentarius Commission and European Commission. Most of the PRs in water, sediments, and shrimps did not vary significantly (p > 0.05) from days of culture (DOC-01) to DOC-90. The hazard quotient (HQ) and hazard ratio (HR) were found to be < 1, indicating that consumption of shrimps has no noncarcinogenic and carcinogenic risks. PRs in shrimp feed ranged from ND to 0.777 μg/kg and were found to be below the MRLs set by EC, which confirms that the feed fed is safe for aquaculture practices and does not biomagnify in animals. The risk quotient (RQ) and toxic unit (TU) ranged from insignificant level (ISL) to 0.509 and ISL to 0.022, indicating that PRs do not pose acute and chronic ecotoxicity to aquatic organisms. The study suggested no health risk due to PRs in shrimps cultured in India and exported to the USA, China, and Japan. However, regular monitoring of PRs is recommended to maintain a sustainable ecosystem.

Pollution level and health risk assessment of the total petroleum hydrocarbon in marine environment and aquatic products: a case of China

To evaluate the pollution level and health risk of total petroleum hydrocarbon (TPH), seawater, sediments, and aquatic organisms were sampled from the southern sea area of Zhejiang Province (Yangtze River Delta, China) between 2017 and 2019. TPH was widely present in the aquatic environment and products, and its concentration was highly variable. The average value of pollution index (PI) exceeded 1 from 2017 to 2018, and 45.46-69.19% of seawater samples and 56.87-50.00% of sediment samples were polluted. The results showed significant differences in the TPH concentration in various species of aquatic organisms. The average TPH value in aquatic organisms could be ranked in the order as follows: bivalve > shrimp > crab > fish, further reflecting that the ability to accumulate and metabolize TPH existed differently among aquatic organisms within the same pond aquaculture environment. It was relatively safe to eat aquatic products since the exposure risk index was found to be far below the threshold value in this study. Therefore, it would be prudent to undertake regular monitoring of TPH to ensure effective ecosystem functioning and seafood safety in the southern Zhejiang ocean.

The occurrence, distribution and removal of adsorbable organic halogens (AOX) in a typical fine chemical industrial park

Coastal water quality in China has been impacted by direct discharge of industrial wastewater, and various kinds of AOX pollutants have been detected in the seawater and sediment. As the dominant pollution source of Hangzhou Bay, a typical fine chemical industry park "HSEDA" was selected as the study area in this research. The AOX in both wastewater and sludge phases from 22 large-scaled enterprises were simultaneously investigated. The results quantitatively illustrated the AOX flows from engineered wastewater and sludge treatment systems to natural environment. It can be seen that industrial enterprises discharged at least 160 t AOX every year, and about 105.4 t/a AOX eventually entered the natural environment. The dye manufacturing industry, which accounted for more than 60% of the total AOX emission load in HSEDA, was identified as the AOX pollution-intensive sector. The occurrence, characteristic pollutants and fate of AOX in dye wastewater were discussed, on the basis of which the improvements of cleaner production and wastewater treatment technologies have been put forward.

Spatio-temporal variations and ecological risks of organochlorine pesticides in surface waters of a plateau lake in China

Qilu Lake is one of the 9 plateau lakes in Yunnan, China, with a lake surface altitude of 1796.62 m above sea level. In spite of the importance and agriculturally-intensive phenomenon in Qilu Lake Basin, few studies have provided a modern evaluation of pesticide residues and potential effects to local aquatic organisms. The primary goal of this study was to determine the spatio-temporal variations of organochlorine pesticides (OCPs) in this area, and to further assess the related ecological risks. Of the 25 OCPs analyzed, 14 were detected, and the concentrations of ∑₂₅OCPs were highest in the upstream of rivers, followed by regions close to the lake shore, and the lowest concentrations were found in Qilu Lake in every season except winter. The concentrations of ∑₂₅OCPs were the highest in summer, and the lowest in winter. OCP concentrations in spring and in autumn were similar. 4,4'-DDD, γ-HCH, HCB, trans-chlordane, and cis-chlordane were 5 OCPs with relatively high risk in Qilu Lake Basin. Interestingly, higher OCP concentrations do not necessarily correspond to higher ecological risk levels. Low predicted no-effect concentration (PNEC) values and relatively high toxicity of these OCPs led to their high risk quotient (RQ) values. This work further illustrated that although OCPs have been banned for many years, they were still frequently detected in surface waters, and caused risks to aquatic animals.

Evaluation of changes in the microbial community structure in the sediments of a constructed wetland over the years

This study presents the results of the long term (2007-2014) monitoring of the microbial community structure in the surface sediments of the H-02 constructed wetland system, which was built on the Savannah River Site in Aiken, SC, USA, to treat the waste water generated at the Tritium facility. Microbial community structure provides valuable information about the functioning of constructed wetlands and helps understand the biogeochemical cycling of nutrients and contaminants. Phospholipids fatty acid (PLFA) analysis and qPCR were used to identify major bacterial phyla in the sediments. The physiochemical properties of the sediments were also used to deduce potential effects on the microbial community structure over the years. Sulfate-reducing bacteria (SRB) were the most dominant bacterial groups, and their prevalence was progressively increasing throughout the years most likely on the account of methane producers. Concentrations of trace metals (copper and zinc) were negatively associated with methane producers and oxidizer while positively correlated with SRB. Overall, the H-02 wetland system was efficient in immobilizing copper and zinc through the anaerobic respiration of sulfate by SRB and minimizing methane emission through the progressive elimination of methane producers by SRB and Geobacter. The aim of this study was to monitor the changes in the microbial community structure in the surface sediments of a constructed wetland during the first 7 years of operation.

Legacy and emerging persistent organic pollutants in the marginal seas of China: Occurrence and phase partitioning

Emerging per-and polyfluoroalkyl substances (PFASs) and traditional organochlorine pesticides (OCPs), polycyclic aromatic hydrocarbons (PAHs) in the marginal seas of China were analyzed to study the occurrence, transport and phase partitioning. The influence of organic carbon (OC) and element carbon (EC) on particulate emerging pollutants in seawater was studied for the first time. The concentrations of PFASs, OCPs and PAHs in the seawater (dissolved phase plus particulate phase) ranged from 1.4 to 8.6, 0.76 to 4.3 and 8.4 to 130 ng L^-1, respectively. Pollutants in the northern East China Sea were generally higher than that in the southern East China Sea and South China Sea, which may be attribute to river discharges and land sources in the Yangtze River Delta. The Yellow Sea Coastal Current and Yangtze River Dilute Water drove the transport of contaminants from north to south marginal seas. Positive correlations between EC and PAHs were found, which can be explained by co-emission of them during combustion. Moreover, positive correlations between OC, EC and Log K_d for BkF, BeP, HCB, 6:2 FTSA were found, which demonstrated that OC and EC promoted the partitioning of these high oleophilic compounds to suspended particle.

A review on magnetic sensors for monitoring of hazardous pollutants in water resources

Water resources have long been of interest to humans and have become a serious issue in all aspects of human life. The disposal of hazardous pollutants in water resources is one of the biggest global concerns and poses many risks to human health and aquatic life. Therefore, the control of hazardous pollutants in water resources plays an important role, when it comes to evaluating water quality. Due to low toxicity, good electrical conductivity, facile functionalization, and easy preparation, magnetic materials have become a good alternative in recent years to control hazardous pollutants in water resources. In the present study, the idea of using magnetic sensors in controlling and monitoring of pharmaceuticals, pesticides, heavy metals, and organic pollutants have been reviewed. The water pollutants in drinking water, groundwater, surface water, and seawater have been discussed. The toxicology of water hazardous pollutants has also been reviewed. Then, the magnetic materials were discussed as sensors for controlling and monitoring pollutants. Finally, future remarks and perspectives on magnetic nanosensors for controlling hazardous pollutants in water resources and environmental applications were explained.

Inter-annual variation and comprehensive evaluation of organophosphate esters (OPEs) in the Yellow Sea, China

Considering the extensive production and continuous usage of organophosphate esters (OPEs) around the urbanized coasts in recent years, the inter-annual variation and the ecological risks of OPEs in the Yellow Sea (YS), China were systematically evaluated in summer 2015 and 2019. The major component of OPEs, halogenated-OPEs in 78 surface and bottom seawater samples collected from 39 locations in the YS in 2019 were compared with 62 samples at 31 sites conducted in the same periods and similar stations in 2015. The average concentration of halogenated-OPEs increased 1.57, 2.50 folds in the surface and bottom seawater, respectively, in recent 5 years. The proportion of TCPP to halogenated-OPEs exhibited an increasing trend from 56.49% in 2015 to 79.95% in 2019. The peak values of halogenated-OPEs changed from the nearshore regions (33°N-38°N) in 2015 to the nearshore and offshore regions (33°N-35°N) in 2019, implying the growing terrigenous emission sources, especially some large OPEs producers nearby the coastal zones in the northern area of Jiangsu province. The targeted halogenated-OPEs posed no significant or low ecological risks to the aquatic organisms in 2015 and 2019, however, the values of RQ showed an elevated trend in 2019. Therefore, the ecological risks of OPEs in this region still need continuous concern due to the gradually increasing OPEs usage and production.

Baseline occurrence, distribution and sources of PAHs, TPH, and OCPs in surface sediments in Gorgan Bay, Iran

Baseline polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPH) and organochlorine pesticides (OCPs) in surface sediments were measured in Gorgan Bay, Iran. Total PAHs, TPH, and OCPs concentrations ranged between 13.70 and 23.68 ng g^-1, 2.97 to 11.51 μg g^-1 dry weight, and below detection to 1.41 ng g^-1, respectively. Benzo [k] fluoranthene and anthracene had the highest (BkF; 19.77 ± 0.08 ng g^-1), and lowest (Ant; 4.38 ± 1.72 ng g^-1) individual PAH concentrations, respectively. The most abundant OCPs were β-Endosulfan, followed by methoxychlor and endrin. PAH isomeric ratios in sediments revealed that contamination originated from mixed sources, with a strong indication of pyrogenic sources. Ecological risk assessments based on sediment quality guidelines (SQGs) suggested that individual PAHs and OCPs posed low ecological risks in Gorgan Bay.

Does aquatic sediment pollution result in contaminated food sources?

The sediment pollution of the aquatic environment by waste due to anthropogenic activity is of an increasing concern. The contaminants coming from the aquatic environment can enter the aquatic food chain and accumulate in the tissues of fish and shellfish used for human consumption. The aim of this study was to sum up the current level of knowledge concerning the pollution of aquatic sediments and its transfer to aquatic foods as well as to indicate whether such contamination has the potential to affect the health and welfare of aquatic organisms as well as the quality and safety of the species intended for human consumption. Based on the results of scientific studies, the European Food Safety Authority, and the Rapid Alert System for Food and Feed, contamination of fish and seafood occurs predominantly through their diet and the levels of bioaccumulative contaminants are higher in fish which rank higher in the food chain. Contamination of aquatic habitats can not only significantly affect behavior, development, and welfare of aquatic organisms, but it can also affect the safety of fish and seafood for human consumption.

The concentration of persistent organic pollutants in water resources: A global systematic review, meta-analysis and probabilistic risk assessment

The persistent organic pollutants (POPs) are environmentally stable and highly toxic chemicals that accumulate in living adipose tissue and have a very destructive effect on aquatic ecosystems. To analyze the evolution of the concentration and prevalence of POPs such as α-HCH, β-HCH, γ-HCH, ∑-HCH, Heptachlor, Aldrin, p,p'-DDE, p,p'-DDT, ∑-DDT, and ∑-OCP in water resources, a search between January 01, 1970, to February 10, 2020, was followed using a systematic review and meta-analysis prevalence. Among the 2306 explored articles in the reconnaissance step, 311 articles with 5315 exemplars, 56 countries, and 4 types of water were included in the meta-analysis study. Among all studied POPs, the concentration of p,p'-DDT in water resources was the highest, especially in drinking water resources. The overall rank order based on the concentration and prevalence of POPs were surface water > drinking water > seawater > groundwater. To identify POPs-contaminated areas, the distance from the mean relative to their distribution was considered. The most to the least polluted areas included: South Africa, India, Turkey, Pakistan, Canada, Hong Kong, and China. The highest carcinogenic risk was observed for β-HCH (Turkey and China), followed by α-HCH (Mexico). The highest non-carcinogenic risk was identified for Aldrin (all analyzed countries), followed by Dieldrin (Turkey) and γ-HCH (Mexico). The Monte Carlo analysis (under the assumption that γ-HCH has a normal distribution), the mean obtained was 8.22E-07 for children and 3.83E-07 for adults. This is in accordance with the standard risk assessment approach. In terms of percentiles, the Monte-Carlo approach indicates that 75% of child population is under the 1.07E-06 risk and 95% of adults under 7.35E-06.

[Determination of atmospheric organochlorine pesticides using isotope dilution high-resolution gas chromatography/high-resolution mass spectrometry]

建立了测定大气中25种有机氯农药(OCPs)的同位素稀释-高分辨气相色谱/高分辨质谱法(ID-HRGC/HRMS)。样品用正己烷/二氯甲烷(1:1, v/v)进行加速溶剂萃取(ASE)。通过柱洗脱实验、单柱和组合柱净化实验,最终确定样品的净化方案为弗罗里硅土固相萃取柱和石墨化炭黑固相萃取柱组合净化。样品萃取液净化后进行HRGC/HRMS分析。采用平均相对响应因子(RRF)法对样品中目标物进行定量,6点校准溶液RRF的相对标准偏差(RSD)均≤20%。线性范围为0.4~800 μg/L,相关系数R²均>0.992。对空白样品依次进行100 pg、400 pg和15 ng水平下的加标试验,各添加水平下OCPs测定值的RSD为0.64%~16%,加标回收率为67.2%~135%。穿透试验表明,滤膜+聚氨酯泡沫/聚氨酯泡沫作为吸附介质的大体积主动大气采样器(AAS)在采集环境空气时,五氯苯极易发生穿透,有效采样模式待进一步研究。在上述采样模式下,六氯苯的有效采样体积较小,标准状态(101.325 kPa, 273 K)采样体积应≤30 m³,其他OCPs应≤1200 m³。以上述体积计算,25种目标化合物的检出限为0.002~0.7 pg/m³。对北京环境空气样品分析测定,结果显示除反式-环氧七氯、异狄氏剂、顺式-九氯和4,4'-滴滴滴在部分样品中未检出外,其他OCPs均为100%检出;六氯苯浓度在514~563 pg/m³之间,其他OCPs的浓度在0.01~18.9 pg/m³之间;替代标回收率为33.9%~155%。由于现有相关监测标准的仪器灵敏度较低、方法检出限较高,已无法满足目前空气中痕量OCPs的测定需求,因此亟待修订新的高灵敏度监测方法标准。该方法适用于目前大气中OCPs的超痕量水平分析,为新标准的制订奠定基础,也为国家履行相关国际公约提供有力技术指导。