Polycyclic Aromatic Hydrocarbons Residues Research Articles

Concentration and health risk valuation of polycyclic aromatic hydrocarbons in Tilapia zilli in selected wetlands

Globally, food safety is growing, and the residues of PAHs (polycyclic aromatic hydrocarbons) in fish species above the standard threshold could elicit serious public and community health concerns. This study investigated the PAHs contamination concentrations of <i>Tilapia zilli</i> in the wetlands of the Niger Delta. The study was conducted from March to August 2023, and fish samples were collected within these periods from 5 wetlands. The results obtained were as follows: pyrene; 2.46±0.11 µg/kg, chrysene; 2.54±0.12 µg/kg, BaP; 2.52±0.11 µg/kg, BaA; 2.54±0.13 µg/kg and BbF; 2.54±0.13 µg/kg. The mean results of characterising the PAHs in the fish were insignificant at <i>p>0.05</i>. The results of the health risk evaluation showed that Beneze (a) pyrene had the highest value (12.33 µg/kg), followed by Benzo (a) anthracene and Benzo (b) fluoranthene (1.51 and 1.20) of the toxicity equivalent factors. Meanwhile, the sum across the station was significantly higher than the standard limits. The CDI (chronic daily intake) results obtained in this study for each PAH (polycyclic aromatic hydrocarbon) congener were considerably high and fluctuated across the stations. However, the results for the ILCR (incremental life cancer risk) showed that the values were higher (1 × 10<sup>−2</sup>) than the threshold set for this study (1 × 10<sup>−6</sup> to 1 × 10<sup>−4</sup>). The fish were thus contaminated above the acceptable limit; therefore, they are not fit for human consumption or for compounding animal feed.

Strategies and mechanisms for improving the detection accuracy of nonextractable residues of polycyclic aromatic hydrocarbons in soils

The methods that can accurately measure the concentrations of nonextractable residues (NERs) of hydrophobic organic contaminants (HOCs) in soil are still lacked in current studies. In this study, three methods, namely methanolic saponification treatment (MST), silylation treatment (ST), and acid deashing treatment (ADT), were investigated and then combined to extract the NERs of six types of polycyclic aromatic hydrocarbons (PAHs) from nine soil samples. The NER concentrations of PAHs obtained by ST (2.43–521.73 ng g−1) were comparable to or significantly higher than those obtained by MST (1.94–291.54 ng g−1), owing to the properties of soil and target compounds. Additionally, ADT could further release a considerable amount of PAH NERs (0.39–276.99 ng g−1) from the soils that had been treated with ST. The mechanism was that acid solution dissolved mineral components, significantly increasing the pore size of the soil matrices from 9.37–15.57 nm to 17.11–27.51 nm. The average percentage of each PAH obtained by ADT (the ratio of the amount obtained by ADT to the total NER content) exhibited a negative correlation with their ring numbers (R2 = 0.62, p < 0.05), whereas the percentage of targets recovered through ST increased linearly with their log KOW values (R2 = 0.75, p < 0.05). Moreover, there is a positive correlation (R2 = 0.73, p < 0.05) between the NER percentages of phenanthrene (obtained by ST–ADT) and the specific surface areas of soils, and the NER percentages of benzo(g,h,i)perylene is positively correlated to the content of total organic carbon (R2 = 0.62, p < 0.05). These results suggested that the amounts and locations of NERs were influenced by both the physicochemical characteristics of PAHs and soils. These findings provide some basic understandings of the entrapped mechanisms of PAH NERs, helping to establish strategies for improving their detection accuracy.

Characteristics and Biodegradation of Nonextractable Residues of Polycyclic Aromatic Hydrocarbons in Historically Polluted Soils

Characteristics and Biodegradation of Nonextractable Residues of Polycyclic Aromatic Hydrocarbons in Historically Polluted Soils

Concentrations, Sources and Health Risk Assessment of Polycyclic Aromatic Hydrocarbons in Chinese Herbal Medicines.

The determination and evaluation of 16 polycyclic aromatic hydrocarbons (PAHs) in seven Chinese herbal medicines (CHMs) were conducted through a rapid and straightforward extraction and purification method, coupled with GC-MS. A sample-based solid-phase extraction (SPE) pretreatment technique, incorporating isotopic internal standards, was employed for detecting various medicinal parts of CHMs. The assay exhibited linearity within the range of 5 to 500 ng/mL, with linear coefficients (R2) for PAHs exceeding 0.999. The recoveries of spiked standards ranged from 63.37% to 133.12%, with relative standard deviations (RSDs) ranging from 0.75% to 14.54%. The total PAH content varied from 176.906 to 1414.087 μg/kg. Among the 16 PAHs, phenanthrene (Phe) was consistently detected at the highest levels (47.045-168.640 μg/kg). Characteristic ratio analysis indicated that oil, coal, and biomass combustion were the primary sources of PAHs in CHMs. The health risk associated with CHMs was assessed using the lifetime carcinogenic risk approach, revealing potential health risks from the consumption of honeysuckle, while the health risks of consuming Lycium chinense berries were deemed negligible. For the other five CHMs (glycyrrhizae, Coix lacryma, ginseng, lotus seed, seed of Sterculia lychnophora), the health risk from consumption fell within acceptable ranges. Furthermore, sensitivity analyses utilizing Monte Carlo exposure assessment methods identified PAH levels in CHMs as health risk sensitizers. It is crucial to recognize that the consumption of herbal medicines is not a continuous process but entails potential health risks. Hence, the monitoring and risk assessment of PAH residues in CHMs demand careful attention.

Reduction strategies of polycyclic aromatic hydrocarbons in farmland soils: Microbial degradation, plant transport inhibition, and their mechanistic analysis

This study focuses on the abatement of polycyclic aromatic hydrocarbons (PAHs), a global pollutant, in farmland soils. Seven controlled PAHs in China were used as the target ligands, and four key target receptors degradable PAHs and two key target receptors transport PAHs were used as the target receptors. Firstly, the degradation abilities of the four key target receptors on PAHs were quantified, and the dominant target receptors that could efficiently degrade PAHs were screened out. Then, the co-degradation abilities of PAHs under the coexistence of the dominant target receptors (microbial diversity) were assessed, and 30 external condition-adding schemes to promote the microbial (co-)degradation of PAHs were designed. In addition, the microbial dominant target receptor mutants and the plant key target receptor mutants were obtained, the degradation and transportation of PAHs were improved by 8.06%∼22.27% and 39.86%∼45.43%. Finally, the mechanism analysis of PAHs biodegradation and transportation found that the Van der Waals interactions dominated the enhancement of PAHs’ degradation in soil, and the solvation capacity dominated the decrease of PAHs’ transportation in plant. This study aims to provide theoretical support for the prevention and control of PAHs residue pollution in farmland soil, as well as the protection of human dietary health.

The addition of Glomalin-related soil protein and functional microbial consortium increased bound PAH residue degradation in soil

Bound Polycyclic Aromatic Hydrocarbons (PAHs) residues are the “end point” of soil pollution remediation. However, bound PAH residues can be released and become bioavailable exerting ecological and human health impacts. Remediation of soils contaminated with bound PAHs is a critical pollution control issue that support safe and healthy agricultural production We conducted microcosmic experiments to study the degradation of bound PAH residues in the soil by exogenous functional microbial consortium with and without the addition of glomalin-related soil protein (GRSP). Our results showed limited degradation of bound PAHs by the functional microbial consortium, however, a high concentration of 1000 mg/kg could accelerate the process. The removal rates of low molecular weight PAHs, medium molecular weight PAHs, high molecular weight PAHs, and total PAHs increased by 6.6%–14.2%, 8.2%–14.6%, 5.2%–7.5% and 6.7%–12.0%, respectively. The application of high- concentration GRSP increased the content of PAHs degrading bacteria such as Sphingomonas and Arthrobacter in soil and the abundance of some vital functional genes during PAH biodegradation (phe, nahAc, and nidA) thus promoting the degradation of bound PAHs residues. This study fills the cognitive gap of GRSP in regulating the degradation of bound PAH residues in soil, and provides an important basis for the subsequent development of bound PAH residue removal technology. These findings contribute to our understanding of the role of GRSP in regulating the degradation of soil-bound PAHs.

SERS with Flexible β-CD@AuNP/PTFE Substrates for In Situ Detection and Identification of PAH Residues on Fruit and Vegetable Surfaces Combined with Lightweight Network.

The detection of polycyclic aromatic hydrocarbons (PAHs) on fruit and vegetable surfaces is important for protecting human health and ensuring food safety. In this study, a method for the in situ detection and identification of PAH residues on fruit and vegetable surfaces was developed using surface-enhanced Raman spectroscopy (SERS) based on a flexible substrate and lightweight deep learning network. The flexible SERS substrate was fabricated by assembling β-cyclodextrin-modified gold nanoparticles (β-CD@AuNPs) on polytetrafluoroethylene (PTFE) film coated with perfluorinated liquid (β-CD@AuNP/PTFE). The concentrations of benzo(a)pyrene (BaP), naphthalene (Nap), and pyrene (Pyr) residues on fruit and vegetable surfaces could be detected at 0.25, 0.5, and 0.25 μg/cm2, respectively, and all the relative standard deviations (RSD) were less than 10%, indicating that the β-CD@AuNP/PTFE exhibited high sensitivity and stability. The lightweight network was then used to construct a classification model for identifying various PAH residues. ShuffleNet obtained the best results with accuracies of 100%, 96.61%, and 97.63% for the training, validation, and prediction datasets, respectively. The proposed method realised the in situ detection and identification of various PAH residues on fruit and vegetables with simplicity, celerity, and sensitivity, demonstrating great potential for the rapid, nondestructive analysis of surface contaminant residues in the food-safety field.

The impact of temperature-controlled smoldering smoking on polycyclic aromatic hydrocarbons and heterocyclic amines contents in Frankfurter-type sausages

The impact of temperature-controlled smoldering smoking conditions on the accumulations of polycyclic aromatic hydrocarbons (PAHs) and heterocyclic amines (HAs) in Frankfurter-type sausages was investigated. Depending on the temperature, smoking can be divided into two phases: an unstable pyrolysis stage (≈ 200 s) and a stable pyrolysis stage (>200 s), which had different effects on hazardous substances contents. The unstable pyrolysis stage, which contributed 66.9 ∼ 89.6% of PAH accumulations by comparing with sausages smoked for 15 min, has significant impact on high PAH residues. By contrast, the contents of HAs showed steady increase trends with smoking time. Few types of free-HAs with low concentrations (3.05 ∼ 22.9 ng/g DW), but more types of bound-HAs with much higher levels (10.8 ∼ 396 ng/g DW) were found. In addition, the formation of some HAs followed the first-order reaction model. However, the detailed formation mechanisms of PAHs and HAs under temperature-controlled smoldering smoking conditions remain to be studied.

Residues of Polycyclic Aromatic Hydrocarbons in Breast Milk Collected from Jinhua (China) and the Influence of Exercise Habit: Levels and the Potential Health Effects

Residues of Polycyclic Aromatic Hydrocarbons in Breast Milk Collected from Jinhua (China) and the Influence of Exercise Habit: Levels and the Potential Health Effects

Fabrication and application of Zn5 functionalized copolymer monolithic column for pipette tip micro-solid phase extraction of 4 polycyclic aromatic hydrocarbons in edible oil

The contamination of polycyclic aromatic hydrocarbons (PAHs) in edible oil is a health threat. Thus, trace analysis of PAHs is of high necessity. Based on the efficient adsorption of PAHs on Zn5 metal cluster, a Zn5 functionalized copolymer monolithic column was rationally designed for pipette tip micro-solid phase extraction (μ-SPE). The modified Zn5 improved the adsorption selectivity and capacity of the monolith for naphthalene, phenanthrene, fluoranthene and pyrene. Chemical doping and copolymerization stabilized the monolith with a long life. Under optimal extraction conditions, a μ-SPE-high performance liquid chromatography with ultraviolet detector method was established for the detection of 4 PAHs in edible oils. The method yielded detection ranges of 0.15–250 μg L−1 (R2 > 0.997), detection limits of 0.050–1.5 μg L−1, satisfactory recoveries (86.3–101.5 %), and high precisions (RSDs < 7.9 %). The results indicated that the Zn5 functionalized copolymer monolithic column was an ideal separation medium for the detection of PAHs residues in edible oils.

Molecular advances in mycoremediation of polycyclic aromatic hydrocarbons: Exploring fungal bacterial interactions.

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous high global concern environmental pollutants and tend to bioaccumulate due to hydrophobic properties. These xenobiotics, having variable concentrations along different matrices, gradually undergo various physical, chemical, and biological transformation processes. Myco-remediation aids accelerated degradation by effectively transforming complex ring structures to oxidized/hydroxylated intermediates, which can further funnel to bacterial degradation pathways. Exploitation of such complementing fungal-bacterial enzymatic activity can overcome certain limitations of incomplete bioremediation process. Furthermore, high-throughput molecular methods can be employed to unveil community structure, taxon abundance, coexisting community interactions, and metabolic pathways under stressed conditions. The present review critically discusses the role of different fungal phyla in PAHs biotransformation and application of fungal-bacterial cocultures for enhanced mineralization. Moreover, recent advances in bioassays for PAH residue detection, monitoring, developing xenobiotics stress-tolerant strains, and application of fungal catabolic enzymes are highlighted. Application of next-generation sequencing methods to reveal complex ecological networks based on microbial community interactions and data analysis bias in performing such studies is further discussed in detail. Conclusively, the review underscores the application of mixed-culture approach by critically highlighting in situ fungal-bacterial community nexus and its role in complete mineralization of PAHs for the management of contaminated sites.

Levels, sources, and risk assessment of PAHs residues in soil and plants in urban parks of Northwest China

Polycyclic aromatic hydrocarbons (PAHs) will be ingested by people through different ways to threaten their health during play, so the environmental quality of the park directly affects the health of tourists and residents. Using eight typical parks in Urumqi in Northwest China as the study area, we used GC–MS to detect the PAHs content in the park surface soil and 10 common plants in the park in different seasons. The results showed that the content of PAHs in park soil in the summer was 5–6 times that in the winter, and the monomer PAHs in some park soil sampling points were higher than the soil pollution risk screening value. And the contamination level at these sampling sites was also higher compared to other sampling sites. In summer, the plants with high PAHs content in leaves are short herbs, while in winter, they are tall arbors. The PAHs of the park soil are mainly composed of high-cyclic aromatic hydrocarbons, and are mainly of traffic origin. The proportion of low-ring aromatic hydrocarbons in the winter was significantly higher than that in the summer. The source of PAHs in plants in summer is similar to that in soil, but the source of PAHs in plants in winter is more complex. The toxicity equivalent concentration method values of soil PAHs in South Park, Zhiwu Park, Shihua Park and Toutunhe Park were higher than that in other parks. The lifetime carcinogenic risk (ILCRs) values of some sampling points in these four parks in the summer were relatively high. The average ILCRs of adults and children in all parks reached a low-risk level in summer. The carcinogenic risk in children is much higher than that of adults.

Preparation of Monoclonal Antibody against Pyrene and Benzo [a]pyrene and Development of Enzyme-Linked Immunosorbent Assay for Fish, Shrimp and Crab Samples

Polycyclic aromatic hydrocarbons (PAHs) are significant environmental and food pollutants that can cause cancer. In this work, a specific monoclonal antibody (mAb) to identify pyrene (PYR) and benzo [a]pyrene (BaP) was prepared, and an indirect competitive enzyme-linked immunoassay (ic-ELISA) was established to detect PYR and BaP residues in living aquatic products for the first time. The effects of complete antigens with different coupling ratios on the production of high-sensitivity mAb was explored. Under the optimal conditions, the IC50 value was 3.73 ± 0.43 µg/L (n = 5). The limits of detection (LODs) for PYR and BaP in fish, shrimp, and crab ranged from 0.43 to 0.98 µg/L. The average recoveries of the spiked samples ranged from 81.5–101.9%, and the coefficient of variation (CV) was less than 11.7%. The validation of the HPLC-FLD method indicated that the ELISA method set up in this experiment provided a trustworthy tool for PAHs residues detection in aquatic products.

Contribution of dicarboxylic acids to pyrene biodegradation and transcriptomic responses of Enterobacter sp. PRd5.

The colonization of degrading endophytic bacteria is an effective means to reduce the residues of polycyclic aromatic hydrocarbons (PAHs) in crops. Dicarboxylic acids, as the main active components in crops, can affect the physiological activities of endophytic bacteria and alter the biodegradation process of PAHs in crops. In this study, malonic acid and succinic acid were selected as the representatives to investigate the contribution of dicarboxylic acids to pyrene biodegradation by endophytic Enterobacter sp. PRd5 in vitro. The results showed that dicarboxylic acids improved the biodegradation of pyrene and altered the expression of the functional gene of strain PRd5. Malonic acid and succinic acid reduced the half-life of pyrene by 20.0% and 27.8%, respectively. The degrading enzyme activities were significantly stimulated by dicarboxylic acids. There were 386 genes up-regulated and 430 genes down-regulated in strain PRd5 with malonic acid, while 293 genes up-regulated and 340 genes down-regulated with succinic acid. Those up-regulated genes were distributed in the functional classification of signal transduction, membrane transport, energy metabolism, carbohydrate metabolism, and amino acid metabolism. Malonic acid mainly enhanced the central carbon metabolism, cell proliferation, and cell activity. Succinic acid mainly improved the expression of degrading gene. Overall, the findings of this study provide new insights into the regulation and control of PAH stress by crops. KEY POINTS: • Dicarboxylic acids improved the biodegradation of pyrene by Enterobacter sp. PRd5. • The degrading enzyme activities were stimulated by dicarboxylic acids. • There are different facilitation mechanisms between malonic acid and succinic acid.

Investigation of monthly residues of polycyclic aromatic hydrocarbons in water and sediment samples from Kirikkale Kizilirmak River Basin.

Polycyclic aromatic hydrocarbons (PAHs) contain two or more benzene rings and are categorized as general environmentally harmful pollutants. PAHs occur because of various combustion and pyrolysis processes with different environmental and anthropogenic sources. The Kizilirmak River is one of the major important water sources used for drinking water and irrigation purposes in Turkey. There are important industrial facilities around the river and PAH pollution is important in terms of environmental health. This study was carried out to determine the residues of PAHs in water and sediment samples according to month and to identify the pollution sources. Thus, water and sediment samples were collected from five different stations in the Kirikkale basin of the Kizilirmak River every 15days for a year. In this way, 120 water and 120 sediment samples were collected over a year and analyzed in terms of 16 priority PAHs according to the Environmental Protection Agency. The monthly average of the water and sediment samples was calculated. Analyses were carried out with high-performance liquid chromatography based on solid phase extraction. GC-MS was used for confirmation. Acenaphthene, acenaphthylene, benzo[b]fluoranthene, benzo[a]pyrene, indeno[1,2,3-cd]pyrene, and dibenzo[a,h]anthracene were not found in the water samples. The total PAH levels in water and sediment were detected in the range of 0.04 to 1.545μg/L and 43.15-386.115μg/kg, respectively. PAHs found in water and sediment samples had pyrogenic and petrogenic origin and pollution changed significantly between autumn and winter. As a result, precautions should be taken in terms of preventing environmental pollution.

Integrated ultrasound-assisted magnetic solid-phase extraction for efficient determination and pre-concentration of polycyclic aromatic hydrocarbons from high-consumption soft drinks and non-alcoholic beers in Iran.

In the present research, an ultrasound-assisted magnetic solid-phase extraction coupled with a gas chromatography-mass spectrometry hybrid system was developed for the extraction/determination of trace amounts of polycyclic aromatic hydrocarbons in high-consumption soft drinks and non-alcoholic beers in Iran using magnetite graphene oxide adsorbent. The magnetite graphene oxide was characterized by scanning electron microscope, transmission electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, and vibrating-sample magnetometer techniques. The highest extraction recovery (73.05%-95.56%) and enrichment factor (90.65-106.38) were obtained at adsorbent mass: 10mg, adsorption time: 30min, salt addition: sodium chloride 10% w/v, desorption time: 20min, eluent type: hexane: acetone (1:1, v/v), and desorption solvent volumes: 200 μl. Under optimum conditions, the linearity range for polycyclic aromatic hydrocarbons determination was 0.2-200ng/mlwith a coefficient of determination>0.993, the limit of detection=0.09-0.21ng/ml, the limit of quantitation=0.3-0.7ng/ml, and relative standard deviation<8.1%, respectively. Relative recoveries in spiked real samples ranged from 94.67 to 109.45% with a standard deviation<6.05%. The proposed method is effective, sensitive, and reusable and it is promising for the analysis of polycyclic aromatic hydrocarbons residues in environmental samples.

Rapid Screening of 22 Polycyclic Aromatic Hydrocarbons Residues in Vegetable Oils by Gas Chromatography-Electrostatic Field Orbitrap High Resolution Mass Spectrometry.

A method for simultaneous determination of 22 polycyclic aromatic hydrocarbons (PAHs) residues in vegetable oils by gas chromatography-electrostatic field orbitrap high resolution mass spectrometry (Orbitrap GC-MS) was established. The samples were vortexed with acetonitrile, centrifuged at 8,000 r/min for 5 min, and frozen at −70°C for 10 min. The extracts of upper layer were poured out, dried with nitrogen at 40°C, redissolved in dichloromethane, and measured by Orbitrap GC-MS. The matrix interference in vegetable oil could be effectively removed by determining the accurate mass number of target compounds under the full scan mode. Six typical vegetable oil samples (soybean oil, sesame oil, peanut oil, olive oil, rapeseed oil, sunflower oil) were used for method validation. The calibration curve displayed good linearity in the range of 1–100 ng/mL, with correlation coefficients > 0.9950. The limits of detection (LODs) were in the range of 0.10–0.60 μg/kg, and the limits of quantification (LOQs) were in the range of 0.35–2.00 μg/kg. The average spiked recoveries of 22 PAHs in 6 matrices at 5, 50 and 100 μg/kg levels were 76.4–115.4%, and the average relative standard deviations (RSDs) were 1.8–10.8%. The results showed that 22 PAHs were detected in 6 types of 90 edible vegetable oil samples in the Chinese market by this method. Meanwhile, the abundance of light PAHs (LPAHs) was higher than that of heavy PAHs (HPAHs), and its relative contribution of LPAHs to the total PAHs was higher. All levels of BaP conformed to the Chinese requirement of upper limit, 10 μg/kg. However, 13.3 and 11.1% of the samples exceeded the maximum limits of BaP and PAH4 set by EU, 2 and 10 μg/kg, respectively. The total concentrations of 22 PAHs (defined as PAH22) varies greatly among different oil species, and the average PAH22 contents were listed in descending order as follows: peanut oil > sesame oil > olive oil > rapeseed oil > soybean oil > sunflower seed oil. The established method effectively avoided interference from large amounts of lipids and pigments. Therefore, the method is simple, sensitive and suitable for rapid screening and confirmation of PAHs in vegetable oil.

Pollution Characteristics and Risks of Polycyclic Aromatic Hydrocarbons in Underground and Surface Drinking Water Sources in Northeast Inner Mongolia

Polycyclic aromatic hydrocarbons (PAHs) are hazardous and ubiquitous pollutants in the aquatic environment, and understanding the pollution characteristics and risk levels of PAHs is of great significance to the sustainable development of drinking water sources and drinking water safety. Hence, PAHs residues were measured qualitatively and quantitatively with solid-phase extraction-gas chromatography-mass spectrometry (SPE-GC-MS) in 33 water samples (including 22 groundwater and 11 surface water samples) of the drinking water sources in the Manzhouli and Xinyouqi areas of northeast Inner Mongolia, and assessments of the pollution level of PAHs and the health and ecological risks were carried out. The results showed that PAHs were detected in all 33 sampling points of Manzhouli drinking water sources, except for benzo[k] fluoranthene, benzo[a] pyrene, and dibenzo[a,h] anthracene, with detection rates ranging from 36.36% to 95.45%; the detection rates of the other 13 PAHs monomers were 100%. The detection range of ρ（ΣPAHs） was 42.76-164.50 ng·L-1, and the mean value was 90.82 ng·L-1. The detection ranges of ρ（ΣPAHs） in surface water and groundwater were 66.39-164.50 ng·L-1 and 42.76-147.70 ng·L-1, respectively. The concentration of the detected naphthalene was the highest, with a mean value of 36.91 ng·L-1, and the concentration of anthracene was the lowest, with a mean value of 0.81 ng·L-1; there were no significant differences among the concentrations of all the PAHs monomers of the surface and groundwater (P>0.05). The pollution of PAHs was at a median level in China and abroad, mainly in the middle and low loops (3-4 loops). The analysis of the sources of PAHs in groundwater and surface water in Manzhouli using the ratio feature method and principal component analysis showed that the PAHs in the drinking water source water bodies in the Manzhouli area were mainly affected by the combustion of coal and biomass and oil, and some surface water sources were affected by the oil source. The human health and ecological risk assessment results showed that the water body of drinking water would not cause health risks to the human body, and the ecological risk was at a medium level; however, the high risk of benzo[b] fluoranthene (BbF) monomer production should be continuous cause for concern. From the perspective of the sustainable development of drinking water sources and drinking water safety, the necessary supervision and protection measures should be considered to prevent further pollution. The results of this research provide a scientific basis for the pollution control and prevention and control of PAHs in drinking water sources.

Nitrogen addition enhanced the polycyclic aromatic hydrocarbons dissipation through increasing the abundance of related degrading genes in the soils

High concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in the soils cause significant threats to human health. Since nitrogen plays a crucial role in controlling microbial composition and functions in terrestrial ecosystems, bio-stimulation based on nitrogen has been used in PAHs contaminated environments remediation. Recent studies show that microbial community composition and organic pollutants dissipation correlate with nitrogen addition. Here, we investigated the effect of nitrogen addition on the abundance of microbial community, degrading genes, and their relationship to PAHs dissipation. After a 32-day experiment, PAHs residues in nitrogen treatment soil were reduced by 23.23%−34.21%. The application of 80 mg·kg−1 nitrate and ammonium nitrogen resulted in higher PAHs removal efficiency, and the dissipation rate of PAHs was 59.61% and 62.09%, respectively. Nitrogen application could improve the abundance and the diversity of soil microbial community. Degrading genes involved in PAH detoxification were enhanced after nitrogen addition, particularly those encoding ring-hydroxylating and catechol dioxygenases such as nahAc and nidA, thus, accelerating PAH dissipation in the soil. The results will facilitate the development of beneficial microbiome-based remediation strategies and improve agricultural production safety in PAHs-contaminated soils.

Live in same region, respond differently: Canine and human response to pollutants in placental accumulation

Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs) are endocrine-disrupting chemicals (EDCs). Their presence in the environment is particularly concerning in cases of fetal exposure, which is the most vulnerable period of life for both human and animals who share the same environment. Placenta, as a sample collected using noninvasive methods to screen EDCs, is a good indicator for potential fetal exposure. Although recent studies indicate that companion animal may correspond to human exposure, species-specific anatomo-morphological and metabolic differences are controversial. In this study, placenta samples of 60 women and 25 dogs living and giving birth within the same region were evaluated for the presence of PCB, OCP, PBDE, and PAH residues; where, socio-demographic factors were also assessed to identify the possible sources. Gas chromatography-mass spectrometry method was validated for the matrix, and among 45 screened and targeted pollutants, only 18 were found in human placentas. While the most frequently detected pollutants were DDTs, followed by PAHs and PCBs in decreasing order, the pollutants with the highest concentrations were PAHs, followed by PCBs and DDTs. Only five of the target contaminants were detected in the dog placentas. These results indicate that; as dogs have different bioaccumulation capacities and higher excretion rates than humans, the life-long effects of exposure to endocrine compound and possible consequences related to adverse health outcomes are expected to vary and concentrations cannot be directly correlated.