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Sewage sludge is considered to be an important sink for polycyclic aromatic hydrocarbons (PAHs) in wastewater treatment plants and the potential risks from sludge contaminated with PAHs during land application has attracted attention. To identify the priority PAHs for control and enhance their removal from sludge, the occurrence characteristics, removal efficiency, and risk assessment of PAHs in sewage sludges from across China were analyzed. Data collection was from 2001 to 2023. Results showed that 16 PAHs were widely detected in Chinese sewage sludge with total amounts (∑16PAHs) between 0.06 and 34.93 mg kg dw -1 . Fossil fuel, coal, and biomass combustion are main anthropogenic sources of PAHs in China. In general, phenanthrene (PHE), anthracene (ANT), fluorescein (FL), chrysene (CHR), pyrene (PYR), and benzo[b]fluoranthene (BbF) are regarded as the main components and PAHs with 3-5 rings dominate (84.01%-91.53%) sewage sludge in China. Although aerobic composting and anaerobic treatment significantly improve ∑16PAHs removal, sludge stabilization treatment only reduced the risk by a small amount, especially for high-molecular-weight (HMW) PAHs. The benzo[a]anthracene (BaA), benzo[a]pyrene (BaP), and dibenzo[a,h]anthracene (DahA) are proposed as the priority control contaminants for sewage sludge in China because they have consistently high-risk quotient (RQ) values of 2.42-7.47, 1.28-3.16, 1.06-1.83 before and after sludge stabilization, respectively. More attention should be paid to BaA, BbF, benzo[k]fluoranthene (BkF), BaP, DahA, and indeno[1,2,3-cd]pyrene (IcdP) in Beijing; ANT, BaA, and BaP in Shanghai; and BaA and BaP in Guanghzou. Although the toxic equivalent quotient (TEQ) for PAHs met the limit concentration requirements of the national standard, the potential health risks due to long-term exposure to HMW PAHs cannot be ignored because the incremental lifetime cancer risk (ILCR) was consistently in the risk threshold range (>1 × 10 -6 ). Some suggestions on enhanced treatment approaches and land use standards are proposed to further alleviate the risk from HMW PAHs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Nitrated polycyclic aromatic hydrocarbons (NPAHs) are widespread organic pollutants that possess carcinogenic and mutagenic properties, so they may pose a risk to the environment and human health. In this study, the concentrations of 15 NPAHs and 16 polycyclic aromatic hydrocarbons (PAHs) in 30 surface water samples and 26 sediment samples were measured in 2018 from the Taige Canal, one of the main rivers flowing into Taihu Lake, China. The total NPAH concentrations in water and sediment ranged from 14.7 to 235 ng/L and 22.9 to 96.5 ng/g dw, respectively. 9-nitrophenanthrene (nd-76.3 ng/L) was the dominant compound in surface water, while 2+3-nitrofluoranthene (1.73-18.1 ng/g dw) dominated in sediment. Among PAHs, concentration ranging from 1,097 to 2,981 ng/L and 1,089 to 4,489 ng/g dw in surface water and sediment, respectively. There was a strong positive correlation between the log octanol-water partition coefficient (K ow ) and log sediment-water partition coefficient due to hydrophobic interaction. The fugacity fraction value increased with the decrease of log K ow , and chrysene was transferred from water into sediment. The residual NPAHs in surface water and sediment of the Taige Canal have partial correlation. Diesel engine and coal combustion emissions were probably the principal sources of NPAHs in surface water and sediment. The results of ecological risk assessment showed that some NPAHs in water (e.g, 1-nitropyrene and 6-nitrochrysene) and sediment (e.g., 2-nitrobiphenyl, 5-nitroacenaphthene, 9-nitrophenanthrene and 2+3-nitrofluoranthene) had moderate ecological risks, which should be of concern., (Copyright © 2022. Published by Elsevier B.V.)

Mangroves are situated in convergence zones between fresh and marine water and are prone to pollution and deforestation. This study explored the microbiome structure, function and antibiotic resistome of Indian Sundarban. The taxonomic Chao1 estimated diversity was highest in uninhabited Kalash (1204.64 ± 12.72) and lowest in Godkhali, which experiences considerable human activities (1158.76 ± 11.18). The alpha diversity showed negative correlation (p < 0.05) with PAH such as Acenaphthene (r = -0.56), Acenaphthylene (r = -0.62), Fluoranthene (r = -0.59), Fluorene (r = -0.55), Phenanthrene (r = -0.57), while the biochemical parameters phosphate (r = 0.58) and salinity (r = 0.58) had a significant (p < 0.05) positive correlation. The data suggest the importance of physicochemical parameters in maintaining the mangrove microbiome. The taxonomic composition was dominated by Proteobacteria (54.12 ± 0.37). All sites were dominated by ARGs such as rpoB2, cpxR, ompR, camP, and bacA. Comparing the Sundarban mangrove sediment resistome with mangrove from other sites in India (Kerala) and China (Guangxi, Hainan, and Shenzhen) suggested that resistome from Indian mangrove has a significantly (p < 0.05) higher ARG diversity compared to Chinese mangroves. Yet, the abundance of the ARG was significantly (p < 0.05) lower in the Indian mangroves posing a much greater risk if enriched. The study suggests that anthropogenic activities and pollution degrade the microbiome diversity, disturb the microbiome functions, and enrich ARGs., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The pollution of polycyclic aromatic hydrocarbons was serious in sediments of the Pearl River estuary, China. A fluorene-degrading bacterium, strain A2-3, was isolated from hydrocarbon contaminated sediment of this estuary and identified as Rhodococcus sp. based on the analyses of 16S rRNA gene sequence and morphology. Rhodococcus sp. A2-3 can take naphthalene, p-Teropheny, fluorene, pyrene, salicylic acid, citric acid, acetic acid, diethyletheranhydrous, methanol or 4,4'-dibromodiphenyl ether as sole carbon source. 100% of 100 mg/L fluorene or 89% of 400 mg/L fluorene was removed in 7 days by strain A2-3 at 30 °C and pH 7.5. The strain A2-3 showed a high degradation efficiency of fluorene when pH values ranged from 5.5 to 8.5. The proposed pathway of fluorene catabolism by strain A2-3 was initially attacked by 3,4 dioxygenation. Our results suggested Rhodococcus sp. A2-3 can degrade PAHs under aerobic conditions and can function in bioremediation, particularly for weakly acid environment.

Fingerprinting technique is a universal method for tracing oil spill. It is usually achieved by means of diagnostic ratios (DRs) of biomarkers. In the process of severely weathering, the important components usually change greatly and the relevant diagnostic ratios may also change. Therefore, it is more difficult to trace severely weathered oil to its source. On 22 November 2013, the huge explosion of Sinopec pipeline occurred in Qingdao, China. The beaches near the explosion site were contaminated and damaged by oil spills. After the explosion, an actual weathering experiment was carried out on an oil-polluted beach. The original and weathered spilled oil samples have been collected from this site. Synchronized with actual coastal weathering, a 360-day Lab simulated weathering experiment was carried out using the sampled original oil spill samples. According to data analysis techniques including similarity, t -test method and repeatability limit analysis, 27 new diagnostic ratios of dibenzothiophenes and fluorenes in the weathered oil samples were selected and verified. 6 of them maintained good stability during both of the simulated and actual weathering process. It is recommended that these stable DRs be used for tracing the source of severely weathered oil spills to promote the efficiency and accuracy.

Polycyclic aromatic hydrocarbons (PAHs) are widely distributed in various environmental media and have thus attracted extensive attention worldwide. To prevent and control PAH pollution in China, the study of ambient water quality criteria (AWQC), human health risks, and aquatic ecological risk is critical. There are no reports to date on the human health AWQC of PAHs in China. Therefore, this study first derived the human health AWQC values of 12 PAHs based on exposure data and bioaccumulation factor in China. We found that local exposure parameters and other relevant factors were key during the development of AWQC in different countries and regions, which led to differences with the reference value recommended by USEPA. Based on the incremental life time cancer risk (ILCR), hazard quotients (HQ) and potentially affected fraction (PAF) methods, the health and ecological risks of 16 PAHs were assessed subsequently. And the results are as follows: the non-carcinogenic PAHs' health risks ranged from 1.01 × 10 -10 to 1.60 × 10 -9 , and carcinogenic PAH health risks ranged from 5.03 × 10 -7 to 4.74 × 10 -5 . The toxic effects of 8 PAHs on aquatic organisms exhibited the following order: benzo (a) pyrene (BaP) > anthracene (Ant) > pyrene (Pye) > phenanthrene (Phe) > fluoranthene (Flua) > acenaphthene (Ace) > fluorene (Flu) > naphthalene (Nap). Among these, the ecological risks posed by Ant and BaP were the highest, according to the HQ and PAF methods., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

We investigated the concentrations, distributions, and sources of PAHs in the air and soils of Dalian, China, as well as their air-soil exchange trends. Total concentrations of PAHs in the air ranged from 6.37 to 124 ng/m 3 with an average of 23.1 ± 26.6 ng/m 3 , while Σ 15 PAHs in the soils ranged from 42.8 to 28600 ng/g with an average of 2580 ± 5730 ng/g. Significant spatial distribution of PAHs was discovered in the soils with a clear urban-suburban-rural decreasing gradient, suggesting urban area is more contaminated by PAHs due to frequent and intensive human activities. However, high PAH concentrations were also discovered in the air from several rural sites, implying some PAH sources have shifted from urban to suburban or rural areas. Source apportionment indicated that major sources of PAHs in the urban and suburban soils were traffic emission/oil spill and coal combustion respectively, whereas major sources in the rural soils were diverse. Air-soil partitioning result suggested that 3-ring PAHs were mostly volatilized from soil, 6-ring PAHs were deposited into soil, while the trends of 4∼5-ring PAHs varied with sampling site. Fluoranthene, Pyrene, and Chrysene were mostly discovered to be volatilized in the urban and suburban areas, but equilibrium or deposited in the rural area, indicating a potential urban-to-rural transport of PAHs. The atmospheric transport and source shift of PAHs from urban to rural areas highlighted the importance of PAH source control on a regional scale., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Urinary polycyclic aromatic hydrocarbon (PAH) metabolites, biomarkers of internal PAH exposure, are commonly used to explore the effects of PAH on human health. However, the correlation between environmental PAH exposure and the species or levels of urinary PAH metabolites remains unclear. We collected detailed information on PAH exposure sources, including cigarette smoking, cooking, traffic and diet habits via structured questionnaires, and determined 12 urinary monohydroxylated PAH metabolites (OH-PAHs) among 4092 participants from the Wuhan-Zhuhai cohort. Linear mixed models and generalized linear models were conducted to explore the associations of urinary metabolite levels with single or multiple PAH exposure sources. We also calculated the standardized regression coefficients to further compare the contributions of different sources to urinary OH-PAH levels. Our results showed that increasing levels of urinary 1-, 2-hydroxynaphthalene (1-, 2- OHNa) and 2-hydroxyfluorene (2-OHFlu) were significantly correlated with tobacco smoking (all P < 0.01). The concentrations of 1-, 2- OHNa and 9-hydroxyfluorene (9-OHFlu) were positively correlated with dietary intake (all P < 0.05). Individuals who spent a long time in traffic showed elevated levels of 9-OHFlu and 1-hydroxyphenanthrene (1-OHPh) compared with individuals who spent a short time in traffic (all P < 0.05). Self-cooking was associated only with elevated 1-hydroxypyrene (1-OHP) levels. Moreover, good kitchen ventilation resulted in significantly decreased urinary low-molecular-weight OH-PAH levels. These findings suggested that cigarette smoking, self-cooking, high dietary PAH intake and a long time spent in traffic were associated with increased levels of specific urinary PAH metabolites, and good kitchen ventilation effectively reduced the exposure to low-molecular-weight PAHs in self-cooking participants., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

During the summer of 2015, polycyclic aromatic hydrocarbons (PAHs) in the atmosphere were collected by passive air samplers in typical urban-rural fringe of Wuhan-Ezhou region, Central China. The results showed that 16 kinds of PAHs were ubiquitous with the concentrations of ∑16PAHs from 14.69 to 136.30 ng·m -3 and the mean concentration of 43.03 ng·m -3 . Phenanthrene (Phe), fluoranthene (Fla) and pyrene (Pyr) were major components, which accounted for 81% of ∑16PAHs. PAHs atmospheric concentrations presented obvious spatial variation, being significantly related to geographical environment and influenced by anthropogenic activity. Air-soil exchange status of PAHs was discussed according to the fugacity fraction (ff). The results showed that HMW-PAHs behaved as net deposition, while LMW-PAHs were more likely to establish dynamic equilibrium between atmosphere and soil than MMW-PAHs and HMW-PAHs. For some PAHs, such as acenaphthylene (Acy) and anthracene (Ant), the soil acted as second sources of them.

Polycyclic aromatic hydrocarbons (PAH) are well-known to be carcinogenic and the mechanisms that it contributes to oxidative DNA damage and aryl hydrocarbon receptor (AhR)-dependent induction are also well understood. However, little is known about the associations between PAH exposure, AhR expression, and oxidative DNA damage. We investigated their associations of AhR expression and oxidative DNA damage related to PAH exposure among 310 workers from a coke-oven plant in China. Urine biomarkers of PAH exposure (2-hydroxynaphthalene, 2-NAP; 2-hydroxyfluorene, 2-FLU; 9-hydroxyphenanthren, 9-PHE; and 1-hydroxypyrene, 1-OHP) and a marker of oxidative damage (8-hydroxy- 2'- deoxyguanosine, 8-OHdG) were measured by high performance liquid chromatography. AhR expression in venous blood was measured by reverse transcription -polymerase chain reaction. The results showed that increasing levels of urinary 1-OHP was positively associated with high 8-OHdG (OR (95% CI) was 4.01 (1.41-11.45) for 4th quartile, compared with 1st quartile, P for trend = 0.013). The similar associations were also found between urinary 1-OHP and high-AhR expressions (4th vs. 1st quartile = 3.50, 95% CI: 1.24-9.87, P for trend = 0.029). A significant association between AhR expression and high 8-OHdG was also found (4th vs. 1st quartile = 2.44, 95% CI: 1.05-5.70, P for trend = 0.027). In addition, mediation analysis showed the AhR expression could explain 35.9% of the association of oxidative DNA damage related to PAH exposure. Our findings implicated that the association between PAH exposure and oxidative DNA damage may be mediated by AhR expression among Chinese occupational workers., (Copyright © 2018 Elsevier Ltd. All rights reserved.)