Behavior and Fate of Chromium and Carbon during Fe(II)-Induced Transformation of Ferrihydrite Organominerals.

The mobility of chromium (Cr) is controlled by minerals, especially iron (oxyhydr)oxides. The influence of organic carbon (OC) on the mobility and fate of Cr(VI) during Fe(II)-induced transformation of iron (oxyhydr)oxide, however, is still unclear. We investigate how low-weight carboxyl-rich OC influences the transformation of ferrihydrite (Fh) and controls the mobility of Cr(VI/III) in reducing environments and how Cr influences the formation of secondary Fe minerals and the stabilization of OC. With respect to the transformation of Fe minerals, the presence of low-weight carboxyl-rich OC retards the growth of goethite crystals and stabilizes lepidocrocite for a longer time. With respect to the mobility of Cr, low-weight carboxyl-rich OC suppresses the Cr(III)non-extractable associated with Fe minerals, and this suppression is enhanced with increasing carboxyl-richness of OC and decreasing pH. The presence of Cr(III) mitigates the decrease in total C associated with Fe minerals and increases the Cnon-extractable especially for Fh organominerals made with carboxyl-rich OC. Our study sheds new light on the mobility and fate of Cr in reducing environments and suggests that there is a potential synergy between Cr(VI) remediation and OC stabilization.

[Comprehensive Review on Environmental Biogeochemistry of Nonylphenol and Suggestions for the Management of Emerging Contaminants].

In recent years, China's air environment, water environment, and soil environmental quality have been improved, and a "clear water blue sky" has become a normal state. However, as persistent organic pollutants, endocrine-disrupting chemicals, antibiotics, microplastics, and other emerging contaminants are continuously detected in the environment, these emerging contaminants have gradually been attracting wide attention. Nonylphenol, as a typical endocrine disrupting chemical, has also attracted the attention of researchers. The environmental behaviors and exposure levels of nonylphenol in Chinese water bodies were summarized systematically, and the ecological risks caused by nonylphenol were evaluated based on the risk quotient method and joint probability curve method. The results showed that the toxic effects of nonylphenol on aquatic organisms mainly included acute toxicity, growth and development toxicity, and estrogenic effect and reproductive toxicity. Nonylphenol was commonly found in the water bodies of major drainage areas in China, and the average concentration of nonylphenol ranged from 60 to 1000 ng·L-1, with the highest concentration being as high as 4628 ng·L-1. The results of risk assessment based on the risk quotient method and joint probability curve method showed that nonylphenol had certain risks to aquatic life in the major basins of China. Finally, the commonly used nonylphenol treatment, disposal, and risk management and control technologies were summarized, and the international supervision methods of endocrine-disrupting chemicals were compared. Aiming at addressing the problems existing in China's environmental management, targeted policy suggestions were put forward. The research results can provide reference for the management and control of emerging contaminants in China.

Bound PAHs in Sediment and Related Environmental Significance.

Extractable polycyclic aromatic hydrocarbons (EPAHs) and bound PAHs (BPAHs) were measured in a sediment core using conventional Soxhlet extraction and a more astringent extraction method, with the objectives of determining the influence of BPAHs on the historical reconstruction of PAHs and exploring the formation of BPAHs and long-term behaviors of PAHs in sediment. The results indicated that the formation of BPAHs was clearly sediment-depth and molecular-size dependent. BPAHs represents an important portion of PAHs in sediment and cannot be extracted by conventional Soxhlet extraction. This suggests that the previously developed vertical profile of PAHs is not the real chronology of PAHs and the plausible interpretation derived from the sedimentary records of PAHs needs reexamination. Based on the previous findings, a biphase model was proposed and the formation of BPAHs was predicted. Due to the different nature of geosorbents in sediment, redistribution of PAHs among these geosorbents logically leads to the formation of BPAHs and is kinetically favorable for smaller molecular PAHs. This is consistent with the obtained results. Many factors may influence the formation of BPAHs, such as the physicochemical structure of sediment and environmental conditions. There is still a long way to reveal the thermodynamical characteristics in action during the formation of BPAHs.

Fugacity gradients of hydrophobic organics across the air-water interface measured with a novel passive sampler.

Mass transfer of hydrophobic organic contaminants (HOCs) across the air-water interface is an important geochemical process controlling the fate and transport of HOCs at the regional and global scales. However, few studies have characterized concentration or fugacity profiles of HOCs near both sides of the air-water interface, which is the driving force for the inter-compartmental mass transfer of HOCs. Herein, we introduce a novel passive sampling device which is capable of measuring concentration (and therefore fugacity) gradients of HOCs across the air-water interface. Laboratory studies indicated that the escaping fugacity values of polycyclic aromatic hydrocarbons (PAHs) from water to air were negatively correlated to their volatilization half-lives. Results for field deployment were consistent between the passive sampler and an active method, i.e., a combination of grab sampling and liquid-liquid extraction. In general, the fugacity profiles of detected PAHs were indicative of an accumulation mechanism in the surface microlayer of the study regions (Haizhu Lake and Hailing Bay of Guangdong Province, China), while p,p'-DDD tended to volatilize from water to the atmosphere in Hailing Bay. Furthermore, the fugacity profiles of the target analytes increased towards the air-water interface, reflecting the complexity of environmental behavior of the target analytes near the air-water interface. Overall, the passive sampling device provides a novel means to better characterize the air-water diffusive transfer of HOCs, facilitating the understanding of the global cycling of HOCs.

Tracking human footprints in Antarctica through passive sampling of polycyclic aromatic hydrocarbons in inland lakes.

Freely dissolved polycyclic aromatic hydrocarbons (PAHs) were monitored in seven inland lakes of Antarctica by a polyethylene (PE)-based passive sampling technique, with the objective of tracking human footprints. The measured concentrations of PAHs were in the range of 14-360 ng L(-1) with the highest values concentrated around the Russian Progress II Station, indicating the significance of human activities to the loading of PAHs in Antarctica. The concentrations of PAHs in the inland lakes were in the upper part of the PAHs levels in aquatic environments from remote and background regions across the globe. The composition profiles of PAHs indicated that PAHs in the inland lakes were derived mainly from local oil spills, which was corroborated by a large number of fuel spillage reports from ship and plane crash incidents in Antarctica during recent years. Clearly, local human activities, rather than long-range transport, are the dominant sources of PAH contamination to the inland lakes. Finally, the present study demonstrates the efficacy of PE-based passive samplers for investigating PAHs in the aquatic environment of Antarctica under complex field conditions.

[Simultaneous Analysis of 18 Glucocorticoids in Surface Water].

A method of ultra-performance liquid chomatography tandam mass spectrometry(UPLC-MS/MS) combined with solid-phase extraction (SPE) has been developed for simultaneous analysis of 18 glucocorticoids in surface water. The analytes were first enriched and purified through a HLB cartridge, and eluted with acetonitrile/ethyl acetate (1:1, V/V), then detected by UPLC-MS/MS. The detection used gradient elution process with methanol and 0. 1% formic acid/water (V/V) as the mobile phase to achieve baseline separations of these 18 analytes. The linear range was 1. 0-1 000 µg.L-1. The method detection limits (MDLs) were 0. 10-1. 0 ng.L-1 except for cortisone acetate and cortisol acetate(10 ng.L-1) with overall mean recoveries of 65% - 108% in surface water. Application of this method for 5 surface waters from Beijing area showed that 8 glucocorticoids were detected with the concentration range of 0. 20-476 ng.L-1. Triamcinolone, triamcinolone acetonide, cortisol acetate and clobetasol propionate were detected for the first time in surface water samples, suggesting that this method is efficient for real sample analysis.

Seasonal deposition fluxes and removal efficiency of atmospheric polybrominated diphenyl ethers in a large urban center: importance of natural and anthropogenic factors.

Wet deposition is an effective and important mechanism for removal of atmospheric pollutants, particularly in urban regions. To examine the effectiveness of natural and anthropogenic factors in such removal mechanisms, we conducted a study in Guangzhou, a mega metropolitan center in South China. Rainwater and dry particle deposition samples were simultaneously collected from Guangzhou during the entire year of 2010, and analyzed for polybrominated diphenyl ethers (PBDEs), a group of pollutants mainly derived from industrial and household consumer products. Concentrations of ΣPBDE (sum of the 21 congeners of PBDEs) and BDE-209 in wet deposition samples ranged from 0.11 to 640 (average: 23 ± 36 ng L(-1)) and 0.071 to 420 (average: 20 ± 31 ng L(-1)), respectively. Assessed by conditional inference tree, particulate matter was recognized as the most important factor controlling concentration levels of PBDEs. The combined wet and dry deposition flux of ΣPBDE (1.4 (± 1.2) × 10(4) ng m(-2) quarter(-1)) in the first quarter of 2010 was not significantly different from that (1.3 (± 0.46) × 10(4) ng m(-2) quarter(-1)) in the fourth quarter, indicating that source control measures implemented by local governments for the 16th Asian Games and 10th Asian Para Games (held in November and December 2010, respectively) were ineffective in reducing the loadings of atmospheric PBDEs. In addition, the lower removal efficiency of ΣPBDE was found in the fourth quarter compared to other quarters. This result suggested that rain interventions conducted to maintain clear weather conditions for the Asian Games turned out to lower the efficacy for removal of PBDEs by wet deposition.

Health risk characterization for resident inhalation exposure to particle-bound halogenated flame retardants in a typical e-waste recycling zone.

Inhalation of pollutants is an important exposure route for causing human health hazards, and inhalation exposure assessment must take into account particle size distribution because particle-bound pollutants are size-dependent. Such information is scarce, particularly for residents dwelling within e-waste recycling zones where abundant atmospheric halogenated flame retardants (HFRs) commonly used in electronic/electrical devices have been widely reported. Atmospheric size-fractioned particle samples were collected using a 10-stage Micro-Orifice Uniform Deposit Impactor from an e-waste recycling zone in South China. The deposition efficiencies and fluxes of size-fractioned HFRs including polybrominated diphenyl ethers (PBDEs), alternative brominated flame retardants, and Dechlorane Plus in the human respiratory tract were estimated using the International Commission on Radiological Protection deposition model. The majority of HFRs was found to deposit in the head airways, with coarse particles (aerodynamic diameter (Dp) > 1.8 µm) contributing the most (69-91%). Conversely, fine particles (Dp < 1.8 µm) were dominant in the alveolar region (62-80%). The inhalation intake of PBDEs within the e-waste recycling zone was 44 ng/d (95% confidence interval (CI): 30-65 ng/d), close to those through food consumption in non-e-waste recycling regions. The estimated total hazard quotient of particle-bound HFRs was 5.6 × 10(-4) (95% CI: 3.8 × 10(-4)-8.8 × 10(-4)). In addition, incremental lifetime cancer risk induced by BDE-209 was 1.36 × 10(-10) (95% CI: 7.3 × 10(-11)-2.3 × 10(-10)), much lower than the Safe Acceptable Range (1.0 × 10(-6)-1.0 × 10(-4)) established by the United States Environmental Protection Agency. These results indicate that the potential health risk from inhalation exposure to particle-bound HFRs for residents dwelling in the e-waste recycling zone was low.

Utility of soil linear alkylbenzenes to assess regional anthropogenic influences with special reference to atmospheric transport.

Tracing regional anthropogenic influences is important for assessing the magnitude of human interferences with the environment. In the present study, the utility of soil linear alkylbenzenes (LABs) as indicators of anthropogenic influences was examined, with the emphasis on the role of atmospheric transport in dissipating LABs from input sources to remote areas. The Pearl River Delta, South China, which has experienced rapid economic growth and urbanization, was selected as the study region. The concentrations of LABs (mean: 8.6 ng/g and median: 5.7 ng/g, with an outlier of 2,020 ng/g excluded) suggested that sewage contamination throughout the entire study region was generally light. The spatial variation of sewage pollution was significantly positively correlated with population density and per capita gross domestic product, with hot spots concentrated in the central PRD. Atmospheric deposition was hypothesized as an important input route for soil LABs in forestry and drinking water source areas with little impact of irrigation or direct wastewater discharge. This proposition could explain the opposite spatial patterns of LAB concentrations and values of a biodegradation index (5-C12+5-C13)/(5-C11+5-C10), where i-Cn defines a specific LAB congener with i and n indicating the position of the phenyl group and the number of carbon atoms on the alkyl chain, respectively. These findings somewhat validated LABs as tracers of regional anthropogenically derived contamination, with atmospheric transport of LABs as a viable dissipating mechanism.

Anthropogenic activities have contributed moderately to increased inputs of organic materials in marginal seas off China.

Sediment has been recognized as a gigantic sink of organic materials and therefore can record temporal input trends. To examine the impact of anthropogenic activities on the marginal seas off China, sediment cores were collected from the Yellow Sea, the inner shelf of the East China Sea (ECS), and the South China Sea (SCS) to investigate the sources and spatial and temporal variations of organic materials, i.e., total organic carbon (TOC) and aliphatic hydrocarbons. The concentration ranges of TOC were 0.5-1.29, 0.63-0.83, and 0.33-0.85%, while those of Σn-C14-35 (sum of n-alkanes with carbon numbers of 14-35) were 0.08-1.5, 0.13-1.97, and 0.35-0.96 µg/g dry weight in sediment cores from the Yellow Sea, ECS inner shelf, and the SCS, respectively. Terrestrial higher plants were an important source of aliphatic hydrocarbons in marine sediments off China. The spatial distribution of Σn-C14-35 concentrations and source diagnostic ratios suggested a greater load of terrestrial organic materials in the Yellow Sea than in the ECS and SCS. Temporally, TOC and Σn-C14-35 concentrations increased with time and peaked at either the surface or immediate subsurface layers. This increase was probably reflective of elevated inputs of organic materials to marginal seas off China in recent years, and attributed partly to the impacts of intensified anthropogenic activities in mainland China. Source diagnostics also suggested that aliphatic hydrocarbons were mainly derived from biogenic sources, with a minority in surface sediment layers from petroleum sources, consistent with the above-mentioned postulation.

[Quantitative analysis of protein concentration by absorption peak integration method of UV spectroscopy--taking alkaline phosphatase as an example].

Adsorption of alkaline phosphatase (APase) on minerals (goethite, montmorillonite) and sediments from Taihu Lake was studied. However, the concentration of alkaline phosphatase in the supernatant cannot be analyzed by the adsorption at 280 nm due to that the UV spectroscopy was changed. Quantitative analysis of alkaline phosphatase in the supernatant by the absorption peak (252-305 nm) integration method of UV spectroscopy was developed. This method determined the concentrations of alkaline phosphatase well. Compared to the results of Bradford, the absorption peak integration method can determine the concentrations of supernatant fast, conveniently, and accurately. This method can also be applied to other protein solution analysis and similar experiments. The drawbacks of traditional single wavelength method (280nm) were overcome to some extent based on the method of absorption peak integration.

Novel passive sampling device for measuring sediment-water diffusion fluxes of hydrophobic organic chemicals.

Molecular diffusion across the sediment-water interface, as one of the key geochemical processes, dictates whether a sediment is a source or sink of chemicals, providing useful data in designing remedial actions. Despite ample previous efforts in quantifying sediment-water diffusion fluxes, the resulting methods are largely unsatisfactory. Herein, we introduce a novel passive sampling device capable of measuring vertical profiles of chemical concentrations near the sediment-water interface, from which diffusion fluxes can be calculated based on a model that we developed. In laboratory testing, diffusion fluxes (0.032-310 ng m(-2) d(-1)) of dichlorodiphenyltrichloroethane and its metabolites obtained from the present sampling device were consistent with those (0.38-610 ng m(-2) d(-1)) determined by using a conventional active sampling method, solid-phase extraction/liquid-liquid extraction. Field deployment of the sampling device yielded individual diffusion fluxes of p,p'-DDD, p,p'-DDE, p,p'-DDMU, o,p'-DDMU, p,p'-DDNU, and p,p'-DBP in the range of 5.9-150 ng m(-2) d(-1), which were comparable to those (5.5-85 ng m(-2) d(-1)) obtained with a benthic chamber. Moreover, diffusion fluxes of p,p'-DDT and o,p'-DDT obtained with the sampling device were negative; i.e., the sediment is acting as a sink for these chemicals, while that could not be found using the benthic chamber. Thus, the passive sampling device can provide better information about the movement of chemicals through the sediment and overlying water for the choice of remedial strategies.

[Ecological risk assessment of bisphenol A in Chinese freshwaters].

Bisphenol A (BPA) has many toxic effects on aquatic organisms, of which the most obvious effect is the estrogenic effect. The data collected in the study were divided into two parts, based on the response of the tested organisms to the estrogenic effects of BPA and their exposed time, and the risk of BPA to Chinese aquatic water was assessed by using quotient method, quotient exponent and probability method, safety threshold value method and joint probability risk assessment, respectively. Similar results were derived from the above four methods. Aquatic organisms were more sensitive to the estrogenic effects of BPA than other toxic effects. The results of risk assessment from safety threshold value method were more accurate and confident than the other three methods. Using the chronic data of BPA's estrogenic effect on tested organisms as the endpoint for risk assessment in safety threshold value method, it was found that in 64.70% of the Chinese freshwaters more than 5% of aquatic organisms were affected by the estrogenic toxicity of BPA, and the maximum allowable concentration of BPA was 15.72 ng x L(-1). Using the acute data of such effects as endpoint in safety threshold value method, in about 20.43% volume of the Chinese freshwaters more than 5% of aquatic organisms were affected by the estrogenic toxicity of BPA, and the maximum allowable concentration was 2.24 x 10(2) ng x L(-1).

A multisection passive sampler for measuring sediment porewater profile of dichlorodiphenyltrichloroethane and its metabolites.

In situ measurements of hydrophobic organic chemicals in sediment porewater, a central component in assessing the bioavailability and mobility of chemicals in sediment, have been scarce. Here, we introduce a multisection passive sampler with low-density polyethylene (LDPE) as the sorbent phase, which is appropriate for measuring vertical concentration profiles of chemicals in sediment porewater. This sampler is composed of a series of identical sampling cells insulated with seclusion rings. In each section, sorption of chemicals into LDPE is diffusion-controlled through the water layer separated from the sediment by a glass fiber filtration membrane and a porous stainless steel shield. Pilot laboratory testing indicated that the sampler can roughly determine the porewater concentrations of 1,1-dichloro-2,2-bis-(chlorophenyl)ethane (p,p'-DDD) and 1,1-dichloro-2,2-bis-(chlorophenyl)ethylene (p,p'-DDE), comparable to those yielded through centrifugation/liquid-liquid extraction, a conventional technique for sampling sediment porewater. Field deployment of the sampler was performed in an urbanized coastal region to measure the depth profiles of dichlorodiphenyltrichloroethane and its metabolites in sediment porewater. Sampling rate-calibrated and performance reference compound-calibrated concentrations were calculated, which were consistent with those obtained by the centrifugation/liquid-liquid extraction method. These results verified the utility of the sampler for measuring depth profiles of sediment porewater chemicals.

Sedimentary record of polycyclic aromatic hydrocarbons and DDTs in Dianchi Lake, an urban lake in Southwest China.

Unique time trends of polycyclic aromatic hydrocarbons (PAHs) and dichlorodiphenyltrichloroethanes (DDTs) were found in a dated sediment core from Dianchi Lake (DC), an urban lake in Southwest China. The temporal trend of PAHs in DC was not only different from those in China's coastline and remote lakes of China, but also different from those in more developed countries. Identification of sources suggested that PAHs in DC originated primarily from domestic combustion of coal and biomass. However, a change of source from low- and moderate-temperature combustion to high-temperature combustion processes was observed. Different from those in China's coastline and some developed countries, the temporal trend of DDTs in DC mirrored the historical usage of DDTs in China, with erosion of soils and surface runoff from its drainage area the most likely routes of DDT introduction to the lake. Rapid urbanization and industrialization in its catchment, effective interception of point-source pollution, and changes in sources of energy during the last few decades have significantly influenced the vertical profiles of PAHs in DC.

Characteristics of DDTs in fish from Lake Taihu: an indicator of continual DDTs input in China.

Four typical freshwater fish species in Lake Taihu (TH), China, were collected and analyzed for the residue levels of DDT and its metabolites DDD and DDE (sum of o,p'- and p,p'-DDT, DDD, and DDE is designated as DDTs). The DDTs concentrations ranged from 3.24 to 37.1 ng/g, and p,p'-DDE was the dominant isomer, followed by p,p'-DDD and o,p'-DDT. Source identification indicated that DDTs in TH was mostly stemmed from the historical usage of technical DDT mixture, but a new source of DDT, i.e., dicofol-type DDT, also occurred. The results from the present work, together with previously published data, clearly indicate that dicofol-type DDT was widespread and was an important continual source of DDTs in China.

Development of freshwater aquatic life criteria for tetrabromobisphenol A in China.

Tetrabromobisphenol A (TBBPA) is the most widely used brominated flame retardant. It has been detected in the environment and has shown to high toxicity to aquatic organisms. To date no aquatic life criteria for TBBPA have been proposed. This work compiled all literature toxicity data of TBBPA on Chinese aquatic species. Eight resident Chinese aquatic organisms were used in toxicity tests to supplement the existing toxicity data for TBBPA. Ten genera mean acute values and three genera mean chronic values to freshwater aquatic animals, as well as two genera toxicity values to aquatic plants were collected. A criterion maximum concentration of 0.1475 mg/L and a criterion continuous concentration of 0.0126 mg/L were derived based on these data, according to the U.S. Environmental Protection Agency guidelines. These criteria may be useful in risk assessment of TBBPA in the ambient water environment.

[Uncertainty characterization approaches for ecological risk assessment of polycyclic aromatic hydrocarbon in Taihu Lake].

Probabilistic approaches, such as Monte Carlo Sampling (MCS) and Latin Hypercube Sampling (LHS), and non-probabilistic approaches, such as interval analysis, fuzzy set theory and variance propagation, were used to characterize uncertainties associated with risk assessment of sigma PAH8 in surface water of Taihu Lake. The results from MCS and LHS were represented by probability distributions of hazard quotients of sigma PAH8 in surface waters of Taihu Lake. The probabilistic distribution of hazard quotient were obtained from the results of MCS and LHS based on probabilistic theory, which indicated that the confidence intervals of hazard quotient at 90% confidence level were in the range of 0.000 18-0.89 and 0.000 17-0.92, with the mean of 0.37 and 0.35, respectively. In addition, the probabilities that the hazard quotients from MCS and LHS exceed the threshold of 1 were 9.71% and 9.68%, respectively. The sensitivity analysis suggested the toxicity data contributed the most to the resulting distribution of quotients. The hazard quotient of sigma PAH8 to aquatic organisms ranged from 0.000 17 to 0.99 using interval analysis. The confidence interval was (0.001 5, 0.016 3) at the 90% confidence level calculated using fuzzy set theory, and the confidence interval was (0.000 16, 0.88) at the 90% confidence level based on the variance propagation. These results indicated that the ecological risk of sigma PAH8 to aquatic organisms were low. Each method has its own set of advantages and limitations, which was based on different theory; therefore, the appropriate method should be selected on a case-by-case to quantify the effects of uncertainties on the ecological risk assessment. Approach based on the probabilistic theory was selected as the most appropriate method to assess the risk of sigma PAH8 in surface water of Taihu Lake, which provided an important scientific foundation of risk management and control for organic pollutants in water.

[Distribution, source and risk assessment of polycyclic aromatic hydrocarbons in river sediment of Cheng-Yu economic zone].

The USEPA 16 priority pollutant dominated polycyclic aromatic hydrocarbons (PAHs) in the surface river sediments of Sichuan Province and Chongqing City in southwest China were determined using GC-MS. The result showed the content of PAHs in the sediment ranged from 48.2 ng/g to 723.1 ng/g, with an average value of 276.1 ng/g. Among which, the maximum content was found in Shimenzi of Yangtze River, the minimum content was found in Baiqing of Fujiang River. The content order of PAHs in the sediments followed Yangtze River (358.6 ng/g) > Minjiang River (322.2 ng/g) > Tuojiang River (292.7 ng/g) > Qujiang River (260.6 ng/g) > Jialing River (240.2 ng/g) > Fujiang River (82.4 ng/g). The vertical profiles of c(An)/c(An + Phe), c(FlA)/c(FlA + Pyr) and c(InP)/c (InP + BghiP) suggested the PAHs in this zone were mainly originated from pyrogenic source, the main sources of PAHs were petroleum combustion, biomass combustion, and coal burning. Risk assessment suggested that the PAHs in the sediment of this zone had no significantly biological impairment and low toxicological risk.

Screening level of PAHs in sediment core from Lake Hongfeng, Southwest China.

Using data from a 25-year retrospective of polycyclic aromatic hydrocarbons (PAHs) in sediment core from Lake Hongfeng, Southwest China, their possible sources and potential toxicologic significance were investigated. The total PAH concentrations (16 priority PAHs as proposed by the United States Environmental Protection Agency) in sediments ranged from 2936.1 to 5282.3 ng/g and gradually increased from the analyzed deeper sediments to surface sediments. PAHs were dominated by low molecular-weight components, especially phenanthrene (PHEN) and fluorene (FLU). However, a significantly increased number of high molecular-weight (HMW) PAHs was found in upper segments. The temporal trends of individual PAH species suggest that there may have been a change in energy use from low- to high-temperature combustion, especially after approximately 2001. PAH input to Lake Hongfeng originated mainly from domestic coal combustion and biomass burning, whereas fuel combustion characteristics have also been found in recent years. Sediment-quality assessment implied that potential adverse biologic impact could be a probability for most low-ring PAHs (including naphthalene, acenaphthylene, acenaphthylene, FLU, PHEN, and anthracene). Nevertheless, more concern should be paid to HMW PAHs in the future due to their rapidly increasing trends in upper sediments. Because only one core was analyzed in this study, more work is needed to confirm the sources and toxicity of PAHs in Lake Hongfeng.