The concentrations and distribution of polycyclic musks in a typical cosmetic plant

Polycyclic musks [cashmeran (DPMI), celestolide (ADBI), phantolide (AHMI), traseolide (ATII), tonalide (AHTN) and galaxolide (HHCB)] in the air, wastewater, sludge samples of a typical cosmetic plant were analyzed. DPMI, ADBI, HHCB and AHTN were found in all samples, and ATII was not found in any sample. HHCB and AHTN were the major components in all samples. The polycyclic musk concentrations were very high in the air of the cosmetic plant, and polycyclic musks were mostly contained in the gas phase at the percentage of 86.35-97.70%. Average polycyclic musk concentrations in effluent were high, and ranged from 0.62 to 32.06 microgl-1. The removal efficiency during the active sludge wastewater treatment was also high, resulting from the adsorption of those compounds into the sludge. So the polycyclic musk concentrations were very high in the primary sludge and second sludge, and ranged from 1.78 to 92.45 mgkg-1 (dry), and from 2.87 to 65.67 mgkg-1 (dry), respectively. Results suggested that the sludge needed to be further treated to make polycyclic musks less influence to the environment.     

Synthetic polycyclic musks in Hong Kong sewage sludge

Synthetic polycyclic musks [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN), and Galaxolide (HHCB)] were determined in dewatered sludge samples from 10 major sewage treatment plants in Hong Kong using primary treatment (PT), secondary treatment (SecT) or chemical-enhanced primary treatment (CEPT) methods. The concentrations of HHCB, AHTN, AHMI and ADBI ranged from below detection limits to 78.6mg/kg dry weight. HHCB and AHTN were the two predominant polycyclic musks in sludge samples, suggesting the extensive use of these two polycyclic musks in Hong Kong. Polycyclic musk levels in CEPT sludge were significantly higher than those in SecT and PT sludge, suggesting that CEPT sludge has a higher ability to retain polycyclic musks. Comparisons to global concentrations revealed that HHCB and AHTN concentrations detected in Hong Kong sludge ranked first and second respectively. However, the estimated levels of HHCB and AHTN in the discharged effluent from sewage treatment plants may pose low potential risks to aquatic organisms according to the threshold effect levels derived for fish. Nevertheless, the polycyclic musks released in sewage treatment plant effluents may bioconcentrate and bioaccumulate in the marine environment in Hong Kong. Therefore, monitoring studies in marine ecosystems, particularly on the two prevailing polycyclic musks, are necessary.     

A survey of polycyclic musks in selected household commodities from the United States

Occurrence of the polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[g]-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronapthalene (AHTN), in wastewater influent and effluent, as well as in surface waters, has been reported. HHCB and AHTN were also reported to occur in human and wildlife tissues. The major sources for HHCB and AHTN to wastewater are thought to be consumer products such as shampoos, deodorants, laundry detergents, and household surface cleaners. However, the levels of HHCB and AHTN in consumer products are not known. For evaluation of the sources of human and environmental exposures, characterization of levels of HHCB and AHTN in consumer products is needed. In this study, we measured concentrations of HHCB (Galaxolide), AHTN (Tonalide), and HHCB-lactone (Galaxolidone) from a variety of consumer products, including perfumes, body lotions, and deodorants. Concentrations of HHCB, AHTN, and HHCB-lactone in consumer products ranged from <5 ng/g to over 4000 microg/g, <5 ng/g to 451 microg/g, and <5 ng/g to 217 microg/g, respectively. The highest concentrations were found in perfumes, body creams and lotions, and deodorants. The results suggest that a wide variety of source materials exist for HHCB and AHTN, and that these materials are used on a daily basis.     

Determination of polycyclic musks in sewage sludge from Guangdong, China using GC-EI-MS

Polycyclic musks [Cashmeran (DPMI), Celestolide (ADBI), Phantolide (AHMI), Traseolide (ATII), Tonalide (AHTN) and Galaxolide (HHCB)] were Soxhlet extracted, separated and analyzed in sewage sludge from six different wastewater treatment plants from Guangdong, China, using GC and GC-EI-MS. DPMI, ADBI, HHCB, AHTN were found in all samples, and ATII was not found in any sample. AHMI was detected in five out of six samples. HHCB and AHTN were the two major polycyclic musks found in highest concentrations in sludge. The sludge from municipal wastewater treatment plants contained HHCB, AHTN and DPMI at concentrations between 5.416 and 21.214, 0.715 and 6.195 and 0.599 and 2.870 mg/kg (dry), respectively. The highest concentration was found in sludge from one cosmetic plant at 703.681 mg HHCB/kg (dry). The results indicate that there are two sources of polycyclic musks: domestic sewage and industrial wastewater.     

Sample storage and extraction efficiencies in determination of polycyclic and nitro musks in sewage sludge

Analytical technology is continuously improving, developing better methods for isolating and concentrating trace compounds in environmental samples. Polycyclic and nitro musks (PNMs) are one group of emerging trace compounds detected in municipal wastewater. Differences in sample storage, preparation, and extraction methods for their measurement have led to variability in results. We analyzed 11 PNMs by GC/MS and compared the results of different storage times and extraction methods (supercritical fluid (SFE) or microwave-assisted (MAE)) for 202 samples of primary sludge, waste activated sludge (WAS), raw sludge, and aerobically/anaerobically digested biosolids collected from Canadian municipal wastewater treatment plants. Sixty-three air-dried samples were extracted by SFE, and 139 air-dried, centrifuged, or filtered samples were extracted by MAE. The mean surrogate recoveries were 89% (standard deviation (SD)=11%) for d(10)-anthracene by SFE and 88% (SD=14%) for d(10)-phenanthrene by MAE. Storage study results showed that PNM concentrations changed by a mean of 7% and 9% for primary sludge and WAS respectively after four weeks and decreased up to 25% after 13.5 months of storage in amber glass containers at -18 degrees C. Air-drying of sludge at room temperature caused losses of about 50% of PNM concentrations compared to centrifugation. The proportions of PNMs present in the liquid phase of sludge samples were less than 5% compared to proportions in the sludge solids. The most complete liquid-solid separation was achieved by filtration of frozen/thawed sludge samples, producing a liquid phase that contained less than 1% of the total musk content of the sample.     

Occurrence of polycyclic musks in wastewater and receiving water bodies and fate during wastewater treatment

The occurrence of cashmerane (DPMI), celestolide, phantolide, traesolide (ATII), galaxolide (HHCB) and tonalide (AHTN) in sewage and surface waters and their fate during wastewater treatment and anaerobic sludge digestion is investigated. AHTN and HHCB are the most important representatives and influent concentrations of 0.41-1.8 and 0.9-13 μg L⁻¹ are observed. DPMI is detected in influent and effluent samples but in notably lower concentrations than AHTN and HHCB. Major sources of polycyclic musks are households, whereas industrial emitters seem to be of minor importance. This conclusion is supported by the analysis of selected industrial wastewaters (metal, textile and paper industry). Specific emissions of 0.36 ± 0.19 and 1.6 ± 1.0 mg cap⁻¹ d⁻¹ for AHTN and HHCB are calculated. Overall removal efficiencies between approx 50% and more than 95% are observed during biological wastewater treatment and removal with the excess sludge is the major removal pathway. Log K_D values of 3.73-4.3 for AHTN, 3.87-4.34 for HHCB and 2.42-3.22 for DPMI are observed in secondary sludge. During sludge digestion no or only slight removal occurred. Mean polycyclic musk concentrations in digested sludge amounted to 1.9 ± 0.9 (AHTN), 14.2 ± 5.8 (HHCB), 0.8 ± 0.4 (ATII) and 0.2 ± 0.09 (DPMI) mg kg⁻¹ dry matter. In the receiving water systems a comparable distribution as during wastewater treatment is observed. AHTN, HHCB and DPMI are detected in surface waters (ND (not detected) - < 0.04, ND - 0.32 and ND - 0.02 μg L⁻¹) as well as AHTN and HHCB in sediments (ND - 20, ND - 120 μg kg⁻¹). For HHCB an apparent K_OC value of 4.1-4.4 is calculated for sediments. Major source for polycyclic musks in surface waters are discharges from wastewater treatment plants. For HHCB and DPMI 100% of the load observed in the sampled surface waters derive from discharges of treated wastewater.     

Occurrence and fate of polycyclic musks in wastewater treatment plants in Kentucky and Georgia, USA

Wastewater treatment plants (WWTPs) are a potential of source of polycyclic musks in the aquatic environment. In this study, contamination profiles and mass flow of polycyclic musks, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[gamma]-2-benzopyran (HHCB), 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN), and HHCB-lactone (oxidation product of HHCB), in two WWTPs, one located in Kentucky (Plant A, rural area) and the other in Georgia (Plant B, urban), USA, were determined. HHCB, AHTN and HHCB-lactone were detected in the influent, effluent, and sludge samples analyzed. The concentrations in wastewater samples varied widely, from 10 to 7,030 ng/l, 13 to 5,400 ng/l, and 66 to 790 ng/l, for HHCB, AHTN, and HHCB-lactone, respectively. Sludge samples contained HHCB at <0.02-36 microg/g dry weight, AHTN at <0.02-7.2 microg/g dry weight, and HHCB-lactone at <0.05-17 microg/g dry weight. Based on the daily flow rates and mean concentrations of polycyclic musks, the estimated discharge of total polycyclic musks to the rivers was 21 g/day from Plant A and 31 g/day from Plant B. Mass balance analysis suggested that only 30% of HHCB and AHTN entering the plants was accounted for in the effluent and the sludge. Removal efficiencies of HHCB and AHTN in the two WWTPs ranged from 72% to 98%. In contrast, HHCB-lactone concentrations increased following the treatment. Concentrations of polycyclic musks in sludge were on the order of several parts per million. Incineration of sludge at one plant reduced the concentration of polycyclic musks.     

Concentrations and specific loads of polycyclic musks in sewage sludge originating from a monitoring network in Switzerland

Polycyclic musks (HHCB, AHTN, ADBI, AHDI, ATII) and a metabolite of HHCB (HHCB-lactone) were analyzed in sewage sludge samples within the framework of a monitoring network in Switzerland. Mean values in stabilised sludge from 16 wastewater treatment plants were 20.3 mg/kg d.m. for HHCB, 7.3 mg/kg d.m. for AHTN and 1.8 mg/kg d.m. for HHCB-lactone, respectively. Contents of ADBI, AHDI and ATII were between 0.1 and 1.8 g/kg d.m. The results show that polycyclic musks origin mainly from private households and that loads from craft industry, industry and atmospheric deposition are negligible. The technology of wastewater treatment and sludge processing seems to be of minor importance for degradation processes of polycyclic musks. The calculated input in wastewater of polycyclic musks is lower by a factor of 5-7 than the estimates based on use volumes. This discrepancy might be explained by degradation processes, other emission pathways than wastewater or inappropriate estimation of production volumes.     

Nitro musks, nitro musk amino metabolites and polycyclic musks in sewage sludges. Quantitative determination by HRGC-ion-trap-MS/MS and mass spectral characterization of the amino metabolites

Nitro- and polycyclic musks were quantified in sewage sludge samples from different catchment areas using high-resolution gas chromatography (HRGC) and ion-trap MS/MS. Collision induced dissociation (CID) turned out to be a useful tool for quantification of the analytes. Negative chemical ionization (NCI) quadrupole MS in the selected ion mode (SIM) showed similar sensitivities compared to ion trap MS/MS. Among the nitro musks, musk ketone (MK) and musk xylene (MX) were the main compounds in predominantly domestic sewage sludges, found at low microgram/kg dry matter (d.m.) whereas polycyclic musks were present in domestic as well as in industrial sludges up to 12 mg/kg d.m. Galaxolide (HHCB) and Tonalide (AHTN) were the major polycyclic musks found in the sludges. Amino metabolites of the nitro musks, amino musk xylene (AMA), amino musk moskene (AMM) and amino musk ketone (AMK) were detected for the first time in sewage sludges, and reached partly higher concentrations compared to the parent compounds.     

Preliminary study on the occurrence and distribution of polycyclic musks in a wastewater treatment plant in Guandong, China

The occurrence and distributions of six polycyclic musks were studied in influent, primary and effluent waters from a municipal wastewater treatment plant (WWTP) in Guangdong. Five polycyclic musk compounds, 1,2,3,5,6,7-hexahydro-1,1,2,3,3-pentamethyl-4H-inden-4-one (DPMI), 4-acetyl-1,1-dimethyl-6-tert-butylindan (ADBI), 6-acetyl-1,1,2,3,3,5-hexamethylindan (AHMI), 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran (HHCB) and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN) were found in wastewater in the WWTP. DPMI, HHCB and AHTN were measured at 0.38-0.69, 11.5-146, 0.89-3.47 microg/l, respectively, in influents. Meanwhile 0.06-0.10 microg/l DPMI, 0.95-2.05 microg/l HHCB, 0.10-0.14 microg/l AHTN were detected in effluents, ADBI and AHMI were also detected in some primary waters and effluents. The results suggested that wastewater from cosmetic plants cause high loadings of polycyclic musks to this WWTP. Under the currently applied treatment technology, the removal efficiencies achieved were 61-75% for DPMI, 86-97% for HHCB and 87-96% for AHTN by transfer to sludge as the main removal route.     

Acute toxicity, biochemical and gene expression responses of the earthworm Eisenia fetida exposed to polycyclic musks

Phytoremediation is a novel and promising approach for the treatment of pollutants. This study did explore the potential of Aster amellus Linn. to decolorize a sulfonated azo dye Remazol Red (RR), a mixture of dyes and a textile effluent. Induction in the activities of lignin peroxidase, tyrosinase, veratryl alcohol oxidase and riboflavin reductase was observed during RR decolorization, suggesting their involvement in the metabolism of RR. UV-Visible absorption spectrum, HPLC and FTIR analysis confirmed the degradation of RR. Four metabolites after the degradation of the dye were identified as 2-[(3-diazenylphenyl) sulfonyl] ethanesulfonate, 4-amino-5-hydroxynaphthalene-2,7-disulfonate, naphthalene-2-sulfonate and 3-(1,3,5-triazin-2-ylamino)benzenesulfonate by using GC/MS. Textile effluent and mixture of dyes showed 47% and 62% decrease respectively in American Dye Manufacturers Institute value. BOD of textile effluent and mixture of dyes were reduced by 75% and 48% respectively, COD of industrial effluent and mixture of dyes was reduced by 60% and 75% and TOC was reduced by 54% and 69% respectively after the treatment by A. amellus for 60 h; this indicated that the plant can be used for cleaning textile effluents. Toxicity study revealed the phytotransformation of RR into non-toxic products.     

Distributions and determinants of mercury concentrations in toenails among American young adults: the CARDIA Trace Element Study

Since data on mercury (Hg) levels in Caucasians and African Americans (AAs) of both genders are lacking, this study aims to present toenail Hg distributions and explore the potential determinants using data from the Coronary Artery Risk Development in Young Adults Trace Element Study. Data from 4,344 Americans, aged 20–32 in 1987, recruited from Oakland, Chicago, Minneapolis, and Birmingham were used to measure toenail Hg levels by instrumental neutron-activation method. The Hg distribution was described with selected percentiles and geometric means. Multivariable linear regression (MLR) was used to examine potential determinants of Hg levels within ethnicity–gender subgroups. The geometric mean of toenail Hg was 0.212 (95 % CI?=?0.207–0.218)?μg/g. Hg levels varied geographically with Oakland the highest [0.381 (0.367–0.395) μg/g] and Minneapolis the lowest [0.140 (0.134–0.147) μg/g]. MLR analyses showed that male gender and AA ethnicity were negatively associated with toenail Hg levels, and that age, living in Oakland city, education level, alcohol consumption, and total fish intake were positively associated with toenail Hg concentrations within each ethnicity–gender subgroup. Current smokers were found to have higher Hg only in AA men. This study suggested age, gender, ethnicity, study center, alcohol, education level, and fish consumption consistently predict toenail Hg levels. As fish consumption was the key determinant, avoiding certain types of fish that have relatively high Hg levels may be crucial in reducing Hg intake.     

Tissue concentrations, bioaccumulation, and biomagnification of synthetic musks in freshwater fish from Taihu Lake, China

Synthetic musks are ubiquitous pollutants in aquatic environments. As hydrophobic chemicals, they can accumulate in terrestrial and aquatic organisms. Investigations into the bioaccumulation of these chemicals in aquatic ecosystem have, however, been limited, and previous results were inconsistent among species and ecosystem. Studies on this topic have been carried out in European countries, the USA, and Japan, but very few are known of the situation in China. The aim of this study was to investigate contaminant levels of musks in fish from Taihu Lake, the second largest freshwater lake in China, as well as bioaccumulation and biomagnification of the pollutants in the freshwater food chain. Five polycyclic musks and two nitro musks were determined in 24 fish species and nine surface sediment samples from Taihu Lake. HHCB (1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta[γ]-2-benzopyran) and AHTN (7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene) were the predominant contaminants in the fish samples, with concentrations ranging from below the limit of detection (LOD) to 52.9 and from <LOD to 7.5 ng/g lipid weight, respectively. Other contaminants were at low detection frequencies. The results indicated low concentrations of musks yet widespread occurrence of these contaminants in fish from Taihu Lake. Species-specific and lipid-related bioaccumulation characteristics were suggested, but no significant region-specific differences were observed. Normalized biota-sediment accumulation factors for HHCB and AHTN were noted to increase with trophic levels in fish. Trophic magnification factors were estimated at 1.12 for HHCB and 0.74 for AHTN. A biomagnification for HHCB, and probably biodilution for AHTN, in the freshwater food chain are indicated, when trophic magnification factors were concerned. However, the correlations between logarithmic concentrations of the chemicals and trophic levels were not statistically significant. Further study using long food chains in this lake is still needed.     

Polybrominated diphenyl ethers, polychlorinated naphthalenes and polycyclic musks in human fat from Italy: Comparison to polychlorinated biphenyls and organochlorine pesticides

Prior to this study, reports of occurrence of polycyclic musks and polychlorinated naphthalenes (PCNs) in human tissues from Italy were not available. In this study, concentrations of PCNs and polycyclic musks were determined in human adipose tissue from Italy collected during 2005-2006; for comparison, legacy organohalogen pollutants such as organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined. ΣPCN concentrations ranged from 0.5 to 14 ng/g lipid wt (lw). Polycyclic musks such as HHCB and AHTN were found in 92% and 83% of the human samples, respectively. Concentrations of PBDEs in Italian adipose tissue ranged between 3.2 and 35.6 ng/g lw.     

Changing pattern in concentrations of polycyclic aromatic hydrocarbons in the air of Central London

The concentrations of polycyclic aromatic hydrocarbons have been measured in Central London and the levels of some of these have declined markedly. For example the concentration of 3:4-benzpyrene has fallen to about one-tenth of the level found 25 years ago. By using selected ratios of polycyclic aromatic hydrocarbons it has been shown that the contribution to the air of the 3:4-benzpyrene from coal burning sources has declined; at one roof-top site about one-fifth to one-quarter of the total benzpyrene found there now probably comes from the traffic sources.     

Temperature dependence of gas-phase polycyclic aromatic hydrocarbon and organochlorine pesticide concentrations in Chicago air

The temperature dependence of gas-phase atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides measured in Chicago, IL between June and October 1995 were investigated using plots of the natural logarithm of partial pressures (ln P) vs. reciprocal mean temperatures (1/T). For the eight lowest molecular weight PAHs, temperature dependence was statistically significant (at the 95% confidence level) and temperature accounted for 23–49% of the variability in gas-phase concentrations. The relatively higher slopes for most of the PAHs suggested that volatilization from local sources and short-range transport influenced their concentrations. For pesticides, temperature dependence was statistically significant for DDD and for trans-nonachlor (at the 95% and 90% confidence levels), and was not statistically significant for the other five compounds (2–18% of the variability in their gas-phase concentrations). The relatively lower slopes for individual pesticides suggested that they have mostly non-urban and distant sources.Results of back trajectory analyses suggested that the region, southwest of Chicago, might be an important local or regional source sector for PAHs and organochlorine pesticides. No statistically significant relationship was observed between wind speed and PAH or pesticide concentrations. None of the variables (temperature, wind speed, wind direction, local and regional sources) could fully explain the variation in their concentrations measured in Chicago, therefore, this variation can be attributed to the combined effect of those factors.     

The study of temple and pastureland particle-bound polycyclic aromatic hydrocarbons concentrations in central Taiwan

The concentrations of polycyclic aromatic hydrocarbons in the atmosphere were measured simultaneously at Tzu Yun Yen temple and Tung Hai University pastureland in Taichung, central Taiwan. At both sites, 24 h samplings were performed between August 2001 and December 2001. The results indicated that high molecular mass polycyclic aromatic hydrocarbons are predominant at the Tzu Yun Yen temple sampling site. Moreover, the PM_2.5 (fine particulate) fraction of total polycyclic aromatic hydrocarbons was higher than that of the PM_2.5-10 (coarse particulate) fraction by a factor of about 1.48 at the temple sampling site. This ratio was 1.24 for the pastureland environment.     

Considerations about the enantioselective transformation of polycyclic musks in wastewater, treated wastewater and sewage sludge and analysis of their fate in a sequencing batch reactor plant

The present work consists of two distinct parts: in the first part enantioselective GC was used to separate the different enantiomeric/diastereomeric polycyclic musks, PCMs (HHCB, AHTN, AHDI, ATII and DPMI) including the main transformation product of HHCB, HHCB-lactone, in wastewater and sewage sludge. After optimization all PCMs were resolved on a cyclodextrin containing Rt-BDEXcst capillary GC column. Enantiomeric ratios of PCMs in a technical mixture were determined and compared to those obtained from enantioselective separation of wastewater and sewage sludge samples. In general, enantiomeric ratios were similar for most materials in influent, effluent and stabilized sewage sludge. However, the ratios for HHCB, AHDI and particularly ATII suggest some stereospecific removal of these compounds. In the second part, a field study was conducted on a wastewater treatment plant comprising a sequencing batch reactor. Concentrations of HHCB, AHTN, ADBI, AHDI, ATII, DPMI and HHCB-lactone were determined by non-enantioselective GC in daily samples of influent, effluent and activated sludge during one week. Mean concentrations in influent were 6900 and 1520 ng/l for HHCB and AHTN, respectively. The other PCMs exhibited contents 200 ng/l. Mean percent removal was between 61% (AHDI) and 87% (HHCB) resulting in mean effluent concentrations below 860 ng/l. HHCB-lactone concentration increased during wastewater treatment with a mean in the influent of 430 ng/l and in the effluent of 900 ng/l, respectively, indicating a degradation of HHCB.     

Temperature dependent properties of environmentally important synthetic musks

Environmental fate determining physical properties including their temperature dependence for five nitro musks and for seven polycyclic musks were estimated. The properties evaluated were vapor pressure in a solid and liquid state (PS and PL), solubility in water (S), Henry's law coefficient (H = PL/S) and log octanol-water partition coefficient (log KOW). Gas chromatography for starting values of vapor pressure estimation and HPLC experiments at 5-20 degrees C for comparison of the theoretical versus experimental solubilities in water were performed. The values of temperature (T) dependence coefficients (Ai and Bi) in equations: log (Property)i = Ai - Bi/T were determined. Values of properties were compared with literature-based data, and an example of their use in environmental hazard estimation by fate modeling was given.     

Contribution ratio of freely to total dissolved concentrations of polycyclic aromatic hydrocarbons in natural river waters

The bioavailability and ecological risk of hydrophobic organic compounds (HOCs) in aquatic environments largely depends on their freely dissolved concentrations. In this work, the freely dissolved concentrations of polycyclic aromatic hydrocarbons (PAHs) including phenanthrene, pyrene, and chrysene were determined for the Yellow River, Haihe River and Yongding River of China using polyethylene devices (PEDs). The results indicated that the order of ratios of freely to total dissolved concentrations of the three PAHs was phenanthrene (66.8 ± 20.1%) > pyrene (48.8 ± 26.4%) > chrysene (5.5 ± 3.3%) for the three rivers. The ratios were significantly negatively correlated with the log K_ow values of the PAHs. In addition, the ratios were negatively correlated with the suspended sediment (SPS) and dissolved organic carbon (DOC) concentrations in the river water, and the characteristics of the SPS and DOC were also important factors. Simulation experiments showed that the ratio of freely to total dissolved concentrations of pyrene in the aqueous phase decreased with increasing SPS concentration; when the sediment concentration increased from 2 g L^?1 to 10 g L^?1, the ratio decreased from 67.6% to 38.4% for Yellow River sediment and decreased from 50.4% to 33.6% for Haihe River sediment. This was because with increasing SPS concentration, more and more DOC, small particles and colloids (<0.45 μm) would enter the aqueous phase. Because high SPS and DOC concentrations exist in many rivers, their effect on the freely dissolved concentrations of HOCs should be considered when conducting an ecological risk assessment.