The concentration, sources and environmental risks of polycyclic aromatic hydrocarbons (PAHs) in surface water in urban areas of Nanjing were investigated. The range of ∑16PAHs concentration is between 4,076 and 29,455 ng/L, with a mean of 17,212 ng/L. The composition of PAHs indicated that 2- and 3-ring PAHs have the highest proportion in all PAHs, while the 5- and 6-ring PAHs were the least in proportion. By diagnostic ratio analysis, combustion and petroleum were a mixture input that contributed to the water PAH in urban areas of Nanjing. Positive matrix factorization quantitatively identified four factors, including coke oven, coal combustion, oil source, and vehicle emission, as the main sources. Toxic equivalency factors of BaP (BaPeq) evaluate the environmental risks of PAHs and indicate the PAH concentration in surface water in urban areas of Nanjing had been polluted and might cause potential environmental risks. Therefore, the PAH contamination in surface water in urban areas of Nanjing should draw considerable attention.

INTRODUCTION

Polycyclic aromatic hydrocarbons (PAHs) are organic compounds, which include two or more fused aromatic rings of carbon and hydrogen atoms (Zhu et al. 2004). The USEPA has classified 16 PAHs as priority pollutants because of their carcinogenicity, teratogenicity and mutagenicity (Wang et al. 2015). PAHs come mainly from anthropogenic activities like industrial processing, vehicle emissions, waste incineration, oil spills, and chemical manufacturing (Lv et al. 2014). Moreover, natural processes like volcanic eruptions, diagenesis, and forest fires can also form a certain amount of PAHs (Wang et al. 2017).

In recent years, much research on PAH pollution of surface water has been conducted all over the world, such as China (Zhang et al. 2011, 2013, 2015; Nagy et al. 2013a; Lv et al. 2014), USA (McDaniel & Zielinska 2015), Japan (Hayakawa et al. 2016), Ghana (Amoako et al. 2011), France (Net et al. 2014), India (Dhananjayan et al. 2012), Hungary (Nagy et al. 2013b), and Egypt (Badawy & Emababy 2010). Most researchers concentrate on the PAH concentrations in aquatic environments and environmental health risks but none of the studies focus on surface water in urban areas of Nanjing, China.

Nanjing, the provincial city of Jiangsu, is a main port along the Yangtze River. Many famous lakes like Xuanwu Lake and Mochou Lake are also located in the city. Nanjing is a comprehensive industrial city dominated by chemicals, electronics, and automobiles. Nowadays, the city has many serious environmental problems because of the population, industrial manufacture, and traffic. Moreover, the urbanization level of Nanjing is high because the population has exceeded 8 million and more than 6 million live in the urban areas.

In this study, 20 surface water samples were collected from urban areas of Nanjing. The concentration, sources, and environmental risk of PAHs in this water body were analyzed. The results can be a reference for evaluating the quality of the aquatic environment in urban areas of Nanjing.

MATERIALS AND METHODS

Sampling and preparation

Twenty surface water samples were collected from the water body in July 2015 (Figure 1). All the samples were collected with a water bottle and stored in brown bottles. All the water samples were taken back to the laboratory quickly. Finally, all of the samples were kept in a refrigerator at 4 °C until analysis.
Figure 1

Sampling sites of surface water in urban areas of Nanjing, China. A. Mochou Lake (ML) a; B. Yangtze River (YR) a; C. Yangtze River (YR) b; D. Xuanwu Lake (XL) a; E. Yangtze River (YR) c; F. Yangtze River (YR) d; G. Yangtze River (YR) e; H. Mochou Lake (ML) b; I. The East Water Park (EWP); J. Xuanwu Lake (XL) b; K. Qianhu Lake (QL); L. Yueya Lake (YL); M. Pipa Lake (PL); N. Wukesong Reservoir (WR); O. Youyi River (YYR); P. Nan River (NR) a; Q. Qiqiaowen Wetland Park (QWP); R. Yanque Lake (YQL); S. Qinhuai River (QR); T. Nan River (NR) b.

Figure 1

Sampling sites of surface water in urban areas of Nanjing, China. A. Mochou Lake (ML) a; B. Yangtze River (YR) a; C. Yangtze River (YR) b; D. Xuanwu Lake (XL) a; E. Yangtze River (YR) c; F. Yangtze River (YR) d; G. Yangtze River (YR) e; H. Mochou Lake (ML) b; I. The East Water Park (EWP); J. Xuanwu Lake (XL) b; K. Qianhu Lake (QL); L. Yueya Lake (YL); M. Pipa Lake (PL); N. Wukesong Reservoir (WR); O. Youyi River (YYR); P. Nan River (NR) a; Q. Qiqiaowen Wetland Park (QWP); R. Yanque Lake (YQL); S. Qinhuai River (QR); T. Nan River (NR) b.

Chemicals

Each of the PAH standards (Supelco, Bellefonte, PA, USA) had a concentration of 2,000 μg mL−1. The organic solvents (HPLC grade) include n-hexane, dichloromethane, acetone, and methanol, which are used for sample preparation and analysis. Silica gel (through 100–200 mesh sieve) was activated by using acetone, dichloromethane, and n-hexane in order. After extraction, silica gel was baked at 130 °C for 16 h in an oven. In addition, Na2SO4 was warmed at 450 °C for 5 h in muffle and then placed in a well-closed container.

Extraction of PAHs

Water samples were filtered on pre-combusted glass fiber (GF/F) membranes (Whatman, UK). Filtered samples were passed through a C18 solid phase extraction cartridge (Supelco, Bellefonte, PA, USA), and the flow velocity was controlled at 5 mL min−1. Before sample filtration, the columns were activated with dichloromethane (5 mL), then methanol solvent (5 mL) and ultra-pure water (5 mL) in turn. The target compounds were extracted from the column with dichloromethane (10 mL). The eluted PAHs were purified by passage through a glass chromatographic column fitted with a stopcock, and then filled in 5 g activated silica gel and 5 g Na2SO4. After cleaning, the dichloromethane solvent that contained PAHs was evaporated to nearly dry, then the organic solvent was replaced by n-hexane. Finally, the collected PAH fraction was evaporated to 1 mL under a nitrogen blowing instrument.

Analysis of PAHs

The PAH eluates of the water were measured by gas chromatography-mass spectrography using Shimadzu QP2010 Ultra with a 30 m × 0.25 mm Rtx-5MS column (0.25 μm film thickness, fused silica capillary). Helium was used as the carrier gas. The original temperature of 80 °C was maintained for 2 min, then ramped from 80 °C to 180 °C at 20 °C min−1 and next to 290 °C at 10 °C min−1 and maintained for 15 min. In addition, the injector temperature was held at 290 °C. The ion source was kept at 230 °C. The temperature of interface was maintained at 280 °C. A 1 μL aliquot of sample elution was injected into a splitless model. The MSD was operated in the electron impact model. Besides, the data were acquired using the selective ion monitoring mode. The relative retention time and the selected ions were used to identify 16 PAHs.

Quality assurance and quality control

A strict procedure of quality assurance and quality control was conducted. Blank samples were analyzed every 5 samples. PAHs in the blank samples were not detected in this experiment. Duplicates were conducted every 5 samples, and if the difference of the analyzed value exceeded ±15%, the samples were reanalyzed. An external standard method was used for identifying and quantifying the 16 PAHs. Mean recoveries of individual PAHs were 88.9–109.6% for water samples. The present PAH concentration values were not corrected.

Data analysis

The positive matrix factorization (PMF) model, which was developed by Paatero & Tapper (1994), was used to quantitatively identify the source of surface water PAHs in the urban area of Nanjing. This method can be briefly summarized as follows. It defines an original matrix X (n × m), where n was expressed as the number of samples and m was expressed as the number of chemical species, which can be decomposed into two new matrices, namely G and F with an unexplained part E. This expression can be formulated as follows:
formula
1
This equation can be converted into:
formula
2
where xij represents the concentration that measured in the ith sample of the jth chemical species, gik represents source k contribution to the ith sample, fkj represents the jth chemical species concentration in source k, and eij represents the residual for the ith sample and the jth chemical species.
An objective function is introduced in this model:
formula
3
where uij represents the uncertainty for the ith sample in the jth chemical species. Measurement uncertainties and method detection limits (MDLs) were employed to calculate the uncertainties. If the sample concentration ≤ MDL, the u was expressed as:
formula
4
If the sample concentration > MDL, the u was expressed as:
formula
5

PMF analysis was conducted using the USEPA PMF 5.0 model (USEPA 2014).

RESULTS AND DISCUSSION

Level and composition of PAHs

Table 1 shows the level of PAH in water at different sites in the research areas. The level of the ∑16PAHs ranged from 4,076 (J) to 29,455 ng/L (O), with a mean of 17,212 ng/L in surface water. The most serious pollution site was at O, which was located at the Youyi River because the river received large quantities of waste water from the industrial activities and residential sources. At sites P and T (Nan River), the total PAH concentration was also high because of the discharge of a large amount of domestic waste into the Nan River. A high total PAH concentration was also found at Pipa Lake (M) located near Purple Mountain (a famous scenic spot in Nanjing). In the Yangtze River, the total PAH level was relatively low (less than the average value) perhaps because of its greater water mobility. The situation of the PAH pollution in urban areas of Nanjing was compared with other rivers or areas (Table 2). The PAH concentrations in surface water from the urban areas of Nanjing were lower than those in other regions, such as the Daqing surface water (Xiao et al. 2015) and Minjiang River (Zhang et al. 2004), but higher than those in Jiulong, Taizi, Raba, Nile, Mississippi, and Yellow Rivers (Maskaoui et al. 2002; Zhang et al. 2007; Badawy & Emababy 2010; Nagy et al. 2013b; Song et al. 2013; Zhao et al. 2015). Our research suggested that the water PAH from the urban areas of Nanjing were in the high pollution level.

Table 1

Concentrations of PAH (ng L−1) in surface water of Nanjing urban area, China (N = 20)

CompoundsML
YR
XL
NR
EWPQLYLPLWRYYRQWPYQLQR
ababcdeabab
Nap 6,181 6,496 6,334 7,696 4,649 3,261 5,011 8,192 1,428 9,079 10,677 4,230 10,155 9,525 8,995 12,495 10,407 4,144 6,552 9,533 
Acy ND 358 523 ND 362 347 346 450 141 1,001 1,164 ND 733 546 846 649 ND 224 543 825 
Ace 549 902 795 1,000 747 313 637 878 99 3,224 3,840 713 2,002 1,413 2,850 1,565 3,181 355 1,632 2,480 
Fl 838 1,937 1,116 2,080 1,342 855 1,345 1,951 186 4,181 4,047 1,331 3,375 2,430 4,904 2,656 5,605 776 2,939 3,719 
Phe 1,503 3,595 1,928 4,022 2,028 2,630 3,236 3,446 926 7,101 6,542 2,018 5,111 4,244 7,603 3,594 8,668 2,454 5,679 5,260 
Ant 389 219 545 273 498 744 453 309 238 429 425 319 355 276 482 239 530 205 368 409 
Flu 473 305 842 400 698 894 600 372 355 452 361 399 304 300 409 232 457 192 351 293 
Pyr 396 259 793 338 645 833 519 335 344 309 240 351 192 217 270 166 326 138 222 222 
BaA 206 16 85 31 94 103 51 29 45 27 93 32 25 60 36 19 70 18 26 46 
Chr 138 18 91 32 99 106 52 30 54 56 65 34 55 64 111 65 75 38 58 49 
BbF 77 17 78 29 86 87 47 28 49 58 91 31 37 ND 54 39 67 27 30 46 
BkF 68 18 81 25 87 92 49 26 54 43 72 29 36 ND 11 16 25 18 12 45 
BaP 55 12 73 25 76 88 42 25 46 13 69 27 ND 20 19 26 11 22 
IcdP 53 11 57 19 61 69 32 18 34 21 15 ND ND 10 14 
DahA 67 10 64 18 66 77 34 36 32 16 18 10 
BghiP 32 11 62 20 63 74 32 19 41 26 27 22 ND ND 15 14 ND 16 
ΣPAHs 11,025 14,185 13,468 16,007 11,600 10,572 12,485 16,117 4,076 26,038 27,733 9,575 22,399 19,087 26,624 21,760 29,455 8,618 18,431 22,981 
CompoundsML
YR
XL
NR
EWPQLYLPLWRYYRQWPYQLQR
ababcdeabab
Nap 6,181 6,496 6,334 7,696 4,649 3,261 5,011 8,192 1,428 9,079 10,677 4,230 10,155 9,525 8,995 12,495 10,407 4,144 6,552 9,533 
Acy ND 358 523 ND 362 347 346 450 141 1,001 1,164 ND 733 546 846 649 ND 224 543 825 
Ace 549 902 795 1,000 747 313 637 878 99 3,224 3,840 713 2,002 1,413 2,850 1,565 3,181 355 1,632 2,480 
Fl 838 1,937 1,116 2,080 1,342 855 1,345 1,951 186 4,181 4,047 1,331 3,375 2,430 4,904 2,656 5,605 776 2,939 3,719 
Phe 1,503 3,595 1,928 4,022 2,028 2,630 3,236 3,446 926 7,101 6,542 2,018 5,111 4,244 7,603 3,594 8,668 2,454 5,679 5,260 
Ant 389 219 545 273 498 744 453 309 238 429 425 319 355 276 482 239 530 205 368 409 
Flu 473 305 842 400 698 894 600 372 355 452 361 399 304 300 409 232 457 192 351 293 
Pyr 396 259 793 338 645 833 519 335 344 309 240 351 192 217 270 166 326 138 222 222 
BaA 206 16 85 31 94 103 51 29 45 27 93 32 25 60 36 19 70 18 26 46 
Chr 138 18 91 32 99 106 52 30 54 56 65 34 55 64 111 65 75 38 58 49 
BbF 77 17 78 29 86 87 47 28 49 58 91 31 37 ND 54 39 67 27 30 46 
BkF 68 18 81 25 87 92 49 26 54 43 72 29 36 ND 11 16 25 18 12 45 
BaP 55 12 73 25 76 88 42 25 46 13 69 27 ND 20 19 26 11 22 
IcdP 53 11 57 19 61 69 32 18 34 21 15 ND ND 10 14 
DahA 67 10 64 18 66 77 34 36 32 16 18 10 
BghiP 32 11 62 20 63 74 32 19 41 26 27 22 ND ND 15 14 ND 16 
ΣPAHs 11,025 14,185 13,468 16,007 11,600 10,572 12,485 16,117 4,076 26,038 27,733 9,575 22,399 19,087 26,624 21,760 29,455 8,618 18,431 22,981 

Note: naphthalene (Nap), acenaphthylene (Acy), acenaphthene (Ace), fluorene (Fl), phenanthrene (Phe), anthracene (Ant), fluoranthene (Flu), pyrene (Pyr), benz[a]anthracene (BaA), chrysene (Chr), benzo[b]fluoranthene (BbF), benzo[k]fluoranthene (BkF), benzo[a]pyrene (BaP), indeno[1,2,3-cd]pyrene (InP), dibenz[a,h]anthracene (DBA), and benzo[g,h,i]perylene (BP); ND denotes not detected; Mochou Lake (ML), Yangtze River (YR), Xuanwu Lake (XL), The East Water Park (EWP), Qianhu Lake (QL), Yueya Lake (YL), Pipa Lake (PL), Wukesong Reservoir (WR), Youyi River (YYR), Nan River (NR), Qiqiaowen Wetland Park (QWP), Yanque Lake (YQL), Qinhuai River (QR).

Table 2

Concentrations of PAHs in surface water around the world

LocationRange (ng/L)MeanReference
Jiulong River, China 6,960–26,920 17,050 Maskaoui et al. (2002)  
Minjiang River, China 9,900–474,000 72,400 Zhang et al. (2004)  
Yellow River, China 548–2,598 1,375 Zhao et al. (2015)  
Taizi River, China 455–1,380 907 (dry season) Song et al. (2013)  
Taizi River, China 1,802–5,869 3,235 (wet season) Song et al. (2013)  
Taizi River, China 367–5,795 1,818 (normal season) Song et al. (2013)  
Daqing, China 10,020–5,743,370 1,298,250 Xiao et al. (2015)  
Raba River, Hungary 41–437 111 Nagy et al. (2013b)  
Nile River, Egypt 1,110–4,364 1,878 Badawy & Emababy (2010)  
Mississippi River, USA 62.9–144.7 – Zhang et al. (2007)  
Nanjing 4,076–29,455 17,212 This study 
LocationRange (ng/L)MeanReference
Jiulong River, China 6,960–26,920 17,050 Maskaoui et al. (2002)  
Minjiang River, China 9,900–474,000 72,400 Zhang et al. (2004)  
Yellow River, China 548–2,598 1,375 Zhao et al. (2015)  
Taizi River, China 455–1,380 907 (dry season) Song et al. (2013)  
Taizi River, China 1,802–5,869 3,235 (wet season) Song et al. (2013)  
Taizi River, China 367–5,795 1,818 (normal season) Song et al. (2013)  
Daqing, China 10,020–5,743,370 1,298,250 Xiao et al. (2015)  
Raba River, Hungary 41–437 111 Nagy et al. (2013b)  
Nile River, Egypt 1,110–4,364 1,878 Badawy & Emababy (2010)  
Mississippi River, USA 62.9–144.7 – Zhang et al. (2007)  
Nanjing 4,076–29,455 17,212 This study 

On the basis of composition pattern of water PAH, it can be observed in Figure 2 that the 2- and 3-ring PAHs are the highest proportion in all PAHs, which averaged 42.9 and 48.5%. Nap and Phe are the major compounds in the water body. The 4-ring PAHs averaged 6.9%. The 5- and 6-ring PAHs are the least in proportion, which altogether averaged 1.2 and 0.4%, respectively. The reason why LMW PAHs had a very high proportion in total PAHs is that they had relatively high water solubilities and vapor pressures (Wang et al. 2014; Zhao et al. 2015). Similar research results were also obtained in published data (Nagy et al. 2013a, 2013b; Zhao et al. 2015). However, Zhang et al. (2004) estimated that 5- and 6-ring PAHs occupied the most abundant in 16 PAHs, while 2- and 4-ring PAHs only held 21% of all PAHs.
Figure 2

Composition of parent PAH in surface water of urban areas of Nanjing, China. 2-ring PAHs include naphthalene; 3-ring PAHs include acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene; 4-ring PAHs include fluoranthene, pyrene, benzo[a]anthracene and chrysene; 5-ring PAHs include benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene and dibenzo[a,h]anthracene; 6-ring PAHs include indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene.

Figure 2

Composition of parent PAH in surface water of urban areas of Nanjing, China. 2-ring PAHs include naphthalene; 3-ring PAHs include acenaphthylene, acenaphthene, fluorene, phenanthrene and anthracene; 4-ring PAHs include fluoranthene, pyrene, benzo[a]anthracene and chrysene; 5-ring PAHs include benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene and dibenzo[a,h]anthracene; 6-ring PAHs include indeno[1,2,3-cd]pyrene and benzo[g,h,i]perylene.

PAH sources

Diagnostic ratios identify the origin of the pollution by comparing PAH ratios with well-known references and thus qualitatively distinguish pyrolytic and petrogenic sources. The ratios of Antracene/(Antracene + Phenanthrene), and Fluoranthene/(Fluoranthene + Pyrene) were used to distinguish the source of PAHs in this study. The ratio of Fluoranthene/(Fluoranthene + Pyrene) >0.5 corresponds to the biomass burning or coal combustion, the ratio <0.4 corresponds to the petrogenic source, and the ratio between 0.4 and 0.5 corresponds to the petroleum combustion (Wang et al. 2017). The ratio of Antracene/(Antracene + Phenanthrene) >0.1 corresponds to the pyrogenic source, and the ratio <0.1 corresponds to the petrogenic source (Lv et al. 2014). The results of the above ratios are shown in Figure 3. All ratios show that the water PAH sources in the urban areas of Nanjing are from grass/wood/coal combustion. However, the ratios of Antracene/(Antracene + Phenanthrene) at some sites (A, B, E, F, G, I, J) are higher than 0.1, which indicates that the main source for these sites was pyrogenic. The ratios are lower than 0.1 at other sites indicating a petrogenic source. In conclusion, a mixture of combustion and petroleum sources contributed to PAHs in water at the urban areas of Nanjing.
Figure 3

Diagnostic ratios of PAH in the surface water in urban areas of Nanjing, China.

Figure 3

Diagnostic ratios of PAH in the surface water in urban areas of Nanjing, China.

A PMF model is used to quantitatively identify the sources of PAHs in surface water. In this study, three to six factors are carefully examined. Finally, four appropriate factors are identified as the sources of surface water PAHs in urban areas of Nanjing. Figure 4 shows the source composition profiles on the basis of the four-factor solution.
Figure 4

Source profiles obtained from the PMF model.

Figure 4

Source profiles obtained from the PMF model.

Factor 1, explaining 26.00% of the 16 PAHs, was mainly composed of Nap. It was reported that Nap could be derived from sources of incomplete combustion and considered to have evaporated from coal tar (Simcik et al. 1999; Larsen & Baker 2003). As a consequence, factor 1 was classified as an oil source. Factor 2, explaining 32.83% of the 16 PAHs, was mainly composed of Phe, Flu, Ace, and Ant. The factor profile of Flu and Phe always originated from coke ovens (Duval & Friedlander 1981). Khalili et al. (1995) indicated Flu was the dominating PAH in the coke oven molecular characteristic. Factor 2 was classified as coke oven. Factor 3, explaining 29.12% of the 16 PAHs, was mainly composed of Ace, Acy, and Flu. It could be identified as coal combustion because the significant characteristic in coal burning was Acy and Flu (Masclet et al. 1987; Khalili et al. 1995). Therefore, this factor is classified as the coal combustion. Factor 4, explaining 12.05% of the 16 PAHs, is mainly composed of DBA, InP, BP, and BaP. In addition, the high weight molecular PAHs are heavily loaded on this factor. This source profile could be identified as automobile exhaust (Miguel & Pereira 1989; Harrison et al. 1996). As a consequence, factor 4 is identified as the vehicle source.

According to the analyses above, the surface water PAH from urban areas in Nanjing are influenced by coke oven, coal combustion, oil source, and vehicle emissions, in that order.

Potential risk assessment

Toxic equivalency factors of BaP (BaPeq) (Nisbet & Lagoy 1992) were used to assess the environmental risks of water PAH in urban areas of Nanjing (Table 3). Figure 5 shows the BaPeq values ranged from 23.15 to 218.01 ng/L. The result indicated that 100% of BaPeq values were higher than the Chinese National Standard (State General Administration of the People's Republic of China for Quality Supervision and Inspection and Quarantine, State Environmental Protection Administration of China 2002) which specifies that a safe value for BaP in surface water is 2.8 ng/L. The results show that the surface water in urban areas of Nanjing was heavily polluted and may cause potential health risks. Therefore, efforts should be taken to control the PAH emissions and to effectively treat the fossil fuel use in traffic and industrial processes to reduce the PAH environmental concentrations.
Table 3

Toxicity equivalency factors for individual PAHs in urban area surface water, Nanjing, China

Nap Acy Ace Fl Phe Ant Flu Pyr 
0.001 0.001 0.001 0.001 0.001 0.01 0.001 0.001 
BaA Chr BbF BkF BaP InP DBA BP 
0.1 0.01 0.1 0.1 0.1 0.01 
Nap Acy Ace Fl Phe Ant Flu Pyr 
0.001 0.001 0.001 0.001 0.001 0.01 0.001 0.001 
BaA Chr BbF BkF BaP InP DBA BP 
0.1 0.01 0.1 0.1 0.1 0.01 
Figure 5

BaPeq values in the surface water samples in urban areas of Nanjing, China.

Figure 5

BaPeq values in the surface water samples in urban areas of Nanjing, China.

CONCLUSIONS

The results show that surface water in the Nanjing area was heavily polluted with PAHs, predominantly 2- and 3-ring PAHs. The diagnostic ratio analysis indicated that a mixture input of combustion and petroleum origin contributed largely to the pollution. A PMF model used to quantitatively identify the sources of pollution indicated that coke oven (32.83%), coal combustion (29.12%), oil (26.00%) and automobile exhaust (12.05%) were the primary sources of pollution. These levels of PAH pollution of surface water in urban areas of Nanjing demand effective efforts to eliminate sources of PAHs and control of water pollution.

ACKNOWLEDGEMENTS

This work was supported by the National Science Foundation of China (Grant No. 41671085), the Fundamental Research Funds for the Central Universities (Grant No. 020914380046, 020914380033), and the Postdoctoral Research Funding Project of Jiangsu Province (Grant No. 1701089C).

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