DSpace at VNU: Distribution of persistent organic pollutants and polycyclic aromatic hydrocarbons in sediment samples from Vietnam

DSpace at VNU: Distribution of persistent organic pollutants and polycyclic aromatic hydrocarbons in sediment samples fr...

291 Journal of Health Science, 53(3) 291–301 (2007) Distribution of Persistent Organic Pollutants and Polycyclic Aromatic Hydrocarbons in Sediment Samples from Vietnam Masao Kishida,∗, a Kiyoshi Imamura, a Yasuaki Maeda, b Tran Thi Ngoc Lan, c Nguyen Thi Phuong Thao, d and Pham Hung Viete a Environmental Pollution Control Center, Osaka Prefectural Government, 1–3–62 Nakamichi, Higashinari-ku, Osaka 537–0025, Japan, b Graduate School of Engineering, Osaka Prefecture University, 1–1 Gakuen-cho, Naka-ku, Sakai, Osaka 599–8531, Japan, c College of Natural Science, Vietnam National University of Ho Chi Minh City, 227 Nguyen Van Cu Str., Dist.5, Ho Chi Minh City, Vietnam, d National Center for Natural Science and Technology, Hoang Quoc Viet Str., Hghia Do, Cau Giay, Hanoi, Vietnam, and e College of Science, Vietnam National University of Hanoi, T3 Building, 333 Nguyen Trai Str., Thanh Xuan Dist., Hanoi, Vietnam (Received January 11, 2007; Accepted April 2, 2007; Published online April 6, 2007) The presence of eight kinds of persistent organic pollutants (POPs) such as DDT and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), drin compounds (Drins), heptachlor, hexachlorobenzene (HCB), heptachlor-epoxide, polychlorinated biphenyls (PCBs) and sixty-four polycyclic aromatic hydrocarbon compounds (PAHs) was identified using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) to investigate their distribution in surface sediment from Hanoi, Hue, and Ho Chi Minh in Vietnam A survey of sediment samples from Osaka was conducted for comparison The concentrations of ΣDDTs, ΣCHLs, ΣPCBs and ΣPAHs in Vietnam were 0.19–140, N.D.–9.0, 0.11–110, and 30–5500 ng/gdry, respectively Concentrations of these compounds in urban areas were higher than those in other areas In addition, the ΣDDT concentrations in Vietnamese urban areas were higher than those in Osaka These results suggest that most DDTs would be used as insecticides for the purpose of health services rather than as agricultural chemicals PAH pollution in urban areas and suburbs is caused mainly by runoff of petrol, whereas in rural areas, the combustion of fossil fuels and biomass is the major pollutant source Key words —— persistent organic pollutant, polycyclic aromatic hydrocarbon, Vietnam, sediment sample, high resolution gas chromatography/high resolution mass spectrometry INTRODUCTION More than 120 countries participated in the May 2001 Stockholm Convention on persistent organic pollutants (POPs), adopting the reduction and/or prohibition of their use The convention identified twelve types of compounds as POPs, which consist of intentional compounds and unintentional by-products of industrial processes The former are DDT and its metabolites (DDTs), hexachlorocyclohexanes (HCHs), chlordane compounds (CHLs), toxaphene, drin compounds (Drins), hexachlorobenzene (HCB), polychlorinated biphenyls (PCBs), and mirex; and the latter are polychlorinated dibenzo-p-dioxins (PCDDs) ∗ To whom correspondence should be addressed: Environmental Pollution Control Center, Osaka Prefectural Government, 1–3–62 Nakamichi, Higashinari-ku, Osaka 537–0025, Japan Tel.: +81-6-6972-1321; Fax: +81-6-6972-5865; E-mail: KishidaMas@mbox.pref.osaka.lg.jp and polychlorinated dibenzofurans (PCDFs) The issue of POPs has generated a lot of interest in most countries POPs released to the environment can be transported through air and water to regions far from their original sources, such as the Arctic.1) Moreover, POPs bioaccumulate in fatty tissues of living organisms because of low water solubility and/or high fat solubility In Southeast Asia and South Asia, a great deal of POPs have been used since the 1960s.2, 3) Approximately 24000 tons of DDTs were imported to Vietnam between 1957 and 1990 to control malaria vectors and to remove insect pests from grains.4) Although the use of these pesticides has been prohibited since 1993, and the quantity of imported pesticides has been reduced, organochlorine pesticides still remain in the environment of northern Vietnam.5, 6) Import of approximately 27000–30000 tons of oil containing PCBs from socialist countries such 292 Vol 53 (2007) as the U.S.S.R., China, and Romania,4) and a great deal of electric products from Australia has contributed to the presence of PCBs.7) Polycyclic aromatic hydrocarbons (PAHs) are considered serious pollutants because of their carcinogenicity The two main origins of PAH pollution are petroleum runoff and the combustion of fossil fuel and biomass.8) Concentrations of PAHs in industrialized cities such as Boston9, 10) and New York11) were extremely high and are thought to result from petroleum use In contrast, in developing countries such as Malaysia, their concentrations were not as high, and their primary origin was supposed to be the combustion of fossil fuel and biomass.8) Since 1986, the economy of Vietnam has been rapidly expanding due to Doi Moi policy, which introduced a free market economy system to the socialist country The country has been industrialized, and the number of motorcycles in the cities has drastically increased As a result, the consumption of petrol has increased in cities such as Hanoi and Ho Chi Minh Several POP surveys have been conducted in urban areas3, 6, 12) using gas chromatography/electron captured detectors (GC/ECD) However, detailed investigations of their components, such as the congeners and/or isomers of PCBs, have not been conducted In the present study, we determined the concentrations of POPs and PAHs in sediment samples using high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS) to estimate their distribution throughout Vietnam The sampling locations were sites in Hanoi, sites in Hue, sites in Ho Chi Minh, and site in Osaka, Japan, situated at the mouth of the Yamato River POP monitoring has been conducted at the latter sampling site since 1978, to determine the effectiveness of the Chemical Substances Control Law in Japan, which has prohibited their production and use since 1972 MATERIALS AND METHODS Compounds Examined —— The POPs monitored were DDTs (o, p′ -, p, p′ -DDT, o, p′ -, p, p′ -DDD, and o, p′ -, p, p′ -DDE), HCHs (α-, β-, γ-, δ-HCH), CHLs (trans-, cis-chlordane, trans-, cis-nonachlor, and oxchlordane), Drins (aldrin, dieldrin, and endrin), heptachlor, heptachlor-epoxide, HCB, and PCBs PAHs are classified into six categories, depending on the number of rings in the molecule; 2-ring: naphthalene, benzo[b]thiophene, 1-,2methylnaphthalene, biphenyl, 2,6-, 2,7-, 1,3-, 1,4-, 2,3-, 1,5-, 1,2-dimethylnaphthalene, and 2,3,5trimethylnaphthalene; 3-ring: acenaphthylene, biphenylene, acenephthene, fluorene, 9,10-dihydroanthracene, 9,10dihydrophenanthrene, dibenzothiophene, phenanthrene, anthracene, 1-,2-phenylnaphthalene, o-, m-, p-terphenyl, 1-, 2-, 3-, 4-, 9-methylphenanthrene, 2-,9-methylanthracene, 3,6-dimethylphenanthrene, and 9,10-dimethylanthracene; 4-ring: 1,2,3,4-tetrahydrofluoranthene, 4Hcyclopenta[def ]phenanthrene (4H-CdefP), pyrene, fluoranthene, benzo[b]fluorene, 1,1-binaphthyl, 9-phenyanthracene, benz[a]anthrathene (BaA), triphenylene, chrysene, naphthacene, and 7methylbenz[a]anthracene (7-MeBaA); 5-ring: benzo[b]fluoranthene (BbF), benzo[ j] fluoranthene (BjF), benzo[k]fluoranthene (BkF), benzo[e]pyrene (BeP), benzo[a]pyrene (BaP), perylene, 3-methylcholanthrene, 7-methylbenzo[a] pyrene (7-MeBaP), 9,10-diphenylanthracene, and dibenzo[a, h]anthracene; 6-ring: indeno[1,2,3-cd]pyrene (INcdP), benzo [ghi]perylene (BghiP), anthanthrene, naphtho[2,3a]pyrene, and 3,4,8,9-dibenzopyrene; 7-ring: coronene Sampling Methods —— The sample properties and sampling locations are shown in Table Sediments were collected at three points near the sampling site using an Eckmann dredge sampling apparatus The sediments were mixed uniformly and put in a glass vessel for transport to the laboratory The sediments were centrifuged by 3000 rpm for 10 to remove water, and stored in the refrigerator Some samples were dried under moderate conditions in the laboratory Reagents —— Standard POP materials except for p, p′ -DDE, CHLs, and PCBs were purchased from Gasukuro Kogyo Inc (Tokyo, Japan) A standard material of p, p′ -DDE was purchased from Wako Pure Chemical Industries Ltd (Osaka, Japan) Standard solutions of CHLs were purchased from AccuStandard Inc (Shelton, CT, U.S.A.) A standard mixture solution of PCBs (BP-WD) was purchased from Wellington Laboratories, Inc (Ontario, Canada) A standard mixture solution of 16 PAH components (TCL Polynuclear Aromatic Hydrocarbons Mix) cited in Target Compound List/Priority 293 No Table List of Sediment Samples from Vietnam Code Sampling Site City HN1 HN2 HU1 HU2 HU3 HU4 HC1 HC2 HC3 HC4 HC5 Y1a) TrucBach Lake West Lake LangCo Lagoon ThuyTu Langoon CauHai Lagoon R Huong BenNghe Chanel R Saigon ThiNghe Chanel R Saigon MyHung Chanel R Yamato Hanoi Hanoi Hue Hue Hue Hue Ho Chi Minh Ho Chi Minh Ho Chi Minh Ho Chi Minh Ho Chi Minh Osaka Description of area urban urban rural rural rural rural urban suburb urban suburb suburb urban Co-ordinate North East ◦ ′ ′′ 21 02 46 101◦ 50′ 21′′ ◦ ′ ′′ 21 03 27 105◦ 50′ 15′′ ◦ ′ ′′ 16 33 37 107◦ 37′ 15′′ ◦ ′ ′′ 16 29 30 107◦ 43′ 20′′ ◦ ′ ′′ 16 20 19 107◦ 52′ 28′′ ◦ ′ ′′ 16 23 31 107◦ 34′ 35′′ ◦ ′ ′′ 10 45 48 106◦ 41′ 54′′ ◦ ′ ′′ 10 49 08 106◦ 43′ 55′′ ◦ ′ ′′ 10 47 36 106◦ 41′ 46′′ ◦ ′ ′′ 10 48 52 106◦ 45′ 07′′ ◦ ′ ′′ 10 51 04 106◦ 43′ 44′′ ◦ ′ ′′ 34 36 30 135◦ 26′ 06′′ Sampling Date 27/July/2002 27/July/2002 13/January/2002 12/January/2002 10/January/2002 10-12/January/2002 18/July/2002 16/July/2002 16/July/2002 16-18/July/2002 16-18/July/2002 11/October/2002 a) Japan Table Operational Conditions for HRGC/HRMS HRGC Column Column temp Carrier gas Injection temp Injection mode HRMS Ion source Ion source temp Interface temp Ionization voltage SIM mode POPs PAHs HP-5MS (Agilent Technology) 30 m ì 0.25 mm I.D., 0.5 àm f.t 100◦ C (1 min.hold)–30◦ C/min–160◦ C– 5◦ C/min–300◦ C (1 min.hold) He 1.2 ml/min 260◦ C splitless (90 sec) HP-1MS (Agilent Technology) 15 m ì 0.25 mm I.D., 0.25 àm f.t 70◦ C (1 min.hold)–15◦ C/min–130◦ C– 6◦ C/min–300◦ C (2 min.hold) He 1.2 ml/min 300◦ C splitless (120 sec) EI positive 260◦ C 260◦ C 38 eV high resolution >10000 EI positive 260◦ C 260◦ C 70 eV low resolution Pollutant List of US EPA was purchased from Supelco (Bellefonte, PA, U.S.A.) Standard solutions of methylphenanthlene isomers were purchased from Chiron AS (Trondheim, Norway) Standard solutions of 2-phenylnaphthalene, 3,6dimethylphenanthrene, 7-MeBaA, BeP, and anthanthrene were purchased from AccuStandard Inc All other PAH materials were purchased from Wako Pure Chemical Industries Ltd., AccuStandard Inc., Supelco, Aldrich Chemical Co., Inc (Milwaukee, WI, U.S.A.), Tokyo Kasei Kogyo Co., Ltd (Tokyo, Japan), Ishizu Pharmaceutical Co., Ltd (Osaka, Japan), Nakarai Chemicals Ltd (Kyoto, Japan), ICN Biomedicals Inc (Aurora, OH, U.S.A.), Acros Organics (Morris Plains, NJ, U.S.A.), and Alfa Aesar (Ward Hill, MA, U.S.A.) A standard material of fluoranthene-d12 was purchased from Wako Pure Chemical Industries Ltd All other reagents were purchased from Wako Pure Chemical Industries Ltd All chemicals were residual pesticide analytical grade Analysis —— Sample extraction and clean-up followed procedures specified in the manual edited by the Ministry of the Environment, Japan.13) Tentwenty g of wet and/or dry sediment was extracted three times with 25 ml acetonitrile using ultrasonic extraction The extracts were cleaned up with the acetonitrile/n-hexane partition The acetonitrile layer was put into 500 ml of 5% sodium chloride solution and extracted twice with 50 ml n-hexane The concentrate was cleaned up with g of 5% hydrous silica gel column chromatography The first fraction, eluted with 20 ml of n-hexane, was treated with g reduced granular copper (60–80 mesh) The sec- 294 Vol 53 (2007) Fig Representative SIM Chromatograms of POPs (DDTs and PCBs) at the Sampling Site of HC3 (A) and (B): DDTs, (C): PeCBs ond fraction, eluted with 50 ml of 1% acetone/nhexane, was submitted for PAHs analysis The third fraction was eluted with 40 ml of 10% acetone/nhexane 100 ng of fluoranthene-d12 was added to each fraction and submitted for analysis One µl of each concentrate was analyzed by HRGC/HRMS (HP5890; Agilent, DE, U.S.A JMS-700D; JEOL, Japan) and the conditions are shown in Table Representative chromatograms of selected ion monitoring (SIM) for a sediment sample at a location HC3 were shown in Fig RESULTS AND DISCUSSION POPs Analytical results for DDTs are shown in Table The averages of ΣDDTs for Hanoi, Hue, Ho Chi Minh, and Osaka were 43, 1.3, 36, and 13 ng/gdry, respectively The ΣDDT concentrations at sampling sites HN1, HN2, HC1, and HC3, located in urban areas, range between 29 and 140 ng/g-dry, while concentrations at the other sites in Vietnam range between 0.19 and 5.5 ng/g-dry These data 295 No Table Concentrations of POPs (ng/g-dry weight) in Sediment Samples from Vietnam and Osaka HU2 0.48 0.51 0.49 0.14 0.12 0.064 1.8 HU3 0.24 0.39 0.21 0.032 0.059 0.017 1.0 0.16 0.17 0.074 0.081 0.48 0.069 0.087 0.12 0.055 0.33 0.069 0.024 0.033 0.023 0.15 0.015 N.D.e) N.D.e) N.D.e) 0.015 0.015 N.D.e) N.D.e) N.D.e) 0.015 0.013 0.054 N.D.e) N.D.e) 0.068 trans-Chlordane cis-Chlordane Oxychlordane trans-Nonachlor cis-Nonachlor ΣCHLsc) 0.54 0.034 0.29 N.D.e) N.D.e) N.D.e) 0.20 N.D.e) 0.042 N.D.e) 1.1 0.034 0.010 0.013 N.D.e) N.D.e) N.D.e) 0.023 0.007 N.D.e) N.D.e) N.D.e) N.D.e) 0.007 0.016 N.D.e) N.D.e) N.D.e) N.D.e) 0.016 N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) Aldrin Dieldrin Endrin Σdrinsd) N.D.e) 0.65 N.D.e) 0.65 0.008 N.D.e) N.D.e) 0.008 N.D.e) N.D.e) N.D.e) N.D.e) 0.054 N.D.e) N.D.e) 0.054 N.D.e) N.D.e) N.D.e) N.D.e) Heptachlor HCB Heptachlor Epoxide 0.96 0.23 N.D.e) N.D.e) 0.034 N.D.e) N.D.e) 0.015 N.D.e) N.D.e) 0.017 N.D.e) N.D.e) 0.020 N.D.e) p, p -DDT p, p′ -DDD p, p′ -DDE o, p′ -DDT o, p′ -DDD o, p′ -DDE ΣDDTsa) α-HCH β-HCH γ-HCH δ-HCH ΣHCHsb) 0.21 0.17 0.14 0.077 0.60 HN2 4.9 15 20 1.2 2.4 0.61 44 Sampling locations HU4 HC1 HC2 0.43 1.3 0.10 0.33 15 2.9 0.34 9.0 2.2 0.091 0.18 0.029 0.074 3.0 0.15 0.026 0.34 0.13 1.3 29 5.5 HU1 0.29 0.19 0.22 0.11 0.094 0.054 1.0 ′ HN1 1.9 15 21 1.1 2.8 0.65 42 HC3 14 79 34 1.1 13 1.4 140 HC4 0.54 1.8 1.4 0.087 0.33 0.10 4.3 HC5 0.041 0.023 0.079 0.025 0.010 0.012 0.19 Y1 1.0 5.0 3.7 0.31 2.3 0.40 13 0.009 N.D.e) N.D.e) N.D.e) 0.009 0.037 0.11 N.D.e) 0.040 0.19 0.048 0.018 0.056 N.D.e) 0.12 0.017 0.019 N.D.e) N.D.e) 0.036 0.13 0.38 N.D.e) 0.090 0.61 0.37 0.34 N.D.e) 0.20 0.15 1.1 0.014 0.014 N.D.e) N.D.e) N.D.e) 0.028 3.1 2.9 N.D.e) 2.1 0.80 9.0 0.084 N.D.e) N.D.e) 0.064 0.036 0.18 N.D N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) 7.6 7.2 N.D.e) 6.1 2.6 24 N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) 5.9 N.D.e) 5.9 0.012 N.D.e) N.D.e) 0.012 0.095 6.2 N.D.e) 6.3 N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) N.D.e) 0.054 0.54 0.10 0.70 N.D.e) 0.023 N.D.e) N.D.e) 8.9 N.D.e) N.D.e) 0.11 N.D.e) N.D.e) 16 0.066 N.D.e) 0.14 N.D.e) N.D.e) 0.014 N.D.e) 0.41 N.D.e) N.D.e) a) Sum of concentratios of o, p′ -, p, p′ -DDT, o, p′ -, p, p′ -DDD, and o, p′ -, p, p′ -DDE b) Sum of concentrations of α-, β-, γ-, δ-HCH c) Sum of concentrations of trans-, cis-chlordane, trans-, cis-nonachlor, and oxchlordane d) Sum of concentrations of aldrin, dieldrin, and endrin e) N.D., not detected show that the ΣDDT concentrations in urban areas of Hanoi and Ho Chi Minh were higher than those in Osaka In an aqueous environment, p, p′ -DDT decomposes very slowly to p, p′ -DDE and subsequently to p, p′ -DDD through biological and chemical processes.14) The residence time of p, p′ -DDT could be estimated using the ratio of p, p′ -DDT to ΣDDTs The ratio for technical DDTs was reported to be 0.77.15) Ratios of p, p′ -DDT to ΣDDTs at sampling sites HU1, HU2, HU3, HU4, and HC5 were 0.22– 0.33, and those at the other locations were 0.02– 0.13 These results indicate that fields in areas HU1, HU2, HU3, HU4, and HC5 have been sprayed with DDTs more recently Analytical results for HCHs are also shown in Table The averages of ΣHCHs for Hanoi, Hue, Ho Chi Minh, and Osaka were 0.54, 0.13, 0.085, and 0.61 ng/g-dry, respectively ΣHCH concentrations in the sediment samples were lower than those of ΣDDTs, despite the fact that HCHs were used in Vietnam as well as DDTs.16) Nhan et al.6) pointed out that lower concentrations of ΣHCH, compared with ΣDDT, are caused by the relatively short environmental half-lives of HCHs in soils (T1/2 of hours to weeks), lower KOW 3.6–3.8, and higher water solubilities, which are to orders of magnitude higher than those of DDTs In addition, the ΣHCH and ΣDDT concentrations in the atmospheric environment at Hue were reported to be 12000 and 2400 ng/m3 , respectively.2) These results indicate that HCHs are more volatile than DDTs, and evaporate readily into the atmosphere Previously, the technical HCH mixtures have been reported17) to contain 55–80% of α-HCH, 5– 14% of β-HCH, and 8–15% of γ-HCH, and the ratio of α-/γ-HCH was 5.3–6.7 The ratios of α-/γ-HCH at sampling sites HN1, HN2, HU1, HU2, and HC4 were 0.58–2.2, lower than those of technical HCH These results indicate that the HCHs used in Viet- 296 Vol 53 (2007) spectively The concentrations of these compounds were low when compared with DDTs and CHLs Analytical results for PCBs are shown in Table The averages of ΣPCBs in Hanoi, Hue, Ho Chi Minh, and Osaka were 21, 0.46, 33, and 67 ng/g-dry, respectively The ΣPCBs concentrations at sampling sites HN1, HN2, HC1, HC3, and Y1 were 21–110 ng/g-dry and those at the other sites were 0.11–7.3 ng/g-dry These data show that the concentrations of ΣPCBs in urban areas of Hanoi and Ho Chi Minh were at the same levels as those in Osaka Profiles of PCB congeners at the five sampling sites NH1, HN2, HC1, HC3, and Y1 and for the commercial product Kanechlor (KC)21) are shown in Fig The pentachloro-biphenyls (PeCBs) were the highest congeners at sampling sites HN1 and HN2 and the trichloro-biphenyls (TriCBs) were the highest ones at sampling sites HC1 and HC3 These facts indicate that the PCB components in Hanoi (at sampling sites HN1 and HN2) was mainly contributed from the KC-500 product and Ho Chi Minh (at sampling sites HC1 and HC3) were from the KC300 product At the site of Y1, the concentrations of PCB congeners increased as the number of the chlorine atoms in the PCB molecules decreased The dichloro-biphenyls (DiCBs) was the highest congeners However, DiCBs was not main components of any PCB products These facts suggest that the higher chlorinated PCBs would be dechlorinated gradually to the lower ones under anaerobic conditions22, 23) as shown in the Netherlands24) and in Rhode Island, U.S.A.25) As discussed previously, ΣDDTs, ΣCHLs, and ΣPCBs at sampling sites HN1, HN2, HC1, HC3, and Y1, located near the center of cities, were much nam contained higher percentages of γ-HCH, that is, Linden.18) Analytical results for CHLs are also shown in Table The ranges of ΣCHL concentrations in Hanoi, Hue, Ho Chi Minh, and Osaka were 0.034– 1.1, N.D.–0.023, N.D.–9.0, and 24 ng/g-dry, respectively The ΣCHL concentrations at urban areas except for a sampling site NH2 were 1.1–24 ng/g-dry and those at the other sites were N.D.–0.18 ng/g-dry These results indicate that the ΣCHL concentrations in Osaka were higher than those at the urban areas of Vietnam No oxychlordane compounds were detected in the sediments Iwata et al.3) reported that the technical CHLs consist of 24±2 wt% of trans-chlordane, 19±3% of cis-chlordane, 7±3% of trans-nonachlor, and other compounds, and the ratios of trans-nonachlor to trans-chlordane ranged between 0.15–0.45, under continuous CHL usage The ratios of transnonachlor to trans-chlordane at HN1, HC1, HC3, and Y1 were 0.37, 0.54, 0.68, and 0.80, respectively The value at HN1 was close to those of technical chlordane In contrast, the ratios at HC1, HC3, and Y1 were higher than those of technical CHLs In Japan, CHLs remaining in the environment have resided for more than 30 years, since the production and use of POPs was prohibited in 1972 Over a long residence time, the ratio of trans-nonachlor to trans-chlordane changes due to the preferential depletion of trans-chlordane.3, 19, 20) Analytical results for Drins, HCB, heptachlor, and heptachlor-epoxide are also shown in Table The concentration ranges of aldrin, dieldrin, endrin, heptachlor, HCB, and heptachlor-epoxide in Hanoi, Hue, Ho Chi Minh, and Osaka were N.D.–0.96, N.D.–0.054, N.D.–16, and N.D.–0.70 ng/g-dry, re- Table Concentrations of PCBs Congeners (ng/g-dry weight) in Sediment Samples from Vietnam and Osaka MoCBs DiCBs TriCBs TeCBs PeCBs HxCBs HpCBs OcCBs NoCBs DeCBs ΣPCBsa) HN1 N.D.b) 0.43 2.2 3.3 9.3 4.8 0.68 0.17 N.D.b) 0.14 21 HN2 N.D.b) 0.33 1.8 3.8 10 4.6 0.61 N.D.b) N.D.b) N.D.b) 21 HU1 N.D.b) 0.13 0.38 0.18 0.073 N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) 0.77 HU2 N.D.b) 0.18 0.28 0.13 0.088 N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) 0.67 HU3 N.D.b) N.D.b) 0.11 N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) 0.11 Sampling locations HU4 HC1 N.D.b) N.D.b) 0.15 2.6 0.12 16 N.D.b) 7.2 N.D.b) 6.8 N.D.b) 7.5 N.D.b) 3.2 N.D.b) 0.79 N.D.b) 0.12 N.D.b) 0.43 0.27 44 a) Sum of concentrations of Mo to DeCBs b) N.D., not detected HC2 N.D.b) 0.21 1.2 1.5 2.0 1.5 0.66 0.21 N.D.b) N.D.b) 7.3 HC3 0.11 4.2 31 18 19 19 10 2.6 0.36 1.7 110 HC4 0.12 0.34 1.0 0.69 0.80 1.1 0.69 0.22 N.D.b) N.D.b) 5.0 HC5 N.D.b) 0.088 0.10 N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) N.D.b) 0.19 Y1 0.16 31 14 7.9 6.5 4.8 1.4 0.35 N.D.b) 0.073 67 297 No Fig Homologue Profiles of PCBs in Sediment Samples from Vietnam and Osaka Relative concentration was the ratio of each PCBs homologue to the most intense one (A) HN1, (B) HN2, (C) HC1, (D) HC3, (E) Y1, (F) KC-300, (G) KC-400, (H) KC-500, (I) KC-600 higher than those at the other sites The ΣDDT concentrations in Vietnamese urban areas were higher than those in Osaka These facts suggest that they were mainly used as insecticides for public health reasons rather than as agricultural chemicals In contrast, the ΣCHL concentrations in Osaka were higher than those in Vietnamese urban areas The CHLs have been stored in sediment of Osaka for more than 30 years because of long environmental half-lives and the moderate climate of Japan The use and production of CHLs have been prohibited since 1972 by the law in Japan, PAHs Analytical results for PAHs are shown in Table The averages of ΣPAHs in Hanoi, Hue, Ho Chi Minh, and Osaka were 1600, 130, 1900, and 3200 ng/g-dry, respectively The concentrations of ΣPAHs at sampling sites HN1, HN2, HC1, HC3, and Y1, which were located in urban areas, 298 Vol 53 (2007) Table Concentrations of PAHs (ng/g-dry weight) in Sediment Samples from Vietman and Osaka Sampling locations HU4 HC1 HC2 4.6 170 2.5 HN1 27 HN2 23 HU1 10 HU2 8.3 HU3 6.0 phenanthrene 1-methylphenanthrene 2-methylphenanthrene 3-methylphenanthrene 4-/9-methylphenanthrene Σ3-ringsb) 24 12 13 11 13 170 21 9.3 10 9.1 11 150 6.5 1.4 2.7 1.6 1.7 29 6.8 1.6 2.3 1.6 1.9 14 2.8 0.6 0.9 0.7 0.9 7.3 1.4 1.9 1.5 1.3 13 1,2,3,4-tetrahydrofluoranthene 4H-CdefP fluoranthene pyrene benzo[b]fluorene 1,1-binaphthyl 9-phenyanthracene BaA triphenylene/chrysene naphthacene 7-MeBaA Σ4-ringsc) 0.5 21 79 200 53 0.8 3.3 96 30 37 2.0 520 0.4 18 69 170 48 0.6 2.4 79 25 9.1 1.6 420 N.D.i) 0.9 6.0 12 1.2 N.D.i) N.D.i) 3.8 1.8 N.D.i) N.D.i) 25 N.D.i) 1.0 5.7 13 0.8 N.D.i) N.D.i) 3.9 1.9 N.D.i) N.D.i) 26 N.D.i) 0.4 3.1 5.9 0.8 N.D.i) N.D.i) 2.7 1.2 N.D.i) N.D.i) 14 N.D.i) 1.0 4.5 7.6 0.6 N.D.i) N.D.i) 1.7 1.2 N.D.i) N.D.i) 17 BbF/BjF BkF BeP BaP 3-methylcholanthrene 7-MeBaP 9,10-diphenylanthracene dibenz[a, h]anthracene perylene Σ5-ringsd) Σ5-ringsd,e) Σ2-rings a) INcdP BghiP anthanthrene naphtho[2,3-a]pyrene 3,4,8,9-dibenzopyrene Σ6-rings f ) HC3 170 HC4 12 HC5 3.5 Y1 23 53 63 71 56 71 810 13 5.2 6.9 5.9 6.6 110 3.9 0.6 0.9 0.7 0.7 48 9.2 17 8.9 10 250 2.9 41 73 190 170 14 37 260 47 80 15 930 0.5 4.8 13 43 16 1.2 3.7 16 7.2 8.4 0.6 120 N.D.i) 0.7 1.9 3.3 0.4 N.D.i) N.D.i) 0.5 0.4 N.D.i) N.D.i) 7.2 0.9 17 94 250 3.6 150 5.9 49 50 38 3.8 660 81 62 12 9.4 6.0 3.8 120 17 120 12 80 58 11 8.7 5.0 3.0 86 17 220 10 130 99 18 14 8.4 5.7 170 27 300 22 250 190 10 8.4 8.4 4.5 530 66 940 35 6.6 4.0 0.2 N.D.i) N.D.i) N.D.i) 18 3.7 65 1.1 27 16 1.2 0.9 1.0 0.4 49 9.8 150 12 1.9 N.D.i) N.D.i) N.D.i) N.D.i) N.D.i) 0.3 N.D.i) N.D.i) N.D.i) 8.5 4.9 0.8 0.6 0.4 0.2 10 1.8 26 0.9 390 280 17 14 14 20 1200 1500 670 1100 980 710 71 56 43 38 2200 1600 2500 1200 590 430 54 42 29 18 1000 100 1800 100 0.7 0.7 1.0 0.6 N.D.i) N.D.i) N.D.i) N.D.i) 1.0 4.0 3.0 150 160 240 580 18 55 N.D.i) 19 1800 3000 1200 150 260 56 39 N.D.i) 510 46 49 57 44 63 580 2.0 0.2 23 7.2 73 16 210 57 70 19 6.9 0.7 18 2.1 170 25 46 7.7 47 4.9 11 N.D.i) 670 140 97 31 18 14 7.5 180 160 39 25 19 10 340 30 1.4 1.2 0.9 4.1 120 16 5.1 2.5 2.9 0.8 23 N.D.i) N.D.i) N.D.i) N.D.i) N.D.i) N.D.i) 300 77 46 37 23 660 coronene Σ-ringsg) 63 63 34 34 17 17 ΣPAHsh) ΣPAHse,h) 2300 1900 1600 1400 230 210 9.7 9.7 170 160 7.4 7.4 120 100 4.1 4.1 110 93 3.0 3.1 2.8 2.9 4.3 16 63 63 4300 3100 27 510 37 750 37 360 4.2 110 N.D.i) N.D.i) 110 1700 5.3 5.3 1900 400 270 270 6400 5700 19 1.0 300 28 1.2 450 29 1.9 140 0.8 N.D.i) 73 N.D.i) N.D.i) N.D.i) 77 4.1 960 5.0 5.0 1500 420 0.4 0.4 33 32 87 87 5000 3200 a) Sum of 2-ring PAH compound concentrations b) Sum of 3-ring PAH compound concentrations c) Sum of 4-ring PAH compound concentrations d) Sum of 5-ring PAH compound concentrations e) Estimated by subtracting the concentration of perylene from ΣPAHs f ) Sum of 6-ring PAH compound concentrations g) Coronene concentration h) Sum of 2- through 7-ring PAH compound concentrations i) N.D., not detected were 1700–5700 ng/g-dry, while those at other sites were 30–420 ng/g-dry These values were estimated by subtracting the concentration of perylene from ΣPAHs since perylene is considered to be naturally occurring.26) The ΣPAHs concentrations in urban areas of Hanoi and Ho Chi Minh were at the same levels as in Osaka The profiles of 2- to 7-aromatic ring PAHs at HN1, HN2, HC1, HC3, and Y1 are shown in Fig The compositions of the 2- to 7-ring PAHs at the five 299 No Fig Profiles of 2- to 7-Aromatic Rings of PAHs in Sediment Samples from Vietnam and Osaka locations HN1, HN2, HC1, HC3, and Y1 were similar to each other The percentages of 2-, 3-, 4-, 5-, 6-, and 7-ring PAHs to ΣPAHs at the five locations listed above were 1–6%, 7–14%, 17–32%, 31–38%, 22–31%, and 2–5%, respectively Thus, the sedimentary PAHs at these locations mainly consist of 4- to 6-ring PAHs The predominant components observed at sampling sites NH1 and HN2 were BaP, BghiP, pyrene, INcdP, BeP, BaA, BbF/BjF, and BkF and their averages were 220, 210, 190, 120, 120, 87, 72, and 69 ng/g-dry, respectively At HC1 and HC3, the predominant components were BaP, BghiP, INcdP, BeP, methylphenanthrene isomers, BaA, pyrene, BkF, and BbF/BjF and their means were 740, 550, 350, 240, 240, 220, 200, 150, and 120 ng/g-dry, respectively At Y1, the predominant components were BaP, BghiP, INcdP, pyrene, BeP, BkF, and BbF/BjF and their concentrations were 580, 450, 300, 250, 240, 160, and 150 ng/g-dry, respectively Profiles of predominant PAH components at HN1, HN2, HC1, HC3, and Y1 are shown in Fig The two components, BaP and BghiP among eleven predominant ones were mainly observed at the five sampling sites The PAH components in the regional differences were pyrene and methylphenanthrene isomers The concentrations of pyrene were relatively high in Hanoi and Osaka, and those of methylphenanthrene isomers in Ho Chi Minh Zakaria et al.8) reported that the origin of PAHs could be estimated using the ratio of total concentrations of methylphenanthrene isomers (ΣMPs) to that of phenanthrene (P) The ratios in petrol were more than 2.0, whereas those emitted by combustion of Table ΣMPsa) /Pb) Ratios in Sediment Samples from Vietnam and Osaka Sampling locations HN1 HN2 HU1 HU2 HU3 HU4 HC1 HC2 HC3 HC4 HC5 Y1 ΣMPsa) /Pb) 2.0 1.9 1.1 1.1 1.1 0.8 4.6 4.4 4.9 1.9 0.7 4.6 a) Sum of concentrations of 1-, 2-, 3-, 4-, 9methylphenanthrene b) concentration of phenanthrene the materials were less than 1.0 because phenanthrene was a predominant compound produced in the combustion process The ratios of ΣMPs/P are shown in Table The ratios at sampling locations HN1, HN2, HC1, HC2, HC3, HC4, and Y1 were 1.9–4.9 These values show that PAH pollution at these sites was mainly caused by petrol runoff (petrogenic origin) In contrast, ΣMPs/P at other locations were 0.7–1.1 The PAH pollution at these locations was of pyrogenic origin The higher values of ΣPAHs were observed in urban areas, as in the case of POPs The PAHs in the urban areas and suburbs are predominantly of peterogenic origin, whereas in the rural areas, the PAHs are of pyrogenic origin, such as the combustion of fossil fuel and biomass 300 Vol 53 (2007) Fig Profiles of Predominant PAH Components in Sediment Samples from Vietnam and Osaka Relative concentration was the ratio of each PAH component to the BaP (A) HN1, (B) HN2, (C) HC1, (D) HC3, (E) Y1 a: phenanthrene, b: ΣMPs, c: fluoranthene, d: pyrene, e: BaA, f: BbF/BjF, g: BkF, h: BeP, i: BaP, j: INcdP, k: BghiP Acknowledgements We heartily express our thanks to Prof Jyunko Oda, Kibi Kokusai University, for technical support of GC/MS analysis of PAHs and also to Dr Norimichi Takenaka, Osaka Prefecture University, for useful advice REFERENCES 1) Halsall, C J., Bailey, R., Stern, G A., Barrie, L A., Fellin, P., Muir, D C G., Rosenberg, B., Rovinsky, F Y., Kononov, E Y and Pastukhov, B (1998) Multi-year observations of organohalogen pesticides in the Arctic atmosphere Environ Pollut., 102, 51–62 2) Iwata, H., Tanabe, S., Sakai, N., Nishimura, A and Tatsukawa, R (1994) Geographical distribution of persistent organochlorine in air, water, and sediments from Asia and Oceania, and their implication for global distribution from lower latitudes Environ Pollut., 85, 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45–48 Hartkamp-Commandeur, L C M., Gerritse, J., Govers, H A J and Parsons, J R (1996) Reductive dehalogenation of polychlorinated biphenyls by anaerobic microorganisms enriched from Dutch sediments Chemosphere, 32, 1275–1286 Vanier, C., Sylvestre, M and Planas, D (1996) Persistence and fate of PCBs in sediment of the Saint Lawrence River Sci Total Environ., 102, 229–244 Hites, R A., Laflamme, R E., Windsor, J G., Farrington, J W and Deuser, W D (1980) Polycyclic aromatic hydrocarbons in an anoxic sediment core from the Pettaquamscutt River (Rhode Island, USA) Geochim Cosmochim Acta, 44, 873–878  ... concentrations in urban areas of Hanoi and Ho Chi Minh were at the same levels as in Osaka The profiles of 2- to 7 -aromatic ring PAHs at HN1, HN2, HC1, HC3, and Y1 are shown in Fig The compositions of. .. compositions of the 2- to 7-ring PAHs at the five 299 No Fig Profiles of 2- to 7 -Aromatic Rings of PAHs in Sediment Samples from Vietnam and Osaka locations HN1, HN2, HC1, HC3, and Y1 were similar to... These facts indicate that the PCB components in Hanoi (at sampling sites HN1 and HN2) was mainly contributed from the KC-500 product and Ho Chi Minh (at sampling sites HC1 and HC3) were from the