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Persistent manufactured chemicals for non-pesticide applications and
persistent by-products of industrial and combustion process
in China and Hong Kong
Ming H. WongHong Kong Baptist University
GEF PDF-B Workshop, Jan 1999
Table of contents
1. General background of China and Hong Kong.2. The use of persistent organics in China and Hong Kong.3. Case study – PCBs, PCDDs and PCDFs in China.4. PAHs in China.5. Total PCBs, PCDDs, PCDFs and PAHs in abiotic and biotic samples from China, Taiwan and Hong Kong.6. Case study – PCBs and PAHs in Hong Kong.7. Polycyclic aromatic hydrocarbons in water and sediment of
South China River.8. PCBs in freshwater fish and sediments collected from the
Pearl River Delta and Hong Kong.9. Induction of Cytochrome P4501A1 gene expression in Tilapia exposed to coastal sediment.10. General conclusion.
1. General background of China and Hong Kong
Climate- Subtropical, with cool dry winters and hot wet summers.- Rainfall occurs predominantly in the summer, coinciding with the highest air temperatures.
Population- The Pearl River delta, with an area of 23270 km2 (Ma, 1994) and a population of 15 million (Chan, 1995).- Hong Kong with an area of 1,067 km2 and a population of over 6 million.
Industrialization- Since the implementation of the economic reform and open door policy in 1978, the provinces of the South China take the lead.- Organic discharge from the industries textile, plastic, printing, dying, tannery, food, electroplating and paper production.- Heavy industrial activities and residential population close to Victoria
Harbour, but also in the developing New Towns.
Pollution- Environmental policy and legislation in China are neither strict nor effectively enforced.- Pollutants from Guangzhou and Shenzhen are washed into Hong Kong’s
estuarine waters.- The quality of drinking water and local food supplies are affected. - 2,000 major industrial factories and an estimated 200,000 smaller ones in Hong
Kong. - In Hong Kong, agricultural pollution from New Territories is due to rearing of
pigs and poultry, the populations of which are currently estimated to be 0.7 million and 7.5 million, respectively.
- Hong Kong produces about 24,000 tonnes of solid wastes per day (HKEPD, 1995).
- Since 3.5 million people and a large proportion of the industrial base are concentrated around Victoria Harbour of Hong Kong. Sewage and industrial effluents from these sources enter Victoria Harbour with little treatment (Connell et al, 1998).
- In Hong Kong, over 25% of the land in the urban area has been gained from reclamation (Morton, 1989). The reduction in water area due to reclamation has reduced the tidal flushing of both Victoria and Tolo Harbours, and exacerbated the problems of pollution due to sewage discharges.
Table 1a. Manufactured persistent organic chemicals in China: Heat Stabilizer
Use Example Chemical Group Use & Description
Major
Manufacturer
Location
Heat
Dibasic Lead
Phthalate
Phthalate - electric resistant for
PVC
- heat and light
stabilizer for plastic
Shanghai
Stabilizer Pentachlorobiphenyl PCBs - heat resistant for
plastic
- flame retardant and
plasticizer
Shanghai
2. The use of persistent organics in China and Hong Kong
Table 1b. Manufactured persistent organic chemicals in China: Plasticizer
Use Example Chemical Group Use & Description
Major
Manufacturer Location
Dimethyl
Phthalate (DMP)
Phthalate - plasticizer Shanghai, Hunan
Diisooctyl
Phthalate (DOP)
Phthalate - plasticizer for plastic, paint and
rubber
widely distributed in
China
Plasticizer
Butyl Benzyl
Phthalate
Phthalate - plasticizer for PVC & rubber and
use with other plasticizer
Jiangsu, Zhejiang
Chlorinated
Paraffin-42
Polychlorinated
Paraffin
- plasticizer for PVC
- additive for paint and lubricant oil
Shanghai, Guangzhou
Chlorinated
Paraffin-52
Polychlorinated
Paraffin
- plasticizer for PVC
- additive for paint and lubricant oil
Shanghai, Guangzhou
Diisoctyl m-
Phthalate
Phthalate - plasticizer
- substitute for DOP
Tianjian
Table 1c. Manufactured persistent organic chemicals in China: Flame Retardant
Use Example Chemical Group Use & Description
Major
Manufacturer Location
Decabromo Diphenyl
Ether (FR-10)
Polybromo
Diphenyl
- flame retardant for PVC,
nylon, etc
Jiangsu, Tianjian,
Shangdong, Shanghai
Decabromodiphenyl Oxide Polybromo
Diphenyl
- flame retardant for plastic Jiangsu
Tetrabromo Bisphenol A Polybromo Phenol - flame retardant for
plastic, rubber
Tianjian, Zhejiang,
Shanghai
Tetrabromo Bisphenol A
Allyl Ether
Polybromo Phenol - flame retardant for
plastic, rubber
Shangdong, Shanghai,
Beijing
Flame
Retardant
1, 2 - Bis (2, 4, 6-Tribomo
Phenoxy) Ethane (FR-3B)
Polybromo Phenol - flame retardant and heat
stabilizer for plastic
Zhejiang
Chloroparaffin-70 Polychlorinated
Paraffin
- flame retardant for
plastic, paint & adhesive
Shanghai, Shangdong,
Shenyang
Tetrabromophthalic
Anhydride
Phthalate flame retardant for plastic Zhejiang
Dibromocresyl Glycidyl
Ether
Polybromo Phenol flame retardant for plastic Jiangsu
Table 2. Output of manufactured persistent organic chemicals in China
References for Tables 1 & 2:Wang, L. S., Hua Gong Chan Pin Zong Ji, Shanghai Science & Technology Publisher, China, 1997Yu, Z. M., ZhongGuo Hua Gong Shang Pin Da Quan (Dian Wei Hei), ZhongGuo Wu Zi Chu Ban She, Beijing, China, 1993Yu, Z. M. ZhongGuo Hua Gong Shang Pin Da Quan (Dian Wei Hei), ZhongGuo Wu Zi Chu Ban She, Beijing, China, 1991Wu, W. Z., Schramn, K. W., Henkelmann, B., Yediler, A., & Kettrup, A., PCDD/Fs, PCBs, HCHs, and HCB in sediments and soil of Ya-er lake in China: Results on residual levels and correlation to the organic carbon and the particle size , Chemosphere, Vol. 34, No. 1, pp. 191-202, 1997Jiang, K. Li, L. J., Chen, Y. D., & Jin, J., Determination of PCDD/Fs and Dioxin-like PCBs in Chinese commercial PCBs and emissions from a testing PCB incineration, Chemosphere, Vol. 34, No. 5 - 7, pp. 941-950, 1997
Product Chemical 1992 (tonnes) 1993 (tonnes)Dibutyl Phthalate 73,989 85,151Dioctyl Phthalate 153,171 139,162Dimethoxyethyl Phthalate 49 42
Plasticizer Butyl Benzyl Phthalate 313 467Disodecyl Phthalate 1,770 220Mixed Phthalate 228 211Dicotyl-p-Phthalate 12,269 6,505Chlorinated Paraffin 43,787 40,189
Stabilizer for Plastic andRubber
Dibasic Lead Phthalate &Organometallic Stabilizer
4,595 4,635
Table 3. Import & export of persistent organic chemicals in Hong Kong
References:1) Hong Kong Trade Statistics - Import,1993 -1996, Census and Statistics Department, Hong Kong2) Hong Kong Trade Statistics - Exports and Re-exports, 1993 -1996, Census and Statistics Department, Hong Kong
Import StatisticsCommodities Unit 1993 1994 1995 1996
Aromatic Cyclic Alcohols and their Halogenated, Sulphonated, Nitrated or Nitrosated Derivatives kg 1,062,493 1,343,189 1,533,794 1,562,531Halogenated, Sulphonated, Nitrated and Nitrosated Derivatives of Phenols or Phenol-Alcohol kg 758,776 950,525 1,003,327 591,640Phthalic Anhydride kg 2,353,072 5,524,191 15,168,230 81,414Dioctyl-o-Phthalates kg 61,357,396 90,387,720 80,122,197 688,107Dimethyl-t-Phthalates kg NA 16,000 483,000 NAInsecticides kg 15,248,510 16,049,884 16,556,661 12,544,204Compound Plasticizers for Rubber or Plastics HK$ 209,127 351,368 668,319 652,260Liquid Dielectic Transformer No. 47 510 499 10209
Export StatisticsCommodities Unit 1993 1994 1995 1996
Insecticides kg NA 4,082,026 NA 3,934,040Compound Plasticizers for Rubber or Plastics HK$ 40,278 NA 79,961 52,995
Table 4. The order of high priority environmental pollutants of China
Group NameAcute ToxicityLD50 (mg/kg)
Chronic ToxicityTCLO (mg/kg)
Aquatic-lifeToxicity (mg/L)
Dichloromethane 2136 / /Trichloromethane 908 20.1 /Tetrachloromethane 2800 43 (human) /
1. Halogenated 1,2-Dichloroethane 678 1338 / Methane / 1,1,1-Trichloroethane 5100 43 / Ethane 1,1,2-Trichloroethane 582 532 /
1,1,2,2-Tetrachloroethane 30 / /Trichloroethylene 3670 594 /Tetrachloroethane 3005 2100 /Tribromomethane 1147 1100 /
2. Benzene p-Xylene 3810 150 10-100Chlorobenzene 2910 750 1-100
3. Chlorinated o-Dichlorobenzene 670 / / Benzene p-Dichlorobenzene 500 / /
Hexachlorobenzene 10000 / /4. Polychinated Biphenyls
PCBs 2000 0.067 / day /
Table 4. (cont.)
Group NameAcute ToxicityLD50 (mg/kg)
Chronic ToxicityTCLO (mg/kg)
Aquatic-lifeToxicity (mg/L)
Phenol 317 300 /m-Cresol 242 143 /
5. Phenol 2,4-Dichlorophenol 580 / /2,4,6-Trichlorophenol 820 / /Pentachlorophenol 27 50 1p-Nitrophenol 250 10 /p-Nitro-toluene 1960 / /
6.Nitrobenzen 2,4-Dinitro-toluene 268 / /Trinitro-toluene 795 / /p-Nitrochlorobenzene 420 / /2,4-Dinitro-1-chlorobenzene 1070 / /Aniline 250 150 /Dinitroaniline 418 1.1 /
7. Aniline p-Nitroaniline 750 / /2,6-Dilchloro-1-nitroaniline 1500 (oral-mice) / /
Table 4. (cont.)
Group NameAcute ToxicityLD50 (mg/kg)
Chronic ToxicityTCLO (mg/kg)
Aquatic-lifeToxicity (mg/L)
Naphthalene 1250 (oral-mice) / 1-10Fluoranthene 2000 / /
8. Polyaromatic Benzo[b]fluoranthene / / / Hydrocarbon Benzo[k]fluoranthene / / /
Benzo[a]pyrene 50 0.455 /Indeno[1,2,3-c,d]pyrene / / /Benzo[g,h,i]perylene / / /Dimethyl-phthalate 6800 1125 /
9. Phthalate Di-n-butyl-phthalate 8000 140 /Dioctyl-phthalate 6513 5000 /Hexachloro-cyclohexane 88 / /DDT 113 6 <1DDV 25 15 /
10. Pesticides Dimethoate 140 / /Parathion 6 / /Parathion-methyl 9 / /Nithofen 740 37.5 /Trichorfon 150 2.2 /
11.Acrylonitrile Acrylonitrile 78 37.9 /
Reference:National Environmental Protection Agency, Database: Environmental Protection. Hebei Publisher, 1990
The use of persistent organics in China and Hong Kong
Conclusion
1) Many manufactured persistent organic chemicals (eg. phthalate, halowax, polybromophenol, etc.) are actively used in heat stabilizer, plasticizer and flame retardant.
2) More than 200,000 tonnes and 40,000 tonnes of phthalate and halowax are produced every year.
3) China produces about 5000 tonnes of Pentachlorophenol (PCP) annually (Wu et al., 1997).
4) Environmental concerns on liquid dielectric transform are growing owing to the existence of PCBs and PCB substitutes.
5) Input of persistent organic chemicals to HK is much more than output.
3. Case Study – PCBs, PCDDs & PCDFs in China
- Industrial production started from 1965 and ceased at 1974
- 10,000 tonnes produced during that periods- Two different types of Chinese commercial PCBs –
PCB3 and PCB5, which are similar to Aroclor 1242 and 1254 respectively
- Pentachlorobiphenyl is still applied as one of the additives in the manufacture of paint today.
- Starting from 1985, more than 2000 transforms have been demolished.
• Scientific Studies
• Yang Y. H., Sheng G. Y., Fu J. M. & Min Y. S. Organochlorinated compounds in waters of the Pearl River Delta region. Environmental Monitoring and Assessment, 44, 567 – 575, 1997
Ranged from 0.80 to 9.23 g/LSewage water > river water
• Chu S. G., Xu X. B., Fang Y. P., The distribution and environmental behaviour of PCBs in classic polluted sites, Acta Scientia Circumstantiae, 15, 1, 1995
Bio-magnification in reference contaminated area[PCBs] in water < sediment < fish
Bio-accumulation in fish[PCBs] in muscle < bile < gallbladder < liver
• Chu S. G., Xi Z. Q., Xu X. B, Polychlorinated Biphenyl (PCB) Congeners in Mussel and other Mollusc from Da Chen Island, East China Sea, Bull. Environ. Contam. Toxicol., 55, 682 – 688, 1995
Bio-concentration ranged from 1.40 to 9.34 g/kg[PCBs] correlated with distance of sampling sites from the estuary
of the river.
• Chu S., Xi Z., Xu X. Zhang Y., Xu Y, Induction of Micronuclei in peripheral erythrocytes of Misgurnus anguillicaudatus by polychlorinated biphenyls. Bull. Environ. Contam. Toxicol., 57, 179 -182, 1996
Water polluted by PCBs have a possible mutagenicity of aquatic organisms
Increase on the incidence of micronuclei with the increase of [PCB3] and time exposureSuitability of assessing peripheral blood of fish for the induction of
micronuclei as a short term test for monitoring environmental genotoxicants
Xi Z. Q., Chu S. G., Xu X. B., Zhang Y. Y. Xu. Y., Fang Y.P., Li W., Effects of PCBs on the Electrolyte Balance in Blood of Crucian Carp, Research Centre for Eco-Environmental Sciences, Academia Sinica, Beijing, China, (in process)
Effect on dielectric concentration balance in the plasma of carp[Na+] [K+]
No observable change in [Ca2+] & [Mg2+]
Zheng M. H., Bao Z. C., Wang K. O., Xu X. B., Levels of PCDDs and PCDFs in the Bleached Pulp from Chinese Pulp and Paper Industry, Bull. Environ. Contam. Toxicol., 59, 90 – 93, 1997
PCDDs in pulp ranged from 140.0 to 390.5 pg/g dry pulpPCDFs in pulp ranged from 7.3 to 80.4 pg/g dry pulp
• Zheng M. H., Bao Z. C., Wang K. O., Xu X. B., Polychlorinated Dibenzo – p Dioxins and Dibenzofurans in lake Sediments from Chinese Schistosomiasis Area, Bull. Environ. Contam. Toxicol., 59, 653 – 656, 1997
Total PCDDs & PCDFs were 15760 ng/g and 2260 ng/g in Na-PCP respectivelyLevels of PCDDs & PCDFs in lake sediments ranged from 51 to 220 ng/g and 0.3 to 15 ng/g respectively
Table 5. Benzo(a)pyrene concentration in China soil and atmosphere from industrial and non-industrial area
4. Case study - PAHs in China
Soil g/g Atmosphere g/100m3
Wheat, corn field RiceSamplinglocation n mean n mean n mean
Deposition(100t/km2/month)
Industrialarea
17 229.4 133.0 23 179.785.5 20 8.76 4.81 164.0 62.4
Non-industrial
area
16 0.8 0.7 18 3.6 2.9 21 0.5 0.04 27.0 11.9
Table 6. PAH concentrations at different diameter of suspended particulate in air
Reference:Liu, S. J. and Wu, Y. Carcinogenic polycyclic aromatic hydrocarbon in environment. Environment Protection in China. 1995.
Particlediameter
Pyrene Chrysene Benz(a)anthracene
m Industrialarea
Residentialarea
Ruralarea
Industrialarea
Residentialarea
Ruralarea
Industrialarea
Residentialarea
Ruralarea
>7.0 3.68 0.57 0.18 3.25 0.58 0.10 2.49 0.49 0.097.0-3.3 1.67 0.28 0.10 3.38 0.42 0.25 1.57 0.34 0.383.3-2.0 2.53 0.51 0.12 2.73 1.29 0.14 1.63 0.29 0.362.0-1.1 1.79 0.75 0.22 2.82 0.72 0.38 3.46 0.61 0.951.1 5.22 7.94 0.48 7.17 4.51 0.82 9.75 1.22 3.50Total 14.89 10.05 1.10 19.35 7.52 1.69 18.90 2.95 5.28
Particlediameter
Perylene Benzo(a)pyrene
m Industrial area
Residential area
Ruralarea
Industrial area
Residential area
Ruralarea
>7.0 14.26 4.86 0.94 2.04 0.92 0.467.0-3.3 20.57 1.08 2.33 2.24 0.75 0.703.3-2.0 6.21 1.16 1.20 1.49 0.77 0.552.0-1.1 31.90 3.30 2.28 3.39 0.80 0.641.1 41.73 33.09 5.96 6.75 3.08 3.06Total 114.67 43.49 12.71 15.91 6.32 5.41
Case Study - PAHs in China
Conclusion
The background values of benzo(a)pyrene ranged from 1.5-28 g/kg in soil.
Benzo(a)pyrene levels in soils collected from cultivated field in industrial area were 179-223 g/kg.
More than 6 times higher than those in non-industrial area.
Elevated benzo(a)pyrene levels in air of industrial area due to combustion process.
Particle size affects the absorption of PAH to suspended particles in the atmosphere.
94% PAH was associated with the particles smaller than 2.9 m.
PAH containing particles could settle down in lung via respiration
Pose a potential health problem to human beings.
Sediment Water Breast milk Biota Soil Fly ash Food
PC
B (
ppb)
1x10-8
1x10-4
1
1x104
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
China Taiwan Hong Kong
5. Total PCBs, PCDDs, PCDFs and PAHs in abiotic and biotic samples from China, Taiwan and Hong Kong
Figure 1a. Mean concentration (ppb) of total PCBs in differentmonitoring samples from China, Taiwan and Hong Kong.
Sediment Water Breast milk Biota Soil Fly ash Food
1x104
1
1x10-4
1x10-8 N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
PC
DD
(pp
b)
China Taiwan Hong Kong
Figure 1b. Mean concentration (ppb) of total PCDDs in differentmonitoring samples from China, Taiwan and Hong Kong.
Sediment Water Breast milk Biota Soil Fly ash Food
PCD
F (p
pb)
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
1x10-8
1x10-4
1
1x104
China Taiwan Hong Kong
Figure 1c. Mean concentration (ppb) of total PCDFs in differentmonitoring samples from China, Taiwan and Hong Kong.
Sediment Water Breast milk Biota Soil Fly ash Food
PAH
(pp
b)
1x10-8
1x10-4
1
1x104
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
China Taiwan Hong Kong
Figure 1d. Mean concentration (ppb) of total PAHs in differentmonitoring samples from China, Taiwan and Hong Kong.
Total PCBs, PCDDs, PCDFs and PAHs in abiotic and biotic samples from China, Taiwan and Hong Kong
Conclusion
Distribution patterns of PCBs in sediments showed smaller spatial variations.
In HK and Taiwan, total PCBs retained more in sediments than that in China.
Only a few monitoring surveys are available on the PCDD, PCDF, and PAH contamination in air, water, sediments of China.
Spatial distribution of such contamination is unclear.
Multi-compartment monitoring is essential to elucidate the behavior and fate of persistent organic chemicals and to assess the current status of contamination.
Table 7. Concentrationsa of total PCBs and total PAHs in sediments from Victoria Harbour (Connell et al., 1998).
6. Case Study - Study of PCBs and PAHs in Hong Kong
tance Units Harbour station Typhoon sheltersVS1 VS2 VS3 VS4 VS5 VS6 VS8 VS9 VS10 VS14 VS12 to VS14 &
VS16 to VS20Period
l PCBs g kg-1
(dw)10 16 6.8 14 5.6 11 4.3 3.2 27 38-81 1992b
l PCBs g kg-1
(ww)NA 25.5
(23.7)10.2(6.8)
NA 9.5(8.3)
16.7(13.9)
NA 9.0(4.9)
14.5(13.7)
ND-169 1995-1996c
l PAHs mg Kg-1
(dw)5.6 12.7 12.6 14.0 9.6 3.1 3.9 1.20 68 454 ND-139 1992b
l PAHs g Kg -1
(ww)NA 191
(104)125
(126)NA 78
(51)336167)
NA 139(92)
135(88)
1159(811)
ND-824 1995-1996c
ND = not detected; NA = not available; ww = wet weight; dw = dry weight.a Means with standard deviations in parenthese where available.b Hong et al., 1995.c EPD, 1995 - 1996.
Reference:Connell, D. W., Wu, R. S. S., Richardson, B. J., Leung, K., Lam, P. S. K., and Connell, P. A. Occurrence of persistent organic contaminants and related substances in Hong Kong marine areas: an Overview. Marine Pollution Bulletin 36:376-384, 1998
Table 8. Concentrationsa of total PCBs in sediments collected in Hong Kong marine areas (Water Control Zones) during 1995-1996b (Connell et al., 1998)
Stations Average (SD)ZoneS1 S2 S3 S4 S5 S6 S7
Deep Bay 10.0(7.0) 8.75(3.5) 6.75(2.3) 15.5(16.6) NA NA NA 10.25(3.7)Eastern Buffer 6.25(2.5) 5.25(0.5) 33.0(27.4)c 7.25(2.6) NA NA NA 12.9(13.3)
Junk Bay NA 9.0(2.7) NA NA NA NA NA 9.0(2.7)Mirs Bayb 6.75(3.5) 6.5(3.0) 7.75(3.2) 5.0(0) 5.0(0) 9.75(9.5) 6.25(2.5) 6.7(1.5)
North Western NA 6.7(2.0) 7.0(2.8) 7.25(3.8) 14.7(11.8)c 9.75(4.2) NA 9.1(3.4)Port Shelter 12.6(11.5)c 6.75(3.5)c 5.75(2.25) 11.75(12.2) 5.3(0.5) 5.75(1.5) 5.0(1.6) 7.5(3.2)
Southern 5.25(0.5) 5.0(0) 5.5(1.0) 8.3(5.7) 8.25(3.9) 5.0(0) 16.0(1.6)c 7.6(3.9)Tolo Harbour NA 7.0(2.6) 7.7(7.2) 5.0(0) 10.0(9.2) NA 15.25(16.6)c 8.99(3.9)
Western 10.5(4.5) 7.75(5.5) NA NA NA NA NA 9.1(1.9)
NA = not available.a g kg-1 wet weight with standard deviations in parentheses.b EPD, 1995-1996.c Typhoon shelters and sheltered anchorages.d Mirs Bay Stations continued: S8 5.3(0.5); S9 6.6 (2.8); s10 5.0 (0); S11 7.6 (4.6); S12 6.3 (2.3); S13 4.6 (0.5); S14 6.6 (2.0); S15 8.5 (7.0); S16 6.0 (1.7); S17 9.0 (6.9).
Table 9. Concentrationsa of total PAHs in sediments collected in Hong Kong marine areas (Water Control Zones) during 1995-1996b (Connell et al., 1998)
StationsZoneS1 S2 S3 S4 S5 S6 S7
Average (SD)
Humanpopulationc
(x 105)Deep Bay 231(213.7) 64(29.1) 51(15.3) 47(13.1) NA NA NA 98.8(88.9) 3.68
Eastern Buffer 42(5.2) 40(1.4) 230(158.3)d 60(13.2) NA NA NA 93.6(92.5) 2.32Junk Bay 45(9.9) NA NA NA NA NA NA 45.5(9.9) 0.82Mirs Bayb 41(1.5) 41(3.6) 40(1.4) 40(1.2) 40(1.2) 44(3.2) 40(1.4) 40.4(1.5) 0.23
North Western NA 62(19.7) 44(4.9) 49(9.9) 125(51.9)d 61(28.1) NA 68.6(32.6) 3.86Port Shelter 120(117.7)d 42(2.0)d 43(5.3) 48(11.3) 40(1.15) 43(6.9) 51(11.8) 55.7(28.8) 0.48
Southern 43(5.4) 49(8.5) 170(174.4) 104(53.6) 60(5.7) 41(2.8) 156(44.8)d 89.5(55.0) 2.62Tolo Harbour NA 40(2.1) 40(2.1) 39(2.6) 41(2.6) NA 50(13.9)d 42.41(4.4) 7.10
Western 60(13.5) NA NA NA NA NA NA 58.1(3.4) 3.95
NA = not available.a g kg-1 wet weight with standard deviations in parentheses.b EPD, 1995-1996.c Typhoon shelters and sheltered anchorages.d Mirs Bay Stations continued: S8 5.3(0.5); S9 6.6 (2.8); S10 5.0 (0); S11 7.6 (4.6); S12 6.3 (2.3); S13 4.6 (0.5); S14 6.6 (2.0); S15 8.5 (7.0); S16 6.0 (1.7); S17 9.0 (6.9).
Case Study - PCBs and PAHs in HK
Conclusion
Total PCBs and PAH in sediments have been monitored at 13 stations in Victoria Harbour.
PCBs and PAHs in marine sediments at 66 stations in 10 water quality zones in Hong Kong were collated and analysed between 1987 and 1996.
Contamination by the PCBs was lower than world wide standards (up to 25.5 g/kg wet weight).
Substantial petroleum contamination in Victoria Harbour sediments (up to 116 g/kg wet weight)
Total PCBs and PAHs were widely distributed in Hong Kong sediments (background concentrations of 5 to 9.8 g kg-1 and 40 to 60 g kg-1 wet weight respectively).
Substantial contamination was found in typhoon shelters (total PCBs up to 169 g kg-1 wet weight; total PAHs, up to 1159 g kg-1 wet weight).
Much of the PCBs and PAHs due to industrial discharges and stormwater run-off (trace concentration originating from road ways, motor vehicle discharges, disposal of electrical equipment and other items).
Sewage would also be expected to contain trace concentrations.
PAHs are probably of combustion origin and the levels in the various water quality zones show an approximate relationship with the size of the human population in the catchment.
7. Polycyclic aromatic hydrocarbons in water and sediment of South China River
Study sites:
Pearl River, Deep Bay, Shenzhen River, Reservoir (Control site), Hong Kong Rivers
Samples:
River water and sediments at 16 locations in Pearl River Delta.
Analysis:
16 PAHs were investigated.
Figure 3a. Mean concentrations of total PAHs in sediment of South China rivers.
Pearl River
Deep Bay
Shenzhen River
Control
Hong Kong Rivers
Sites
a b c d e f g h i j k l m n o p
(g/
Kg
dry
wt)
0
500
1000
1500
2000
2500
Pearl River
Deep Bay
Shenzhen River
Control
Hong Kong Rivers
Figure 3b. Mean concentrations of total PAHs in surface water of South China rivers
Sites
a b c d e f g h i j k l m n o p
(g/
L)
0
1
2
3
4
5
6
Table 10. Present results compared with Sediment Quality Criteria for organic micro-pollutants (expressed in µg/kg)
Present study Hong Kong and China guidelines European guidelines
CompoundPearlRiver
ShenzhenRiver
HongKong
HK(Target A)
HK(Trigger B)
HK(Action C)
China DutchIntervention value
UK targetvalue
Fluoranthene <10-280 <10-140 <10-459 1200 5250 7000 ND ND NDBenzo(b)fluoranthene
<10-188 <10-52 <10-167 550 2250 3000 ND ND ND
Benzo(k)fluoranthene
<10-134 <10-33 <10-80 550 2250 3000 ND ND ND
Benzo(a)pyrene <10-547 <10-35 <10-136 200 2250 3000 ND ND NDBenzo(ghi)perlene
<10-148 <10-27 <10-120 200 2250 3000 ND ND ND
Indeno (123-cd)pyrene
<10-36 <10-35 <10-40 200 2250 3000 ND ND ND
Total PAH(Sum 10)
455.25-1199.3
185.51-674.25
142.27-1384.2
ND ND ND ND 40000 1000
Target A – indicate the desired quality for fairly clean sediment; they slightly exceed but are close to the background levels. Trigger B – indicate that moderate pollution occurs. The target values proposed equate to about 50% of the trigger levels. Action C – indicate heavily polluted sites (Lau Wong, 1991). Intervention Values are now available to identify “serious contamination” of soils, sludges and groundwaters and to indicate
when remediation is necessary. “Target Values” are specified to indicate desirable uncontaminated chemical contents of both soils and water.
References:Contaminated Spoil Management Study. (1991). Final Report, Vol. 1. Mott MacDonald Hong Kong Ltd., Agreement CE 30/90. Environmental Protection Department, Hong Kong Government.Cairney, T. (1996). Contaminated Land Problems and Solutions.
Table 11. Present results compared with Water Quality Criteria for organic micro-pollutants (expressed in µg/l)
Present study China guidelines European guidelines
Compound Pearl RiverShenzhen
River Hong Kong ChinaUK
target valueDutch
Intervention valueNaphthalene <0.1-1.4 <0.1-1.2 <0.1-0.5 ND 0.1 70Anthracene <0.1-0.1 <0.1-0.2 <0.1-0.2 ND 0.02 5Phenanthrene <0.1-1.8 <0.1-3.0 <0.1-4.3 ND 0.02 5Fluoranthene <0.1-0.2 <0.1-0.3 <0.1-0.2 ND 0.005 1Benz(a)anthracene <0.1-0.1 <0.1 <0.1 ND 0.002 0.5Chrysen <0.1-0.2 <0.1-0.2 <0.1-0.3 ND 0.002 0.05Benzo(b)fluoranthene <0.1 <0.1 <0.1 ND ND NDBenzo(k)fluoranthene <0.1 <0.1 <0.1 ND 0.001 0.05Benzo(a)pyrene <0.1 <0.1 <0.1 0.002 0.001 0.05Benzo(ghi)perlene <0.1 <0.1 <0.1 ND 0.002 0.05Indeno (123-cd)pyrene <0.1 <0.1 <0.1 ND 0.0004 0.05Total PAH (Sum 10) <0.1-2.934 0.1-2.942 <0.1-3.433 ND ND ND
- Target A – indicate the desired quality for fairly clean sediment; they slightly exceed but are close to the background levels.- Trigger B – indicate that moderate pollution occurs. The target values proposed equate to about 50% of the trigger levels.- Action C – indicate heavily polluted sites.- Intervention Values are now available to identify “serious contamination” of soils, sludges and groundwaters and to indicate
when remediation is necessary. - Target Values are specified to indicate desirable uncontaminated chemical contents of both soils and water.
Reference Lu, R. (1995). Standards for domestic drinking water. Handbook of Regulations on Environmental Protection in China.
Polycyclic aromatic hydrocarbonsin water and sediment of South China river
Conclusion
Total PAHs in the different locations show wide variations.
Elevated levels of total PAHs in sediments (up to 2200 g/kg dry wt.) and water (up to 5 g/L) were detected in some locations.
Elevated concentrations of PAHs are observed in location adjacent to industrial area.
Significant PAH contamination was found to be due to Benzo(a)pyrene and chrysene in sediment and water, respectively (slightly exceed the recommended guidelines).
8. PCBs in freshwater fish and sediments collected from the Pearl River Delta and Hong Kong.
Study sites:Pearl River Delta:
fish ponds: Dongguan, Shunde, Nanhai, Zhongshan and Shenzhen
Hong Kong: Fish ponds: Au Tau, Mai Po and San Tin Rivers: Shing Mun River, Lam Tsuen River and Tai Po River
Samples: sediments and freshwater fish
Freshwater fish species: black bass, tilapia, common carp, big head, silver carp and grass carp.
Table 12a. Concentrations of PCBs in sediments collected from the Pearl River Delta and Hong Kong.
PCBs(ng/g dry wt) References
Sediment pond sediment, Pearl River Delta < 1 present studypond sediment, Hong Kong < 1 ibidriver sediment, Hong Kong 43-461 ibid
river sediment, Hong Kong 12.7-46.0 Chui et al. 1990Victoria Harbor 3.2-81 Hong et al. 1995Tolo Harbor 5.0-15.3 Connell et al.
1998
Table 12b. Concentrations of PCBs in fish flesh collected from the Pearl River Delta and Hong Kong.
PCBs(g/g wet wt) References
Fish flesh pond fish, Pearl River Delta 0.0009-0.023 present study
pond fish, Hong Kong 0.0003-0.0075
ibid
Tilapia in river, Hong Kong 0.066-0.078 ibid
Tilapia and Mullet in Mai PoMarshes
0.0025-0.017 Liang et al. 1998
Public health guidelines for fishery products: NEPA, China 0.2 US Food and Drugs Administration 2 US EPA 0.01
If an adult weighing 70 kg consumed 6.5 g of fish every day with PCBs concentration greater than 0.01 g/g wet wt, for 70 years, the risk would correspond to one cancer death per 100,000 person.
Note: Data in the present study printed in bold-face exceeded the US EPD recommended guideline.
Figure 4. Bioaccumulation of PCBs in different fishes
0
1
2
3
4
5
blackbass
tilapia big head silvercarp
grasscarp
PCBsa
cb
b
aµ
g/g
lipi
d
PCBs in freshwater fish and sediments collected from the Pearl River Delta and Hong Kong.
Conclusion
1. PCBs levels in pond sediments were less than 1 ng/g (dry wt).
2. PCBs concentrations in river sediments ranged from 43-461 ng/g (dry wt), which were higher than the previous studies in relation to Shing Mun River (12.7-46.0 ng/g dry wt, Chui et al. 1991), Tolo Harbour (5.0-15.3 ng/g wet wt, Connell et al. 1998) and Victoria Harbour (3.2-81 ng/g dry wt, Hong et al. 1995).
3. Although PCBs concentrations in fish flesh collected from fish ponds in the Pearl River Delta and Hong Kong did not exceed the NEPA maximum permissible limits (0.2 g/g wet wt), 16% of fish collected from the Pearl River Delta and 100% of fish collected from the rivers in Hong Kong exceeded the more stringent guidelines of US EPA (0.01 g/g wet wt).
4. Factors affecting bio-accumulation of PCBs in fish.
Ecological niches: feeding habits affects PCBs accumulation in freshwater fish cultured in wastewater system at Au Tau.
Possible uptake pathways for sediment-sorbed PCBs accumulated in tilapia: ingestion sediment and/or contact with contaminated particles contributed to the major uptake route rather than water.
The Outline Method of Reverse-Transcriptase-Polymerase-Chain-Reaction (RT-PCR)
Liver tissues Total RNA
PCR products
Agarose gel electrophoresis
Specific primersfor CYP1A1
RT-PCR
•The present method is very sensitive in detecting CYP1A1 gene expression, which is specific to organic contaminants.
•The method is simple and rapid.
Marker
Control
PCB/3h
PCB/6h
PCB/12h
Sedimentexposure
Induction of CYP1A1 gene expression in fish liver tissues using RT-PCR..
~270 bp
Induction of Cytochrome P4501A1 gene expression in Tilapia exposed to coastal sediment
Conclusion
Exposure of tilapia to the sediments of PCBs (i.p. injection)
induced CYP1A1 levels in the liver tissues.
The biomarker is highly sensitive to the organic pollutant.
This enables us to monitor trace organic contamination in local waters.
General Conclusion Only a few monitoring surveys are available on the flame
retardant, PCB substitute and phthalates contamination in air, water, and sediment of China, although they are manufactured and used.
The order of highly concern on persistent organic chemicals is PCBs > PAH > phthalate > pesticides.
The data indicates that the sediments of China are contaminated with a relatively high concentration of total PAHs, as well as lower concentrations of total PCBs, PCDDs and PCDFs.
Benzo(a)pyrene is mostly concerned PAH component in China.
In Hong Kong the most concern persistent organic chemicals are PCBs, PAH and pesticides.
Background concentrations of 5 to 9.8 g kg-1wet weight of total PCBs and 40 to 60 g kg-1 wet weight of total PAHs in Hong Kong marine sediment.
Elevated concentrations of PCBs and PAHs were found in Victoria Harbour sediment in the range 9.56 to25.5 g kg-1 and 66 to 116 g kg-1, respectively.
Substantial contamination was found in typhoon shelters (total PCBs, up to 169 g kg-1 wet weight; total PAHs, up to 115 g kg-1 wet weight).
Sediments in Hong Kong rivers contained PAH and PCB concentrations of 194 to 2199 g kg-1 dry wt and 12.7 to 461 g kg-1 dry wt, respectively.
More monitoring work should be done to get a clear geographical distribution of persistent organic chemicals in our region.
Multi-compartment monitoring and bioaccumulation assessment is essential to elucidate the behavior and fate of persistent organics, also to assess the current status of contamination.