Environmental Monitoring and Governance in the East Asian Hydrosphere

Monitoring of POPs in the East Asian Region

2002 Report, China

Huang Yeru, Zhou Li, Di Yian

Sino-Japan Friendship Center for Environmental Protection

No.1 Yuhuinanlu, Chanoyang District, Beijing 100029, P.R. China

    POPs are persistent in the environment and show a common property of long-range transport. They have propensity to enter the gas phase under environmental temperatures. Hence, they may volatilize from soil, vegetation and water bodies into the atmosphere and―because of their resistance to breakdown reactions in air―travel long distances before being re-deposited. The cycle of volatilization and deposition may be repeated many times, with the result that POPs could accumulate in an area far removed from where they were used or emitted. In addition, the combination of resistance to metabolism and lipophilicity means that they are highly concentrated in living organisms through the food chain and their effects on long-lived organism at higher tropic levels are matters of concern.

    Among the important classes of POP chemicals are many families of chlorinated aromatics, including polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins and –furans (PCDDs/PCDFs) and different organochlorine pesticides (e.g. DDT and it’s metabolites, toxaphene, chlordane, etc.). Some are accidental by-products of combustion or the industrial synthesis of other chemicals (e.g. the PCDD/Fs) not produced deliberately. Many have been synthesized for industrial uses (e.g. PCB, chlorinated paraffines) or as agrochemicals (e.g. DDT, Lindane, chlordane). As a result of large production and usage volumes throughout the world in the past, pollution has spread and caused problems in wide areas and across country borders. At present, chemicals such as DDT, mirex and toxaphene are still being produced and used because of lack of cheap and effective alternatives developing countries.

    Data on POPs monitoring are not only basis for the design of effective measures for the reduction of POPs, but are used as a basis for evaluation of efficiency of the POPs treaty and related measures. In addition, the monitoring data can be used as basic information for selecting new POPs candidate substances that have properties similar to established POPs. Furthermore, insight into POPs and pollutants in general, as well as their effective prevention measures, will be facilitated by promoting and enforcing associations with other related domestic and foreign monitoring and investigation.

    The focus of the monitoring in 2002 UNU project is on 21 individual organochlorine pesticides (OCPs). The targeted compounds include a–BHC, b–BHC, g–BHC, d–BHC, p,p’–DDE, p,p’–DDD, p,p’–DDT, hexachlorobenzene, heptachlor, heptachlor epoxide, aldrin, trans-chlordane, cis-chlordane, dieldrin, endrin, endrin Aldehyde, endrin ketone, endosulfan 1, endosulfan 2, endosulfan sulfate and methoxychlor.

Sampling. There are seven key national valleys in China including Huaihe River, Liaohe River, Haihe River, Songhuajiang River, Yellow River, Pearl River and Yangtze River Valleys.

The Haihe River valley is located in North China, comprising the Haihe River and Luanhe River system. The Haihe River system mainly consists of Zhangwei River, Ziya River, Daqing River, Yongding River, Chao Hubai River, North Canal, Ji Canal, as well as some plain drain flooded river course such as Douhai River, Majia River. Luanhe River system consists of Luanhe River and other rivers in east Hebei province (Fig. 1).

The Haihe River valley is 3.19×10⁵km² large, covering most areas of Hebei Province, northeast Shanxi Province, Shandong province, north Henan province, some small parts of Inner Mongolia Autonomous Region as well as Beijing and Tianjin. Its average runoff is 2.92×10¹⁰m³/a and most of them are concentrated from July to October (about 70%). The average amount of water resource per person is 10.5% of the national average, and is a region that has the most acute conflict between supply and demand of water resource in the whole country.

Because of the increasing utilization of surface water in the region, the down flow of the river is sharply decreased, combined with the increasing pollutants discharged by cities and industries, the average ratio of wastewater discharge capacity to runoff of rivers has reached 0.12. Many parts of the water body are heavily polluted.

In 2002, water samples were collected in Ziya River, Yongding river, Chaobai River, Haihe River and Guanting Reservoir (Fig.2 and Table 1). River waters were sampled both in autumn of 2002 and winter in 2003.

Figure 1 Haihe River valleys

Table 1 Sampling sites in 2002 and 2003

Sampling site	Number labeled	Longitude	Latitude
Caihong Bridge	1	117º43’20.2”	39º06’17.7’’
Haimen Bridge	2	117º39’12.5’’	39º00’36.6’’
Erdaozha Sluice Gate	3	117º27’20.9’’	39º01’13.9’’
Jingang Bridge	4	117º11’01.9’’	39º08’54.7’’
Beian Bridge	5	117º11’18.4’’	39º08’02.1’’
Ziya River	6	117º08’46.7’’	39º09’52.6’’
Guanting Reservoir	7	115º37’20.5’’	40º16’23.4’’
Guanting Bridge	8	115º36’22.5’’	40º13’42.4’’
Youzhou	9	115º36’38.9’’	40º13’07.6’’
Mentougou Sluice	10	116º06’12.2’’	39º57’17.2’’
Mentougou	11	116º02’23.3’’	39º59’57.0’’
XifengVilla	12	115º58’42.0’’	39º59’00.7’’
Zhenzhu Lake	13	115º47’25.9’’	40º03’34.6’’
Yanchi	14	115º53’11.2’’	40º01’43.0’’
Miyun Rubber Dam	15	116º50’47.5’’	40º22’40.2’’
Qikong Bridge	16	116º49’56.5’’	40º28’17.3’’
Xinzhuang Bridge	17	117º08’18.3’’	40º34’46.2’’
Chaohe River Dam	18	116º58’48.3’’	40º26’55.9’’
Niumutun Village	19	116º56’48.3’’	39º46’48.4’’
Shamian Sands	20	116º47’18.1’’	39º48’50.7’’
Baimaozhuang	21	117º25’42.2’’	39º33’03.9’’
Chaobai River Left Embankment	22	117º28’44.0’’	39º27’50.6’’
Leshan Bridge	23	117º34’21.7’’	39º16’20.6’’
Yujialing Bridge	24	117º38’10.3’’	39º12’19.8’’

Figure 2 Sampling sites in 2002 in China

Sample preparation and analysis. Samples collected in 5L glass bottles were transported to laboratory within 12hr and stored at 4℃ in refrigerator. Extractions were carried out within 48hrs generally. Final solutions were stored at -35℃ in freezer. The samples were analyzed by gas chromatography with mass spectrometric detection (GC-MS). The analysis was performed with a Shimadzu QP-2010 GC-MS (Japan) equipped with a Shimadzu AOC-20A auto injector (Japan). 30m ´0.32mm i.d. DB-1 (film thickness 0.25m)(J&W Scientific, CA, USA) fused-silica capillary columns were used for the analysis of targeted organochlorine pesticides.

Organochlorinated pesticides. 2―4L of water sample added with 60―120g of NaCl was extracted twice with 100―200ml of hexane for 10min, respectively. The hexane layer was Transferred and dehydrated with 6―12g of sodium sulfate. The dehydrated hexane solution was concentrated to 5ml by rotary evaporator and further to 1ml by N₂ purge and transferred into a pre-conditioned silica gel cartridge for cleanup. The cartridge was eluted with 5ml of 5% acetone/n-hexane. This solution was further condensed to 1ml by N₂ purge. 2ml of final solution was injected into GCMS for measurement.

The GC-MS analysis was performed with an oven temperature program from 70 (hold for 2min) to 130°C at 20°C min^-1, then to 200°C at 5°C min^-1 and finally to 300°C at 20°C min^-1, injector and interface temperatures of 280°C, and helium as carrier gas. Data were acquired in the EI mode (70eV), scanning from 35 to 400 mass units at 0.5s. SIM was used for quantitative analysis. Sampling rate was 0.2sec. Monitoring ions were listed in Table 2. The injector was in the splittless mode, the split valve being closed for 2min. Total ion chromatogram of standard solution of 21 organochlorine pesticides is shown in Fig. 3

Table 2 Targeted organochlorine pesticides and their monitoring ions

No.	Compound	Formula	m/z
			Quantitative ion	Reference ions
1	a–BHC	C6H6Cl6	218.9	180.95, 216.9
2	b–BHC	C6H6Cl6	218.9	180.95, 216.9
3	g–BHC	C6H6Cl6	218.9	180.95, 216.9
4	d–BHC	C6H6Cl6	218.9	180.95, 216.9
5	p,p’ –DDE	C14H8Cl4	248.0	246.0, 318.0
6	p,p’ –DDD	C14H10Cl4	235.0	237.0, 165.0
7	p,p’ –DDT	C14H9Cl5	235.0	237.0, 165.0
8	Hexachlorobenzene	C6Cl6	283.9	285.9, 248.9
9	Heptachlor	C10H5Cl17	100.0	271.9, 336.9
10	Heptachlor epoxide	C10H5Cl17O	353	81.0
11	Aldrin	C12H8Cl16	262.9	264.9, 292.9
12	Trans-chlordane	C10H6Cl8	374.8	372.8, 407.8
13	Cis-chlordane	C10H6Cl8	374.8	372.8, 407.8
14	Dieldrin	C12H8Cl16O	262.9	278.9, 379.8, 242.9
15	Endrin	C12H8Cl16O	262.9	278.9, 242.9, 316.9
16	Endrin aldehyde	C12H8Cl16O	345.0	67.0
17	Endrin ketone	C12H8Cl16O	317.0	67.0
18	Endosulfan 1	C9H6Cl16O3S	195	159
19	Endosulfan 2	C9H6Cl16O3S	195	159
20	Endosulfan sulfate	C9H6Cl16O4S	272	229
21	Methoxychlor	C16H15Cl13O2	227	114

Results and Discussion

1. Reappearance test for 5ng/ml standard solution of some organochlorine pesticides. Good precision of determination and low detection limits for some pesticides were obtained for both 5ppb and 50ppb solutions (Table 3 and Table 4).

Table 3 Reappearance of pesticides (5ng/ml)

Compound	m/z	1	2	3	4	5	Average	Deviation	CV(%)	3S	10S
a-BHC	218.9	5.29	4.79	5.31	5.01	5.47	5.174	0.242	4.69	0.73	2.42
b-BHC	218.9	5.72	4.51	5.27	4.19	4.96	4.930	0.541	10.98	1.62	5.41
g-BHC	218.9	5.44	6.24	5.94	5.13	4.94	5.538	0.487	8.80	1.46	4.87
d-BHC	218.9	5.02	4.92	5.32	5.41	5.13	5.160	0.182	3.53	0.55	1.82
Anthracene-d10	188.0	I.S.	I.S.	I.S.	I.S.	I.S.
Aldrin	262.9	4.73	5.47	5.35	5.23	5.01	5.158	0.262	5.09	0.79	2.62
p,p'-DDE	248.0	5.42	4.81	5.09	5.11	4.79	5.044	0.231	4.58	0.69	2.31
Dieldrin	262.9	4.84	4.86	5.56	5.78	5.02	5.212	0.385	7.40	1.16	3.85
Endrin	262.9	5.52	6.38	6.39	6.56	6.43	6.256	0.374	5.97	1.12	3.74
p,p'-DDD	235.0	5.63	5.62	5.28	5.69	5.33	5.510	0.170	3.08	0.51	1.70
p,p'-DDT	235.0	5.25	5.17	5.16	4.97	4.83	5.076	0.154	3.03	0.46	1.54
Benzo(a)anthracene-d12	240.0	I.S.	I.S.	I.S.	I.S.	I.S.

Table 4 Reappearance of pesticides (50ng/ml)

Compound

m/z

1

2