Continuous Monitoring of Persistent Organic Pollutants in China for

Downloaded by UNIV OF CALIFORNIA SAN DIEGO on December 12, 2016 | http://pubs.acs.org Publication Date (Web): December 7, 2016 | doi: 10.1021/bk-2016-1244.ch004

Chapter 4

Continuous Monitoring of Persistent Organic Pollutants in China for the Effectiveness Evaluation of the Stockholm Convention: 2007–2014 Lirong Gao,1 Minghui Zheng,*,1 Yibing Lv,2 Qiang Fu,2 Li Tan,2 and Qingqing Zhu1 1Research

Center For Eco-Environmental Sciences, Chinese Academy of Sciences, No. 18 Shuangqing Road, Haidian District, Beijing 100085, China 2National Environmental Monitoring Center of China, No. 8 Anwai Dayangfang Road, Chaoyang District, Beijing 100012, China *E-mail: [email protected]

Article 16 of the Stockholm Convention requires the Conference of the Parties to periodically evaluate whether the Convention is an effective tool for achieving the objective of protecting human health and the environment from persistent organic pollutants (POPs). A global monitoring plan for POPs, which has been put in place under the Convention, is a key component of the effectiveness evaluation that provides a harmonized framework for identifying changes in POP concentrations over time and information on the regional and global transport of POPs in the environment. To meet the requirements of the effectiveness evaluation of the Stockholm Convention, we monitored concentrations of polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCBs), including dioxin-like (DL-PCBs) and indicator PCBs, in air in China from 2007 and 2011. We also monitored perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) in water in 2013. We collected air from 11 remote sites in China, 3 © 2016 American Chemical Society Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


urban sites, and 3 rural sites using high volume samplers with a size-selective inlet that only accepted particles with diameters less than 10 µm. The remote air sampling sites were referred to as background sites because the PCDD/F and DL-PCB concentrations were typical of background levels and ranged from 2.64 to 101.7 World Health Organization toxic equivalents (WHO-TEQ) fg/m3 (average 21.7 WHO-TEQ fg/m3). The concentrations of PCDD/F were highest in eastern China, where there is intensive economic activity. The PCDD/F and DL-PCB concentrations in the air samples from the 3 urban and 3 rural sites ranged from 98.1 to 212.2 WHO-TEQ fg/m3 and from 11.2 to 46.4 WHO-TEQ fg/m3, respectively. The average PCDD/Fs concentrations were much higher at urban sites than at the background and rural sites. The indicator PCB concentrations in the air samples from the 11 background sites, 3 urban sites, and 3 rural sites ranged from 5.2 to 44.9 pg/m3 (average 18.5 pg/m3), from 55.1 to 90.6 pg/m3 (average 71.6 pg/m3), and from 4.62 to 10.3 pg/m3 (average 7.32 pg/m3), respectively. The levels of PCDD/Fs and PCBs in the air samples from the background sites were lower than, or comparable to, those detected in the air at other sites worldwide. The concentrations of PFOA and PFOS were monitored in two lakes and two coastal marine areas. The average concentration of PFOS and PFOA in Taihu Lake was 32 ng/L. The concentrations of PFOA and PFOA at the other sites were below the detection limit. There were no consistent temporal trends in the POP concentrations in the air samples from the background sites.

Introduction Background and Objectives Persistent organic pollutants (POPs) are chemicals that remain intact in the environment for long periods of time. They are mobile and can be transported over long distances in the global environment. They bioaccumulate in fatty tissues of living organisms, and are harmful for humans and wildlife. The Stockholm Convention on POPs, hereafter referred to as the Stockholm Convention, is an international treaty that aims to protect human health and the environment from the potential toxic effects of POPs. Twenty-six POPs are listed in annexes to the Stockholm Convention. The initial list included polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs). As unintentionally produced compounds, PCDD/Fs form mainly through processes such as combustion, production of chlorinated compounds, metal smelting, paper and pulp production, and petroleum refining. Polychlorinated biphenyls are thermally and chemically stable, and have electrical insulating properties. These properties mean that they have been used extensively in industrial applications, such as in the dielectric fluids of transformers and 74 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


capacitors, and in heat-transfer and hydraulic fluids. As well as having industrial applications, PCBs also form unintentionally in industrial processes. Both PCDD/Fs and PCBs are highly toxic to humans and in ecosystems, and are able to persist in various environmental compartments. Atmospheric PCDD/F and PCB concentrations have been examined recently in urban areas in China to evaluate their impact on local residents. Few studies have established background concentrations of PCDD/Fs and PCBs in remote areas in China. Perfluorooctane sulfonyl fluoride substances (PFASs) were added to the Stockholm Convention in 2009. Perfluoroalkyl substances (PFASs) are persistent global pollutants that have been used in numerous industrial processes and consumer products for more than 60 years. PFASs can be used to provide stain-resistant coatings on surfaces; they are also used in firefighting foams, cosmetics, pesticides, and cleaners. Some PFASs, such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), have been detected in a wide range of environmental compartments, wildlife species, and human populations worldwide. Given their long half-lives and ability to cross the placental barrier, there is considerable concern about the effects of these substances on fetal growth and development. Article 16 of the Stockholm Convention requires the Conference of the Parties to periodically evaluate whether the Convention is an appropriate method for achieving the objective of protecting human health and the environment from POPs. A global monitoring plan (1) for POPs has been put in place under the Convention. This is a key component of the effectiveness evaluation, and provides a harmonized framework for identifying changes in POP concentrations over time, as well as information on regional and global transport of POPs in the environment. For the first effective evaluation, various initiatives were implemented to ensure broad application of the Convention worldwide, and to obtain at least core representative data from all regions. This evaluation was seen as an opportunity to establish a global-scale set of baseline data for POP concentrations in the environment. The first monitoring reports from five United Nations Regions were submitted at the fourth meeting of the Conference of the Parties in May 2009. Also at this meeting (SC4/32), the Conference agreed that a 6-year period was appropriate for effectiveness evaluations. The second monitoring reports were therefore submitted at the seventh meeting of the Conference of the Parties in May 2015. The aim of this study was to monitor PCDD/Fs and PCBs in air and PFOS and PFOA in water, in line with the requirements of the effectiveness evaluation of the Stockholm Convention in China. Monitoring of POPs in China for the effectiveness evaluation commenced in 2007, and was the first time that POPs had been monitored at locations all over China. Eleven remote sites, referred to as background sites, were selected to determine the background concentrations. Sites corresponded with national air monitoring sites, and were distributed through different geographical regions of China. The monitoring of POPs under the Stockholm Convention in China was supported and organized by the Foreign Economic Cooperation Office of the Ministry of Environmental Protection. The 11 POPs, PCDD/Fs, PCBs, aldrin, chlordane, dichlorodiphenyltrichloroethane, dieldrin, endrin, heptachlor, hexachlorobezene and mirex were determined in air samples collected from the 11 remote sites in China through 3 different time 75 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

periods, namely 2007–2008, 2008–2009, and 2010–2011. The sampling and analytical methods followed those specified in the global monitoring plan (1) for POPs. Concentrations of PFOS and PFOA were determined in water samples from two lakes and two coastal marine areas in 2013 by the China National Environmental Monitoring Center. Description of China


Country Profile China is in eastern Asia, to the west of the Pacific Ocean. It has a land area of about 9.6 million km2, and a sea area of about 4.73 million km2. China stretches 5,500 km from north to south, from the center of the Heilongjiang River (53°31′N) to the Zengmu Reef (3°52′N) at the southernmost tip of the Nansha Islands in the South China Sea. The distance from the easternmost point of China, at the confluence of the Heilongjiang and Wusuli Rivers in Heilongjiang Province (135°5′E), to the westernmost point on the Pamir Plateau (73°40′E) in the Xinjiang Uygur autonomous region, is 5,200 km. Latitudes, longitudes, and altitudes in China span large ranges, meaning that the climate is diverse with temperate, subtropical, and tropical climate zones. China has more than 22,000 km of land borders, which it shares with 14 other countries. To the east, China is bordered by various seas, including the Bohai Sea, East China Sea, Yellow Sea, and South China Sea, and its total territorial sea area is 4.7 million km2. There are about 7,600 islands in China’s territorial waters. The coastline of mainland China is 18,000 km long, to which the coastlines of the Chinese islands add a further 14,000 km, such that China’s total coastline extends to 32,000 km. China also has a large number of rivers and lakes, and, because of its topographical features, most of the rivers flow east or south into the ocean. The gross domestic product (GDP) of China was 1,098,283,000,000,000 US dollars in 2015. The GDP value of China represents 17.71% of the world economy. Economic development among the different regions of China is unbalanced. The coastal areas in eastern China are comparatively well-developed, and the GDPs of only 5 provinces (municipalities) in the southeastern coastal area (Guangdong, Jiangsu, Shandong, Zhejiang, and Shanghai) account for about 40% of the GDP of the whole country. By comparison, the economies in the middle and western areas lag behind those in eastern provinces, and there are considerable disparities between the technical levels, enterprise scales, and environmental awareness in the eastern and western areas.

Emission and Use Inventories of POPs in China As with all unintentionally produced POPs, any estimation of PCDD/Fs emissions in China is difficult and complex because of the vast range of industries involved. Using the guidelines in the Standardized Toolkit for Identification and Quantification of Dioxin and Furan Releases of the UNEP Chemicals Branch, the potential emission sources of PCDD/Fs in China in 2004 were estimated. 76 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


The total releases of PCDD/Fs from all types of sources in China was 10.2 kg toxic equivalents (TEQ), 5.0, 0.04, 0.17, and 5.0 kg TEQ of which were released to air, released to water, found in products, and found in residues, respectively. Out of all the industries, most PCDD/Fs were released from metal production, including iron, steel, and other metals, and accounted for 45.6% of the total. This was followed by power and heat generation, and waste incineration. These three sources accounted for 81% of the total PCDD/Fs released (2). In China, approximately 10,000 t of PCBs were produced from 1965 to 1974, 9000 t as trichlorobiphenyl and 1000 t as pentachlorobiphenyl. The production and use of PCBs were banned in China in 1974. An earlier investigation found that the most common PCB-containing electrical devices in use in China were capacitors, which are typically used by various large enterprises and industries in the nonpower sector. Because of the wide range of sectors involved, the large number of enterprises, management weaknesses, and the time period required, there are a number of difficulties associated with investigating PCB-containing capacitors in the non-power sector in China. Investigators concluded that there were about 554 PCB-containing capacitors in use in the non-power sector in Liaoning Province, China . For many decades, PFOS and PFOA and their corresponding derivatives were the most widely-used perfluoroalkyl and polyfluoroalkyl substances worldwide. Because of the diverse sources of PFOS, including industrial and consumer uses of PFOS-containing products, it is difficult to establish an emission inventory of PFOS in China; China, however, does have experience in establishing emission inventories for other POPs. Internationally, excellent progress has been made towards establishing emission inventories for global PFOS and PFOA, and existing studies have provided important results that can be applied to China. Two global emission estimations indicated that the production and emissions of PFOS were highest in Asian countries, and, in particular, in China (3, 4). Recently, identified industrial sources of PFOS, including PFOS manufacturing, textile treatment, metal plating, fire-fighting, and semiconductors, were used to compile a national PFOS emission inventory in China (5), which showed that, in general, the emission rates, emission densities, and emission intensities of PFOS were higher in eastern China than in other regions of China.

Materials and Methods Sampling Sampling Sites for Air Samples Monitoring of POPs in ambient air at 11 background sites (B1–B11) in China between 2008 and 2014 was led by the China National Environmental Monitoring Center. The 11 background sites were located in the provinces of Qinghai, Hubei, Liaoning, Heilongjiang, Fujian, Anhui, Hebei, Yunnan, and Shandong, the Tibet Autonomous Region, and the city of Chongqing. These background areas were selected to correspond with national air monitoring sites in different geographical regions of China. Three urban sites (U1–U3) were chosen in Nanjing, Wuhan, 77 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

and Chongqing, and three rural sites (R1–R3) were located in the county-level divisions of Rizhao, Luan, and Yangshuo. Details of the sampling sites are provided in Table 1.


Table 1. Locations of the ambient air sampling sites The codes of the sampling sites

Sampling sites

Longitude

Latitude

B1

Qingyuan

124° 56′ 16″ E

41° 51′ 08″ N

B2

Changdao

120° 41′ 44″ E

37° 59′ 23″ N

B3

Wuyishan

117° 43′ 48″ E

27° 35′ 12″ N

B4

Luan

116° 09′ 36″ E

31° 33′ 05″ N

B5

Lasa

90° 44′ 32″ E

29° 21′ 13″ N

B6

Lijiang

100° 14′ 60″ E

26° 52′ 54″ N

B7

Shennongjia

110° 16′ 16″ E

31° 27′ 26″ N

B8

Daxinganling

121° 14′ 59″ E

50° 52′ 51″ N

B9

Wulong

107° 44′ 47″ E

29° 30′ 39″ N

B10

Chengde

116° 29′ 40″ E

41° 07′ 11″ N

B11

Qinghaihu

100° 29′ 36″ E

36° 35′ 02″ N

R1

Rizhao

119° 18′ 52″ E

35° 41′ 37″ N

R2

Yangshuo

110° 30′ 36″ E

24° 47′ 33″ N

R3

Luan

116° 22′ 15″ E

31° 29′ 09″ N

U1

Chongqing

106° 33′ 43″ E

29° 38′ 44″ N

U2

Wuhan

114° 09′ 36″ E

29° 58′ 20″ N

U3

Nanjing

118° 44′ 44″ E

32° 02′ 35″ N

The criteria for selecting the 11 remote air sampling sites at which to establish background levels followed the guidelines in The Global Monitoring Plan for Persistent Organic Pollutants, as follows: 1.

2.

Regional representation–the location should not be influenced by local sources of POPs and other pollutants, and the air being sampled should be representative of a large region around the site; Minimal meso-scale meteorological circulation influences–the location should be free from strong systematic diurnal variations in local meteorological circulation caused by topography (e.g., upslope/downslope mountain winds, coastal land breezes, or lake breezes);

78 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

3.

4.


5.

Long-term stability–the parameters relating to many aspects of the environment and environmental management should be stable, and these aspects should include the infrastructure, institutional commitment, and land development in the surrounding area; Ancillary measurements–other atmospheric composition and meteorological measurements (wind speed, temperature, humidity, and boundary layer stability) should be taken at the sampling sites; Appropriate infrastructure and utilities–the site should have electrical power, buildings, platforms, towers, and roads, and should be accessible.

Sampling Sites for Water Samples In 2013, the Chinese National Environmental Monitoring Center monitored PFOS and PFOA concentrations in water from 16 sampling sites at 4 locations, as follows: 3 sites in Qinghaihu Lake, 3 sites in Taihu Lake, 5 sites in the Bohai Sea, and 5 sites in the Huanghai Sea. Details of these sampling sites are provided in Table 2.

Air Sampling Methodology Samples of ambient air to be analyzed for POP concentrations were collected at the 11 background sites from 2007 to 2008, from 2008 to 2009, and from 2010 to 2011. Air samples were also collected from the three rural sites and three urban sites in 2012. In line with the Guidance for the Global Monitoring Plan for Persistent Organic Pollutants published by the Secretariat of the Stockholm Convention on POPs in April 2007, and the updated version issued at COP-6 in 2013 (UNEP/POPS/COP.6/INF/31), the air samples were collected at each site by high volume air samplers (Echo Hi Vol, Tecora, Italy) with quartz fiber and PUF filters and size-selective inlets that only accepted particles with diameters of less than 10 µm (PM10). Two samples and a blank sample were collected at each sampling site. Each sample was collected over a period of more than 3 days. The maximum flow rate of the high volume air sampler was 250 mL/min, and each sample had a total volume of approximately 1000 m3.


80


Table 2. Information about the water sampling sites in China Sampling sites

C1–C5

C6–C10

W1

W2

Sampling areas

Huanghai Sea

Bohai Sea

Qinghaihu Lake

Taihu Lake

Sampling date

26–27 Apr 2013

17–18 Jun 2013

28 Jun 2013

29 Aug 2013

The codes of the sampling sites

Longitude

Latitude

LN0214

38° 32′ 27.60′′ N

121° 21′ 50.40′′ E

LN0212

38° 40′ 44.40′′ N

121° 54′ 21.60′′ E

LN0211

38° 53′ 56.40′′ N

122° 23′ 52.80′′ E

LN0206

39° 16′ 52.32′′ N

123° 08′ 24.00′′ E

LN0220

39° 07′ 59.88′′ N

122° 46′ 59.88′′ E

LN0201

40° 09′ 36.00′′ N

121° 04′ 55.20′′ E

LN0208

39° 12′ 39.60′′ N

121° 05′ 31.20′′ E

TJ13

38° 39′ 56.55′′ N

118° 04′ 29.82′′ E

TJ17

38° 36′ 53.86′′ N

118° 28′ 03.81′′ E

TJ14

38° 38′ 59.79′′ N

118° 53′ 53.24′′ E

QH-B

36° 53′ 32.59′′ N

100° 03′ 33.99′′ E

QH-D

36° 47′ 51.39′′ N

100° 16′ 22.36′′ E

QH-E

36° 44′ 32.16′′ N

100° 24′ 15.99′′ E

XSX

31° 08′ 04.92′′ N

120° 11′ 22.92′′ E

PTS

31° 13′ 32.88′′ N

120° 06′ 11.88′′ E

JSN

31° 17′ 02.51′′ N

120° 06′ 39.26′′ E

Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

POP Analysis Methods


Analysis of PCDD/Fs The entire analytical process was carried out as outlined in method 1613B of the United States Environmental Protection Agency (US EPA). The quartz fiber filter and the PUF filter were combined during sample preparation and spiked with 13C-labeled compound solution (Wellington Laboratories, Guelph, Canada). The combined sample was then extracted with dichloromethane and hexane (1:1, v/v) using accelerated solvent extraction (ASE 300, Dionex, U.S.A.). After concentration, an automated sample preparation system (Power-Prep™, Fluid Management System, U.S.A.) was used for sample cleanup. This cleanup process comprised, in the following order, a multilayer acid/base/neutral silica column, a basic alumina column, and a carbon column. The final eluate was concentrated under a gentle stream of purified nitrogen, and the residue was dissolved in nonane (10 μL) in a mini vial. To evaluate the recovery, the sample extract was spiked with a 13C-labeled internal standard (Wellington Laboratories) immediately before instrumental analysis. PCDD/Fs were determined by a gas chromatograph (Agilent 6890, Agilent Technologies, U.S.A.) coupled with a high-resolution mass spectrometer (Waters Autospec Ultima, Waters Corp., U.S.A.) by tracing the M+, (M+2)+, or the most intense ions of the isotope cluster. PCDD/F congeners were determined on a DB 5 MS column (60 m × 0.25 mm i.d., 0.25 µm film thickness, Agilent Technologies). Helium, at a flow rate of 1.2 mL/min, was the carrier gas. The injection volume was 1 µl in splitless mode with a splitless period of 60 s. The MS was operated at a resolution of >10 000 in electron ionization mode (35 eV) with selected ion monitoring. Calibration standard solutions were analyzed with each batch of samples to check the instrument stability and variance in the relative response factor. For quality control, the retention times of the analytes in a sample had to be within 2 s of the retention times of the internal standards. Isotope ratios of the two monitored ions for each compound had to be within 15% of the theoretical chlorine values. The limit of detection for PCDD/Fs in a given sample was defined as a signal-to-noise ratio greater than three times the average baseline variation.

Analysis of DL-PCBs Analysis of the samples for DL-PCBs followed US EPA method 1668A. Stable isotope labeled analogs of the DL-PCB congeners were quantitatively spiked into the PUF and quartz fiber filter samples, and then the samples were Soxhlet-extracted using toluene or extracted using ASE with hexane and dichloromethane. The extracts were cleaned up by column chromatography using acidic silica gel, multi-layer silica gel, activated alumina, and dual-layer carbon columns. The extracts were then evaporated to near dryness, and stable isotope labeled PCB congeners were added as recovery standards before HRGC-HRMS analysis. 81 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


Analysis of Marker PCBs The samples were analyzed for marker PCBs by HRGC-HRMS. Stable isotope labeled analogs of the marker PCB congeners were quantitatively spiked into the PUF and quartz fiber filter samples, and then the samples were extracted using ASE with hexane and dichloromethane. The extracts were cleaned up by column chromatography using acidic silica gel, multi-layer silica gel, and activated alumina columns. The extracts were then evaporated to near dryness, and stable isotope labeled PCB congeners were added as recovery standards before HRGC-HRMS analysis. Stable isotope labeled analogs of the marker PCB congeners (PCBs 28, 52, 101, 118, 153, and 180) were quantitatively spiked into the PUF and quartz fiber filter samples, and then the samples were Soxhlet-extracted using toluene. The extracts were cleaned up using an acid–base partitioning method and column chromatography comprising acidic silica gel, multi-layer silica gel, and activated alumina columns. The extracts were then evaporated to near dryness, and stable isotope labeled PCBs 70, 111, 138, and 170 were added as recovery standards before GC-MS analysis.

Analysis of PFOS and PFOA The water samples were analyzed for PFOS and PFOA concentrations following US EPA method 537. Each water sample was filtered through a 0.22-µm filter, and then extracted and cleaned up using an Oasis WAX solid phase extraction cartridge. Before use, each column was activated using ammonia in methanol followed by methanol. After adding a sample to a cartridge, it was eluted with an acetic acid buffer solution, methanol, and ammonia in methanol. The extracts were concentrated and PFOS and PFOA were determined by liquid chromatography-electrospray ionization-tandem mass spectrometry. Quality Assurance and Quality Control Quality Assurance and Quality Control for the PCDD/F and PCB Analyses All of the laboratories that analyzed the samples for PCDD/Fs and PCBs were ISO/IEC 17025 accredited. To ensure that high quality data were collected in this study, procedures were carefully followed during collection of field and lab blanks, duplicates from collocated samplers, and breakthrough samples. Field and laboratory blanks were collected with each set of samples and processed following the same methods. The method detection limits were determined using the background concentrations in these blanks rather than the instrumental detection limit. None of the less-chlorinated congeners were detected in the blanks. Octachlorodibenzodioxin (OCDD) was the most prevalent congener in the blanks, followed by 1,2,3,4,7,8-hexachlorodibenzodioxin. Together, these two congeners made up 90% of the total PCDDs and PCDFs detected in the blanks. However, their concentrations in the blanks corresponded to less than 8% 82 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


of the concentrations found in the air samples. The concentrations in duplicate samples obtained at the collocated sites agreed well with each other. Among the 17 congeners, 2,3,7,8-tetrachlorodibenzodioxin was the most difficult to measure because its concentrations were extremely low. Recoveries of each chemical during the clean-up procedure were calculated and determined separately from surrogates. The average recoveries of the 13C12-PCDD/Fs ranged from 56% to 122%. DL-PCB congeners were not detected in the blank samples. The most prevalent congener in the blanks was CB28, followed by CB52. Together, these two congeners made up 96% of the total indicator PCBs detected in the blanks. However, their concentrations in the blanks corresponded to less than 5% of the concentrations detected in the air samples. The average recoveries of the 13C12-DL-PCBs and indicator PCBs ranged from 40% to 118%. The laboratories participated in several global POPs interlaboratory assessments, and the analytical results agreed well with the median values from all of the participating laboratories worldwide.

Quality Assurance and Quality Control for PFOA and PFOS Analyses Quality Assurance and Quality Control for the PFOS and analyses followed US EPA method 537. The recoveries of PFOS ranged from 70% to 130%, and the analytical replicates were within 25%.

Results Levels of PCDD/Fs and PCBs in Ambient Air The PCDD/F concentrations detected in the background air samples between 2007 and 2011 are shown in Table 3, and the PCDD/F concentrations detected in the urban and rural air samples in 2012 are shown in Table 4. The World Health Organization (WHO)-TEQ is the TEQ calculated using WHO toxic equivalency factors (TEF). The PCDD/F and DL-PCB concentrations in the background air samples ranged from 2.64 to 101.7 WHO-TEQ fg/m3 (with an average of 21.7 WHO-TEQ fg/m3). The PCDD/F concentrations in the background air samples ranged from 0.84 to 98.05 WHO-TEQ fg/m3 (with an average of 20.03 WHOTEQ fg/m3). The concentrations were highest at site B3, in Southeast China. The concentrations were lowest at site B10, in North China. The concentrations of PCDD/Fs were higher in eastern China than in western China, and may reflect the more intensive economic development in eastern regions relative to that in western regions. The PCDD/F concentrations in the air samples from the three urban and three rural sites were between 91.3 and 202 WHO-TEQ fg/m3 (average of 164 WHO-TEQ fg/m3) and between 9.45 and 42.7 WHO-TEQ fg/m3 (average of 22.2 WHO-TEQ fg/m3). The average concentrations of PCDD/Fs were much higher at the urban sites than at the background and rural sites. Comparison showed that the concentrations of PCDD/Fs were lower than the annual average concentrations of PCDD/Fs in ambient air in Porto, Portugal (range 29.4–298.3 fg/m3) (6). Chen et al. reported PCDD/F concentrations of between 2.6 and 120 pg/m3 (0.04–1.93 83 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.


pg I-TEQ /m3) at various sampling sites in China (7), which were higher than the levels of PCDD/Fs detected in this study. In addition, the concentrations at the background, rural, and urban sites were all below the ambient air standard of 600 fg TEQ/ m3 proposed by the government of Japan (8). The DL-PCB and marker PCB concentrations in the background air samples between 2007 and 2011 are shown in Table 5, while the DL-PCB and marker PCB concentrations found in the air samples from the three urban and three rural sites in mainland China in 2012 are shown in Table 6. The DL-PCB concentrations in the background, urban, and rural air samples ranged from 0.10 to18.6 WHOTEQ fg/m3, from 6.84 to 14.2 WHO-TEQ fg/m3 (average 10.2 WHO-TEQ fg/ m3), and from 0.93 to 3.73 WHO-TEQ fg/m3 (average 2.14 WHO-TEQ fg/m3), respectively. DL-PCB levels in South Korea were similar, and ranged from not detected to 16 WHO-TEQ fg /m3 (average of 8 WHO-TEQ fg/m3) (9). The marker PCB concentrations in the air samples from the 11 background sites, 3 urban sites, and 3 rural sites were between 4.70 and 44.9 pg/m3 (average 18.5 pg/m3), 55.1 and 90.6 pg/m3 (average 71.6 pg/m3), and 4.62 and 10.3 pg/m3 (average 7.32 pg/m3), respectively. The annual average of the sum of the seven marker PCBs in the atmosphere in Nordic regions in 2011 was 12.5 pg/m3 (10), which was similar to the levels of indicator PCBs at the background sites in the present study.

Congener Profiles of PCDD/Fs and PCBs The major contributors to atmospheric 2,3,7,8-PCDD/Fs measured at the background sites during the sampling periods of this study were 1,2,3,4,6,7,8-heptachlorodibenzofuran, octachlorodibenzofuran, and OCDD (Figure 1), and accounted for between 54% and 92% of the Σ2,3,7,8-PCDD/Fs. As with other studies (11, 12), OCDD was the major contributor to the total annual average PCDD/Fs congener concentration, with a concentration and a percentage contribution to the total of 223 fg/m3 and 27%, respectively. In the ambient air samples, PCDD/Fs tended to have a higher degree of chlorination. Most of the 2,3,7,8-PCDD/Fs congeners were detected, except for 2,3,7,8-trichlorodibenzodioxin and 2,3,7,8-tetrachlorodibenzodioxin. PCDFs accounted for between 11% and 47% of total PCDD/Fs. These results are consistent with those reported in samples collected for national dioxin inventories in ambient air in both the United Kingdom (13), and in Catalonia, Spain (14). The dominant DL-PCB congeners were CB118, CB105, and CB77, as shown in Figure 2. The congener profiles of indicator PCBs were dominated by CB28 and CB52, which are tri- and tetra-PCBs, respectively. The percentage contributions of the two less-chlorinated congeners (CB28 and CB52) to the Σ7PCBs concentrations were between 54% and 98% (Figure 3). Generally, less-chlorinated PCBs have lower vapor pressure than highly chlorinated PCBs, and the lighter congeners are expected to be more readily transferred to air. The DL-PCB concentrations were much lower than those of indicator PCBs, but they were still detected because of the relatively low method detection limit. The most abundant congeners were CB118 (mono-ortho), CB77 (non-ortho), and CB105. Because of its high TEF, CB126 accounted for more than 85% of the total TEQ 84 Loganathan et al.; Persistent Organic Chemicals in the Environment: Status and Trends in the Pacific Basin Countries II ... ACS Symposium Series; American Chemical Society: Washington, DC, 2016.

for all samples. These results agree with those reported by Die et al. (15) for samples collected from industrial sites in Shanghai, China.


Levels of PFOS and PFOA in Water The PFOS and PFOA concentrations were measured in water samples collected from the Bohai Sea and Huanghai Sea (Table 7) and Qinghai Lake and Taihu Lake (Table 8). The average PFOS concentration in the water samples from Taihu Lake was 32 ng/L, while the levels in all the water samples from the Bohai Sea, Huanghai Sea, and Qinghai Lake were below the detection limit. Comparison showed that our results were lower than, or comparable with, the ranges for the concentrations of PFOA (4–93 ng/L) and PFOS (3–29 ng/L) in surface water from Tamil Nadu, India (16). PFOA and PFOS levels in this study were below the permissible limits set by the US EPA (17).


86


Table 3. Concentrations (fg/m3) of 2,3,7,8-PCDD/F in air samples collected at background (B) sites in China B1

B1

B1

B2

B2

B2

B3

B3

B4

B4

B4

20072008

20082009

20102011

20072008

20082009

20102011

20072008

20102011

20072008

20082009

20102011

2378-TCDF

23.6

4.6

4.41

32.1

18.9

18.4

36.50

12.6

3.7

21.8

9.5

12378-PeCDF

19.7

5.2

3.72

18.45

21.5

13.3

49.25

22.3

2.85

33.3

14

23478-PeCDF

35.3

7.1

5.63

24.45

29.6

17.1

82.00

23.1

3.35

44.8

29

123478-HxCDF

66.65

7.7

5.77

66.3

32.9

14.3

125.95

64.7

5.8

81.4

47.3

123678-HxCDF

46.5

7.5

4.44

46.2

32.5

13.3

91.60

33.1

5.65

79.1

64.8

234678-HxCDF

47.75

8.4

5.77

56.55

37.4

10.2

115.30

33.7

5.7

69.2

50

123789-HxCDF

14.3

1.7

3.1

14.25

9.2

2.86

39.70

18

1.25

14.8

14

1234678-HpCDF

289.45

27.1

70

222.2

124

31.4

449.25

203

28.4

400

392

1234789-HpCDF

37.05

3.7

3.86

11.6

16.7

2.54

68.30

39.6

3.35

50.4

57.3

OCDF

531.9

22.5

87.4

358.4

106

26.4

744.55

420

145.7

458

431

2378-TCDD

2.6

0.4

0.69

3.8

0.7

0.32

3.60

0.98

0.75

0.8

0.54

12378-PeCDD

7.95

1.2

2.58

3.85

4.3

2.44

2.80

5.73

0.9

5.2

3.76

123478-HxCDD

4.75

0.8

2.15

5.15

3.2

0.63

7.85

5.07

0.7

3.9

4.84

6

2.22

14.60

9.99

0.9

6.5

6.81

123678-HxCDD

5.3

1.7

1.76

5

123789-HxCDD

7.7

1.1

2.15

4.9

4.7

0.63

15.10

6.55

1.1

6.1

18.6

1234678-HpCDD

95.55

8.6

14.1

54.2

36.7

17.8

145.05

129

19.6

43.6

67.7


87


B1

B1

B1

B2

B2

B2

B3

B3

B4

B4

B4

20072008

20082009

20102011

20072008

20082009

20102011

20072008

20102011

20072008

20082009

20102011

OCDD

445.65

24.5

103

272.95

80.1

82.5

589.70

466

334.7

91.6

219

WHO-TEQ

49.6

9.1

7.23

45.45

37.2

14.9

98.05

37.4

5.6

63.3

40.1

B5

B5

B5

B6

B6

B6

B7

B7

B8

B8

B8

20072008

20082009

20102011

20072008

20082009

20102011

20072008

20102011

20072008

20082009

20102011

2378-TCDF

3.7

2.7

0.17

5.75

11.5

9.1

66.8

2.22

25.6

8.8

9.86

12378-PeCDF

1.5

2

0.75

2.45

11.2

9.17

81.9

0.66

5.25

3.2

2.57

23478-PeCDF

6.3

5

0.2

4

13.8

13.7

96.9

0.87

10.8

6

4.91

123478-HxCDF

3.7

11.8

1.7

4.3

11.7

11.7

267.3

3.52

22.35

3.7

1.76

123678-HxCDF

4.1

14

0.78

5.05

11.5

11.8

261.65

1.95

14

3.9

3.51

234678-HxCDF

5.2

13.1

1.12

5.2

10

11.3

285.3

2.44

16.4

4.1

3.87

123789-HxCDF

4.3

2.9

0.66

3.25

2.8

3.4

61.6

0.68

2.25

0.7

0.41

1234678-HpCDF

111.2

106

6.95

58.45

21.7

32.3

2098.7

15.6

56.15

10.2

11.7

1234789-HpCDF

5.2

11.7

1.06

2.05

3.2

4.98

255.05

1.53

6.05

1

1.67

OCDF

186

121

29

140.7

9.5

24

2867.85

38.1

77.4

13.2

32.1

2378-TCDD

4.4

ND

ND

2.65

1

0.69

4.8

0.83

2.35

ND

1.02

12378-PeCDD

4.8

1.1

0.37

2.75

2

1.93

8.2

1.3

1.9

ND

1.15

Continued on next page.


B5

B5

B5

B6

B6

B6

B7

B7

B8

B8

B8

20072008

20082009

20102011

20072008

20082009

20102011

20072008

20102011

20072008

20082009

20102011

123478-HxCDD

3.8

1.1

0.37

2.45

2.2

1.77

5.55

0.84

1.3

0.5

0.72

123678-HxCDD

3.7

1.7

1.47

2.1

3.7

2.45

35.85

0.68

2.15

1.2

0.8

123789-HxCDD

2.6

1.9

1.84

2.45

2.8

3.04

29.8

0.44

1.45

0.4

1.02

1234678-HpCDD

35

9.5

10.6

26.8

27.6

22.9

208.95

12.6

18.4

9.1

12.4

439.2

35.8

67.4

285.05

178

59.9

735.2

83.2

168.25

174

66.6

10.2

10.3

2.35

8.35

16.6

12.7

186.25

3.01

16.25

5.7

5.7

OCDD WHO-TEQ

88


Table 3. (Continued). Concentrations (fg/m3) of 2,3,7,8-PCDD/F in air samples collected at background (B) sites in China

B9

B9

B9

B10

B10

B10

B11

B11

B11

2007-2008

2008-2009

2010-2011

2007-2008

2008-2009

2010-2011

2007-2008

2008-2009

2010-2011

2378-TCDF

6.95

6.7

3.35

17.55

5.8

0.1

2.50

3.8

7.85

12378-PeCDF

5.4

9.3

1.39

13.75

6.6

0.2

2.50

2.1

11.8

23478-PeCDF

5.7

10.3

4.74

19.3

4.4

0.1

1.00

4.2

7.85

123478-HxCDF

14

19.8

6.13

22.15

13.9

0.8

3.40

4.9

9.97

123678-HxCDF

10.05

25.2

5.58

21.4

14.2

0.5

6.00

4

9.36

234678-HxCDF

12.95

18.2

5.58

16.05

15.8

0.9

6.30

4.1

11.2

123789-HxCDF

4.15

2.1

1.12

9.6

4.2

0.4

0.50

0.8

0.30

1234678-HpCDF

159.95

110

37.1

76.05

60

6

54.60

18.9

36.50



89

B9

B9

B9

B10

B10

B10

B11

B11

B11

2007-2008

2008-2009

2010-2011

2007-2008

2008-2009

2010-2011

2007-2008

2008-2009

2010-2011

1234789-HpCDF

12.85

11.9

4.74

11.2

8.6

0.8

6.15

1.6

3.93

OCDF

249.75

69.4

62.2

114.55

68.7

14.3

136.00

44.5

71.60

2378-TCDD

3.55

ND

0.24

10.95

0.5

0.06

1.55

ND

0.60

12378-PeCDD

2.8

0.4

0.84

9.85

0.4

0.04

5.20

ND

4.83

123478-HxCDD

3

1.2

0.28

3.95

0.7

0.2

1.70

1.3

1.51

123678-HxCDD

1.2

1.6

1.67

1.65

1.5

0.6

1.35

2.8

3.62

123789-HxCDD

2.15

1.6

1.39

4.2

1.2

0.2

1.15

1.4

4.23

1234678-HpCDD

23.05

19.9

26.2

23.3

18.4

5.8

19.10

25.4

22.60

OCDD

232.35

120

55.8

330.6

194

17.7

197.10

555.00

65.2

WHO-TEQ

12.3

15.6

7.17

28.6

10

0.84

6.80

6.80

13.9

Toxic equivalent (TEQ) values were calculated using World Health Organization- toxic equivalency factors (TEF2005) was used to calculate the TEQ when the concentration was below the limit of detection (LOD).

ND = not detected


A value of 0

90


Table 4. PCDD/F concentrations (fg/m3) in urban (U) and rural (R) air samples collected in China Urban

Rural

sampling sites

U3

U2

U1

U2

R1

R3

sampling date

Oct 2012

Nov 2012

Nov 2012

Jun 2012

Nov 2012

Dec 2012

2378-TCDF

66.6

107

108

10.4

20.3

4.40

0.04

12378-PeCDF

35.4

113

111

9.80

ND

ND

0.2

23478-PeCDF

99.2

169

182

8.75

46.8

10.2

0.2

123478-HxCDF

116

168

187

9.80

56.6

16.6

0.1

123678-HxCDF

88.3

146

164

9.90

43.8

13.7

0.1

234678-HxCDF

106

176

205

6.60

48.2

21.2

0.1

123789-HxCDF

29.8

44.2

47.0

ND

12.0

4.60

0.1

1234678-HpCDF

387

553

639

33.3

190

94.4

0.1

1234789-HpCDF

51.4

74.8

78.4

3.75

22.4

12.0

0.1

OCDF

409

364

380

26.2

221

124

0.1

2378-TCDD

ND

12.2

9.50

ND

ND

ND

0.1

12378-PeCDD

ND

15.8

32.8

ND

ND

ND

0.1

123478-HxCDD

8.20

20.2

27.7

ND

5.30

ND

0.2

123678-HxCDD

21.1

40.4

65.0

2.20

8.70

3.80

0.2

123789-HxCDD

14.2

30.4

54.6

2.10

6.80

3.20

0.2

1234678-HpCDD

160

222

482

32.1

70.4

44.4

0.1


LOD

Rural

sampling sites

U3

U2

U1

U2

R1

R3

sampling date

Oct 2012

Nov 2012

Nov 2012

Jun 2012

Nov 2012

Dec 2012

194

198

134

0.1

9.45

42.7

14.5

--

OCDD

376

411

1.18×103

WHO-TEQ

91.3

202

198

Toxic equivalent (TEQ) values were calculated using World Health Organization-toxic equivalency factors (TEF2005) was used to calculate the TEQ when the concentration was below the limit of detection (LOD).

ND = not detected

91


Urban


LOD

A value of 0

92


Table 5. Concentrations of DL-PCBs (fg/m3) and marker PCBs (pg/m3) in air samples collected at background (B) sites in China B1

B1

B1

B2

B2

B2

B3

B3

B4

B4

B4

20072008

20082009

20102011

20072008

20082009

20102011

20072008

20102011

20072008

20082009

20102011

CB77

4.9

25.3

8.98

94.4

272

737

222

30.1

289

96.9

41

CB81

3.4

5.6

4.24

19.2

11.7

15.4

21.7

12

22.6

14.7

13.3

CB105

65.2

38.1

15.1

288

98.6

44.5

128

38.9

66.7

76.3

34.2

CB114

10.3

9.7

5.57

144

23.7

17.6

22.7

12.5

33.6

24.9

13.3

CB118

211

122

64

606

278

101

434

119

416

228

91.2

CB123

Continuous Monitoring of Persistent Organic Pollutants in China for

Recommend Documents