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Emission factors of carbonaceous particles, including black carbon (BC) and organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) were determined for five coals, which ranged in maturity from sub-bituminous to anthracite. They were burned in the form of honeycomb briquettes in a residential coalstove, one of the most common fuel/stove combinations in China. Smoke samples were taken through dilution sampling equipment, with a high volume sampler that could simultaneously collect emissions in both particulate and gaseous phases, and a cascade impactor that could segregate particles into six fractions. Particulate BC and OC were analyzed by a thermal-optical method, and PAHs in emissions of both phases were analyzed by GC-MS. Burning of bituminous coals produced the highest emission factors of particulate matter (12.91 g/kg), BC (0.28 g/kg), OC (7.82 g/kg), and 20 PAHs (210.6 mg/kg) on the basis of burned dry ash-free (daf) coal, while the anthracite honeycomb-briquette was the cleanest household coal fuel. The size-segregated results show that more than 94% of the particles were submicron, and calculated mass median aerodynamic diameters (MMAD) of all particles were under 0.3 microm. Based on the coal consumption in the residential sector of China, 290.24 Gg (gigagrams) of particulate matter, 5.36 Gg of BC, 170.33 Gg of OC, and 4.72 Gg of 20 PAHs mass were emitted annually from household honeycomb-briquette burning during 2000. Anthracite coal should be selected preferentially and more advanced burning conditions should be applied in domestic combustion, from the viewpoint of both climate change and adverse health effects.

The occurrence of alkylphenols (APs) was investigated in surface water and sediments from the Pearl River Delta and adjacent northern South China Sea. Most of the water samples contained detectable amounts of APs, ranging up to 0.628 microg l(-1) for nonylphenol (NP) and 0.068 microg l(-1) for octylphenol (OP). APs were found in all of the sediment samples with concentrations ranging from 59 to 7808 microg kg(-1) for NP and from 1 to 93 microg kg(-1) for OP. The Zhujiang River showed the highest concentrations of APs in both water and sediments. Significant decrease of APs concentrations going from the Zhujiang River to the Shiziyang River was observed. The Xijiang River contained concentrations of APs slightly higher in water but relatively lower in sediments than the Lingding Bay, which might be attributed to their different hydrodynamic and sedimentary characteristics. There was a decreasing trend of APs in water from the rivers to the estuary and further to the sea on the whole. In the Lingding Bay and its outer waters, concentrations of APs in sediments increased to a maximum and then decrease seaward, which was consistent with the distribution trend of the sediment organic carbon contents. Linear regression analyses showed the concentrations of APs were markedly correlated with the sediment organic carbon contents, indicating that the sediment organic carbon is an important factor controlling the levels of APs in sediments.

Despite the recent efforts to investigate the distribution and fate of persistent organic pollutants in the tropical and subtropical regions of Asia, very little was known about the temporal change of polychlorinated biphenyls (PCBs) in the environmental ecosystem of China. In this study, three dated sediment cores collected from the Pearl River Delta of southern China were analyzed for a large suite of PCB congeners, from which the temporal profiles of PCB abundances, fluxes, and homologue patterns were constructed. The sedimentary inventories of total PCBs at the sampling sites ranged from 480 to 1310 ng/cm2, at the low end of the worldwide figures. Although production and use of PCBs have been banned or highly restricted in China since the early 1980s, the fluxes of total PCBs continued to increase in the Pearl River Delta sediments. There was a concurrent increase of PCB fluxes and gross domestic product per capita in the region from 1980 to 1997, and a decline of agricultural land use was evident at the same time. Apparently, large-scale land transform since the early 1980s as well as emissions from the PCB-containing electrical equipments were responsible for the sharp rise of PCB fluxes in the recent sediments. The difference in the PCB homologue patterns from 1940 to the mid-1970s was probably indicative of the different timelines of PCB usage in Macao/Hong Kong and mainland China and the differenttypes of technical PCBs commercially used. PCBs were detectable in sediments deposited well before the time frame when production of PCBs began (before 1930) and were relatively enriched in the less chlorinated homologue groups (3Cl and 4Cl PCBs), suggesting the downward mobility of lightly chlorinated PCB congeners in the sediment column.

The summer contamination of dissolved nonylphenols (NPs) and octylphenol (OP) in surface water of Zhujiang estuary and other rivers of Zhujiang Delta was analyzed. The result reveals that NPs concentration in The Pearl River remains20-40 ng/L, apart from the NPs concentrations of the mouth of The Pingzhou Channel the mouth of The Shawan Channel and Hutiaomen reaching a higher level of 98.84, 129.82 and 164.98 ng/L respectively. The Lingding Sea and open sea surface water keep at a lower level with the NPs concentration of10-14 ng/L. In terms of OP concentration in The Pearl River, any other sampling location is below LOD 2 ng/L, except for Baiertan, the mouth of The Shawan Channel and Hutiaomen being 2.89, 2.44, 2.12 ng/L respectively and inside Macao harbor being the highest level of 8.54 ng/L. The OP concentrations of The Lingding Sea and open sea surface water are lower than LOD 1 ng/L.

The spatial distribution, composition, and sources of polycyclic aromatic hydrocarbons (PAHs) in sediments and suspended particulate matter (SPM) from the Pearl River Estuary and adjacent coastal areas were examined. Total PAH concentrations varied from 189 to 637 ng/g in sediments and 422 to 1,850 ng/g in SPM. PAHs were dominated by 5,6-ring compounds in sediments and by 2,3-ring compounds in SPM samples. Assessment of PAH sources suggested that biomass and coal combustion is the major PAH source to the outer part of the estuary sediments and that petroleum combustion is the major PAH source to the inner part of estuary sediments. As for SPM samples, PAH isomer pair ratios indicated multiple (petroleum, petroleum combustion, and biomass and coal combustion) PAH sources, and significant temporal variations could exist for the sources of water column PAHs in the study area. The distribution of perylene in SPM samples indicated that the river was the dominant source of perylene in SPM and that perylene could be taken as an index to assess the contribution of river inflow to the total PAHs in SPM samples. The high concentration of perylene in the sediment was indicative of an in situ biogenic origin.

Six water samples were collected, and twenty-one compounds of organochlorine pesticides (OCPs) in surface water from the Pearl River Artery estuary were analyzed quantitatively, based on USEPA 8000 series methods and under quality assurance and quality control (QA/QC). The total (particulate plus dissolved phase) concentration of OCPs in surface water from the Pearl River Artery estuary in both high flow season and low flow season were 9.7 ng/L-26.3 ng/L and 41.7 ng/L-122.5 ng/L respectively. The concentration of total HCHs and total other OCPs was much higher than that of DDTs. The seasonality of the concentration of OCPs was significantly, and the level of OCPs in low flow season was higher than that of OCPs in high flow season. The spatial and temporal distribution of OCPs suggested that there were significant differences of OCPs between the East River (Dongjiang) network and Guangzhou channel and the nonpoint-source pollution of OCPs was found in the Pearl River Artery estuary, particularly in high flow season.

The coastal region off Macao is a known depositional zone for persistent organic pollutants (POPs) in the Pearl River Delta and Estuary of southern China and an important gateway for the regional contributions of contamination to the globe. This paper presents a comprehensive assessment of the input sources and transport pathways of polycyclic aromatic hydrocarbons (PAHs) found in the coastal sediments of Macao, based on measurements of 48 2-7 ring PAHs and 7 sulfur/oxygenated (S/O) PAH derivatives in 45 sediment, 13 street dust, and 68 aerosol samples. Total sediment PAHs concentrations ranged from 294 to 12741 ng/g, categorized as moderate contamination compared to other regions of Asia and the world. In addition, the PAH compounds appeared to be bound more strongly to aromatics-rich soot particles than to natural organic matter, implying a prevailing atmospheric transport route for PAHs to Macao's coast. Compositional analysis and principal component analysis (PCA) suggested that different classes of PAHs in the coastal sediments of Macao may have been derived from different input sources via various transport pathways. For example, alkylated and S/O PAHs were likely derived from fossil fuel leakage and transported to sediments by both aerosols particles and street runoff. High-molecular-weight parent PAHs were predominantly originated from automobile exhausts and distributed by direct and indirect atmospheric deposition. Low-molecular-weight parent PAHs, on the other hand, may have stemmed from lower temperature combustion and fossil fuel (such as diesel) spillage from ships and boats and were transported to sediments by river runoff or direct discharge as well as by air-water exchange.

Atmospheric concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs), and polybrominated diphenyl ethers (PBDEs) were measured in Taizhou, a large electronic equipment waste (e-waste) recycling area in East China. The mean concentrations (in summer and winter) of PCDD/Fs (0.45 and 0.39 pg WHO-TEQ m⁻³, where WHO-TEQ is the toxic equivalent set by the World Health Organisation), PBDD/Fs (0.22 and 0.18 pg WHO-TEQ m⁻³), and PBDEs (270 and 225 pg m⁻³) in this region have declined compared with those in 2005, due to regulations on primitive e-waste recycling activities. However, these concentrations remain higher than the historically highest levels in Europe and North America. The congener profiles of 2,3,7,8-substituted PCDD/Fs were similar, with OCDD, 1,2,3,4,6,7,8-HpCDF, OCDF, and 1,2,3,4,6,7,8-HpCDD being the most abundant congeners at all sites. The PCDD/F homologue profiles in the present study were different from those typically observed at non-e-waste locations, indicating a distinct source in this region. Seasonal differences were found in the lower brominated PBDE profiles. These differences indicate that the PBDE emission sources in summer (e.g., strong evaporation sources) differed from those in winter. However, the relatively steady congener profiles of the highly brominated PBDEs suggest that these PBDEs were controlled primarily by similar emission mechanisms. The lifetime excess cancer risks from exposure to PCDD/Fs and PBDD/Fs via inhalation ranged from 0.7 × 10⁻⁵ to 5.4 × 10⁻⁵, or approximately 80 cancer cases in the Taizhou population.

Samples of surface water, suspended particulate matter (SPM), and surface sediment, collected from the Pear River Estuary, Guangdong Province, China in July of 2002 and April of 2003, were analyzed for hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) using gas chromatography with electron capture detection. The levels of total HCHs in water varied from 213 to 3,116 pg/L, although in sediments they ranged from 181 to 1,388 pg/g dry weight. The levels of DDTs were in the range of 228 to 3,284 pg/L in water and 57 to 2,244 pg/g dry weight in sediments, respectively. The observed spatial and temporal variability of concentrations of the target compounds in water body could be attributed to the differences of SPM contents in water body and organic carbon contents in SPM between the two sampling periods. Seven of the 10 water samples collected in July of 2002 had the ratio of dichlorodiphenyltrichloroethane/(dichlorobischlorophenylethane + dichlorodiphenyldichloroethylene) (DDT/[DDD + DDE]) higher than one, indicating that there were likely fresh inputs of DDT to the Pearl River Estuary. The significant positive correlations between the organochlorine pesticide concentrations and organic carbon contents in SPM and sediments indicated that organic matter played an important role in controlling the distributions of these pollutants in the marine environment. Varied correlations between the partition coefficients of pollutants and total organic carbon, salinity, and total SPM contents have been observed, which indicated the influences of these factors on controlling the transport and fate of pollutants in the marine environment.

Polybrominated diphenyl ethers (PBDEs) were analyzed in three invertebrate species, five fish species with different living and feeding habits, and surface sediments collected from the Pearl River Estuary, South China. The concentrations of 10 PBDE congeners (BDEs 28, 47, 66, 99, 100, 85, 154, 153, 138, and 183) ranged from 34.1 to 444.5 ng/g lipid and from 9.88 to 39.0 ng/g organic carbon in biota and sediment samples, respectively. In sediments and some biota samples, BDE 209 was found as the major congener, ranging from nondetectable to 623.5 ng/g lipid in biota samples and from 792 to 4,137 ng/g organic carbon in sediment samples. Different levels of PBDEs in various biota species were attributed to the different feeding habits of the aquatic species or their ability to metabolize PBDE. Different congener profiles between the biota and sediment samples were observed and attributed to the bioaccumulation potential or the ability to metabolize individual BDE congeners. Polybrominated diphenyl ether levels in the biota from the Pearl River Estuary correlated well with lipid contents but did not correlate with the biota lengths. The distribution of biota-sediment accumulation factors for individual PBDE congeners was consistent with the general pattern predicted from a widely used bioaccumulation model.

Polycyclic musks were measured in surface sediments collected from the Pearl River Delta and Macao coastal region, South China, to investigate contamination from domestic sewage. Three polycyclic musk compounds-4-acetyl-1,1-dimethyl-6-tert-butylindan, 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta(g)-2-benzopyran (HHCB), and 7-acetyl-1,1,3,4,4,6-hexamethyl-1,2,3,4-tetrahydronaphthalene (AHTN)-were detected in sediment samples. Two polycyclic musks, HHCB and AHTN, were dominant components in sediment, consistent with the use pattern of polycyclic musks by perfume industries in the Pearl River Delta region. The concentrations of total polycyclic musks ranged from 5.76 to 167 microg/kg. Because of the large amount of domestic sewage and industrial wastewater discharged from the city of Guangzhou, the highest concentration of polycyclic musks was found in sediments from the Zhujiang River. The significant positive correlation between the HHCB to AHTN ratios and the concentrations of polycyclic musks suggested that the HHCB to AHTN ratio could be used as a tracer for source discrimination and for the degree of degradation in the environment.

A total of 390 individual fish, including seven species of freshwater-farmed fish, three species of seawater-farmed fish, and three species of wild marine fish, from China were analyzed to determine the concentrations and congener distribution of polybrominated diphenyl ethers (PBDEs). The levels of Sigma(10)PBDEs (sum of BDEs 28, 47, 66, 100, 99, 85, 154, 153, 138, and 183) in seawater-farmed fish (median, 13.6 ng/g) were significantly higher than those in freshwater-farmed fish (median, 10.1 ng/g) and in wild marine fish (median, 4.5 ng/g) on a lipid-weight basis. Lipid contents positively correlated with Sigma(10)PBDEs concentration (wet wt) in all fish species except for tilapia, bighead carp, bluntsnout bream, and common mullet; however, no significant relationship was found between fish length or weight and Sigma(10)PBDEs concentration except for one fish species. In general, BDE 47 was the dominant congener, with a mean contribution of 53.2%. Brominated diphenyl ether 209 was only detected in 14 samples, reflecting its low bioavailability or high degree of debromination. In addition, the ratios of BDE 47 to BDE 99 and of BDE 100 to BDE 99 in freshwater-farmed fish were significantly higher than those in seawater-farmed and wild marine fish. Freshwater-farmed fish had a relatively higher proportion of BDE 28, whereas seawater-farmed and wild marine fish contained more abundant BDE 66, BDE 100, and BDE 99. The difference in congener distribution might be indicative of different exposure pathways for PBDEs in three types of fish.