PCDD/DFs and coplanar PCBs in sediment and fish samples from the Er-Jen river in Taiwan

Evaluation of Acid Leaching on the Removal of Heavy Metals and Soil Fertility in Contaminated Soil

Heavy metal-contaminated soils were leached with various acid reagents, and a series of treatments was assessed to understand soil fertility after acid leaching. Aqua regia digestion and a five-step sequential extraction procedure were applied to determine heavy metal distribution. The average total concentrations of Zn, Cd, Cu, and Pb for contaminated soil were 1334, 25, 263, and 525 mg·kg−1 based on the ICP/AES quantitative analysis. Other than Pb extracted by H2SO4, over 50% removal efficiency of other heavy metals was achieved. A five-step sequential extraction revealed that the bound-to-carbonate and bound-to-Fe-Mn oxides were the major forms of the heavy metals in the soil. The addition of organic manure considerably promoted soil fertility and increased soil pH after acid leaching. Seed germination experiments demonstrated that after acid leaching, the soil distinctly inhibited plant growth and the addition of manure enhanced seed germination rate from 35% to 84%. Furthermore, the procedure of soil turnover after acid leaching and manure addition greatly increased seed germination rate by 61% and shortened the initial germination time. Seed germination in untreated soil was superior to that in acid-leached soil, illustrating that the phytotoxic effect of acid leaching is more serious than that of heavy metals.

Effect of coplanar PCB concentration on dechlorinating microbial communities and dechlorination in estuarine sediments

The effect of concentration of coplanar PCB on the dechlorinating microbial community and dechlorination were investigated in anoxic estuarine sediment collected from Er-Jen River and enriched with 10 and 50 mg L⁻¹ of 3,4,4',5-tetrachlorobiphenyl, 3,3',4,4',5-pentachlorobiphenyl, and 3,3',4,4',5,5'-hexachlorobipheny. Dechlorination rates were similar in the cultures enriched with 10 and 50 mg L⁻¹ of 3,4,4',5-tetrachlorobiphenyl, whereas significantly higher dechlorination rates were observed in cultures enriched with 10 mg L⁻¹ of 3,3',4,4',5-pentachlorobiphenyl. No dechlorination was observed in sediment slurries enriched with 3,3',4,4',5,5'-hexachlorobipheny. Para dechlorination occurred prior to meta dechlorination during reductive dechlorination of 3,4,4',5-tetrachlorobiphenyl and 3,3',4,4',5-pentachlorobiphenyl. GC-MS and denaturing gradient gel electrophoresis (DGGE) were used to detect dechlorination products and dechlorinating microorganisms in the enriched sediment cultures during the process of degradation. Two Chloroflexi phylotypes observed in DGGE were responsible for para and meta dechlorination respectively. Phylotype Cp-1 has 98% similarity to uncultured bacterium N5-12. Phylotype Cm-1 has 99% similarity to uncultured dechlorinating bacterium m1 or SF1 belonging to the ο-17/DF-1 group of PCB-dechlorinating bacteria.

Impact of coplanar PCBs on microbial communities in anaerobic estuarine sediments

The toxicity of three coplanar PCBs on microbial communities of an estuarine sediment were assessed. Sediment slurries were amended with 2, 10 and 50 mg/L of 345-4 CB, 345-34 CB and 345-345 CB, respectively under anaerobic conditions. The fate and effects of these coplanar PCBs were studied over 250 days. Bacterial communities in sediment slurries were described by dehrdogenase activity and by bacterial populations deduced from the clone libraries. Dechlorination of 345-4 CB and 345-34 CB occurred at least after 100 days of incubation, but dechlorination of 345-345 CB was not observed over the entire incubation period. However, time profiles of dehydrogenase activity were similar in sediment slurries amended with 345-4 CB, 345-34 CB or 345-345 CB. After normalization of the effect of acetone we found that dehydrogenase activity was increased in sediment slurries amended with 50 mg/L, but were inhibited in those amended with 2 and 10 mg/L of coplanar PCBs. Extra addition of electron donors plus sulfate or sulfate could increase dehydrogenase activity significantly. The major microbial populations in the sediment slurries incubated with 2, 10, and 50 mg/L of 345-4 CB were delta-Proteobacteria, Chloroflexi, and epsilon-Proteobacteria, respectively. This study shows that (1) dechlorination of coplanar PCBs did not change their effects on microbial metabolic activities, (2) concentration of coplanar PCBs had effects on microbial metabolic activities and community composition, (3) extra addition of electron donors plus sulfate or sulfate could increase dehydrogenase activity significantly, but this did not always lead to higher dechlorination rates, (4) coplanar PCBs induced perturbations of sediment microbial communities in terms of population structures (but not always as an inhibition).

Polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofurans and polychlorinated biphenyls in farmed fish, water, sediment, and feed

This investigation was undertaken to determine the levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dizenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (DL-PCBs) in farmed grouper tissues and environmental medium samples, including sediment, water, and feed. The water concentrations of DL-PCBs were low at 4.33-7.63 pg/L, and those of PCDD/Fs were 0.399-0.794 pg/L. The concentrations of PCDD/Fs in sediment samples were 21.4-35.3 pg/g, and those of PCBs were 54.7-100 pg/g. To identify changes in PCDD/Fs and PCBs levels in fish throughout growth, the tissue samples from hatchlings, 2-month, 15-month, 24-month, and 36-month-old orange spotted grouper (Epinephelus coioides) were analyzed. In grouper tissue samples, the total toxicity equivalent (TEQ) of the total PCBs were 0.129-0.745 pg World Health Organization- toxicity equivalent (WHO-TEQ/g) wet weight (w.w.), while total PCDD/Fs TEQ were 0.022-0.073 pg WHO-TEQ/g w.w The DL-PCBs were contributed more to the TEQ than PCDD/Fs in all fish tissue samples. Both PCDD/F and DL-PCB concentrations increase as grouper age increased. Results of this study demonstrate that PCDD/Fs and PCBs accumulate in fish tissues, and diet is the main source of PCDD/Fs and PCBs accumulations.

Intersex tilapia (Oreochromis spp.) from a contaminated river in Taiwan: A case study

River pollution in Taiwan is rather serious, but so far there have been no reports of fish intersex problems. This report reveals that 50% male tilapia in the Era-Jiin River of southern Taiwan were found to be feminized in an October 8, 1994 collection from station EJ-2 of this river. After discounting all other possible causative factors, and correlating with endocrine disrupting chemicals found in this river, we suggest that there is a great possibility that the occurrence of intersex tilapia was caused by these chemicals. The above finding suggests that greater attention needs to be given to endocrine disrupting chemicals problems.

Morphological deformities as biomarkers in fish from contaminated rivers in Taiwan

Tilapia (Oreochromis spp.) were collected seasonally from four contaminated rivers in southwestern Taiwan for studies of morphological deformities that could be used as biomarkers of contamination. Morphological deformities found in tilapia were separated into 15 categories. Overall, the prevalence of deformities such as split fins, lower lip extension and gill deformities were significantly related to various water quality parameters, including low DO and high ammonium, lead and zinc concentrations. The persistence of tilapia in polluted waters and the development of a suite of morphological deformities suggest that tilapia can be used as sentinels of non-point source pollution in rivers.

Polychlorinated dibenzo-p-dioxins/furans and polychlorinated biphenyls in fresh fishes from Qiantangjiang River, China

Muscles of two species of fish collected in Qiangtangjiang River were analyzed for polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) by high resolution gas chromatography/high resolution mass spectrometry (HRGC/HRMS). Average concentrations of total PCDD/Fs in Crucian carp and White Amur bream were 1.14-7.88 pg g(-1)ww and 1.02-8.18 pg g(-1)ww respectively. Corresponding values for PCBs were 469.36-10972 pg g(-1)ww and 364.79-4948.0 pg g(-1)ww. Average total WHO-TEQ of Crucian carp and White Amur bream from five areas ranged from 0.25 to 2.33 pg g(-1)ww and 0.30 to 1.70 pg g(-1)ww. The contamination level was compared with other studies and risk assessment was discussed.

Seasonal variation of the distribution of PCBs in sediments and biota in a PCB-contaminated estuary

To elucidate the effects of seasonal variation of precipitation on the distribution of polychlorinated biphenyls (PCBs) in estuarine sediments and benthic feeders, PCB concentrations of river surface sediments and mullet fish (Liza macrolepis) were investigated in the estuary of Er-Jen River near former PCB contamination sites before and after each wet season from 2002 to 2004. Analyses of grain size distribution and organic matter revealed that the pre-existing surface sediments were covered by and mixed with the soil particulates brought by surface runoff after each wet season. Obvious increment of PCB content and significantly elevated fraction (p<0.005) of light PCBs of the river mouth's sediments after each wet season indicated that the invading particles were rich in un weathered PCBs. PCBs previously buried in the surface soil of heavily contaminated sites were flushed into this estuary through surface runoff. The precipitation altered the PCB patterns in sediment organic matter, the dietary source of mullet, and consequently changed that of mullets accordingly, which all possessed significant greater fraction of light PCBs. In this study, it was demonstrated that seasonal summer precipitation affected the distribution of PCBs on surface sediments and the mullets of this estuary. PCB residuals retained in this region still pose potential threats to biota resided here.

Bioaccumulation of polychlorinated biphenyls in mullet fish in a former ship dismantling harbour, a contaminated estuary, and nearby coastal fish farms

This study investigated the bioaccumulation of polychlorinated biphenyls (PCBs) toward mullet fish (Liza macrolepis) living in former PCB contaminated areas, the Ann-Ping harbour and the Er-Jen estuary, and fish farms located near the above two areas in 2003. The PCB body burdens of collected fish samples are proportional to the contamination level of their locations with the following rank order (greatest to least) from the Er-Jen estuary, the Ann-Ping harbour to the fish farms. Concentration of PCBs of the estuarine mullet has been approximately decreased to one-half of the peak concentration of the 1990s. Although the concentration of PCBs in farmed fish inhabiting near the two contaminated areas was greater than the average of those of fish from local fish markets in Taiwan, no particularly great contamination level was observed in their bodies. Using the less chlorinated PCB fraction (triCB + tetraCB)/total PCBs as the indicator of the origins of PCBs, fish near former contaminated areas had greater body burdens of the more chlorinated PCB congeners, while the farmed fish exhibited a PCB pattern more like that known to originate from air-water exchange with less chlorinated PCBs predominating. Although the PCB contamination has been stopped for a decade, the residual contaminants, supposedly existing in soil and sediments, still contribute to the body burden of fish residing in the estuary and the harbour.

The emission inventory of PCDD/PCDF in Taiwan

Establishment of a country or region-based dioxin inventory was considered a crucial step toward elimination of worldwide dioxins/POPs contaminations, although no harmonized method for the preparation of an inventory is available at present. In this study, we used limited data and information to generate an inventory of dioxin emissions from some major sources in Taiwan. A total of 67.25 g I-TEQ of dioxins released annually was estimated. Unlike most of the industrialized countries, municipal waste incineration is not the highest contributor for dioxins released into the atmosphere. In contrast, secondary copper smelting accounts for more than 39% of the total dioxin emissions, and is higher than those from all waste incinerators combined (23.7%). Cement kilns and electric arc furnaces for steels also produced significant portion (both >10%) of dioxins into the environment, followed by secondary aluminum smelting (6.53%), industrial oil combustion (5.02%) and power plants fueled by coal (5.01%). Other known sources are either insignificant with respect to their dioxin emissions or not included in this inventory due to lack of information or uncertainty of the results. Data presented in this report provide a general picture of dioxin emissions in Taiwan, but were mostly based on less reliable or representative information, especially with respect to emission factors from different emission sources. It is necessary to establish background information relative to our own environment at present. Upon available, the inventory should be updated accordingly for proper environmental management on dioxins.

Evidence of aryl hydrocarbon receptor ligands in Presque Isle Bay of Lake Erie

The purpose of the present studies was to use a biomarker approach to examine xenobiotic exposure of brown bullhead in Presque Isle Bay, Lake Erie (USA). In particular, the presence of compounds that act through the aryl hydrocarbon receptor (AhR) was of interest due to its central role in gene regulation and carcinogenesis of dioxins and certain polycyclic aromatic hydrocarbons (PAHs). Initial screening of Presque Isle Bay sediment samples by gene expression microarray in mouse hepatocytes revealed prototypical dioxin-response genes such as cytochrome P450 1A1 and 1B1 (CYP1A1 and CYP1B1). The presence of AhR ligands in sediment samples was confirmed and quantified using an in vitro assay, the Chemical Activated Luciferase Expression (CALUX) assay. The CALUX assay system, by using different incubation times, allows for determination of total dioxin induction equivalents (IEQ) for less persistent compounds such as PAHs as well as for stable compounds such as polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), and certain polychlorinated biphenyls (PCBs). Parts of Presque Isle Bay have significant concentrations of AhR ligands in sediment ranging from 200 to 1400 parts per trillion (ppt) dioxin IEQ equivalents (dry weight). This is much higher than levels of dioxin equivalents found in similar sediment samples (approximately 10 ppt). Cascade Creek appears to be a major source of dioxin-like contaminants as IEQs in sediments taken from various regions of this tributary ranged from 1300 to 42000 ppt IEQ. In addition, the CALUX assay indicated that the majority of the IEQs (>90%) in PIB samples were in fact derived from less stable compounds. To determine if brown bullhead are exposed and respond to these high levels of AhR ligands, CYP1A cDNA was cloned from this species and quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was used to examine mRNA levels. The CYP1A mRNA concentration was lower and less variable in fish taken from Presque Isle Bay than from a body of water with much lower AhR ligand concentration. Taken together, these studies show that sediment in Presque Isle Bay is highly contaminated with AhR ligands including dioxins and PAHs, but the brown bullhead are either not exposed or are non-responsive to these carcinogenic compounds.

Mussel watch: a review of Cu and other metals in various marine organisms in Taiwan, 1991-98

This study presents the distribution of Cu, Zn, Pb, Cd, Hg and As in various marine organisms collected along the western coast of Taiwan from 1991 to 1998, and also evaluates the time variation of Cu in oysters before (1980-85) and after (1986-98) the "green oyster" incident. The results show that relatively high geometric mean (GM) concentrations of Cu, Zn, Pb, Cd, As and Hg were generally found in Crassostrea gigas (Cu=229 microg/g, Zn=783 microg/g), Gomphina aeguialtera (Pb=30.3 microg/g), Tegillarca granosa (Cd=2.85 microg/g), Thais clavigera (As=96.9 microg/g) and Parapenaeopsis cornuta (Hg=1.35 microg/g), respectively. Especially, maximum Cu and Zn concentrations (GM=229 and 783 microg/g, respectively) in oysters (C. gigas) from different culture areas were much higher than those of the other organisms by about 1.13-458 and 2.40-63.7 times, respectively. Similarly, rock-shells (Thais clavigera) had a high capacity for accumulating Cu (GM=202 microg/g) and Zn (GM=326 microg/g) under the same physico-chemical conditions. The highest GM Cu and Zn concentrations of 1108 (range from 113 to 2806) and 1567 (range from 303 to 3593) microg/g were obtained in oysters from the Hsiangshan coastal area, one of the most important oyster culture areas in Taiwan. However, the highest GM Cd and As concentrations of 6.82 and 19.3 microg/g were found in oysters from the Machu Islands. Mean Cu concentrations in the oysters from the Erhjin Chi estuary declined from 2194+/-212 microg/g in 1986-90 to 545 microg/g (GM) in 1991-96. In the Hsiganshan area, GM Cu concentrations of 909 microg/g (1991-96) and 1351 microg/g (1997-98) in oysters were significantly higher than those of 201 microg/g (1980-85) and 682 microg/g (1986-90). The gradually increasing levels of Cu and Zn in the oysters from the Hsiangshan area have been observed year by year.

Reassessment of PCDD/DFs and Co-PCBs toxicity in contaminated rice-bran oil responsible for the disease "Yu-Cheng"

Reassessment of dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and coplanar polychlorinated biphenyls (Co-PCBs) in toxic Yu-Cheng rice-bran oil was carried out. The contaminating source appears to be a mixture of KC-400 and KC-500. The oil contains 176 micrograms/g PCBs and 37.194 ng/g 2,3,7,8,-TCDD toxicity equivalency (TEQ). The TEQ contributions from the PCDDs (4.472 ng/g), PCDFs (19.568 ng/g), and Co-PCBs (13.154 ng/g) are 12% 53% and 35%, respectively. Complete identification and quantitation suggests that 2,3,4,7,8-PeCDF, 1,2,3,4,7,8-HxCDF, 2,3,7,8,-TCDF. 2,3,7,8-TCDD, 1,2,3,7,8-PeCDD and PCB# 77 are candidates for the primary causal agents of Yu-Cheng disease.