Assessing the spatial variability,level and source of organic chemical contaminants in bivalve fishing grounds on the Galician coast (NW Spain)

Polychlorinated biphenyls, organochlorine pesticides, organotin compounds and triazines were quantified in sediments and bivalves collected in four areas on the Galician coast. One or several species were analysed at each site depending on their availability, including mussels (Mytilus galloprovincialis), cockles (Cerastoderma edule), clams (Venerupis pullastra and Ruditapes decussatus) and razor shells (Ensis siliqua). The general spatial distribution of contaminants was consistent in spite of the different sources of contamination. High inter-species variability was also observed. M. galloprovincialis and V. pullastra showed the highest levels of contaminants and intra-spatial variability, which highlights them as suitable species to be used as sentinel organisms. The area of O Burgo showed some worrisome results: PCB sediment concentrations were within the range that could cause biological effects. Also the level of heptachlor observed in V. pullastra was above limits accepted on edible seafood. Finally TBT concentration in mussels correlated with concentrations causing imposex in snails.     

微量注射器中有机氯农药和多氯联苯类化合物的残留与清洗研究

微量注射器越来越多地用于转移微量液体,但是微量注射器中有机化合物的残留可能造成的交叉污染易被忽视。本文系统地研究了微量注射器中有机氯农药类和多氯联苯类化合物的残留和清洗效果。结果表明,三个品牌的微量注射器清洗的难易不同,在选择微量注射器时应根据实验结果选择满足实验要求的类型;正己烷清洗液的体积与稀释倍数成正比,原因在于0.1 mL、0.2 mL、0.5 mL和1 mL第一针清洗液洗出的化合物质量接近,清洗液体积甚至与洗出化合物的量负相关,因此选用体积最小的0.1 mL效果和成本优势最大;相同浓度的有机氯农药类和多氯联苯类化合物清洗效果接近,原因可能是这两类化合物的理化性质相近;不同浓度的标准溶液需要清洗的次数不同,浓度越高的标准溶液需要清洗的次数越多。本文总结出三条清洗规律:①1 mL微量注射器中的残留量约为吸取量的1%左右;②第一针洗出化合物的量超过残留量的90%;③随着清洗次数的增加,呈现清洗效果越来越差、稀释倍数越来越小的趋势。根据这些规律,可以针对不同浓度的不同化合物采取相应的清洗措施,在标准溶液配制和气相色谱仪方法设置过程中更有效地预防污染和节约成本。     

珠江虎门潮汐水道难降解有机污染物入海通量研究

对采自虎门潮汐水道狮子洋4个采样点表层水样中的多环芳烃、有机氯农药进行了定量分析.洪、枯水期水体中多环芳烃总量(颗粒相和溶解相)分别是786～964 ng/L、11 360～19 603 ng/L;有机氯农药总量分别是9.68～26.29 ng/L、41.65～96.23 ng/L.根据4个采样点洪、枯水期有机污染物浓度的平均值估算多环芳烃、有机氯农药的年均入海通量.初步估算结果显示:多环芳烃的总入海通量(溶解相和颗粒相)为438.4×103 kg/a,其中颗粒相是52.5×103 kg/a;16种优控多环芳烃的入海通量为247.9×103 kg/a.有机氯农药的总入海通量是2.6×103kg/a,其中六六六的入海通量为1.1×103 kg/a,滴滴涕类的入海通量为0.3×103kg/a,其它有机氯农药的入海通量为1.2×103 kg/a.     

土壤中25种有机氯农药和多氯联苯的气相色谱分析方法研究

研究了土壤中17种有机氯农药和8种多氯联苯组分的气相色谱分析方法。采用加速溶剂萃取技术提取,优化了萃取条件。提取液用固相萃取技术进行净化,采用20 mL含3%(体积分数)甲苯的正己烷-乙酸乙酯(体积比8∶2)进行淋洗,得到很好的净化效果。方法检出限在0.06~0.27μg/kg,线性范围在1.38~55.2 ng/mL,目标化合物的平均添加回收率在65%~97%,相对标准偏差(RSD,n=6)小于17.11%。方法快速、灵敏、准确,适合批量样品的分析。     

Polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides in water columns from the Pearl River and the Macao harbor in the Pearl River Delta in South China

Polycyclic aromatic hydrocarbons (PAHs) and organochlorine pesticides (OCPs) were measured in suspended particles and dissolved phase from the Baiertang water column and the Macao water column samples as collected from the Guangzhou channel of the Pearl River and the Macao harbor, where the sediments were heavily contaminated with organic pollutants. Total OCPs concentration varies from 23.4 to 61.7 ng/l in Baiertang water column and from 25.2 to 67.8 ng/l in Macao column, while total PAHs concentration varies from 987.1 to 2878.5 ng/l in the Baiertang water column and from 944.0 to 6654.6 ng/l in the Macao column. The vertical distribution profiles of pollutants and the partition of pollutants between particles and dissolved phases indicate that the sediments in Baiertang act as an important source of selected pollutants, and the pollutants in water of this region were mainly originated from the release and re-suspension of contaminants residing in the sediments. The sediments in Macao harbor act as a reservoir for organochlorine pesticides, such as DDTs mainly introduced by river inflow from Xijiang and PAHs input by brackish water from the Lingdingyang estuary. Combustion of fossil fuels and petroleum input are the main sources of PAHs in the Macao water column, while combustion of fossil fuels and coal is responsible for the PAHs in the Baiertang water column. The ratios of DDT/(DDD+DDE) for the Macao water column samples demonstrate that such chemicals were input into this region in recent times.     

Field validation of antioxidant enzyme biomarkers in mussels (Perna viridis) and clams (Ruditapes philippinarum) transplanted in Hong Kong coastal waters

Green-lipped mussels, Perna viridis, and Manila clams, Ruditapes philippinarum were sourced from “clean” sites in the Hong Kong region, depurated in a laboratory using uncontaminated filtered seawater for 8 days, and transplanted to a suspected gradient of chemically polluted sites in Hong Kong. After 14- and 28-days of field exposure, several antioxidant parameters including glutathione S transferase (GST), catalase (CAT), glutathione peroxidase (GPx), and glutathione (GSH) were quantified in gill and hepatopancreas tissues. Whole body tissue concentrations of polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCs) were determined in pooled site samples. Chemical analyses indicated that: (a) clams had higher levels of PAHs, PHCs, DDTs and PCBs, whereas mussels had higher hexachlorocyclohexane (HCHs) and there was no difference between species for dieldrin and remaining OCs; (b) Kat O should not be continued as a “clean” reference site for Hong Kong, because of the levels of contaminants measured and (c) PAH concentrations in the current survey were similar to those previously measured. Toxicological conclusions were: (a) antioxidant responses were different between species; (b) CAT and GST have highest utility in clams for field use in Hong Kong, whereas CAT in both gill and hepatopancreas tissue showed most potential in mussels; (c) significant induction of antioxidant responses over day 0 (excluding GPx in both tissues, and GST in mussel hepatic tissue); (d) groups of contaminants do not consistently induce antioxidant responses and (e) organochlorines and PCBs correlated significantly with CAT and GST in clam hepatopancreas and with CAT in mussel gill and hepatic tissue. Multivariate statistical techniques indicated little relationship between the site patterns for antioxidant responses and the contaminant gradients identified in body burden analysis.     

Organochlorine micropollutants in the Jiulong River Estuary and Western Xiamen Sea, China

Organochlorine contaminants including 12 polychlorinated biphenyl (PCB) congeners and 18 insecticides were determined in water, pore water and sediments of the Jiulong River Estuary and Western Xiamen Sea, China. The results showed that the levels of the total PCBs ranged from non-detectable to 1500 ng l⁻¹ in water, from 209 to 3870 ng l⁻¹ in pore water, and from 2.78 to 14.8 ng g⁻¹ dry weight in sediments. Total organochlorine insecticide concentrations were from below the limit of detection to 2480 ng l⁻¹ in water, from 267 to 33400 ng l⁻¹ in pore water, and from 4.22 to 46.3 ng g⁻¹ dry weight in sediments. Concentrations of PCBs and insecticides in pore water were significantly higher than those in surface water, due to the high affinity of these hydrophobic compounds for sediment phase. The PCB congeners with the highest concentrations were CB153, CB180 and CB194, which together accounted for 68–87% of total PCBs in water, pore water and sediment. Among the hexachlorocyclohexane (HCH) compounds, beta-HCH was found to be a major isomer. Analysis of 1,1,1-trichloro-2,2-bis-chlorophenyl-ethane (DDT) and its metabolites showed that 1,1-dichloro-2[o-chlorophenyl]-2[p-chlorophenyl]-ethylene (DDE) was dominant in the group. In comparison to a 1998 study in the Western Xiamen Sea, levels of organochlorines were enhanced due probably to recent inputs and changes in sediments.     

Molecular cloning and mRNA expression of cytochrome P4501A1 and 1A2 in the liver of common minke whales (Balaenoptera acutorostrata)

This study presents full-length cDNA sequences of CYP1A1 and 1A2, in common minke whale (Balaenoptera acutorostrata) from the North Pacific. Both CYP1A1 and CYP1A2 cDNAs had an open reading frame of 516 amino acid residues, and predicted molecular masses were 58.3 kDa and 58.1 kDa, respectively. The deduced full-length amino acid sequence of CYP1A1 revealed higher identities with those of sheep (86%) and pig (87%), and that of CYP1A2 was most closely related to human (82%) and monkey CYP1A2 (82%) among species from which CYP1A2 has been isolated so far. Differences in certain conserved and functional amino acid residues of CYP1A1 and 1A2 between common minke whale and other mammalian species indicate the possibility of their specific metabolic function. Concentrations of organochlorine compounds (OCs) including PCBs and DDTs analyzed in common minke whale liver showed no significant correlation with hepatic mRNA expression levels of CYP1A1 and CYP1A2, indicating no induction of these enzymes by such OCs.     

Spatial aspects of organochlorine contamination in northern fur seal tissues

Northern fur seals from the Pribilof Islands, Alaska (St. George Is. and St. Paul Is.) were examined for organochlorine contamination (OC) and whether the organochlorine levels differed between the populations and were at levels that may adversely affect their health. Fur seal blubber and milk samples were obtained from pups, sub-adult males, and adult females on both Pribilof Islands. These samples were analyzed for organochlorine contaminants including dioxin-like PCBs and other selected PCBs and pesticides by high performance liquid chromatography/photodiode array. Results showed that there are clear differences between the two islands in the patterns of fur seal OC distribution. Generally, these differences are confined to the PCBs with only minimal differences in the DDTs. There are also clear biological differences in the levels shown between milk, pup blubber, and sub-adult male blubber. When considering blubber, St. George Is. fur seals show higher OC levels than St. Paul Is., for both pups and sub-adults. On the other hand, milk samples from St. Paul Is. showed higher PCB levels than St. George Is. For the milk, the overall OC levels may impact the immune function of the pups, but are probably of only minimal impact to humans. However, for blubber, the overall toxic equivalency shows levels exceeding those levels recommended for human consumption at St. George Is. and approaching those levels at St. Paul Is. The concentration curves suggest that the movement of OC in and out of milk follows a complex set of reactions dependent on how the OC compounds on a congener level are associated with lipid. In fact, there is some evidence that they may not follow the lipid as closely as we had thought and that lipid levels can vary without impacting the total OC level in the milk.     

Environmental and pollution condition of the huizache-caimanero lagoon, in the north-west of Mexico

The fish and shrimp production of the Huizache-Caimanero Lagoon, located on the Mexican Pacific, has been decreasing in recent years, which may be due to environmental and pollution conditions. Therefore, water and sediment samples were analysed to quantify nutrients, pesticides, and coliform bacteria. The results indicated that the system is polluted considerably during the rainy season due to continental runoff carrying municipal and agricultural wastes, thereby increasing coliform pollution and nitrate concentrations. This is less apparent for phosphates and pesticides. We conclude that pollution and environmental changes are important causes decreasing production; recent studies have reported biochemical and physiological alteration in aquatic organisms exposed to similar levels of pesticides as reported here. During the rainy season, coliform levels are above permissible levels established by sanitary regulations, and are thus pose a risk to public health.