Seasonal and spatial character of PCBs in a chemical industrial zone of Shanghai,China

As one of China’s great metropolises, Shanghai is suffering from the impact of manufacture and the use of chemical industrial products, and it faces serious pollution from polychlorinated biphenyls (PCBs). Therefore, in this study, in order to assess the seasonal and spatial character of contamination from chemical industrial zones, the concentrations of PCBs have been measured in various environmental media, including soil, leaves, and atmospheric particulate samples collected in a chemical industrial zone of Shanghai and compared with samples from presumably unpolluted sites of rural areas. In soils, the PCB concentrations ranged from 0.5 ng g⁻¹ (unpolluted site) to 586.85 ng g⁻¹ (chlor-alkali industry site). The concentrations of PCBs in evergreen leaves ranged from 0.3 ng g⁻¹ to 32.46 ng g⁻¹, and more chlorinated biphenyls congeners, such as penta-biphenyls and hexa-biphenyls, were the dominant contributors in winter and spring. Seasonal differences and the constitution patterns of congeners might be affected by the temperature and industrial activities. The PCB concentrations in the leaves of deciduous trees increase over time as the leaves grow. The PCB concentration in atmospheric particulates was in the range of 9.22–14.15 × 10³ pg m⁻³, which might be the result of influence from climate and industrial activities. The relativity of PCB contents among the environmental media was discussed. The results in this paper provide an important profile of the current contamination status of a key chemical industrial zone in China.     

Coral calcification: Sources of error in radioisotope techniques

Isotopic exchange occurs between coral skeleton and ⁴⁵Ca⁺⁺ and H¹⁴CO ₃ ^- in seawater. Exchange of ¹⁴C onto skeletons is more rapid than exchange of ⁴⁵Ca⁺⁺. Exchange of ¹⁴C from skeletons to seawater takes place more slowly than exchange of ⁴⁵Ca⁺⁺ to seawater. When living coral is incubated in the dark with radioisotopes for 1 h, the tissues contain considerably more radioactivity than is associated with the skeleton. The tissue radioactivity reflects permeation of tissues and coelenteron by radioactive compounds from the incubation seawater. Addition of alkalis to cardioactive seawater results in a radioactive precipitate, part of which becomes associated with any coral skeleton present, and part of which forms on the wall of the containing vessel. Strong alkali removes biologically-deposited radioisotope from coral skeletons. Deposition, of ¹⁴C from H¹⁴CO ₃ ^- in skeletons of living coral incubated in the dark is greater than in dead coral. The reverse situation occurs with ⁴⁵Ca⁺⁺.     

水生和陆生生物体中卤系阻燃剂的差异性富集研究:以鲶鱼和家鸽为例

分析了水生(鲶鱼)和陆生(家鸽)生物体中卤系阻燃剂(HFRs)的组成和浓度。鲶鱼中短链氯化石蜡(SCCPs)浓度均值为30 800 ng·g~(-1)lw(脂肪归一化浓度),是最主要的HFRs,然后依次是多溴联苯醚(PBDEs)(2 300 ng·g~(-1)lw)、四溴双酚A(TBBPA)(37 ng·g~(-1)lw)、六溴环十二烷(HBCD)(21 ng·g~(-1)lw)、德克隆(DP)(14 ng·g~(-1)lw)、十溴二苯乙烷(DBDPE)(7.1 ng·g~(-1)lw)和六溴苯(HBB)(6.2 ng·g~(-1)lw);而家鸽中PBDEs含量最高(17 000 ng·g~(-1)lw),其次是SCCPs(7 600 ng·g~(-1)lw)DP(1 600 ng·g~(-1)lw)DBDPE(14 ng·g~(-1)lw)HBB、TBBPA和HBCDs(未检出)。鲶鱼和家鸽HFRs组成比较发现,鲶鱼中具有较高百分含量的低溴代PBDE单体和较低的fanti值,而家鸽中具有较高百分含量的高溴代PBDE单体和较高的fanti值。实验结果初步表明,水生生物较多地富集水溶性较大的化合物,陆生生物则较多地富集疏水性较强的化合物。研究认为以上水生和陆生生物体中污染物的差异性富集现象可能与化合物因不同物理化学性质导致的不同环境迁移行为有关。     

Persistent organochlorine pesticides,polychlorinated biphenyls,polybrominated diphenyl ethers in fish from coastal waters off Savannah,GA, USA

Contamination profiles of organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and polybrominated diphenyl ethers (PBDEs) were determined in six fish species from three selected regions along coastal waters off Savannah, GA, USA. Concentrations of PCBs were predominant (12–493 ng g^?1 lw) followed by PBDEs (10–337 ng g^?1 lw), OCPs such as DDTs (2.7–153 ng g^?1 lw), chlordanes (3.8–34 ng g^?1 lw), cyclodienes (<0.1–35 ng g^?1 lw), mirex (<0.1–8.6 ng g^?1 lw), γ-hexachlorocyclohexane (<0.1–1.4 ng g^?1 lw), and hexachlorobenzene (<0.1–0.68 ng g^?1 lw). The results indicated no region-specific difference in the contaminants however inter-species as well as intra-species differences were evident. Comparison of DDTs, PCBs, and PBDEs profiles in fish with those from other countries revealed that fish from coastal waters off Savannah contained relatively less concentrations of PCBs and chlorinated pesticides, while PBDE concentrations were comparable or even higher than fish samples from other regions. Polychlorinated biphenyl congeners and chlorinated pesticide tempoal trend data exhibited no increase of contamination levels. The levels of PCBs and chlorinated pesticides in fish from Savannah coastal waters were below the Food and Drug Administrations (FDA) established limits for human consumption.     

Assessment of the effect of environmental pollution in a marina on caged mussels using chemical and genotoxic analysis

An integrated approach using the contamination levels and DNA damage in mussels (Mytilus galloprovincialis) was applied in order to assess the chemical contamination in a marina (Eastern coastline of Aegean Sea). Mussels, which were harvested from a reference site (Foca), were transplanted into a marina situated along the coast of Izmir Bay. The transplanted mussels were collected at the 14th, 30th and 60th day of the experimental period. Polycyclic aromatic hydrocarbon (PAH) levels (27–51?ng?g^?1?wet?weight) detected in the mussels were similar to the levels detected in other coastal areas of the Mediterranean Sea. The marina’s sediment was found to be contaminated with PAHs (∑PAH?=?25?µg?g^?1) of pyrolytic origin and may become a source of pollution and a threat to the marine environment. In order to assess the DNA damage, the haemolymph and gill cells of the mussels were used for the comet analysis and considered as an indicator of exposure to genotoxic chemicals including 16 PAH compounds and metals. The highest levels of DNA damage expressed as %Tail-DNA (%T-DNA) were observed at the end of the experiment (21.5% T-DNA). The correlation analyses conducted between 2-, 3-, 4-ring PAHs in mussels and %T-DNA in haemolymph and gill cells showed a significant positive correlation. This investigation confirmed that transplanted mussel can be a useful tool to determine PAH contamination in marinas.     

High rates of nitrogen fixation on coral skeletons after predation by the crown of thorns starfish Acanthaster planci

At One Tree Reef, Great Barrier Reef, Australia, between 1983 and 1985, corals killed by the crown of thorns seastar Acanthaster planci L. gave rise to skeletons which were colonised rapidly by blue-green and other algae. For the next 3 to 9 mo these coral skeletons showed over three times more nitrogen fixation (acetylene reduction) than control substratum rates (9 to 32 nmol vs 3 to 10 nmol C₂H₂ cm^-2 h^-1, over all seasons). These values convert to relatively high annual fixation rates of 37 to 127 kg N ha^-1 yr^-1 but, at the low densities of A. planci on One Tree Reef (ca. 0.65 ha^-1), this has little impact on the total nitrogen fixation rate and, as a result, on the level of organic nitrogen in the system. However, it is suggested that on reefs subjected to high aggregations of a. planci such an effect would enhance the level of organic nitrogen and lead to greater primary and secondary production throughout the reef system.     

Concentrations of lead in cosmetics commonly used in South Africa

In this study, we present evidence of lead in lip liner, oil absorbent powder, mascara, concealer, lipsticks, lip gloss, and foundation. The samples were analyzed for lead by flame atomic absorption spectrometry. The levels of lead in concealer, mascara, lip liner, and oil absorbent powder were found to be 7.4?±?1.3?µg?g^?1, 15.8?±?0.2?µg?g^?1, 29.0?±?9.2?µg?g^?1, and 17.3?±?2.9?µg?g^?1, respectively. The levels of lead in lipsticks, lip gloss, and foundation ranged from not detected to 73.1?±?5.2?µg?g^?1, 4.7 to 11.7?±?2.8?µg?g^?1, and 7.8 to 32.9?±?1.4?µg?g^?1, respectively. Thus, in the majority of samples, the concentrations of lead are higher than the USFDA maximum permissible concentration of 0.10?µg?g^?1 in candy and cosmetics. In lipsticks alone, only 25% of 40 samples were found to meet the requirement. Therefore, continuous use of cosmetic products in which lead concentration exceeds the maximum permissible level may pose a health hazard for the female population of South Africa in the long run.     

Lead content of plants and soils from three abandoned smelter areas in and near Socorro,New Mexico

Two primary lead smelters and one secondary lead smelter have been active in the Socorro, New Mexico (USA) area in the last 110 years: the Billing smelter from 1883 to 1894, the Cuba Road smelter from 1881 to 1900, and Cal West from 1979 to 1984. Samples of plants and surface soil under each plant from all three sites were analysed for lead. The plants consisted of sparse grasses, cacti, creosote bush, snakeweed, mesquite and fourwing saltbush. Lead levels in the plants increased (2-440 g g^–1) as the lead in the alkaline soils (25-10000 ng g^–1) increased. However, the BAC (biological absorption coefficient), which is the ratio of lead content in the plant to the lead content in the soil, a measure of relative accumulation, decreased by one to two orders of magnitude, except for grasses and snakeweed. At background lead levels, there was little difference between lead in rootsversus foliage. At high lead levels, there was higher lead in roots versus foliage at the Billing and Cuba Road sites. The reverse was noted at Cal West. Because this is a recent operation, the higher lead in foliage may be due to foliar uptake. Plant growth at all sites appeared healthy.     

Liver and renal histopathology of North Atlantic long-finned pilot whales (Globicephala melas) contaminated with heavy metals and organochlorine compounds

Long-finned pilot whales (Globicephala melas) from the Faroe Islands are known to be heavily polluted with contaminants, such as mercury (Hg) and organochlorine compounds (OC). This is postulated to exert adverse health effects on whales as well as the human population who rely on its meat and blubber as food sources. It was therefore decided to conduct a screening pilot study to determine contaminant concentrations and histopathology of liver and renal tissues in a total of 14 specimens from this subpopulation. In blubber, the mean ∑OC concentration was 31,887 ng g^?1 lw (range: 18,170–47,425 ng g^?1 lw) of which ∑PCB concentration was 23,416 ng g^?1 lw (range: 13,947–34,543 ng g^?1 lw; n = 3). In liver, mean Hg concentration was 138 µg^?1 ww (range: 54–351 µg g^?1 ww; n = 7) and mean cadmium (Cd) concentration 15 µg g^?1 ww (range: 7–31 µg g^?1 ww; n = 7). In the kidney, the mean Cd concentration was 36 µg g^?1 ww (range: 23–47 µg g^?1 ww; n = 7). Of the liver Hg concentrations, two were at the suggested toxic threshold levels of 60 µg g^?1 ww and five were 2–6-fold above. Liver selenium (Se) : Hg was on average 1.11 (range: 0.97–1.41; n = 7) indicating that Se was in excess, which decreased the risk of acute Hg poisoning. Histopathological examinations showed high prevalence (>35%) of renal glomerular arteriosclerosis, glomerular capillary dilatation, dilatation and hyalinization of Bowman's space/capsule and tubular hyaline casts. In liver tissue, high prevalence was found for portal cell infiltrates, lipid granulomas, hepatocytic lipid accumulation, bile duct proliferation, lipid-filled Ito cells, and focal necrosis. In a single juvenile male, 4 of 8 renal and 3 of 7 liver lesions were present. Cadmium concentrations increased significantly in the presence of glomerular arteriosclerosis and a similar trend was found for tubular hyaline casts. Based on these findings, as well as the nature of the lesions, data indicate that the histopathological changes were a result of age and that contaminants are likely to be the co-factors in the development in at least three renal and four liver lesions.     

广东典型湿地环境沉积物及鱼体中多环芳烃的污染特征及风险评估

为了解广东典型湿地环境表层沉积物及鱼体中多环芳烃(PAHs)的污染特征,分别于2014年10月和2015年4月采集沉积物及鱼类样品,分析其中16种US EPA优控多环芳烃的主要来源和风险。结果表明,广东典型湿地环境表层沉积物中多环芳烃的含量范围为139.4～1 134.3 ng·g~(-1)干重,鱼类肌肉中多环芳烃含量范围为11.1～33.9 ng·g~(-1)湿重。表层沉积物中有机碳与不同环数的多环芳烃含量均呈现显著的正相关关系。来源分析的结果表明,研究区域表层沉积物中多环芳烃的主要来源为石油排放及燃烧来源的混合。风险评估的结果表明,该区域表层沉积物中多环芳烃存在一定的生态风险,需引起重视;通过食用鱼类造成的致癌风险为2.25×10~(-6)～4.23×10~(-6),略高于美国环保局(US EPA)推荐的可接受风险(10~(-6)),存在一定的潜在致癌风险。对于成年人来说,研究区域鱼类肌肉中多环芳烃产生致癌风险允许的最大日食用量(CR_(lim))范围为124.5～234.6 g·d~(-1),尽管食用这几种鱼的致癌风险不大,居民摄入时仍应加以控制。     

基于统计方法的辽东湾沉积物中多环芳烃来源特征分析

为研究辽东湾表层沉积物中多环芳烃(PAHs)的来源特征,2014年5月采集了20个辽东湾海域表层沉积物样品,并利用气相色谱质谱联用仪对优先控制的16种PAHs进行测定,采用聚类分析、主成分分析-多元线性回归分析、异构体比值3种统计方法对辽东湾表层沉积物中PAHs来源特征进行了研究。结果表明,辽东湾表层沉积物中PAHs含量范围88.5~199.3 ng·g-1,平均值为(126.3±35.3)ng·g-1,其中,萘、菲和荧蒽是PAHs优势组分。通过统计分析结果表明,辽东湾北部表层沉积物中PAHs含量低于西南部,沉积物中PAHs的来源包括石油燃烧来源、煤炭、木材等生物质燃烧来源和石油来源,其中燃烧来源是主要来源,煤炭、木材等生物质燃烧来源占49.9%,石油燃烧来源和石油来源占50.1%。     

Crassostrea virginica as an indicator of lead pollution

After treatment with 1.0 and 3.3 g Pb kg^-1 for 20 weeks in flowing seawater at ambient salinity and temperature, Crassostrea virginica accumulated as much as 6.57 and 11.42 g g^-1 dry weight, respectively, and no mortalities were recorded. Lead uptake was curvilinear; however, the general trend was an increase in lead concentration over time. Dry weight of the oyster had no significant relation with tissue lead concentration (g g^-1); however, a significant positive relationship existed between weight and lead content (g). A decrease in lead concentration in the tissues occurred from mid-August to mid-September despite continuous addition of lead to the seawater. Addition of lead to the seawater was terminated after 20 weeks (October), and lead loss was studied for the following 12 weeks. Lead loss was studied well after spawning in an attempt to eliminate any influence this might have on lead concentration in the tissues. After 4 weeks, approximately 54% of the accumulated lead was lost under conditions of a natural temperature decline. The biological half-life of lead in C. virginica tissues was calculated to be 5.5 weeks. In the ensuing 8 weeks, little or no lead loss was observed. Larvae from each treatment developed to the straight-hinged stage within 48 h with no apparent abnormalities. Lead appeared to have no adverse effect on larvae when parents had been treated with 1.0 and 3.3 g kg^-1 seawater for 10 weeks.     

The functions of octopine dehydrogenase and D-lactate dehydrogenase in the pedal retractor muscle of thedog whelk Nassarius coronatus (Gastropoda: Nassariidae)

The pedal retractor muscle of Nassarius coronatus, unlike most mollusc muscles, contains high activities of both octopine dehydrogenase (159 IU g^-1 wet wt muscle) and D-lactate dehydrogenase (40 IU g^-1 wet wt muscle). Pedal retractor muscles show accumulation of octopine (increase of 4.7 mol g^-1 wet wt muscle), and a fall in arginine phosphate concentration (decrease of 4.1 mol g^-1 wet wt musscle) after exercise. During recovery from exercise, octopine returns to resting levels after about 120 min, D-lactate accumulates (5.1 mol g^-1 wet wt muscle), and arginine phosphate returns to resting levels within 30 min. D-lactate (2.0 mol g^-1 wet wt muscle) accumulates during long-term exposure to air. The results show that octopine dehydrogenase and D-lactate dehydrogenase can function to catalyze the terminal step of glycolysis during muscle anoxia associated with these different physiological states.     

长三角地区池塘养殖水产品体内农药类污染与食用风险评价

为了解池塘养殖水产品体内的农药污染情况,以便为水产品质量评价及保障当地居民的饮食健康提供科学依据,本研究采用气相色谱质谱联用法(GC-MS)对长三角地区13个养殖池塘中5类(蟹类、鳖类、蚌类、虾类、鱼类)水产品体内9种有机磷农药(OPPs)、8种有机氯农药(OCPs)以及4种拟除虫菊酯类农药(SPs)进行了检测,并初步分析了其污染来源。结果表明,水产品体内3类农药均有检出,但残留水平均不高,OPPs残留总量为未检出至299 ng·g-1(dw),三唑磷、伏杀硫磷、喹硫磷和毒死蜱较易在水产品体内蓄积;OCPs残留总量为16~82 ng·g-1(dw),主要污染物为六六六(HCHs),主要来自历史残留;SPs残留总量为44~89 ng·g-1(dw),主要污染物为高效氯氟氰菊酯。水产品体内的农药污染可能与养殖池塘中的沉积物污染密切相关。5类水产品体内3类农药的总风险指数(HI)为0.0020~0.046,远小于1,因此,长三角地区由3类农药造成的健康风险处于安全水平。     

活性氧和钙信号参与铅对酵母细胞的毒性作用

以模式生物酵母菌为材料,研究铅对细胞的毒性效应,探讨胞内活性氧(ROS)和Ca~(2+)在铅诱导细胞死亡中的作用。结果显示,浓度为5~100 mg·L~(-1)的硝酸铅可降低酵母细胞活性,诱导酵母细胞死亡,随着铅浓度的提高和作用时间的延长,细胞死亡率增高。在铅处理组酵母细胞中,ROS和Ca~(2+)水平显著升高,线粒体膜电位明显下降;用1 mmol·L~(-1)的外源抗坏血酸(AsA)能降低铅引发的酵母细胞死亡,0.5 mmol·L~(-1)的钙离子螯合剂乙二醇双四乙酸(EGTA)或0.1 mmol·L~(-1)的质膜Ca~(2+)通道特异性抑制剂氯化镧(LaCl_3)亦可明显抑制铅引起的酵母细胞死亡。研究结果表明,铅诱发的酵母细胞死亡与处理组胞内ROS和Ca~(2+)升高有关,高浓度的Ca~(2+)可能通过诱导线粒体膜通透性转变孔道开放,或者高水平ROS可能损伤线粒体膜,致线粒体膜电位下降,继而激活相关下游信号导致细胞死亡。     

Freshwater Mussel,Lamellidens Marginalis (Lamarck) (Mollusca: Bivalvia: Unionidae) As an Indicator of River Pollution

Abstract

Analyses were made of heavy metals, manganese, nickel, copper, zinc and lead in water samples and soft body, shell and different tissues (gills, digestive glands, mantle and viscera) of the Unionid mussel, Lamellidens marginalis collected from two tributaries of the Cauvery river. Water samples from Station I contained higher concentrations of the metals than those from Station II. the concentration of metals in water at both stations were in the descending order: Mn > Zn > Pb > Ni > Cu. However, the concentrations of metals in the soft body were in the descending order: Zn > Mn > Pb > Ni > Cu at both stations in all size groups of mussels tested. the concentration of zinc maintained a linear relationship with the size of the mussels, but manganese showed a reverse trend. Small size (4-5 cm) mussels accumulated more manganese (105.5 μg.g^?1 dry wt.) than larger ones (7-8 cm; 6.5 μg.g^?1 dry wt.). Both young and old is accumulate the same level of lead, copper and nickel in the soft body. the order of concentrations of metals (Mn, Pb, Zn, Ni and Cu) in the shell of mussels from both stations coincided with the order of concentrations of background water except for lead. the accumulation of lead was higher in shell (30.4-36.2 μg.g^?1 dry wt.) than in soft body (6.4-12.0 μg.g^?1 dry wt.). the pattern of concentration of metals in the various tissues reveal that the digestive glands have greater ability than other tissues to concentrate most metals under study. the concentration factors for soft body, shell and different tissues are presented. the advantages in using the common mussel for biomonitoring of contaminants in water is also discussed.     

Accumulation of lead and cadmium by four tropical forage weeds found in the premises of an automobile battery manufacturing company in Nigeria

The potentials of tropical weeds namely, Nephrolepis biserrata, Panicum maximum, Eleusine indica, and Chromolaena odorata to accumulate lead (Pb) and cadmium (Cd) from soil within the premises of an automobile battery manufacturing company in Ota, south-western Nigeria, were explored. The weed samples were collected in both wet and dry seasons. Standard analytical methods were employed to collect, digest, and analyze the weeds. Lead levels in the weeds for both seasons ranged from 1990–4870, 1090–1730, 4800–7890, and 400–1210 µg g^?1 dry weight (DW) for Nephrolepis biserata, Panicum maximum, Eleusine indica, and Chromolaena odorata, respectively, while the cadmium level in the weeds for both seasons ranged from 3.92–6.78 µg g^?1 DW for N. biserata, 1.99–6.85 µg g^?1 DW for P. maximum, 2.90–7.40 µg g^?1 DW for E. indica, and 2.90–5.09 µg g^?1 DW for C. odorata. There was no significant difference in the accumulation of both Pb and Cd for the two seasons. All the weeds showed Pb levels higher than the phytotoxic range. On the contrary, 99% of the weeds showed Cd concentration within the phytotoxic range. The weeds demonstrate good phytoremediation potentials of contaminated soil.     

The Distribution and Impacts of Dioxins and Polychlorinated Biphenyls in the Taiwan Er-Jen River

Abstract

The distribution and impacts of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/DFs) and polychlorinated biphenyls (PCBs) in the Taiwan Er-Jen River were investigated by monitoring fish distribution and measuring PCDD/DFs and PCBs levels in sediment and fish samples. Most of the fish collected are pollution-resistant species such as Oreochromis spp, Liza macrolepsis, Channa spp and Megalops cyprinoides. the most polluted river sections are in the upstream where large amount of waste effluents from households, livestock rearing and nearby dumping sites were discharged into the river, and the lower reaches of the river where metal recovery activities including open burning of waste electrical wire/scrap occurred. Sediment samples collected near the burning site show 2,3,7,8-TCDD toxicity equivalents (TEQ) ranging from 0.014 to 14.2 ng g^?1 by PCDD/DFs and from 0.015 to 1.03 ng g^?1 by coplanar PCBs (Co-PCBs). the fish samples show TEQ ranging from 0.029 to 0.615 ng g^?1 by PCDD/DFs and from 0.012 to 0.12 ng g^?1 by Co-PCBs. Possible PCDD/DFs sources are discharged PCBs, open burning of waste wire/scrap, and pentachlorophenol. the consumption of these fish will cause an average intake of 54 pg kg^?1 d^?1 TEQ. the prevention of direct discharge of livestock and the dumping of waste effuents into River Er-Jen as well as the control of metal recovery activities appears to be the first step toward the restoration of River Er-Jen.     

Benzo [a] pyrene concentrations in topsoils of North Bahrain

A comprehensive field study was conducted to determine the background concentrations of benzo [a] pyrene (B[a]P) in soil samples collected at different points on a grid covering most of the northern and middle parts of the Kingdom of Bahrain. The average B[a]P concentration was 108.4?ng?g^?1 in winter and 73.0?ng?g^?1 in summer. The capital city, Manama, and the industrial areas of the country showed the highest levels of B[a]P.     

北江流域抗生素污染水平和来源初探

北江是发源于湖南(武水)和江西(浈水),汇于广东韶关,流经广东全境并入海的三大河流之一。为了解整个北江抗生素污染情况,共设置44个采样点,并采集了河水及部分沉积物样品,较全面地分析了各样品中12种典型抗生素含量并初步探究了其污染来源。研究发现,包括北江源头在内的全河段均有抗生素的检出,5类抗生素在表层水和沉积物中的平均浓度分别为77.8 ng·L~(-1)和3.6 ng·g~(-1)。其中,大环内酯类污染最为严重,其含量范围为11.7~114.6 ng·L~(-1)和0~435.3 ng·g~(-1),远高于其他类抗生素。表层水中磺胺类的磺胺甲恶唑和氯霉素类的检出率达100%,其中以磺胺甲恶唑(14.7 ng·L~(-1))和阿奇霉素(25.0 ng·L~(-1))为主,而沉积物中以阿奇霉素(35.9 ng·g~(-1))、氧氟沙星(5.4 ng·g~(-1))和四环素(3.3 ng·g~(-1))为主。由于流域污染源种类和数量不同,各抗生素在北江中的分布也存在差异。表层水中抗生素含量水平表现为下游高于上中游,在沉积物中则主要集中于中、下游之间河段。这反映了人类活动强度对北江抗生素污染的直接影响。