Typical features of particulate phosphorus in the Seine estuary (France)

During the 2001–2002 hydrological cycle, 8,000 tons P year⁻¹ (44% as particulate phosphorus) originating from the Seine basin entered the Seine estuary. P content in suspended sediments (SS) is 2.9 g P kg⁻¹ (80% as inorganic form) at Poses (the upstream limit of the Seine estuary). During the transfer from Poses to Caudebec (the limit of saline water intrusion), Particulate Inorganic Phosphorus (PIP) in SS decreases by 40% whereas Particulate Organic Phosphorus (POP) remains stable. This decrease is explained as the result of (i) a dilution by SS poorer in P, originating from storage zones (mudflats) within the estuary, and (ii) a loss of P by sedimentation, especially in the Rouen harbour where 15% to 20% of SS are yearly trapped and extracted. Downstream, in the turbidity maximum of the estuary, P content in SS is twice as low as at Poses (1.5 g P kg⁻¹, 70% as inorganic form). PIP content is fairly homogeneous both vertically and throughout an annual survey. On the other hand, POP varies by season. Higher POP content is observed during vernal period with phytoplankton accumulation. In a salinity gradient from 0 to 30 (PSS78), PIP content further decreases by 30%. POP does not vary much in this gradient, leading to the assumption that PIP is submitted to desorption in response to the dilution by marine waters (poor in orthophosphates). Using ³²P isotopic method, we establish a mathematical formulation of P exchangeable between the suspended solid and water phases of the Seine estuary. Particulate P in the turbidity maximum zone is shown to represent a possible source of dissolved P, available for algal growth in the Seine Bight. Instead of playing a role of nutrient retention, the turbidity maximum zone of the Seine estuary could favour coastal eutrophication.     

Health risk assessment of atmospheric polycyclic aromatic hydrocarbons over the Central Himalayas

Carcinogenic risk assessments of polycyclic aromatic hydrocarbons (PAHs) in four sites from the Central Himalayas (Bode, Lumbini, Pokhara, and Dhunche) were performed. Lifetime Average Daily Dose (LADD), Lifetime lung cancer risk (LLCR) and Incremental lifetime cancer risk (ILCR) were calculated in order to evaluate the cancer risk. PAHs levels were converted to BaP equivalent concentrations (B[a]Peq), and models of health risk assessment were applied. B[a]Peq concentrations exceeded the standard limited value (1 ng/m³) in all the four sites. The human health risk assessment (HHRA) demonstrated high carcinogenic risk on residents of Bode and Lumbini. Further, LLCR in all sites were over the acceptable range (1.15E-03, 7.90E-04, 1.40E-04 and 9.96E-05, respectively); however, ILCR ranking exhibited acceptable range in Lumbini, Pokhara, and Dhunche (7.10E-06, 1.26E-06, and 8.95E-07). The risk variation among the sites is due to the difference in pollution status. The study shows health risk due to atmospheric PAHs via inhalation prevails all the seasons throughout, differing only seasonally; nevertheless, the concentration and carcinogenic risk decreased remarkably from south-north transect of the central Himalaya. Keeping some uncertainties aside, this study provides noble insights and helps to formulate new advance assessment on the carcinogenic risk of atmospheric PAHs over the Central Himalayas.     

长江口南支表层沉积物中多环芳烃分布特征及生态风险

2008年5月和8月先后2次采集长江口南支表层沉积物样品,采用高效液相色谱进行多环芳烃测定,研究其分布、来源与生态风险。结果表明:长江口南支表层沉积物中PAHs总量在8.9~312.2ng.g-1;PAHs组成以芘、菲、苯并[b]荧蒽、苯并[a]蒽、苯并[a]芘为主,各站芘的含量均最高,本研究PAHs总含量与长江口、黄河口和鸭绿江口近期的调查数据相近,但明显低于珠江口和闽江口数据,以及长江口潮滩沉积物中PAHs数据;PAHs环数组成以中、高环为主,表明长江口南支PAHs主要来源于相对高温条件下不完全燃烧过程。采用平均效应中值商法评价长江口南支PAHs生态风险结果表明,调查区域PAHs产生生态风险的概率较小(<10%)。     

荒漠草地中氮添加与多环芳烃降解的关系

多环芳烃作为环境污染物中一类极为重要的物质,探索它的去除方法吸引了全球环境学者及政府的高度重视。大气氮沉降在过去几十年不断增加,已影响到陆地生态系统氮循环过程。但目前,氮沉降与多环芳烃降解之间的关系尚不明确。通过在新疆克拉玛依市石油化工厂附近的荒漠草地上,模拟氮沉降实验,通过在4氮添加梯度(CK=0; N1=10; N2=30; N3=90 kg N hm~(-2) a~(-1))上调查土壤中16种优先控制多环芳烃的含量和总量(∑PAHs),以及它们与生物非生物环境因子(土壤环境因子、土壤酶活性和土壤微生物功能多样性)之间的关系,旨在揭示氮沉降对多环芳烃降解的影响。结果表明:除苊烯(Acenaphthylene)和苊(Acenaphthene)两种多环芳烃在4个N添加梯度上未检测到含量外,∑PAHs和其他14种优先控制多环芳烃在土壤中的含量均随氮添加量增加显著减小(N2≤N3N1CK)(P0.01);对照样地(CK)在施氮前后,低高分子多环芳烃含量的比值1.00,且0.40荧蒽(Fluoranthene)/[(荧蒽(Fluoranthene)+芘(Pyrene)]0.50,石油污染物是当地土壤中多环芳烃的主要来源;9月份克拉玛依市荒漠草地土壤中∑PAHs约(28.91±2.32) mg/kg,属于多环芳烃重污染土壤;广义线性混合效应模型结果显示,在大多数情况下,∑PAHs和14种多环芳烃的含量与土壤有机质、铵态氮、硝态氮、总氮、有效磷和脲酶活性显著相关(P0.05),但其与生物非生物环境因子之间的回归关系在不同种类多环芳烃之间差异较大。综上可知,土壤中多环芳烃的降解是一个非常复杂的过程,它是自身属性、植物根系和土壤微生物等多重因子相互共同作用的结果。在干旱区荒漠草地中,氮添加能提升土壤中营养物质的可利用性、植物根系和土壤微生物的活性,有利于降解土壤多环芳烃。     

城市土壤中多环芳烃分布和风险评价研究进展

随着城市化进程的加快,城市土壤中的多环芳烃（PAHs）污染日趋严重.本文从城市土壤中多环芳烃的分布和来源等方面综述了国内外取得的最新研究成果,对影响城市土壤多环芳烃分布的人为因素、自然因素,常见的多环芳烃源解析方法,以及城市土壤多环芳烃污染的风险评价进行了全面的阐述,尤其对地统计学在多环芳烃空间分析及风险评价上的应用进行了总结.最后,对未来城市土壤中多环芳烃研究的重点与发展趋势进行了展望.     

Convergent signs of degradation in both the capacity and the quality of an essential fish habitat: state of the Seine estuary (France) flatfish nurseries

The Bay of Seine is a potentially important nursery ground, especially for flatfish. This area, however, is also strongly anthropogenically influenced. A composite approach was chosen to compare the flatfish nursery function of the Seine estuary with other coastal and estuarine areas and to determine the impact of anthropogenic disturbances. It emerges that alteration of the nursery function in the Seine estuary is related to the loss of nursery habitat and to a lower quality of the residual surfaces. These observations stressed the importance of habitat destruction and decreased quality of remaining habitat for fish stocks renewal.     

Evaluating ecosystem-level anthropogenic impacts in a stressed transitional environment: The case of the Seine estuary

During 2002–2005, a new container terminal in the commercial harbour of Le Havre, named “Port2000”, was built on the northern flank of the Seine estuary, northern France. This extension is already known to have modified the estuary current and sediment dynamics, as well as reducing biomass of the suprabenthos assemblage, for the whole downstream part of the system. However, studies on other biotic communities were largely inconclusive, and an ecosystem-wide analysis was still lacking. Here, we performed a before/after study of ecosystem dynamics of the different habitats of the Seine estuary, using a Linear Inverse Modelling technique (LIM-MCMC) to estimate all flows occurring in the food web. Ecological Network Analysis indices were calculated, summarising ecosystem functioning traits and giving indications about the habitat health status. Results showed that the southern flank (FS, Fosse Sud) exhibits all characteristics to be considered as the least stressed habitat of the estuary: system activity and functional specialisation of flows were stable between periods, ecosystem recycling processes and detrital dynamics were also stable; an increase in trophic specialisation (decrease in system omnivory) was the only change confirming a general ecological succession. The northern flank (FN, Fosse Nord), where the actual terminal was built, showed a food web with increased importance of lower trophic levels (increased detritivory and carbon recycling), increased stability and flow efficiency, but possibly regressed to a previous step in ecological succession. In the central navigation channel (CH), patterns of network indices were overall inconclusive and the general image is one of a constantly shifting food web, a condition possibly caused by the year-round dredging activities. The functioning of the Seine estuary – especially of FN and FS – seems to have been modified by the combination of harbour construction and the related mitigation measures. Network indices partially captured this combination of changes and, although not fully operational yet, they are promising tools to comply with the European Union mandate of defining ecosystem health status.     

The food web in the lower part of the Seine estuary: a synthesis of existing knowledge

The Seine estuary illustrates the alterations to estuaries due to human activities heavy releases of pollutants of various origins and significant morphological changes beginning in the middle of the 19th century. The intertidal mudflat surface has been seriously reduced (< 30km²) since the channels of the Seine River came under management. While the role of the Seine estuary in the dynamics of the eastern English Channel ecosystem is recognized as important, the biological characteristics of the estuary remained relatively unknown until the 1990s. Biological diversity was progressively impoverished from the polyhaline zone to the oligohaline zone. In spite of a heavily contaminated environment, the macrobenthic and planktonic fauna of the Seine estuary remains similar to those of other northeastern Atlantic estuaries. The fauna exhibit clear contrasts between areas with very high abundance and others with very low abundance. The pelagic fauna, especially the copepod Eurytemora affinisand the shrimp Palaemon longirostris, are more abundant in the Seine estuary than in other estuaries. Diversified and abundant, Abra alba-Pectinaria koreni and Macoma balthica benthic communities occur, respectively, in the outer and inner parts of the estuary. In subtidal flats, benthic fauna is especially poor in terms of specific richness, abundance and biomass. Paradoxically, considering the high abundance of prey, fish are particularly scarce. Two food webs have been identified. In the oligohaline zone, where turbidity is maximum, the food web is exclusively planktonic, due to dredging that prevented benthic fauna from settling. In the polyhaline zone, fish populations that feed particularly on benthic fauna benefit from low turbidity and high oxygen concentrations. So, in spite of heavy organic and metallic contamination and human activities, the Seine estuary remains a highly productive ecosystem, which provides a nursery for marine fish and feeding grounds for migratory birds. A global management plan appears to be necessary in order to guarantee that the Seine estuary continues to function as it currently does.     

Cooxidation of naphthalene and other polycyclic aromatic hydrocarbons by the nitrifying bacterium,Nitrosomonas europaea

The soil nitrifying bacterium Nitrosomonas europaea has shown the ability to transform cometabolically naphthalene as well as other 2- and 3-ringed polycyclic aromatic hydrocarbons (PAHs) to more oxidized products. All of the observed enzymatic reactions were inhibited by acetylene, a selective inhibitor of ammonia monooxygenase (AMO). A strong inhibitory effect of naphthalene on ammonia oxidation by N. europaea was observed. Naphthalene was readily oxidized by N. europaea and 2-naphthol was detected as a major product (85%) of naphthalene oxidation. The maximum naphthol production rate was 1.65 nmole/mg protein-min in the presence of 240 M naphthalene and 10 mM NH₄ ⁺. Our results demonstrate that the oxidation between ammonia and naphthalene showed a partial competitive inhibition. The relative ratio of naphthalene and ammonia oxidation, depending on naphthalene concentrations, demonstrated that the naphthalene was oxidized 2200-fold slower than ammonia at lower concentration of naphthalene (15 M) whereas naphthalene was oxidized only 100-fold slower than ammonia oxidation. NH₄ ⁺- and N₂H₄-dependent O₂ uptake measurement demonstrated irreversible inhibitory effects of the naphthalene and subsequent oxidation products on AMO and HAO activity.     

Biotreatability of polycyclic aromatic hydrocarbons in brackish sediments: Preliminary studies of an integrated monitoring

An integrated monitoring, of chemical, microbiological and ecotoxicological parameters, was performed for a biotreatability study of polycyclic aromatic hydrocarbons (PAHs)—contaminated brackish sediments. Three slurry reactors were prepared, consisting of (a) a slurry with sediment and seawater called TQ slurry, to evaluate the intrinsic bioremediation potential, (b) a slurry with the addition of a selected microbial consotrium called BIO slurry, to evaluate the bioaugmentation effect, (c) a slurry with the addition of Soya lecithin called LEC slurry, to evaluate the effect of the addition of a natural surfactant. Biodegradation results showed that both BIO and LEC slurries enhanced PAHs removal, increasing the biodegradation rate for 5- and 6-ring PAHs. Furthermore, ecotoxicological response (Microtox® assay on whole sediment, aqueous extract and organic extract) demonstrated a detoxification of the PAHs initial mixture only for BIO slurry. The findings that aerobic PAHs degradation can be stimulated via inoculation with adapted sediment bacteria suggest that a bioaugmentation process may be a useful strategy for ex-situ treatment.     

Occurrence and risk assessment of polycyclic aromatic hydrocarbons in the Hanjiang River Basin and the Danjiangkou Reservoir,China

This study was conducted to investigate the occurrence, distribution, and source of 16 polycyclic aromatic hydrocarbons (PAHs) in the Hanjiang River Basin and the Danjiangkou (DJK) Reservoir. The concentrations of total PAHs in surface water, sediments, and bank soils ranged from 9.42 to 137.94 ng/l, 86.23 to 2514.93 ng/g, and 133.17 to 671.93 ng/g dry weight, respectively. The composition pattern of PAHs showed that 3-ring PAHs were dominated in all of the samples, while the proportion of high molecular weight PAHs (5- to 6-ring PAHs) in sediments and bank soil samples was almost three times higher than water. The source apportionment analysis showed that most of the PAHs in water were derived from sources of petroleum and combustion, while combustion was the predominant source of PAHs in sediments and bank soils. The methods based on toxic equivalency factors, risk quotient, and incremental lifetime cancer risk were used to assess the ecosystem risk and potential health risk of PAHs. The risk assessments showed that PAHs in the DJK Reservoir were out of potential health risk, but the ecological risk for majority of 16 PAHs was in the moderate level.     

Phytoremediation of polycyclic aromatic hydrocarbons in soil: part I. Dissipation of target contaminants

Phytoremediation has been demonstrated to be a viable cleanup alternative for soils contaminated with petroleum products. This study evaluated the application of phytoremediation to soil from a manufactured gas plant (MGP) site with high concentrations of recalcitrant, polycyclic aromatic hydrocarbons (PAHs). Two greenhouse studies investigated the potential dissipation and plant translocation of PAHs by fescue (Festuca arundinacea) and switchgrass (Panicum virgatum) in the first experiment and zucchini (Curcubita pepo Raven) in the second. The MGP soil was highly hydrophobic and initially inhibited plant growth. Two unplanted controls were established with and without fertilization. In the first experiment, concentrations of PAHs decreased significantly in all treatments after 12 mo. Plant biomass and microbial numbers were statistically equivalent among plant species. PAH concentrations in plant biomass were negligible for fescue and switchgrass. In the second experiment, zucchini enhanced the dissipation of several PAHs after 90 d of treatment when compared to the unvegetated soil. Plant tissue concentrations of PAHs were not elevated in the zucchini roots and shoots, and PAHs were not detectable in the fruit.     

污灌土壤中多环芳烃（PAHs）的积累与动态变化研究

对污灌土壤中 1 4种多环芳烃的分析表明 ,各灌区土壤中 PAHs的积累一般以渠首最高 ,渠中次之 ,渠尾含量与对照相当 .但在沈抚石油灌区上、中和下游土壤中均有PAHs的积累 .此外 ,水稻生长期污灌可明显增加土壤中 PAHs的总量 ,各单一污染物的增、减趋势有所不同 .     

Multispecies and monoculture rhizoremediation of polycyclic aromatic hydrocarbons (PAHs) from the soil

In this study, we investigated the potential of multispecies rhizoremediation and monoculture rhizoremediation in decontaminating polycyclic aromatic hydrocarbon (PAH) contaminated soil Plant-mediated PAH dissipation was evaluated using monoplanted soil microcosms and soil microcosms vegetated with several different grass species (Brachiaria serrata and Eleusine corocana). The dissipation of naphthalene and fluorene was higher in the "multispecies" vegetated soil compared to the monoplanted and nonplanted control soil. The concentration of naphthalene was undetectable in the multispecies vegetated treatment compared to 96% removal efficiencies in the monoplanted treatments and 63% in the nonplanted control after 10 wk of incubation. Similar removal efficiencies were obtained for fluorene. However, there was no significant difference in the dissipation of pyrene in both the mono- and multispecies vegetated treatments. There also was no significant difference between the dissipation of PAHs in the monoplanted treatments with different grass species. Principle component analysis (PCA) and cluster analysis were used to evaluate functional diversity of the different treatments during phytoremediation of PAHs. Both PCA and cluster analysis revealed differences in the metabolic fingerprints of the PAH contaminated and noncontaminated soils. However, the differences in metabolic diversity between the multispecies vegetated and monoplanted treatments were not clearly revealed. The results suggest that multispecies rhizoremediation using tolerant plant species rather than monoculture rhizoremediation have the potential to enhance pollutant removal in moderately contaminated soils.     

土壤－植物系统中多环芳烃和重金属的行为研究

对土壤中多环芳烃和重金属的行为研究表明,与对照相比,０—２０ｃｍ以上表土层存在多环芳烃和重金属积累,２０ｃｍ以下土层未发现积累;与春、秋两次采样结果相比,土壤中多环芳烃的含量有所下降,表明土壤微生物对多环芳烃有一定降解作用,且其降解程度与土壤－植物系统的生态结构有关．菲在地下水中检出浓度较高,表明这一污染物有向下迁移的可能性．此外,柳树对土壤中重金属Ｃｄ的积累有明显的削减与净化作用．本研究表明,严格限制污水中多环芳烃和重金属的污染负荷以及设计合理的生态结构是避免多环芳烃和重金属在土壤中积累的关键．     

Distribution, sources and potential toxicological significance of polycyclic aromatic hydrocarbons (PAHs) in Taihu Lake sediments, China

Taihu Lake is one of the largest freshwater lakes in China. The lake is very shallow with a mean depth of 1.9 m and an area of 2428 km². This is the first time that polycyclic aromatic hydrocarbon concentrations in the surface sediments of Taihu Lake have been analyzed. A distinctive spatial distribution of PAHs was observed. Sediments from Lake Wulihu and Meiliang Bay (sites 1–5) had significantly higher PAH concentrations (858–5260 g kg^–1 dw) than any other area of Taihu Lake. These high PAH levels were associated with the input of untreated and partially treated domestic and industrial sewage from Wuxi, Changzhou, Wujin and other cities. Special PAH ratios, such as phenanthrene/anthracene and fluoranthene/pyrene, were calculated to evaluate the relative importance of different origins. The data confirmed a relatively high level of petrogenic contamination in sites 1–5 (mainly sewage discharge and the river runoff). The other samples were further from the sources of pollution and have relatively low PAH concentrations (410–768 g kg^–1 dw). The sources of PAHs in these sites (6–13) were characterized by combustion-derived PAH contamination associated with atmospheric deposition. In addition, effects range low (ERL) and effects range median (ERM) guidelines (Long et al., 1995) were used to estimate the potential of adverse effects resulting from PAH contamination in Taihu Lake sediments. The results indicated that some sites in the northern part of the lake had levels of PAH that exceeded the ERL value. This was interpreted to mean that acute biological effects may occasionally be expected to occur.     

基于吐温-80下2株功能菌协同降解多环芳烃的特性研究

【目的】研究恶臭假单胞菌B6-2和克雷伯氏菌CW-D3T构建的混合功能菌对多环芳烃的协同修复效能,并探究非离子表面活性剂吐温-80对混菌降解多环芳烃的影响,以期为芳烃化合物的生物修复提供技术参考和理论依据。【方法】通过生长曲线及平板菌落计数法反映混菌生长情况及比例,从而评估混菌降解体系的可行性;通过高效液相色谱法探究各体系以及不同吐温-80浓度下混培体系对多环芳烃的降解效能;最后通过烷烃吸附法测定细胞表面疏水性,以探究吐温-80对混合功能菌降解多环芳烃的影响机制。【结果】等比例混合的2株菌共培养生长状态优于纯培体系,对混合多环芳烃(菲、荧蒽、芘)的降解率分别为33.4%、30.1%、28.6%(7 d),相较于菌CW-D3T,分别提高了1.31倍、1.46倍、1.42倍。混培体系中加入500 mg/L的吐温-80对菲、荧蒽、芘的降解率分别为47.7%、43.2%、38.8%(7 d),相较于对照组各提高了1.55倍、1.38倍、1.31倍,而更高浓度的吐温-80无明显促进作用或轻微抑制。添加吐温-80使菌CW-D3T和混菌的表面疏水性提高,而菌B6-2表面疏水性降低。结合细菌生长量分析...     

两种植物条件下土壤中矿物油和多环芳烃（PAHs）的生物修复研究

选择苜蓿草和水稻为供试植物,以污染物水平、有机以、专性细菌和真菌为调控因子,进行土壤中矿物油和PAHs的生物修复研究,结果表明,投肥对苜蓿草土壤中矿物油降解有促进作用,但对水稻土壤中矿物油降解无明显作用,投肥均使苜蓿草和水稻土壤中多环芒烃总量（11种列于美国EPA黑名单上的多环芳烃）降解率提高,这一降解促进效果在水稻土壤中好于苜蓿草土壤,有机肥量与苜蓿草根际土著真菌、细菌数量明显呈正相关,但仅与水稻根际土著细菌数量呈明显正相关,两种土壤中实测真菌和细菌总数均与试验投加专性真菌和细菌量无关,水稻土和苜蓿草土壤中3环多环芳烃的降解随投肥量增大而降解率提高,其在水稻土蓑中的效果好于苜蓿草土壤,投肥怪4环多环芳烃的降解并未产生有效作用。     

Measurement of biodegradability parameters for single unsubstituted and methylated polycyclic aromatic hydrocarbons in liquid bacterial suspensions

Substrate depletion experiments were conducted to characterize aerobic biodegradation of 20 single polycyclic aromatic hydrocarbons (PAHs) by induced Sphingomonas paucimobilis strain EPA505 in liquid suspensions. PAHs consisted of low molecular weight, unsubstituted, and methyl-substituted homologs. A material balance equation containing the Andrews kinetic model, an extension of the Monod model accounting for substrate inhibition, was numerically fitted to batch depletion data to estimate extant kinetic parameters including the maximal specific uptake rates, q(max), the affinity coefficients, K(S), and the substrate inhibition coefficients, K(I). Strain EPA505 degraded all PAHs tested. Applied kinetic models adequately simulated experimental data. A cell proliferation assay involving reduction of the tetrazolium dye WST-1 was used to evaluate the ability of strain EPA505 to utilize individual PAHs as sole energy and carbon sources. Of the 22 PAHs tested, 9 supported bacterial growth. Evaluation of the biokinetic data showed that q(max) correlated highly with transmembrane flux as theoretically estimated by a diffusion model, pointing to transmembrane transport as a potential rate-determining process. The biodegradability data generated in this study is essential for the development of quantitative structure-activity relationships (QSARs) for biodegradability and for modeling biodegradation of simple PAH mixtures.     

Seasonal variations of metal pollution and distribution,sources, and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in sediment of the Al Hawizah wetland,Iran

The pollution of surface sediments of Al Hawizah wetland by metals and polycyclic aromatic hydrocarbons (PAHs) has been fully investigated. For determination of PAHs and metals concentration in sediments, eight sampling stations were selected in the study area. The results showed that the concentration of Mn is the highest, while the content of Cr is the lowest in both the seasons. The concentration of Cr and V is lower than mean crust content, while Cu concentration is more than mean crust content. The results obtained from Muller's geochemical index are indicative of range from uncontaminated to moderately contaminated. Based on potential ecological risk (RI), the Al Hawizah wetland had low ecological risk. The total PAHs concentrations ranged from 1071 to 15540 ng/g dry weight, with a mean of 9417.50 ng/g in the summer, while total amounts of PAHs in the winter ranged from 1542 to 17283 with a mean 10321.25 ng/g dry weight. The area of study was affected by pyrogenic and petrogenic sources (51.74 and 48.26%, respectively), in the winter. The concentrations of polycyclic aromatic hydrocarbons (PAHs) compounds were lower than effects range median (ERM) standard while were higher than effects range low (ERL) standard, except station 1, in both seasons.