Terrestrial Model Ecosystems (TMEs) are frequently used to assess the potentially harmful effects of contaminants on terrestrial organisms. Therefore we have used this tool to simulate the leaching phenomena from agricultural soils, within the drainage basin of Lake Vela (Figueira da Foz, Central Portugal), and to perform a subsequent evaluation of the toxicity of the leachates obtained, after the treatment of soil-cores with the herbicide Lasso® on non-target freshwater species. Hence, standard (algae: Pseudokirchneriella subcapitata; cladoceran: Daphnia magna) and autochthonous (algae: Aphanizomenon flos-aquae; cladoceran: Daphnia longispina) species were exposed to several dilutions of leachates obtained from the application of different treatments to soil-cores collected in an agricultural field in the Lake Vela surrounds: RW-soil-core irrigated with artificial rain water; RW+L-soil-core irrigated with artificial rain water after the application of Lasso®; GW+L-soil-core irrigated with groundwater collected in local wells, after the application of Lasso®. Chemical analysis confirmed the presence of alachlor (active ingredient of Lasso®) in the leachates RW+L and GW+L at concentrations of 88 and 16.9 μg L⁻¹ respectively. As expected, the results demonstrated that the leachate RW was not toxic for the tested species. However, leachates where the herbicide was applied, particularly the RW+L, was highly toxic to P. subcapitata (96 h-IC₅₀ = 9.7%), contrasting with the absence of toxic effects in A. flos-aquae. Notwithstanding the effects on algae, the reproduction and growth of both daphnids were not affected by the potential toxicity of leachates. Nevertheless, our results were consistent with the chemical analysis and alachlor ecotoxicity data reported in the literature. Our study confirmed that the current use of pesticides in the lands near Lake Vela, especially Lasso®, combined with the specific properties of local soils, can contribute to the contamination of surface and groundwater resources, through leaching, and could compromise the weak balance of the freshwater ecosystem by affecting one of the main trophic levels: the primary producers.

Two environmental relief compartments from Sinos Valley, Rio Grande do Sul State, Brazil, interpreted in the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) images, are contaminated, in different ways, by two industrial landfills. One of the landfills is located in a fluvial plain with thin superficial sediments made of expansive clays. In this landfill, metals like Cr, Co, Ni, Cu, Pb, Zn, and Ba, have concentrated more than that of other landfill, which is located on a low hill in a sedimentary arenitic terrain. The metals have also accumulated in plant tissues in the investigated areas. Plants have accumulated more Mn, Zn, Ba, and Cu.

A gully pot is often cleaned with the help of an eductor truck, which uses hydrodynamic pressure and a vacuum to loosen and remove the solids and standing liquid from a gully pot. This paper considers the polycyclic aromatic hydrocarbons (PAH) content in the gully pot mixture (water and sediment) after it has been discharged from the eductor truck. The results show that most PAH was attached to particles, and the dissolved phase represented approximately 22% of the total water concentration. No significant difference was found for the water phase between a housing area and a road, whereas a significant difference was found for NAP, ACE, FL, ANT, FLR, PYR, BaF, and BPY in the sediment at a 95% confidence level. Source identification showed that the PAH in the gully pot mixture came from mixed sources. Both the water and sediment phase exceed all or some of the compared guidelines. The result from this paper shows that not only the sediment needs to be discussed, but also the water phase created during the maintenance of different BMPs.

Environmental regulations often rely on limits or thresholds to indicate an acceptable pollutant load. Estimates of the Risk of Exceeding such Thresholds (RET) are often based on a single model deemed to be the best for the particular pollutant or particular case. However, if many models make different predictions but explain the data almost equally well, predictions based on a single model may omit important information contained in other models that fit almost as well as the “best” single model. More accurate assessments of RET may result if multiple models are considered. We compared performance of the single best model relative to that of an ensemble of models estimated by bagging (Bootstrap AGGregatING) using the example of soil P concentrations and the risk of exceeding environmental limits of soil P concentrations in the watershed of Lake Mendota, Wisconsin, USA. Bagging yielded significantly better predictions of the risk of exceeding a threshold level of soil P (99.6% accuracy versus 74% for single-model prediction at a 20 mg kg⁻¹ threshold). Use of multiple model techniques can improve estimates of RET over a range of realistic thresholds in other management situations where thresholds are important including eutrophication, desertification, fisheries, and many types of pollution control.

Different nitrogen (N) fractions from 14 sediments from the shallow lakes in the middle and lower reaches of Yangtze River area before and after N release experiments were investigated, and the content of different N fractions, and contribution of different N fractions to the N released from sediments were also studied. Ion-exchangeable form (IEF-N), carbonate form (CF-N), iron-manganese oxide form (IMOF-N) and organic matter-sulfide form (OSF-N) accounted for 2.72~17.67%, 0.47~4.43%, 1.18~3.49% and 31.05 to 71.61% to total N, respectively. The N released was higher than 50% from IEF-N, approximately 35% from OSF-N, 6 and 8% from CF-N and IMOF-N on the average. Approximately 27.32~70.02% of IEF-N, 10.37~32.11% of CF-N, 11.37~33.43% IMOF-N and 2.02~8.19% OSF-N were released. For the sediments that were slightly polluted, IEF-N was the main N fraction that may be released and its contribution to total N released was more than 63.07%, for the sediments that TN was higher than 3,540.27 mg·kg-¹, OSF-N would become the main N fraction that can be released and its contribution to total N released was more than 45%.

The presence of pharmaceuticals and personal care products (PPCPs) and endocrine disrupting chemicals (EDCs) in treated wastewater is gaining attention due to their potential environmental impact. An analytical method was developed to quantify estrogen compounds in samples from a concentrated wastewater matrix typical of water recycling systems used in space. The method employed conventional HPLC with UV detection. Solid phase extraction (SPE) was used to isolate the compounds of interest from wastewater. Spike-recovery tests in clean and wastewater matrices were used to test the extraction process. The results of these experiments suggest that deconjugation is the most predominant reaction occurring in the systems, as effluent concentrations of free estrogens typically exceeded influent concentrations. Despite the long retention times of the system or the near infinite solids retention time, free estrogens were not removed from graywater representative of space waste streams. For a closed-loop wastewater treatment system, these compounds may accumulate to levels requiring other removal mechanisms (i.e., reverse osmosis).

We determined the concentrations and residue patterns of 20 persistent organochlorine pesticides (OCPs), including hexachlorocyclohexanes (HCHs), hexachlorobenzene, dichlorodiphenyltrichloroethanes (DDTs), chlordane-related compounds (CHLs), mirex, dieldrin, endrin, and aldrin, in muscle of rainbow trout from Lake Mashu, Japan. Total concentrations of OCPs varied from 1.0 to 132 ng g-¹ lipid weight. α-HCH was the most prevalent OCP contaminant in the fish muscle. Using the daily fish consumption in Japan (95.2 g), the mean weight of a Japanese adult (50.0 kg), and residual pesticide concentrations, we calculated the estimated daily intakes of γ-HCH, DDTs, CHLs, and dieldrin for humans to be 0.39, 0.48, 0.68, and 0.08 ng kg-¹ day-¹, respectively. Judging from acceptable daily intakes established by the Food and Agriculture Organization of the United Nations and the World Health Organization, we believe that these OCP levels would not adversely affect human health.

The Paraíba do Sul river is located in one of the most developed part of Brazil and receives many organic and industrial effluents directly affecting the ichthyofauna. Concentration of four heavy metals (Cu, Cr, Zn and Pb) were determined in two tissues (muscle and gonads) of three abundant fish species from different trophic levels (Oligosarcus hepsetus--carnivore, Geophagus brasiliensis--omnivore and Hypostomus luetkeni--detritivore) between November 2002 and April 2003. The aim was to test the hypothesis that the trophic level and the proximity from impacted areas influence levels of contamination and to assess if these species are indicators of large-scale habitat quality. Levels of heavy metals were detected by Total Reflection X-ray Fluorescence with Synchrotron Radiation (SR-TXRF) at the Brazilian National Synchrotron Radiation Laboratory (LNLS). Generally, gonads showed higher metal concentration than muscles, except for Cr. All examined metals, but Cu, exceeded the maximum permitted concentration (mpc) by the Brazilian legislation for human consumption in at least one tissue. O. hepsetus (carnivore) showed the highest contamination levels, followed by G. brasiliensis (omnivore) and H. luetkeni (detritivore). The middle-upper segment, which encompasses large urban areas, showed the highest levels of metal contamination in most cases. O. hepsetus showed the highest levels of contamination in muscles for Pb in the middle-upper river segment (7.98 ± 3.73; mpc = 2.0 μg g-¹) and for Cr in the upper (5.53 ± 0.05; mpc = 0.10 μg g-¹) and middle-upper (4.20 ± 0.85; mpc = 0.10 μg g-¹) segments, which indicates that human population should avoid to consume these fishes species from these segments of the Paraíba do Sul river.

Atrazine-contaminated soil may require remediation to mitigate ground and surface water contamination. We determined the effectiveness of nano zerovalent iron (nano ZVI) to dechlorinate atrazine (2-chloro-4ethylamino-6-iso-propylamino-1,3,5-triazine) in contaminated water and soil. This study determined the effects of iron sources, solution pH, Pd catalyst and presence of Fe or Al sulfate salts on the destruction of atrazine in water and soil. Our results indicate nano ZVI can be successfully used to remediate atrazine in water and soil. Aqueous solution of atrazine (30 mg l⁻¹) was treated with 2% (w/v) of nano ZVI and 5% (w/v) of commercial ZVI. Although, iron dose in nano ZVI treatment was less than that in commercial ZVI treatment, atrazine destruction kinetic rate (k obs) of nano ZVI treatment (1.39 days⁻¹) was around seven times higher than that of commercial ZVI treatment (0.18 days⁻¹). Reductive dechlorination was the major process in destruction of atrazine by nano ZVI. The dechlorination product was 2-ethyl-amino-4-isopropylamino-1,3,5-triazine. Lowering the pH from 9 to 4 increased the destruction kinetic rates of atrazine by nano ZVI. Moreover, nano ZVI/Pd enhanced destruction kinetic rates of atrazine (3.36 day⁻¹). Pd played the important role as a catalyst during treatment of atrazine by nano ZVI. Atrazine destruction kinetic rates were greatly enhanced in both contaminated water and soil treatments by nano ZVI when sulfate salts of Fe(II), Fe(III) or Al(III) was add with the following order of removal rates: Al (III) (2.23 day⁻¹) > Fe (III) (2.04 day⁻¹) > Fe(II) (1.79 day⁻¹). The same results were found in atrazine-nano ZVI-soil incubation experiments.

The transport, bioavailability and fate of aqueous metals in rainfall-runoff are determined, in part, by speciation. In the framework of a monitoring program to investigate the predominant species of zinc, copper, and water chemistry in runoff subject to aviation land use and activities, two rainfall-runoff monitoring stations were installed at the international airport of Genoa (Italy). One catchment was a boarding area (airside) apron and the other a parking area for vehicles (landside). Utilizing water chemistry analyses, ion balances and speciation modelling for a series of five event loadings for each site, results indicated that Zn²⁺ dominated Zn speciation and Cu complexes with carbonate or dissolved organic matter, dominated Cu speciation. With respect to wash-off processes a mass limited behaviour was generally observed for particulate matter (measured as TSS) and TOC; while the mass delivery of aqueous metal species tended to be more proportionate with respect to runoff volume.