Background, aim and scope Precipitation samples collected from 1995 to 2000 at meteorological station in the eastern outskirts of Herceg Novi (Montenegro) were analysed on Na⁺, K⁺, Mg²⁺, Ca²⁺, Cl⁻, SO₄ ²⁻, NO₃ ⁻ and NH₄ ⁺. Four-day backward trajectory simulations were conducted during the precipitation period to investigate the regional transport of main ions and their deposition in the region of the southeastern Adriatic Sea. The air mass trajectories were classified into six trajectory categories by the origin and direction of their approach to Herceg Novi. Materials and methods A bottle and funnel with a small net between them was used for sampling at a height of 1.5 m above the ground. The concentrations of Cl⁻, NO₃ ⁻, NH₄ ⁺ and SO₄ ²⁻ were determined spectrophotometrically, the concentrations of Na⁺ and K⁺ were determined by the FAES method and the concentrations of Mg²⁺ and Ca²⁺ by the FAAS method. The factor analysis technique (PCA analysis) based on the calculation of the factors was employed to differentiate the contribution of emission sources to the content of the main ions in the precipitation. The obtained data sets were processed using the SPSS 11.5 statistical program. The Hybrid Single-Particle Lagrangian Integrated Trajectory model was used to study the air origin for the city of Herceg Novi (42°27′N, 18°33′E), Montenegro. Discussion The following origins of the air masses were considered: northern Europe (NE), eastern Europe-northeastern Europe (EE-NE); eastern Mediterranean-southeastern Europe (EM-SE); Africa-Central Mediterranean (A-CM); western Mediterranean (WM); western Europe-Central Europe (WE-CE) and undefined. The heights and frequencies of precipitation coming by air masses from northern Europe and eastern-northeastern Europe are the lowest. On the contrary, the heights and frequencies of precipitation coming by air masses from the western Mediterranean (36.6%) and Africa and the Central Mediterranean (30.6%) are the highest. The sea salt components (Na⁺, Cl⁻, Mg²⁺) are significantly correlated, except for air masses originating from the northern and eastern European regions. Significant correlations between SO₄ ²⁻ and NO₃ ⁻ are found in air masses coming from the western Europe and North Africa, over the Mediterranean. Conclusions The highest volume-weighted mean (VWM) of: SO₄ ²⁻ , NH₄ ⁺ and Mg²⁺ are for precipitation from EE-NE while the highest values of VWM of Cl ⁻ are from WM and of K⁺ are from WE-CE. Long-range transport of Sahara dust is confirmed. Recommendations and perspectives For better estimation of origins of water-soluble ions in precipitation expanding list of analysis on anions of organic acids, such as HCOO⁻, CH₃COO⁻, and C₂H₂COO⁻, could be indicative of volatile organic compounds emitted by vegetation but also traffic. The chemical composition of precipitation together with a study of air backward trajectories is the proper tool for tracking the long-range transport of water-soluble ions and estimating transboundary pollution.

Background, aim and scope Australia is the largest producer of bauxite in the world, with an annual output of approximately 62 million metric dry tons in 2007. For every tonne of alumina, about 2 tonnes of highly alkaline and highly saline bauxite-processing residue are produced. In Western Australia, Alcoa World Alumina, Australia (Alcoa) produces approximately 15 MT of residue annually from its refineries (Kwinana, Pinjarra and Wagerup). The bauxite-processing residue sand (BRS) fraction represents the primary material for rehabilitating Alcoa's residue disposal areas (RDAs). However, the inherently hostile characteristics (high alkalinity, high salinity and poor nutrient availability) of BRS pose severe limitations for establishing sustainable plant cover systems. Alcoa currently applies 2.7 t ha⁻¹ of di-ammonium phosphate ((NH₄)₂HPO₄; DAP)-based fertiliser as a part of rehabilitation of the outer residue sand embankments of its RDAs. Limited information on the behaviour of the dominant components of this inorganic fertiliser in highly alkaline BRS is currently available, despite the known effects of pH on ammonium (NH₄) and phosphorus (P) behaviour. The aim of this study was to quantify the effects of pH on NH₃ volatilisation and residual nitrogen (N) in BRS following DAP applications. Methods The sponge-trapping and KCl-extraction method was used for determining NH₃ volatilisation from surface-applied DAP in samples of BRS collected from each of Alcoa's three Western Australia Refineries (Kwinana, Pinjarra, Wagerup) under various pH conditions (pH 4, 7, 9 and 11). Following cessation of volatilisation, the residual N was extracted from BRS using 2 M KCl and concentrations of NH ₄ ⁺ -N and NO ₃ ⁻ -N were determined by flow injection analysis. Results The quantities of NH₃ volatilised increased dramatically as the pH increased from 4 to 11. Much of the N lost as NH₃ (up to 95.2%) occurred within a short period (24 h to 7 days), particularly for the pH 9 and 11 treatments. Concentrations of residual NH ₄ ⁺ -N recovered in DAP-treated BRS at the end of the experiment decreased with increasing pH. This finding was consistent with increasing loss of N via volatilisation as pH increased. The concentration of NO ₃ ⁻ -N was very low due to no nitrification in BRS. Discussion The pH was a key driver for NH₃ volatilisation from DAP-treated BRS and primarily controlled N dynamics in BRS. Results indicate that NH₄ not adsorbed by BRS was highly susceptible to volatilisation. The likely lack of nitrifying bacteria did not allow conversion of ammonium to nitrate, thereby further exacerbating the potential for loss via volatilisation Conclusions It was demonstrated that the pH is the key factor controlling the loss of inorganic N from BRS. Although volatilisation was considerably lower at pH 4, achieving this pH reduction in the field is not possible at present. Findings from this study highlight the need to better understand which forms of N fertiliser are most suitable for use in highly alkaline BRS. Recommendation and perspectives Although pH reduction is the most likely means of stopping NH₃ volatilisation in BRS, it is economically and operationally unfeasible to add sufficient acidity for adequately lowering pH in the BRS for revegetation. More attention on forms of fertilisers more suitable to highly alkaline, microbially inert soil conditions appears to be warranted.

Purpose As one component of the German ecological environment observation, the Environmental Specimen Bank program was initiated in the mid-1980s. Under the program, representative specimens of marine, fresh water, and terrestrial ecosystems are sampled regularly and archived under chemically stable conditions. An initial characterization of the samples provides data regarding the status quo of the respective ecosystems. The aim of the present publication is to give insight into these real-time monitoring data, which have been generated for the last 10 to 20 years. This is done exemplarily for the heavy metals cadmium (Cd), mercury (Hg), and lead (Pb) in marine specimens of the Baltic and the North Sea. Methods Bladder wrack (Fucus vesiculosus), blue mussel (Mytilus edulis), eelpout (Zoarces viviparus), and eggs of herring gulls (Larus argentatus) were sampled at one location in the Baltic Sea and at two sites in the North Sea (Schleswig-Holstein Wadden Sea and Lower Saxony Wadden Sea). Annual samples were pooled, homogenized, and analyzed for a set of elements. Cd and Pb were quantified after freeze-drying and microwave digestion using inductively coupled plasma-mass spectrometry. Total Hg in freeze-dried samples was determined by atomic absorption spectrometry using a direct mercury analyzer. Results Time series data covering up to two decades revealed comparable cadmium levels at all three locations. Concentrations in bladder wrack ranged between 0.10 and 0.37 µg/g on a wet weight basis (ww). Respective values for blue mussel and eelpout liver were 0.07-0.29 and 0.01-0.10 µg/g ww. Herring gull eggs were not included in cadmium analyses. Declining trends were observed in North Sea bladder wrack and mussels, eelpout from the Lower Saxony site, and mussels from the Baltic Sea. Upward trends were apparent in eelpout from the Schleswig-Holstein location. Mercury concentrations in Baltic Sea specimens ranged from 1.1-2.7 ng/g ww in bladder wrack to 2.6-5.1, 26-52, and 86-226 ng/g ww in blue mussel, eelpout muscle, and herring gull eggs, respectively. No temporal trends were observed. North Sea bladder wrack had accumulated 5.4-24 ng/g ww Hg. The respective Hg values for blue mussel and eelpout muscle were 19-64 and 73-187 ng/g ww. Highest Hg contents were detected in herring gull eggs (90-1,100 ng/g ww). Declining trends of Hg were observed in herring gull eggs at both North Sea locations and in blue mussels at the Lower Saxony site. Lead concentrations in Baltic Sea specimens were 48-222 ng/g ww in bladder wrack, 85-189 ng/g ww in blue mussel, 2.0-9.5 and 10-42 ng/g ww in eelpout muscle and liver, and 2.7-26 ng/g ww in herring gull eggs. In the North Sea, Pb concentrations were as follows: 68-397 ng/g ww in bladder wrack, 101-507 ng/g ww in blue mussels, 2.6-35 and 5.9-158 ng/g ww in eelpout muscle and liver, and 3.5-55 ng/g ww in herring gull eggs. Highest Pb-levels were found at the Lower Saxony site. Declining Pb-trends were observed in bladder wrack from the Baltic Sea; in bladder wrack and mussel at the Schleswig-Holstein location; and in bladder wrack, mussels, eelpout liver, and herring gull eggs at the Lower Saxony site. Conclusions During the 10 to 20 years of monitoring, reliable data were obtained which allow a good insight into metal contamination of marine biota. Assessment of the data according to OSPAR criteria (OSPAR 2005) revealed cadmium levels above the derived background concentrations in mussels of all three sites. Mercury levels above background concentrations were found at both North Sea locations, whereas only mussels at the Lower Saxony site had Pb concentrations above the reference value. Archived specimens are available for further analyses and questions which may arise in the future (speciation of elements, metallomics).

Background The Atacama Desert in Northern Chile is one of the most arid places on earth. However, fog occurs regularly at the coastal mountain range and can be collected at different sites in Chile to supply settlements at the coast with freshwater. This is also planned in the fog oasis Alto Patache (20°49′S, 70°09′W). For this pilot study, we collected fog water samples in July and August 2008 for chemical analysis to find indications for its suitability for domestic use. Methods Fog water samples were taken with a cylindrical scientific fog collector and from the net and the storage tank of a Large Fog Collector (LFC). Results The pHs of advective fog, originating from the stratus cloud deck over the Eastern Pacific, varied between 2.9 and 3.5. Orographic fog, which was formed locally, exhibited a pH of 2.5. About 50% of the total ionic concentration was due to sea salt. High percentages of sulfate and very high enrichment factors (versus sea salt) of heavy metals were found. Both backward trajectories and the enrichment factors indicate that the high concentrations of ions and heavy metals in fog were influenced by anthropogenic activities along the Chilean Pacific Coast such as power plants, mining, and steel industry. Conclusions We found no direct indication for the importance of other sources such as the emission of dimethyl sulfide from the ocean and subsequent atmospheric oxidation for acidity and sulfate or soil erosion for heavy metal concentrations. When fog water was collected by the LFC, it apparently picked up large amounts of dry deposition which accumulated on the nets during fog-free periods. This material is rinsed off the collector shortly after the onset of a fog event with the water collected first. During the first flush, some concentrations of acidity, nitrate, As, and Se, largely exceeded the Chilean drinking water limits. Before any use of fog water for domestic purpose, its quality should be checked on a regular basis. Strategies to mitigate fog water pollution are given.

Background and purpose In Pakistan, almost 70% of the population lives in rural areas. Ninety-four percent of households in rural areas and 58% in urban areas depend on biomass fuels (wood, dung, and agricultural waste). These solid fuels have poor combustion efficiency. Due to incomplete combustion of the biomass fuels, the resulting smoke contains a range of health-deteriorating substances that, at varying concentrations, can pose a serious threat to human health. Indoor air pollution accounts for 28,000 deaths a year and 40 million cases of acute respiratory illness. It places a significant economic burden on Pakistan with an annual cost of 1% of GDP. Despite the mounting evidence of an association between indoor air pollution and ill health, policy makers have paid little attention to it. This review analyzes the existing information on levels of indoor air pollution in Pakistan and suggests suitable intervention methods. Methods This review is focused on studies of indoor air pollution, due to biomass fuels, in Pakistan published in both scientific journals and by the Government and international organizations. In addition, the importance of environmental tobacco smoke as an indoor pollutant is highlighted. Results Unlike many other developing countries, there are no long-term studies on the levels of indoor air pollution. The limited studies that have been undertaken indicate that indoor air pollution should be a public health concern. High levels of particulate matter and carbon monoxide have been reported, and generally, women and children are subject to the maximum exposure. There have been a few interventions, with improved stoves, in some areas since 1990. However, the effectiveness of these interventions has not been fully evaluated. Conclusion Indoor air pollution has a significant impact on the health of the population in Pakistan. The use of biomass fuel as an energy source is the biggest contributor to poor indoor air quality followed by smoking. In order to arrest the increasing levels of indoor pollution, there is a dire need to recognize it as a major health hazard and formulate a national policy to combat it. An integrated effort, with involvement of all stakeholders, could yield promising results. A countrywide public awareness campaign, on the association of indoor air pollution with ill health, followed by practical intervention would be an appropriate approach. Due to the current socioeconomic conditions in the country, development and adoption of improved cooking stoves for the population at large would be the most suitable choice. However, the potential of biogas as a fuel should be explored further, and modern fuels (natural gas and LPG) need to be accessible and economical. Smoking in closed public spaces should be banned, and knowledge of the effect of smoking on indoor air quality needs to be quantified.

Purpose Dissolved humic acids abiotically reduced inorganic arsenic to varying degrees, depending on solution pH, ionic strength, and type of humate used. The functionalities of dissolved organic matter responsible for these redox reactions remained in question, but quinoid moieties undoubtedly played an important role. It is not fully understood whether the quinoids are solely responsible for arsenate reduction, and what the kinetics of the relevant processes are. Methods Electron spin resonance (ESR) spectroscopy was used to monitor the radical content of the humates, both as bulk material and as size fractions. Information on the redox status of the humates was obtained from fluorescence excitation-emission matrices and correlated with the observed spin count. Size data were obtained from fractionation and UV-Vis spectrometry. Arsenic speciation was carried out by ion chromatography. Results ESR spectroscopy showed a free radical content of 3.4 × 1,017-20 × 1,017 spins/g for bulk and fractionated aqueous humic acids. The number of electrons corresponding to these counts could not account for the entire charge transferred to arsenate during abiotic reduction. The rate constants of the reactions were found to be independent of the humic concentration. Leonardite humic acid separated on a XAD-8 resin yielded fractions that on the short time frame (0-5 h) had rate constants of 0.035 h⁻¹ for the hydrophobic fraction compared to 0.0052 h⁻¹ for the hydrophilic fraction. The rate constants for the hydrophobic and hydrophilic fractions over the longer time frame (100-200 h) were similar—7.3 × 10⁻⁴ and 7.2 × 10⁻⁴ h⁻¹, respectively. Fluorescence excitation-emission matrices of humates involved in arsenate reduction exhibited shifts typical of quinoid components undergoing redox transformations. These gradual shifts took place during the first 24 h of reduction process, after which the spectra no longer changed. The reduction of arsenate, however, continued after this period, indicating that species other than quinoids were involved. This was consistent with the fact that the rate constants for the later processes were smaller. Conclusions The existence of different redox pools within the humate was confirmed, with the quinoid-centered redox entities showing the fastest kinetics. The results pertained to all size and polarity fractions.

PURPOSE: Organophosphate pesticides (OPs) are among the most used insecticides in agriculture, causing the inhibition of esterases like acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and carboxylesterase (CbE). Pesticides can reach the aquatic environment, posing risks to non-target organisms, including tadpoles. METHODS: In this work, we characterized the activities of AChE, BChE and CbE in tadpoles of the snouted treefrog Scinax fuscovarius, and verified their in vitro sensibility to different inhibitors [phenylmethane sulfonyl fluoride (PMSF), tetra-isopropylpyrophosphamide (iso-OMPA) and the OP diazinon]. In vivo effects of diazinon and esterase recovery after 2-pyridine-aldoxime (2-PAM) treatment of the protein extract were also studied in tadpoles with distinct stages of development exposed to 1 and 3 mg/l for 2 and 7 days. RESULTS: Optimal conditions were established for AChE and CbE; BChE activity was negligible. PMSF affected esterase activities and is not recommended for homogenization buffers. Iso-OMPA treatment caused no changes in AChE and CbE activities, but diazinon inhibited these enzymes in a dose-responsive manner. In vivo, CbE activity was insensitive to diazinon in younger tadpoles, but inhibited after 2 days of exposure in more developed tadpoles. AChE activity was inhibited after 2 and 7 days of exposure, in a dose-responsive manner. Esterase reactivation by 2-PAM was obtained both in vitro and in vivo. CONCLUSIONS: (1) Tadpoles can be adequate sentinel organisms in biomonitoring studies of OP contamination; (2) AChE was more sensitive than CbE to diazinon; (3) tadpoles from earlier developmental stages seems to be less responsive to OPs; (4) AChE activity was sensitive to diazinon in both development stages, being a better OP biomarker.

Background, aim and scope Polychlorinated biphenyls (PCB) and dichlorodiphenyltrichloroethane (DDT) concentrations were determined in the liver of two deep sea fish species, Mediterranean slimehead and blackfin sorcerer, from the Adriatic Sea (southeastern Mediterranean Sea). Results and discussion The examination of congener profiles showed that hexachlorinated molecules were dominant (hexa-CBs, 55.3-56.2%), followed by penta-CBs (21.5-21.8%) and hepta-PCB 180 (14.9-16.0%). PCB 138, 153 and 180 were the prominent congeners accounting for 69.3% of the total PCBs. Among the compounds of DDT, p,p′-DDE was the most dominant molecule (Mediterranean slimehead, 86.6%; blackfin sorcerer, 92.8%), demonstrating the old age of these compounds in the environment. In both species, PCB contents were higher than those of DDTs. Contaminant load was higher in Mediterranean slimehead (PCBs, 1,086 ng g⁻¹ lipid weight; DDTs, 799 ng g⁻¹ lipid weight) than in blackfin sorcerer (PCBs, 561 ng g⁻¹ lipid weight; DDTs, 224 ng g⁻¹ lipid weight). Conclusion The high ratios ΣPCBs/ΣDDTs indicated predominantly industrial versus agrarian activities in the area. Dioxins toxic equivalent (TEQ) concentrations (8.1-18.7 pg TEQ per gram wet weight) reached those encountered in marine organisms at higher levels in the trophic chain, revealing the onerous status of contamination by PCBs in Mediterranean deep sea biota.

Introduction Within the last decade, numerous studies have investigated the role of environmental history on tolerance to stress of many organisms. This study aims to assess if Manila clams Ruditapes philippinarum may react differently to cadmium exposure and trematode parasite infection (Himasthla elongata) depending on their origin and environmental history in Arcachon Bay (France). Materials and methods Clams were exposed to Cd (15 µg L⁻¹) and parasites (25 cercariae per clam), alone or in combination, at 15°C under controlled laboratory conditions for 7 days. Metal accumulation and success of parasite infestation were examined, also physiological parameters such as metallothionein response and hemocyte counts and activities (phagocytosis, oxidative burst, viability, and adhesion). Results and Discussion Sensitivity of Manila clams to both stressors differed from one site to another, suggesting local adaptation of populations. Clams from the more parasitized site presented better resistance to trematodes than the others in terms of first line defense, i.e., avoidance of infection. On the other hand, clams that adapted to chronic Cd contamination showed better detoxification mechanisms, both in a faster transfer of metal from gills to visceral mass and in a higher metallothionein baseline, than clams which had never experienced Cd contamination. Finally, hemocyte concentration and viability differed between clam origin site, highlighting the fact that populations living in different environments may adapt their physiological and biochemical responses to environmental stressors. Conclusion It is therefore important to be cautious when extrapolating results from field studies of one species and one site, if the life history of the organisms is not taken into account.

Introduction and background Primary producers play critical structural and functional roles in aquatic ecosystems; therefore, it is imperative that the potential risks of toxicants to aquatic plants are adequately assessed in the risk assessment of chemicals. The standard required macrophyte test species is the floating (non-sediment-rooted) duckweed Lemna spp. This macrophyte species might not be representative of all floating, rooted, emergent, and submerged macrophyte species because of differences in the duration and mode of exposure; sensitivity to the specific toxic mode of action of the chemical; and species-specific traits (e.g., duckweed's very short generation time). Discussion and perspectives These topics were addressed during the workshop entitled “Aquatic Macrophyte Risk Assessment for Pesticides” (AMRAP) where a risk assessment scheme for aquatic macrophytes was proposed. Four working groups evolved from this workshop and were charged with the task of developing Tier 1 and higher-tier aquatic macrophyte risk assessment procedures. Subsequently, a SETAC Advisory Group, the Macrophyte Ecotoxicology Group (AMEG) was formed as an umbrella organization for various macrophyte working groups. The purpose of AMEG is to provide scientifically based guidance in all aspects of aquatic macrophyte testing in the laboratory and field, including prospective as well as retrospective risk assessments for chemicals. As AMEG expands, it will begin to address new topics including bioremediation and sustainable management of aquatic macrophytes in the context of ecosystem services.