Copper and cadmium effects on growth and extracellular exudation of the marine toxic dinoflagellate Alexandrium catenella: 3D-fluorescence spectroscopy approach

In this study, metal contamination experiments were conducted to investigate the effects of copper and cadmium on the growth of the marine toxic dinoflagellate Alexandrium catenella and on the production of dissolved organic matter (Dissolved Organic Carbon: DOC; Fluorescent Dissolved Organic Matter: FDOM). This species was exposed to increasing concentrations of Cu²⁺ (9.93 × 10⁻¹⁰–1.00 × 10⁻⁷ M) or Cd²⁺ (1.30 × 10⁻⁸–4.38 × 10⁻⁷ M), to simulate polluted environments. The drastic effects were observed at pCu²⁺ = 7.96 (Cu²⁺: 1.08 × 10⁻⁸ M) and pCd²⁺ = 7.28 (Cd²⁺: 5.19 × 10⁻⁸ M), where cyst formation occurred. Lower levels of Cu²⁺ (pCu²⁺ > 9.00) and Cd²⁺ (pCd²⁺ > 7.28) had no effect on growth. However, when levels of Cu²⁺ and Cd²⁺ were beyond 10⁻⁷ M, the growth was totally inhibited. The DOC released per cell (DOC/Cell) was different depending on the exposure time and the metal contamination, with higher DOC/Cell values in response to Cu²⁺ and Cd²⁺, comparatively to the control. Samples were also analyzed by 3D-fluorescence spectroscopy, using the Parallel Factor Analysis (PARAFAC) algorithm to characterize the FDOM. The PARAFAC analytical treatment revealed four components (C1, C2, C3 and C4) that could be associated with two contributions: one, related to the biological activity; the other, linked to the decomposition of organic matter. The C1 component combined a tryptophan peak and a characteristic humic substances response, and the C2 component was considered as a tryptophan protein fluorophore. The C3 and C4 components were associated to marine organic matter production.     

Valuing Improvements in The Water Rights System in South Africa: A Contingent Ranking Approach1

Speelman, Stijn, Stefano Farolfi, Aymen Frija, and Guido Van Huylenbroeck, 2010. Valuing Improvements in the Water Rights System in South Africa: A Contingent Ranking Approach. Journal of the American Water Resources Association (JAWRA) 46(6):1133–1144. DOI: 10.1111/j.1752-1688.2010.00480.x Abstract: In the context of increasing water scarcity, understanding is growing that irrigation water rights are important and that a lack of an effective water rights system constitutes a major reason for inefficient water management. This study carried out a contingent ranking experiment to study how smallholder irrigators in South Africa would value potential changes in water rights. Three specific dimensions of water rights, relevant for the South African case, are considered: duration, quality of title, and transferability. Results indicate that smallholder irrigators are prepared to pay considerably higher water prices if improvements are made in the water rights system. This implies that the proposed interventions in the water rights system would improve the efficiency and productivity of the small-scale irrigation sector. The increased willingness to pay could furthermore also assist the South African government to reach the objective of increased cost recovery.     

Multivariate analysis of mineral constituents of edible Parasol Mushroom (Macrolepiota procera) and soils beneath fruiting bodies collected from Northern Poland

Caps and stipes of 141 fruiting bodies of Parasol Mushroom (Macrolepiota procera) and surface layer of soils collected from 11 spatially distant and background (pristine) areas in Northern Poland were analyzed for Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, P, Pb, Rb, Sr, and Zn by inductively coupled plasma optical emission spectroscopy and cold vapor atomic absorption spectroscopy. In terms of bioconcentration and bioexclusion concept, K, Ag, Cu, Rb, and P were highly bioconcentrated in caps, and their bioconcentration factor values varied for the 11 sites between 120 and 500—67–420, 70–220, 10–170, and 45–100, respectively. Cd, Zn, Mg, and Na showed bioconcentration factors (BCFs) between 3.3 and 36, 3.7–15, 0.92–6.3, and 1.4–44 while Al, Ba, Ca, Co, Cr, Mn, Ni, Pb, and Sr were excluded (BCF < 1). The Parasol Mushroom is a species harvested in the wild, and its caps are of unique taste and can contain a spectrum of essential and hazardous mineral compounds accumulated at elevated concentrations, even if collected at the background (pristine) areas. These elevated mineral concentrations of the caps are due to the efficient bioconcentration potential of the species (K, Ag, Cu, Rb, P, Cd, Zn, Mg, and Na) and abundance in the soil substrates (Al, Ca, Fe, Mn). The estimated intake rates of Cd, Hg, and Pb contained in Parasol Mushroom’s caps show a cause for concern associated with these metals resulting from the consumption of between 300- and 500-g caps daily, on a frequent basis in the mushrooming season.     

Genotoxicity of organic extracts of urban airborne particulate matter: an assessment within a personal exposure study

Airborne particulate matter, PM(10) and PM(2.5), are associated with a range of health effects including lung cancer. Their complex organic fraction contains genotoxic and carcinogenic compounds such as polycyclic aromatic hydrocarbons (PAHs) and their derivatives. This study evaluates the genotoxicity of the PM(10) and PM(2.5) organic extracts that were sampled in the framework of a personal exposure study in three French metropolitan areas (Paris, Rouen and Strasbourg), using the comet assay, performed on HeLa S3 cells. In each city, 60-90 non-smoking volunteers composed of two groups of equal size (adults and children) carried the personal Harvard Chempass multi-pollutant sampler during 48h along two different seasons ('hot' and 'cold'). Volunteers were selected so as to live (home and work/school) in 3 different urban sectors contrasted in terms of air pollution within each city (one highly exposed to traffic emissions, one influenced by local industrial sources, and a background urban environment). Genotoxic effects are stronger for PM(2.5) extracts than for PM(10), and greater in winter than in summer. Fine particles collected by subjects living within the traffic proximity sector present the strongest genotoxic responses, especially in the Paris metropolitan area. This work confirms the genotoxic potency of particulate matter (PM(10) and PM(2.5)) organic extracts to which urban populations are exposed.     

Responses of the mussel Anodontites trapesialis (Unionidae) to environmental stressors: effect of pH, temperature and metals on filtration rate

To evaluate the suitability of the tropical freshwater mussel Anodontites trapesialis for ecotoxicity assays, we tested the effects of temperature, pH, and Cd, Cu and Zn on its filtration rate. This is a relevant, sensible sublethal endpoint given the ecological role that this mussel plays in Amazonian environments. Filtration rate was calculated from the clearance of algae, fed to mussels at different temperature, pH and metal concentrations. Filtration rate was highest at 20 degrees C and pH 8, and decreased at low temperatures and pH. For all metals clear dose-response relationships were found. Cd exerted the most toxic effects (EC(50filtration) 64microg/L) followed by Cu (605microg/L) and Zn (4064microg/L). Metal mixtures representing present pollution levels clearly affected filtration rates. The results suggest that A. trapesialis is a suitable ecotoxicological test organism for the Amazonian region.     

The trophic status of Suwałki Landscape Park lakes based on selected parameters (NE Poland)

This study describes changes in the trophic status of 12 lakes within Suwa?ki Landscape Park (SLP). All of the trophic classifications of the lakes were based on the trophic continuum division. Trophic status was determined by means of multiparameter indices using several diverse criteria. In this study, the assessment of the trophic status of lakes included water quality; abundance and biomass of bacterioplankton, phytoplankton, and zooplankton; and primary production of phytoplankton. The Carlson trophic state index (TSI) describes the level of water fertility and indicated the dominance of moderately eutrophic waters. Lakes Perty, Jeglówek, and Hańcza have a trophic status that indicates mesotrophy (TSI <50). The trophic status of the studied lakes was determined based on the bacterial abundance and clearly showed a lack of oligotrophic lakes in SLP. Based on the number of bacteria, only Lake Szurpi?y can be classified as β-mesotrophic, whereas Lake Linówek can be characterized as hypertrophic with some features typical for humic waters. The greatest value of gross primary production was observed in Lake Linówek (126.4 mg C/m³/h). The phytoplankton trophy index varied from 1.59 to 2.28, and its highest value, which indicated eutrophy, was determined for Lake Udziejek. In the case of Lakes Hańcza, Szurpi?y, Perty, Jeglówek, and Kojle, the index ranged from 1.25 to 1.74, which indicated mesotrophy. The majority of the lakes were classified as mesoeutrophic (1.75–2.24). The highest trophic status was assessed for lakes with a marked dominance of cyanobacteria (Lake Przechodnie, Lake Krajwelek, Lake Udziejek, and Lake Pogorza?ek), which is commonly recognized as an indicator of high trophic status. Considering all of the indices of trophic status, the analysis of rotifer community structure indicates that the studied group of lakes is mesoeutrophic or eutrophic. The values of crustacean zooplankton indices indicated that the trophic status of the studied lakes was close to that determined using a TSI. The parameters of zooplankton abundance and species structure allowed for the observance of changes in the tropic levels of lakes, which are difficult to detect by a chemical assay alone.     

Polycyclic aromatic hydrocarbon concentrations,mutagenicity, and Microtox® acute toxicity testing of Peruvian crude oil and oil-contaminated water and sediment

The oil industry is a major source of contamination in Peru, and wastewater and sediments containing oil include harmful substances that may have acute and chronic effects. This study determined polycyclic aromatic hydrocarbon (PAH) concentrations by GC/MS, mutagenicity using TA98 and TA100 bacterial strains with and without metabolic activation in the Muta-ChromoPlate? test, and Microtox® 5-min EC₅₀ values of Peruvian crude oil, and water and sediment pore water from the vicinity of San José de Saramuro on the Marañón River and Villa Trompeteros on the Corrientes River in Loreto, Peru. The highest total PAH concentration in both areas was found in water (Saramuro?=?210.15 μg/ml, Trompeteros?=?204.66 μg/ml). Total PAH concentrations in water from San José de Saramuro ranged from 9.90 to 210.15 μg/ml (mean?=?66.48 μg/ml), while sediment pore water concentrations ranged from 2.19 to 70.41 μg/ml (mean?=?24.33 μg/ml). All water samples tested from Saramuro and Trompeteros sites, and one out of four sediment pore water samples from Trompeteros, were found to be mutagenic (P?<?0.001). One sediment pore water sample in Saramuro was determined to have a measurable toxicity (Microtox EC₅₀?=?335.1 mg/l), and in Trompeteros, the EC₅₀ in water and sediment pore water ranged from 25.67 to 133.86 mg/l. Peruvian crude oil was mutagenic using the TA98 strain with metabolic activation, and the EC₅₀ was 17.18 mg/l. The two areas sampled had very high PAH concentrations that were most likely associated with oil activities, but did not lead to acute toxic effects. However, since most of the samples were mutagenic, it is thought that there is a greater potential for chronic effects.     

Floating aquatic macrophytes for the treatment of aquaculture effluents

Environmental Science and Pollution Research - Aquaculture is an activity with economic and social importance since it generates food, employment, and income. However, like other human activities,...