Showing papers by "Ingrid Chorus published in 2007"
TL;DR: Risks of exposure to cyanotoxins in food are sometimes underestimated and risk assessments should acknowledge this and investigate the partitioning of exposure between drinking-water and food, which may vary depending on local circumstances.
343 citations
TL;DR: CYN occurrence in the German lakes could not be ascribed to the three known CYN-producing species Cylindrospermopsis raciborskii, Anabaena bergii and Aphanizomenon flos-aquae, which were detected in some lakes in low abundances, and the highest correlation coefficients were observed between particulate CYN and the native AphanIZomenon gracile.
188 citations
TL;DR: It is suggested that CYN may be an important cyanobacterial toxin in German water bodies and that further data are needed to assess this, and analyses of phytoplankton data suggest Aphanizomenon sp.
Abstract: Received 15 February 2006; revised 12 June 2006; accepted 20 July 2006ABSTRACT: The frequent occurrence of the cyanobacterial toxin cylindrospermopsin (CYN) in the (sub)-tropics has been largely associated with cyanobacteria of the order Nostocales of tropical origin, in partic-ular Cylindrospermopsis raciborskii. C. raciborskii is currently observed to spread northwards into temper-ate climatic zones. In addition, further cyanobacteria of the order Nostocales typically inhabiting waterbodies in temperate regions are being identified as CYN-producers. Therefore, data on the distribution ofCYN in temperate regions are necessary for a first assessment of potential risks due to CYN in water usedfor drinking and recreation. A total of 127 lakes situated in the north-eastern part of Germany were investi-gated in 2004 for the presence of the toxin CYN and the phytoplankton composition. The toxin could bedetected in half of the lakes (n ¼ 63) and in half of 165 samples (n ¼ 88). Concentrations reached up to73.2 g CYN/g DW. CYN thus proved more widely distributed than previously demonstrated. The analysesof phytoplankton data suggest Aphanizomenon sp. and Anabaena sp. as important CYN producers inGermany, and confirm recent findings of Aphanizomenon flos-aquae as CYN-producing species fre-quently inhabiting water bodies in temperate climatic regions. The data shown here suggest that CYNmay be an important cyanobacterial toxin in German water bodies and that further data are needed toassess this.
98 citations
TL;DR: Monitoring of Mediterranean drinking water reservoirs needs to be intensified during winter, a season usually considered to be less prone to the formation of cyanobacterial blooms.
Abstract: Sicilian reservoirs constitute the most important water resources available on the island. Dur- ing summer 2001, the intense water utilization of Lake Arancio reservoir reduced the water level signifi- cantly, which coincided with the formation of intense blooms formed by the microcystin (MC)-producing cyanobacterium Microcystis aeruginosa. During summer 2003, Lake Arancio was continuously filled and the vertical stratification of the water column was maintained resulting in five to sixfold lower cell numbers of M. aeruginosa. For both years, a significant relationship between MC net production and Microcysytis cell growth was observed, implying that Microcystis cell numbers can be used to infer MC concentrations in water. Unexpectedly, dense blooms of the MC-producing cyanobacterium Planktothrix rubescens occurred during winter 2005/2006 in the reservoirs Lake Pozzillo, Prizzi, Nicoletti, and Garcia but have not been reported earlier. In this season, MC concentrations higher than those recorded in summer were measured, implying that monitoring of Mediterranean drinking water reservoirs needs to be intensified during winter, a season usually considered to be less prone to the formation of cyanobacterial blooms.
74 citations
TL;DR: In this article, the external load reduction was the main cause of the pronounced lake water quality improvements in Lake Tegel and Lake Schlachtensee in Berlin, Germany, by P-stripping their main inflows using P-elimination plants.
Abstract: Two previously highly eutrophic lakes, Lake Tegel and Schlachtensee in Berlin, Germany, were subjected to similar external but different internal restoration measures during the last 20–25 years. External phosphorus (P) load was reduced in both lakes by P-stripping their main inflows using P-elimination plants; internal P load was treated by aeration in Lake Tegel and by hypolimnetic withdrawal in Schlachtensee. Loads before and after treatment are compared with the targets using the Vollenweider model and a modified One-Box model. The results indicate that external load reduction was the main cause of the pronounced lake water quality improvements. The hypolimnetic withdrawal in Schlachtensee was effective only in the initial years. No significant positive effect can be identified for the aeration of Lake Tegel.
36 citations