scholarly journals Meteorological and Nutrient Conditions Influence Microcystin Congeners in Freshwaters

Toxins ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 620 ◽  
Author(s):  
Zofia E. Taranu ◽  
Frances R. Pick ◽  
Irena F. Creed ◽  
Arthur Zastepa ◽  
Sue B. Watson

Cyanobacterial blooms increasingly impair inland waters, with the potential for a concurrent increase in cyanotoxins that have been linked to animal and human mortalities. Microcystins (MCs) are among the most commonly detected cyanotoxins, but little is known about the distribution of different MC congeners despite large differences in their biomagnification, persistence, and toxicity. Using raw-water intake data from sites around the Great Lakes basin, we applied multivariate canonical analyses and regression tree analyses to identify how different congeners (MC-LA, -LR, -RR, and -YR) varied with changes in meteorological and nutrient conditions over time (10 years) and space (longitude range: 77°2′60 to 94°29′23 W). We found that MC-LR was associated with strong winds, warm temperatures, and nutrient-rich conditions, whereas the equally toxic yet less commonly studied MC-LA tended to dominate under intermediate winds, wetter, and nutrient-poor conditions. A global synthesis of lake data in the peer-reviewed literature showed that the composition of MC congeners differs among regions, with MC-LA more commonly reported in North America than Europe. Global patterns of MC congeners tended to vary with lake nutrient conditions and lake morphometry. Ultimately, knowledge of the environmental factors leading to the formation of different MC congeners in freshwaters is necessary to assess the duration and degree of toxin exposure under future global change.

Author(s):  
Gloria Naa Dzama Addico ◽  
Jörg D. Hardege ◽  
Jiri Kohoutek ◽  
Kweku Amoaku Atta DeGraft-Johnson ◽  
Pavel Babica

<p>Although cyanobacterial blooms and cyanotoxins represent a worldwide-occurring phenomenon, there are large differences among different countries in cyanotoxin-related human health risk assessment, management practices and policies. While national standards, guideline values and detailed regulatory frameworks for effective management of cyanotoxin risks have been implemented in many industrialized countries, the extent of cyanobacteria occurrence and cyanotoxin contamination in certain geographical regions is under-reported and not very well understood. Such regions include major parts of tropical West and Central Africa, a region constisting of more than 25 countries occupying an area of 12 million km<sup>2</sup>, with a total population of 500 milion people. Only few studies focusing on cyanotoxin occurrence in this region have been published so far, and reports dealing specifically with cyanotoxin contamination in drinking water are extremely scarce. In this study, we report seasonal data on cyanobacteria and microcystin (MC) contamination in drinking water reservoirs and adjacent treatment plants located in Ghana, West Africa. During January-June 2005, concentrations of MCs were monitored in four treatment plants supplying drinking water to major metropolitan areas in Ghana: the treatment plants Barekese and Owabi, which serve Kumasi Metropolitan Area, and the plants Kpong and Weija, providing water for Accra-Tema Metropolitan Area. HPLC analyses showed that 65% samples of raw water at the intake of the treatment plants contained intracellular MCs (maximal detected concentration was 8.73 µg L<sup>-1</sup>), whereas dissolved toxins were detected in 33% of the samples. Significant reduction of cyanobacterial cell counts and MC concentrations was achieved during the entire monitoring period by the applied conventional water treatment methods (alum flocculation, sedimentation, rapid sand filtration and chlorination), and MC concentration in the final treated water never exceeded 1 µg L<sup>-1</sup> (WHO guideline limit for MCs in drinking water). However, cyanobacterial cells (93-3,055 cell mL<sup>-1</sup>) were frequently found in the final treated water and intracellular MCs were detected in 17% of the samples (maximal concentration 0.61 µg L<sup>-1</sup>), while dissolved MCs were present in 14% of the final treated water samples (maximal concentration 0.81 µg L<sup>-1</sup>). It indicates a borderline efficiency of the water treatment, thus MC concentrations in drinking water might exceed the WHO guideline limit if the treatment efficiency gets compromised. In addition, MC concentrations found in the raw water intake might represent significant human health risks for people living in areas with only a limited access to the treated or underground drinking water.</p>


2017 ◽  
Vol 3 (1) ◽  
Author(s):  
Jing Li ◽  
Linda Parkefelt ◽  
Kenneth M Persson ◽  
Heidi Pekar

Cyanobacteria in fresh water can cause serious threats to drinking water supplies. Managing cyanobacterial blooms particularly at small drinking water treatment plants is challenging. Because large amount of cyanobacteria may cause clogging in the treatment process and various cyanotoxins are hard to remove, while they may cause severe health problems. There is lack of instructions of what cyanobacteria/toxin amount should trigger what kind of actions for drink-ing water management except for Microcystins. This demands a Cyanobacteria Management Tool (CMT) to help regula-tors/operators to improve cyanobacteria/cyanotoxin monitoring in surface waters for drinking water supply. This project proposes a CMT tool, including selecting proper indicators for quick cyanobacteria monitoring and verifying quick analysis methods for cyanobacteria and cyanotoxin. This tool is suggested for raw water management regarding cyano-bacteria monitoring in lakes, especially in boreal forest climate. In addition, it applies to regions that apply international WHO standards for water management. In Swedish context, drinking water producers which use raw water from lakes that experience cyanobacterial blooms, need to create a monitoring routine for cyanobacteria/cyanotoxin and to monitor beyond such as Anatoxins, Cylindrospermopsins and Saxitoxins. Using the proposed CMT tool will increase water safety at surface water treatment plants substantially by introducing three alerting points for actions. CMT design for each local condition should integrate adaptive monitoring program.


2021 ◽  
Vol 5 (5) ◽  
pp. 214-220
Author(s):  
Adriana Sotero - Martins ◽  
Elvira Carvajal ◽  
José Augusto Albuquerque dos Santos ◽  
Priscila Gonçalves Moura ◽  
Natasha Berendonk Handam ◽  
...  

Tastes and odors in tap water are problems faced by water companies worldwide, with consumers complaints mainly during summer, when cyanobacterial blooms occur and produce compounds such as geosmin and 2-methylisoborneol (2-MIB). We analyzed the data on taste and odor intensity and total concentration of geosmin and 2-MIB compounds in drinking water and raw water collected by the sanitation company supplying of the metropolitan region of Rio de Janeiro (Brazil) during the 2020 and 2021 water crises. Statistical and metagenomic analyses of the raw water samples of the year 2020, were performed. Organoleptic data allowed to signal the presence of these taste and odor (T&O) compounds in the drinking water, and the mean values of taste intensity were above the maximum allowed value of the Brazilian legislation, on average 37.5 times in 2020 and 5 times in 2021, indicating that the measures did not eliminate the problem. There was a linear correlation of 0.97 between the standard organoleptic taste and the total concentration of T&O in 2020. Metagenomic data, from raw water in the year 2020, for the mtf, mic and glys genes indicated 2-MIB as responsible for T&O. Modifications in the surveillance system of catchment and drinking water quality need to be adopted to circumvent the problems of cyanobacterial blooms in the Guandu basin, as conditions favorable to blooms will occur as long as the sanitation problems in this watershed are not solved.


2021 ◽  
Vol 24 (2) ◽  
pp. first
Author(s):  
Thanh Luu Pham ◽  
Tran Thi Hoang Yen ◽  
Tran Thanh Thai ◽  
Ngo Xuan Quang

Introduction: Cyanobacterial blooms (CBs) have become a growing concern worldwide. In the natural environment, potentially toxic (can produce toxins) and non-toxic (can not produce toxins) colonies often co-exist within a bloom. Methods: The present study aimed to quantify toxic and non-toxic cells of cyanobacteria in the Tri An Reservoir (TAR) using a quantitative real-time polymerase chain reaction (qRT-PCR). Results: Results showed that the Microcystis genus dominated the cyanobacterial communities in the TAR. Microcystis was also the primary microcystins (MC) producing cyanobacteria in the water. Total cyanobacteria and Microcystis cells ranged from 152103 to 27106 copy/L and from 105103 to 19106 copy/L, respectively. The cell number of potentially MC-producing cyanobacteria (corresponding to the Microcystis mcyD gene) varied from 27103 to 13106 copy/L. MC concentrations often present in raw water with a concentration of up to 4.8 mg/L. Our results showed that the MC concentration in raw water was positively correlated with the mcyD copy number, suggesting that Microcystis spp. are the main toxin producers in the TAR's surface water. Conclusion: Our study suggested that qRT-PCR techniques and traditional count are comparable and could be used to quantify cyanobacteria. In addition, the qRT-PCR techniques can determine the toxic cyanobacterial cells and could be used as a tool for early monitoring of toxic cyanobacteria in lakes and reservoirs.


2017 ◽  
Vol 12 (2) ◽  
pp. 105-116
Author(s):  
Pulung A. Pranantya ◽  
Nurlia Sadikin

In terms of geology, most areas in south of the Gunungkidul District in Central Java consist of the Wonosari formation limestone. The land is generally very dry and source of raw water is also difficult to reach. Findings on the existence of underground river in caves, however, indicate the potential amount of water within the area, especially in the eastern part of the Gunungkidul District. Although limited information available, some fishermen have discovered that Seropan cave contains fresh water source. This cave is situated at 65 m below the cliff. Initial exploration, which done using a multichannel resistivity method, confirmed the availability of freshwater in the cave and underground river. The isopach of cave depth is found in ranges of 80 200 m below the ground surface. The water of Seropan cave can be utilized by implementing pipeline or by drilling at the suggested point based on the interpretation results, i.e. 110o2223.6388 EL 8o42.874 SL. [DY1][PP2][DY1]Perbaiki grammarIn terms of geology, most areas in south of Gunungkidul District in Central Java consist of the Wonosari formation limestone. The land is generally very dry and source of raw water is also difficult to reach. Findings on the exixtence of underground river in caves, however, indicate potential amount of water within the area especially in eastern part of Gunungkidul District. Although limited information available, some fishermans has discovered that Seropan cave contain fresh water source. This cave is situated at 65 m below the cliff. Initial exploration, which done using multichannel resistivity method, confirmed the availability of freshwater in the cave and underground river. The iso pach of cave depth is found in ranges of 80 200 m below the ground surface. The water of Seropan cave can be utilized by implementing pipeline or by drilling at the suggested point based on the interpretation results i.e. 110o2223.6388 EL 8o42.874 SL.[PP2]Sudah diperbaiki


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