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Monitoring Ecosystem Toxins in a Water Body for Sustainable Development of a Lake Watershed
Published in Ni-Bin Chang, Kaixu Bai, Multisensor Data Fusion and Machine Learning for Environmental Remote Sensing, 2018
According to NOAA, a common form of microcystin is Microcystin-LR, one of the most toxic strains of microcystin in the Great Lakes (Leshkevich and Lekki, 2017). NOAA is a long-term provider of the in situ data for microcystin concentration and the monitoring stations located at western Lake Erie are summarized in Figure 17.5. NOAA collects these surface water samples at stations in western Lake Erie periodically to provide surface microcystin concentrations that coincide with the surface reflectance observed in satellite or air-borne remote sensing data products. Total microcystin concentration of each sample was quantified by using ELISA kits (Abraxis; 520011) after cell lysis (Abraxis; Quik-lyse kit 529911QL) of unfiltered samples (Michalak et al., 2013). A total of 44 microcystin measurements were screened out from 2009 to 2011 and are suitable for ground-truth usage in this study (Table 17.2). The data set used in Table 17.2 for the final feature extraction of the corresponding satellite images only includes those with sampling locations free from cloud cover, aerosol contamination, and significant suspended sediment levels in the study region (Chang et al., 2014).
Water pollution
Published in Nick F. Gray, Water Science and Technology: An Introduction, 2017
All algal toxins are highly toxic and difficult to control. In practice, water with blue-green algal blooms is not used for supply purposes, although algal toxins can be removed from drinking water by granular activated carbon (Section 18.7). The WHO (2011) has set a provisional guideline value of 0.001 mg L–1 for microcystin-LR in drinking water. Not all blooms of cyanobacteria result in the release of toxins. However, algal toxins are difficult to monitor and detect, making prevention very difficult (Lawton and Codd, 1991). Currently, analysis of toxins is by liquid chromatography tandem mass spectrometry (Bogialli et al., 2006; Pekar et al., 2016).
Recent Trends and the Future of Electrochemical Immunoassay Systems
Published in Richard O’Kennedy, Caroline Murphy, Immunoassays, 2017
Other nanoparticles that have been used include silver, for example, a label-free capacitive immunosensor for microcystin-LR, in which the nanoparticles were bound onto a thiourea-modified gold electrode and then used to immobilise anti-microcystin-LR antibody [67]. The resultant immunosensor was capable of detecting microcystin-LR toxin to provide a detection limit of 7.0 pg L−1 and a linear response between 10 pg L−1 and 1 μg L−1.
Status of state cyanoHAB outreach and monitoring efforts, United States
Published in Lake and Reservoir Management, 2021
F. Joan Hardy, Ellen Preece, Lorraine Backer
Guidelines are available for exposure to and public health protection from some cyanotoxins; nevertheless, there is a limited amount of available toxicological data to support this effort. For example, the World Health Organization (WHO; Chorus and Bartram 1999) provided provisional guidelines for lifetime exposure to microcystin-LR in drinking water (1 µg/L), but a lack of information at the time prevented creation of guidelines for other cyanotoxins. Since then, several US states have developed their own guidelines that apply to cyanotoxins (i.e., microcystin, anatoxin-a, cylindrospermopsin, and saxitoxin) in drinking water. In 2015, the US Environmental Protection Agency (USEPA) published drinking water health advisories for cylindrospermopsin and microcystin. Although not regulations, the health advisories serve as technical guidance for the protection of public health. However, the USEPA determined there was not enough data available to develop drinking water health advisories for other cyanotoxins (USEPA 2015).
Circular RNA expression profiles following MC-LR treatment in human normal liver cell line (HL7702) cells using high-throughput sequencing analysis
Published in Journal of Toxicology and Environmental Health, Part A, 2019
Shuilin Zheng, Cong Wen, Shu Yang, Yue Yang, Fei Yang
More than 100 naturally occurring variants of MCs were identified with a common chemical structure cyclo-(D-Ala-X-D-MeAsp-Y-Adda-D-Glu-Mdha-), where X and Y represent variable L-amino acids (Wei et al. 2019, Yang et al. 2018a, 2019). Of these variants, microcystin-LR (MC-LR) is the most abundant and toxic, and persists in the environment for months (Chorus et al. 2000; Wu et al. 2019; Yang et al. 2018d). In order to reduce health risks associated with MC-LR exposure, the World Health Organization [World Health Organization (WHO), 1998] set a provisional upper value of 1 µg/L MC-LR in drinking water resources and this guideline level was adopted by many countries including China, USA, and Australia. Cao et al. (2019a, 2019b) also reported that MC-LR produced adverse effects on the gastrointestinal and cardiovascular systems. However, the primary target tissue for MC-LR- mediated damage is the liver (Chen et al. 2019b; Yang et al. 2018b; Zurawell et al. 2005). MacKintosh et al. (1990) proposed that inhibition of the activity of protein phosphatase 1 (PP1) and protein phosphatase2A (PP2A) might be the molecular mechanism underlying MC-LR-induced acute and chronic liver dysfunctions. Subsequent to enzymic phosphoproteins inhibition, gene expression, DNA repair systems, oxidative stress, and apoptosis were noted (Campos and Vasconcelos 2010; Chen et al. 2019a, 2019b). However, the complex interactive molecular mechanisms underlying MC-LR-mediated hepatic toxicity still remain to be determined.
Isolation, molecular identification, and characterization of a unique toxic cyanobacterium Microcystis sp. found in Hunan Province, China
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Pin Liu, Jia Wei, Kun Yang, Isaac Yaw Massey, Jian Guo, Chengcheng Zhang, Fei Yang
With respect to microcystin-producing abilities, the use of morphology to assess microcystin production and toxicity has resulted in contradictory results. Watanabe et al. (1991) were able to distinguish morphologically between toxic and non-toxic microcystin-producing cyanobacteria, while Otsuka et al. (2000) failed to correlate microcystin morphology with toxic vs nontoxic microcystin-producing abilities. However, Kurmayer et al. (2004) were able to distinguish toxic and non-toxic strains of cyanobacteria using PCR molecular analysis. Tillett et al. (2000) reported that in the biosynthesis of microcystins a group of microcystin synthetase (mcy) genes including mcyA, -B, -C, -D, -E, and –G are present and may be amplified in toxigenic cyanobacteria. In particular, the mcyB gene has been widely used to establish molecular techniques for detection of toxigenic cyanobacteria in the lab and field studies (Kaebernick et al. 2000; Neilan et al. 1999; Ouellette, Handy, and Wilhelm 2006; Vichi et al. 2012). Microcystin variants containing highly toxic congeners microcystin-LR, RR, and YR produced by toxic cyanobacteria may be further identified by high-performance liquid chromatography coupled with mass spectrometry equipped with electrospray ionization interface (HPLC-ESI-MS) (Cameán et al. 2004).