title: Cyanotoxins in inland lakes of the United States: Occurrence and potential recreational health risks in the EPA National Lakes Assessment 2007.
abstract: A large nation-wide survey of cyanotoxins (1161 lakes) in the United States (U.S.) was conducted during the EPA National Lakes Assessment 2007. Cyanotoxin data were compared with cyanobacteria abundance- and chlorophyll-based World Health Organization (WHO) thresholds and mouse toxicity data to evaluate potential recreational risks. Cylindrospermopsins, microcystins, and saxitoxins were detected (ELISA) in 4.0, 32, and 7.7% of samples with mean concentrations of 0.56, 3.0, and 0.061μg/L, respectively (detections only). Co-occurrence of the three cyanotoxin classes was rare (0.32%) when at least one toxin was detected. Cyanobacteria were present and dominant in 98 and 76% of samples, respectively. Potential anatoxin-, cylindrospermopsin-, microcystin-, and saxitoxin-producing cyanobacteria occurred in 81, 67, 95, and 79% of samples, respectively. Anatoxin-a and nodularin-R were detected (LC/MS/MS) in 15 and 3.7% samples (n=27). The WHO moderate and high risk thresholds for microcystins, cyanobacteria abundance, and total chlorophyll were exceeded in 1.1, 27, and 44% of samples, respectively. Complete agreement by all three WHO microcystin metrics occurred in 27% of samples. This suggests that WHO microcystin metrics based on total chlorophyll and cyanobacterial abundance can overestimate microcystin risk when compared to WHO microcystin thresholds. The lack of parity among the WHO thresholds was expected since chlorophyll is common amongst all phytoplankton and not all cyanobacteria produce microcystins.
authors.affiliation: U.S. Geological Survey, Organic Geochemistry Research Laboratory, Kansas Water Science Center, Lawrence, KS 66049, USA. Electronic address: kloftin@usgs.gov.
authors.forename: Keith A
authors.initials: KA
authors.lastname: Loftin
authors.affiliation: U.S. Geological Survey, Kansas Water Science Center, Lawrence, KS 66049, USA. Electronic address: jlgraham@usgs.gov.
authors.forename: Jennifer L
authors.initials: JL
authors.lastname: Graham
authors.affiliation: U.S. Environmental Protection Agency, Office of Research and Development, NHEERL, Chapel Hill, NC 27599, USA. Electronic address: hilborn.e@epa.gov.
authors.forename: Elizabeth D
authors.initials: ED
authors.lastname: Hilborn
authors.affiliation: U.S. Environmental Protection Agency, Office of Wetlands, Oceans, and Watersheds, Ariel Rios Bldg., 1200 Pennsylvania Ave., N.W., Mail Code 4503T, Washington, DC 20460, USA. Electronic address: lehmann.sarah@epa.gov.
authors.forename: Sarah C
authors.initials: SC
authors.lastname: Lehmann
authors.affiliation: U.S. Geological Survey, Organic Geochemistry Research Laboratory, Kansas Water Science Center, Lawrence, KS 66049, USA. Electronic address: mmeyer@usgs.gov.
authors.forename: Michael T
authors.initials: MT
authors.lastname: Meyer
authors.affiliation: U.S. Geological Survey, Organic Geochemistry Research Laboratory, Kansas Water Science Center, Lawrence, KS 66049, USA. Electronic address: juliec@usgs.gov.
authors.forename: Julie E
authors.initials: JE
authors.lastname: Dietze
authors.affiliation: U.S. Geological Survey, Organic Geochemistry Research Laboratory, Kansas Water Science Center, Lawrence, KS 66049, USA. Electronic address: cgriffith@usgs.gov.
authors.forename: Christopher B
authors.initials: CB
authors.lastname: Griffith
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000032:analysis* / Q000633:toxicity; D002734:Chlorophyll / Q000032:analysis; D000458:Cyanobacteria / Q000502:physiology; D004784:Environmental Monitoring; D060106:Lakes / Q000737:chemistry*; D051379:Mice; D053719:Tandem Mass Spectrometry; D014481:United States
chemical_list: D001427:Bacterial Toxins; D002734:Chlorophyll
keywords: Cyanobacteria; Cyanotoxins; Cylindrospermopsins; Microcystins; Saxitoxins