Recreational exposure to microcystins during algal blooms in two California lakes

• DOI: 10.1016/j.toxicon.2009.07.006
• Publication Date: 2009-07-17T18:09:47Z
• Authors: Lorraine C. Backer; Sandra V. McNeel; Terry Barber; Barbara Kirkpatrick; Christopher Williams; Mitch Irvin; Yue Zhou; Trisha B. Johnson; Kate Nierenberg; Mark Aubel; Rebecca LePrell; Andrew Chapman; Amanda Foss; Susan Corum; Vincent R. Hill; Stephanie M. Kieszak; Yung-Sung Cheng
• Keywords: Adult; Male; 0301 basic medicine; Microcystis; Adolescent; Microcystins; Harmful Algal Bloom; Fresh Water; Environmental Exposure; Middle Aged; California; 6. Clean water; 3. Good health; Young Adult; 03 medical and health sciences; 13. Climate action; Humans; Recreation; Female; Child; Water Microbiology; Water Pollutants, Chemical; Aged; Environmental Monitoring

We conducted a study of recreational exposure to microcystins among 81 children and adults planning recreational activities on either of three California reservoirs, two with significant, ongoing blooms of toxin-producing cyanobacteria, including Microcystis aeruginosa (Bloom Lakes), and one without a toxin-producing algal bloom (Control Lake). We analyzed water samples for algal taxonomy, microcystin concentrations, and potential respiratory viruses (adenoviruses and enteroviruses). We measured microcystins in personal air samples, nasal swabs, and blood samples. We interviewed study participants for demographic and health symptoms information. We found highly variable microcystin concentrations in Bloom Lakes (<10 microg/L to >500 microg/L); microcystin was not detected in the Control Lake. We did not detect adenoviruses or enteroviruses in any of the lakes. Low microcystin concentrations were found in personal air samples (<0.1 ng/m(3) [limit of detection]-2.89 ng/m(3)) and nasal swabs (<0.1 ng [limit of detection]-5 ng). Microcystin concentrations in the water-soluble fraction of all plasma samples were below the limit of detection (1.0 microg/L). Our findings indicate that recreational activities in water bodies that experience toxin-producing cyanobacterial blooms can generate aerosolized cyanotoxins, making inhalation a potential route of exposure. Future studies should include collecting nasal swabs to assess upper respiratory tract deposition of toxin-containing aerosols droplets.