Human health effects and remotely sensed cyanobacteria
Citation:
Hilborn, E, B. Schaeffer, R. Stumpf, W. Krueger, E. Sams, AND Tim Wade. Human health effects and remotely sensed cyanobacteria. 9th US Symposium on Harmful Algal Blooms, Baltimore, Maryland, November 11 - 17, 2017.
Impact/Purpose:
Remote sensing of cyanobacteria blooms (HAB) promises to fulfill the public health surveillance needs of assessing HAB information in a cost-effective manner over a wide area. However, we show that effectiveness among algorithms may differ by water source. We suggest that use of the MERIS Cyanobacteria Index is a better algorithm for inland fresh water lake HAB. This product partially fulfills work listed under SSWR 4.01E.
Description:
Cyanobacteria blooms (HAB) pose a potential health risk to beachgoers, including HAB-associated gastrointestinal, respiratory and dermal illness. We conducted a prospective study of beachgoers at a Great Lakes beach during July – September, 2003. We recorded each participant’s health status and activity during their beach visit, and the health effects that occurred within 12 days after the beach visit. We evaluated the presence of blooms retrospectively using the default MODIS ocean chlorophyll-a (OC4) algorithm and MERIS cyanobacteria index (CI). During 16 weekend study days, we recruited 2,840 participants, of which 1305 (46%) reported water contact (bathers) and were included in analysis; 55% percent were female, and 26% were children. During a retrospective assessment of MODIS OC4 imagery, chlorophyll-a concentrations suggested a HAB during August 16 – 24, whereas the MERIS CI did not indicate a HAB was present. We detected no significant increase in reported gastrointestinal, respiratory or dermal health effects among bathers who recreated during August 16 – 24 compared to other study days. Although the MODIS OC4 is useful to detect chlorophyll-a and HABs in coastal environments, the MERIS CI appears to have provided a better assessment of bather health risk at this Great Lakes beach. Reliance upon the default MODIS OC4 algorithm alone would have led to erroneous bather HAB exposure assessment. This is the first time concurrent MODIS OC4 and MERIS CI results have been informed by temporally-associated health information. This is an abstract of a proposed presentation and does not necessarily reflect EPA policy.