Exposure to microcystin among coastal residents during a cyanobacteria bloom in Florida

Adam M Schaefer; Luke Yrastorza; Nicole Stockley; Kathi Harvey; Nancy Harris; Robert Grady; James Sullivan; Malcolm McFarland; John S Reif

doi:10.1016/j.hal.2020.101769

Exposure to microcystin among coastal residents during a cyanobacteria bloom in Florida

Harmful Algae. 2020 Feb:92:101769. doi: 10.1016/j.hal.2020.101769. Epub 2020 Feb 5.

Authors

Adam M Schaefer¹, Luke Yrastorza², Nicole Stockley³, Kathi Harvey⁴, Nancy Harris⁵, Robert Grady⁶, James Sullivan⁷, Malcolm McFarland⁸, John S Reif⁹

Affiliations

¹ Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 N, Ft Pierce, FL, 34946, USA. Electronic address: aschaef3@fau.edu.
² Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 N, Ft Pierce, FL, 34946, USA. Electronic address: lyrastorza2017@fau.edu.
³ Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 N, Ft Pierce, FL, 34946, USA. Electronic address: nstockley@fau.edu.
⁴ Christine E. Lynn College of Nursing, Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33431, USA. Electronic address: harveyk@health.fau.edu.
⁵ Christine E. Lynn College of Nursing, Florida Atlantic University, 777 Glades Road, Boca Raton, FL, 33431, USA. Electronic address: harrisn@health.fau.edu.
⁶ Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 N, Ft Pierce, FL, 34946, USA. Electronic address: gradyr@health.fau.edu.
⁷ Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 N, Ft Pierce, FL, 34946, USA. Electronic address: jsullivan@fau.edu.
⁸ Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 N, Ft Pierce, FL, 34946, USA. Electronic address: mmcfarland@fau.edu.
⁹ Department of Environmental and Radiological Health Sciences, Colorado State University 1681 Campus, Fort Collins, CO, 80523, USA. Electronic address: john.reif@colostate.edu.

PMID: 32113588
DOI: 10.1016/j.hal.2020.101769

Abstract

Florida has experienced multiple cyanobacteria blooms in recent years the most severe of which occurred in 2016 and 2018. Several toxins are produced by proliferating cyanobacteria, including the hepatotoxin microcystin (MC). Harmful algal blooms (HABs) caused by cyanobacteria have the potential to impact public health. However, to date there have been limited attempts to quantify exposure in human populations. This study investigated potential exposure to the cyanobacterial toxin, MC by measuring concentrations in swabs of the nasal mucosa. In addition, the relationships between nasal concentrations of MC, environmental concentrations and activity patterns were assessed. Participants (n = 125) were recruited in 2018 during a cyanobacterial bloom of Microcystis aeruginosa and completed a questionnaire which included location, type, and duration of recreational or occupational contact with impacted waterways within the last 10 days. Water samples were collected concurrently. A sterile swab was used to collect a sample from the nasal mucosa. Concentrations of MC were measured by ELISA. Of the 121 participants who provided nasal swabs, 115 (95.0 %) had concentrations of MC above the limit of detection with a mean concentration of 0.61 + 0.75 ppb. There were significant differences (p < 0.01) in mean MC concentration between individuals with direct contact with impacted waters (0.77 + 0.88 ppb) compared to those with no recent contact (0.37 + 0.49 ppb). Higher concentrations were observed among occupationally exposed individuals. Nasal concentrations of MC varied significantly over time and location of exposure to the bloom, concordant with concentrations in water samples. The results suggest that inhalation of aerosols may be an important pathway for exposure to MC. Nasal MC concentrations were generally highest during periods when concentrations in the surrounding waters peaked. Further research is needed to characterize the public health implications of exposure to cyanobacterial blooms.

Keywords: Cyanobacteria; Exposure assessment; Harmful algal blooms (HABs); Microcystin.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Cyanobacteria*
Florida
Harmful Algal Bloom
Humans
Microcystins
Microcystis*

Substances

Microcystins