MA9 Hazard Assessments for Near Coastal Ecosystems
D137-140
8:00 AM - 12:00 PM, Monday
() Aerosolized Harmful Algal Toxins: A Coastal Human Health Hazard.
Pierce, R1, Henry, M1, Blum, P1, Hamel, S1, Kirkpatrick, B1, Cheng, Y2, Zhou, Y2, Naar, J3, Fleming, L4, Backer, L5, 1 Mote Marine Laboratory, Sarasota, FL, USA2 Lovelace Respiratory Research Institute, Albuquerque, NM, USA3 University of North Carolina at Wilmington, Wilmington, NC, USA4 University of Miami Medical School, Miami, FL, USA5 Centers for Disease Control and Prevention, Atlanta, FL, USA
ABSTRACT- A unique characteristic of Karenia brevis harmful algal blooms in the near coastal environment is associated air-borne (aerosolized) neurotoxins that cause severe respiratory irritation in humans and other mammals. K. brevis is a marine dinoflagellate that produces a suite of polyether neurotoxic compounds (brevetoxins) designated PbTx. Brevetoxins are sodium channel activators and also cause eye and respiratory irritation, bronchial constriction and inhibit immune cell function in marine mammals. This study was undertaken in collaboration with human exposure studies to determine the composition of aerosolized brevetoxins to which beach goers are exposed during a coastal K. brevis harmful algal bloom. Brevetoxin composition was monitored in water along the shore and in air during a control test (no K. brevis) and an exposure test (K. brevis bloom). The most abundant brevetoxin recovered from water samples was PbTx-2, followed by PbTx-3 and PbTx-1. Air samples exhibited higher concentrations of PbTx-3 than PbTx-2, with no PbTx-1 detected in aerosol samples. Thjis change in PbTx composition from water to air indicates either a preferential selection for PbTx-3 over -2 during the aerosolization process, or a chemical alteration of PbTx-2 to -3 during the transition from intra-cellular to aerosolized conditions. The naturally-occurring brevetoxin antagonist, brevenal, also was detected in the K. brevis bloom. Aerosol particle size analysis indicated that most of the brevetoxins were associated with particle sizes that would lodge in the upper airway (nasal, oral, pharyngeal regions), with only about 2 to 3 % deposited farther down in the tracheobronchial regions. The aerosol composition of brevetoxins and particle size association provides critical information for assessing human health hazard from exposure to aerosolized brevetoxins. Funded by NIEHS Award PO1 ES 10594-03, and FL DOH Contract # C0082.
Key words: aerosol, karenia, brevetoxins, hab