A prospective study of marine phytoplankton and symptoms of illness among recreational beachgoers in Puerto Rico, 2009

Transcription

1 A prospective study of marine phytoplankton and symptoms of illness among recreational beachgoers in Puerto Rico, 2009 Cynthia Lin ORISE Pre-doctoral fellow Research Participation Program at the U.S. Environmental Protection Agency (EPA) Environmental Public Health Division, Chapel Hill, NC Doctoral student Department of Epidemiology, UNC Gillings School of Global Public Health, Chapel Hill, NC 2014 Water Microbiology Conference May 6, 2014

2 Co-authors Elizabeth Hilborn, Timothy Wade, Elizabeth Sams US EPA, National Health and Environmental Effects Research Laboratory, Environmental Public Health Division, Research Triangle Park, NC Alfred Dufour US EPA, National Exposure Research Laboratory, Microbial Chemical Environmental Assessment Research Division, Cincinnati, OH Andrew Chapman GreenWater Laboratories, Palatka, Florida 2

3 Presentation Overview Background Harmful algal blooms Recreational water quality and health Methods Prospective epidemiologic study design Results Phytoplankton counts and illness Strengths & Limitations Conclusion 3

4 Background Subset of algae can release toxins 85 toxic microalgal species have been documented Harmful algal blooms Influenced by environmental variability (e.g., nutrient enrichment, temperature, light intensity, etc.) Algal groups Cyanobacteria (blue-green algae) Pyrrhophyta (dinoflagellates) Bacillariophyta (diatoms) Red tide bloom in New Zealand 4

5 Background Recreational water exposure to harmful algal species Ingestion, inhalation, direct contact (dermal) No federal regulations or guidelines in the U.S. WHO guideline for recreational waters Guideline derived from an epidemiologic study at a freshwater site. (Pilotto et al., 1997) 5

6 Background Recreational water exposure to harmful algal species Existing literature has focused on freshwater harmful algal blooms. Few studies on health effects of exposure to harmful algal blooms in marine waters. Health effect of recreational exposure to low phytoplankton counts is not established. Marion Lake, KS 6

7 Background Freshwater studies Prospective study in Australia (Pilotto & Douglas, et. al, 1997) Symptoms of illness (e.g., vomiting/diarrhea, cold and flu symptoms) associated with cyanobacteria levels as low as 5,000 cells per ml Prospective study in Canada (Lévesque et al., 2013) Gastrointestinal symptoms associated with contact with lakes with high cyanobacterial counts Algal bloom-associated disease outbreaks in U.S. (Hilborn et al., 2014) Dermatologic, gastrointestinal, respiratory, ear, and eye symptoms 7

8 Background Marine water studies Prospective study in Florida (Backer et al., 2003) Respiratory symptoms associated with aerosolized brevetoxins from harmful algal bloom. Retrospective cohort study in Florida (Kirkpatrick et al. 2010) Total number of gastrointestinal emergency room admissions increased during a harmful algal bloom formed by Karenia brevis compared to period with no harmful algal blooms. 8

9 Study Objective To evaluate the association between phytoplankton counts and symptoms of illness among recreational beachgoers. 9

10 Methods National Epidemiological and Environmental Assessment of Recreational (NEEAR) Water Study Initiated by EPA Marine and freshwater beach sites Designed to examine associations between swimming-associated illnesses and novel and faster approaches to measuring recreational water quality Previous analyses have focus on fecal indicator bacteria and swimming-associated illnesses 10

11 Methods Boquerón Beach, Puerto Rico Phytoplankton counts (cells/ml) Lyngbyatoxin and debromoaplysiatoxin (HPLC/MS) Water sampling 3 locations along beach Waist depth 11am Daily composite sample used for analysis 11

12 Boquerón Beach, Puerto Rico 12

13 Boquerón Beach, Puerto Rico 13

14 Methods 26 days weekends and designated holidays during the summer of 2009 Three interviews 1) Enrollment Demographics, baseline health, chronic health conditions 2) Beach exit Water exposure and other activities engaged in at the beach (e.g., contact with unfamiliar animals, digging in sand) 3) Telephone follow-up days later Occurrence of illness experienced since the beach visit 14

15 Methods Multivariable logistic regression Outcomes were binary indicators for gastrointestinal illness respiratory illness skin rash eye ailments earache Excluded participants with baseline illness 15

16 Methods Multivariable logistic regression Phytoplankton cell count categories (main exposure) High ( 75 th percentile) Medium (25 th -75 th percentile) Low ( 25 th percentile) = referent category Adjusted for potential confounders age, sex, any chronic illness (GI, skin, asthma), contact with seaweed, contact with unfamiliar animals, digging in sand 16

17 Results Respondent characteristics and demographics N=15,726 Enrollment questionnaire Average age = 30 years Range: infant to 92 years <20% under age of 12 55% female 99% Hispanic 25% reported any chronic illness (GI, skin, respiratory) Baseline health (3 days prior to beach visit) 8% sore throat <3% rash, gastrointestinal, earache, eye symptom 17

18 Beach visit activities Results N (%) All (100) No water contact 2995 (19.0) Body immersion (77.0) Head immersion (64.1) Water in mouth 5615 (35.7) Played with algae/seaweed on beach 2499 (15.9) Any contact with unknown animals 646 (4.1) Dug in sand 3699 (23.5) 18

19 Phytoplankton cell counts Results No. (%) of days present Min. Cells per ml for the sampling day 25th percentile Median 75th percentile Max. All groups 26 (100) Bacillariophyta 26 (100) Cyanobacteria* 24 (92) Picocyanophyte 8 (31) Pyrrhophyta 26 (100) Miscellaneous 25 (96) *excluding picocyanophyte 19

20 Results Lyngbyatoxin and debromoaplysiatoxin below the limit of detection Low levels of Enterococcus CFU Daily geometric means below the recommended EPA criteria of 35 CFU per 100 ml (Wade et al, 2011) 20

21 Results Illness after beach visit Respiratory illness 7% Gastrointestinal illness 5% Rash 5% Eye irritation 3% Earache 2% 21

22 Results Total Phytoplankton and Illness Total phytoplankton category (cells/ml) % Eye irritation Adjusted OR (95% CI) % Rash Adjusted OR (95% CI) LOW ( 581.6) 3.2% % 1. MEDIUM (>581.6 & <783.4) 3.0% HIGH ( 783.4) 4.2% 0.93 (0.72, 1.20) 1.32 (1.03, 1.69) 4.2% 5.7% 0.96 (0.77, 1.19) 1.28 (1.03, 1.59) 22

23 Bacillariophyta and Respiratory Illness Bacillariophyta category (cells/ml) Pyrrhophyta and Illness No associations Results Respiratory Illness % Adjusted OR (95% CI) LOW ( 301.2) 6.1% 1. MEDIUM (>301.2 & <442.5) 7.7% 1.27 ( ) HIGH ( 442.5) 6.8% 1.09 ( ) 23

24 Results Cyanobacteria and Illness Associated with all outcomes except for gastrointestinal illness Cyanobacteria category (cells/ml) % Respiratory Illness Adjusted OR (95% CI) LOW ( 36.7) 5.8% 1. MEDIUM (>36.7 & <237.5) 7.4% 1.29 ( ) HIGH ( 237.5) 7.8% 1.37 ( ) 24

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27 Results Phytoplankton exposure and illness Picocyanophyte (presence vs. absence) Not associated with illness among participants with body immersion Among participants who reported swallowing water (N=5,615; 36%) Earache (OR=1.62; 95% CI: ) 27

28 Strengths & Limitations Strengths Prospective study design Large number of participants, high recruitment rate Measurement of multiple covariates Limitations Overall very good water quality Phytoplankton cell counts, no biomass evaluation Low illness rates High pre-existing asthma rate 28

29 Conclusion Phytoplankton cell counts were associated with symptoms of illness Heath risks may vary by algal group Phytoplankton counts could have been markers for other causative factors we did not measure 29

30 Acknowledgements Funding Source: IA # DW Westat, Inc., Rockville, Maryland Lesley Vazquez Coriano, USEPA, Office of Water Mark Aubel, Amanda Foss, GreenWater Laboratory, Palatka, Florida Team Members of the NEEAR Water Study Study participants 30

31 Thank you! Questions? 31