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Toxic cyanobacteria became more widely recognized as a potential health hazard in the 1990s, and in 1998 the World Health Organization (WHO) first published a provisional Guideline Value of 1 μg L −1 for microcystin-LR in drinking-water. In this publication we compare risk assessment and risk management of toxic cyanobacteria in 17 countries across all five continents. We focus on the three main (oral) exposure vehicles to cyanotoxins: drinking-water, water related recreational and freshwater seafood. Most countries have implemented the provisional WHO Guideline Value, some as legally binding standard, to ensure the distribution of safe drinking-water with respect to microcystins. Regulation, however, also needs to address the possible presence of a wide range of other cyanotoxins and bioactive compounds, for which no guideline values can be derived due to insufficient toxicological data. The presence of microcystins (commonly expressed as microcystin-LR equivalents) may be used as proxy for overall guidance on risk management, but this simplification may miss certain risks, for instance from dissolved fractions of cylindrospermopsin and cyanobacterial neurotoxins. An alternative approach, often taken for risk assessment and management in recreational waters, is to regulate cyanobacterial presence – as cell numbers or biomass – rather than individual toxins. Here, many countries have implemented a two or three tier alert level system with incremental severity. These systems define the levels where responses are switched from Surveillance to Alert and finally to Action Mode and they specify the short-term actions that follow. Surface bloom formation is commonly judged to be a significant risk because of the elevated concentration of microcystins in a scum. Countries have based their derivations of legally binding standards, guideline values, maximally allowed concentrations (or limits named otherwise) on very similar scientific methodology, but underlying assumptions such as bloom duration, average body size and the amount of water consumed while swimming vary according to local circumstances. Furthermore, for toxins with incomplete toxicological data elements of expert judgment become more relevant and this also leads to a larger degree of variation between countries’ thresholds triggering certain actions. Cyanobacterial blooms and their cyanotoxin content are a highly variable phenomenon, largely depending on local conditions, and likely concentrations can be assessed and managed best if the specific conditions of the locality are known and their impact on bloom occurrence are understood. Risk Management Frameworks, such as for example the Water Safety Plan concept of the WHO and the ‘bathing water profile’ of the European Union are suggested to be effective approaches for preventing human exposure by managing toxic cyanobacteria from catchment to consumer for drinking water and at recreational sites. [ABSTRACT FROM AUTHOR]

Abstract: 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 (<10μg/L to >500μg/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 (<0.1ng/m3 [limit of detection]–2.89ng/m3) and nasal swabs (<0.1ng [limit of detection]–5ng). Microcystin concentrations in the water-soluble fraction of all plasma samples were below the limit of detection (1.0μg/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. [Copyright &y& Elsevier]

Abstract: Over the last few decades, scientific research has helped to describe the disease neurotoxic shellfish poisoning (NSP) by identifying the causative organism, Karenia brevis, and by characterizing the disease-causing toxins, a suite of polyether toxins called brevetoxins. In addition to causing disease in exposed human populations, K. brevis blooms and associated management responses have been linked to other effects on coastal communities. Some of these effects are negative, such as the loss of tourism dollars and the increased burden on local health care services caused by increases in human disease incidence. However, some of the effects are positive, such as the significant improvement in detecting brevetoxins in environmental samples and clinical specimens. This review discusses the health and economic effects from K. brevis blooms on Florida coastal communities and the current efforts to identify the data needed to assess social and cultural effects. [Copyright &y& Elsevier]

In the United States, the proportion of foodborne illness outbreaks associated with consumption of contaminated domestic and imported fresh fruits and vegetables (produce) has increased over the past several decades. To address this public health concern, the goal of this work was to identify and quantify factors associated with microbial contamination of produce in pre-and postharvest phases of the farm-to-fork continuum. From 2000 to 2003, we collected 923 samples of 14 types of produce (grown in the southern United States or in the northern border states of Mexico) front 15 farms and eight packing sheds located in the southern United States. To assess microbial quality, samples were enumerated for Escherichia coli, total aerobic bacteria, total coliforms, and total Enterococcus. Most produce types had significantly higher microbial concentrations when sampled at the packing shed than when sampled at the farm. In addition, we observed seasonal differences in the microbial concentrations on samples grown in the United States, with higher mean indicator concentrations detected in the fall (September, October, and November). We developed a predictive, multivariate logistic regression model to identify and quantify factors that were associated with detectable concentrations of E. coli contamination on produce. These factors included produce type (specifically, cabbage or cantaloupe), season of collection (harvested in the fall), and packing step (bin, box, conveyor belt, or turntable). These results can be used to identify specific mechanisms of produce contamination and propose interventions that may decrease the likelihood of produce-associated illness. [ABSTRACT FROM AUTHOR]

During two separate Karenia brevis red tide events, we measured the levels of brevetoxins in air and water samples, conducted personal interviews, and performed pulmonary function tests on people before and after they visited one of two Florida beaches. One hundred and twenty-nine people participated in the study, which we conducted during red tide events in Sarasota and Jacksonville, FL, USA. Exposure was categorized into three levels: low/no exposure, moderate exposure, and high exposure. Lower respiratory symptoms (e.g. wheezing) were reported by 8% of unexposed people, 11% of the moderately exposed people, and 28% of the highly exposed people. We performed nasal–pharyngeal swabs on people who experienced moderate or high exposure, and we found an inflammatory response in over 33% of these participants. We did not find any clinically significant changes in pulmonary function test results; however, the study population was small. In future epidemiologic studies, we plan to further investigate the human health impact of inhaled brevetoxins. [Copyright &y& Elsevier]

People living in coastal communities are at risk for exposure to environmental hazards, including legacy chemicals. We can use databases such as NHANES to assess whether contaminants in coastal communities are present in higher levels than in the United States overall. We can use information from studies of local animal populations to assess which of these contaminants could have been transferred to people from their shared environment. Our objectives were to examine the POP profiles in human populations in areas where there are published POP profiles in resident dolphins and to compare our results with data from NHANES and the dolphin studies. We identified three areas where POPs have been analyzed in local resident dolphin populations (total N = 73). We identified human communities in the same areas, and asked 27 eligible adults to read and sign a consent form, complete a questionnaire about demographics and seafood consumption, provide nine 10-mL blood samples, and provide one sample of seafood (N = 33). Blood and seafood were analyzed for a suite of POPs similar to those analyzed in published dolphin population studies. We compared the results from human blood analyses with NHANES and with data from the published reports of dolphin studies. Levels and proportions of specific POPs found in people and animals reflect POPs found in the local environment. Compared with the nationally representative data reported in NHANES, the levels of many POPs found in high levels in dolphins were also higher in the corresponding human communities. Contaminants measured in marine animals, such as dolphins, can be used to identify the types and relative levels of environmental contaminants expected to occur in people sharing the same environment. Likewise, contaminants measured in coastal human populations can provide insight into which contaminants may be found in nearby animal populations. Unlabelled Image • Levels and proportions of specific POPs found in people and animals reflect POPs found in the local environment • Animal populations can be indicators of environmental pollutants of concern to coastal human populations • Humans may be indicators of pollutants of concern to nearby animal populations, including protected species. [ABSTRACT FROM AUTHOR]

Abstract: This paper reviews the literature describing research performed over the past decade on the known and possible exposures and human health effects associated with Florida red tides. These harmful algal blooms are caused by the dinoflagellate, Karenia brevis, and similar organisms, all of which produce a suite of natural toxins known as brevetoxins. Florida red tide research has benefited from a consistently funded, long-term research program, that has allowed an interdisciplinary team of researchers to focus their attention on this specific environmental issue—one that is critically important to Gulf of Mexico and other coastal communities. This long-term interdisciplinary approach has allowed the team to engage the local community, identify measures to protect public health, take emerging technologies into the field, forge advances in natural products chemistry, and develop a valuable pharmaceutical product. The review includes a brief discussion of the Florida red tide organisms and their toxins, and then focuses on the effects of these toxins on animals and humans, including how these effects predict what we might expect to see in exposed people. [Copyright &y& Elsevier]

Abstract: Human exposure to Florida red tides formed by Karenia brevis, occurs from eating contaminated shellfish and inhaling aerosolized brevetoxins. Recent studies have documented acute symptom changes and pulmonary function responses after inhalation of the toxic aerosols, particularly among asthmatics. These findings suggest that there are increases in medical care facility visits for respiratory complaints and for exacerbations of underlying respiratory diseases associated with the occurrence of Florida red tides. This study examined whether the presence of a Florida red tide affected the rates of admission with a respiratory diagnosis to a hospital emergency room in Sarasota, FL. The rate of respiratory diagnoses admissions were compared for a 3-month time period when there was an onshore red tide in 2001 (red tide period) and during the same 3-month period in 2002 when no red tide bloom occurred (non-red tide period). There was no significant increase in the total number of respiratory admissions between the two time periods. However, there was a 19% increase in the rate of pneumonia cases diagnosed during the red tide period compared with the non-red tide period. We categorized home residence zip codes as coastal (within 1.6km from the shore) or inland (>1.6km from shore). Compared with the non-red tide period, the coastal residents had a significantly higher (54%) rate of respiratory diagnoses admissions than during the red tide period. We then divided the diagnoses into subcategories (i.e. pneumonia, bronchitis, asthma, and upper airway disease). When compared with the non-red tide period, the coastal zip codes had increases in the rates of admission of each of the subcategories during the red tide period (i.e. 31, 56, 44, and 64%, respectively). This increase was not observed seen in the inland zip codes. These results suggest that the healthcare community has a significant burden from patients, particularly those who live along the coast, needing emergency medical care for both acute and potentially chronic respiratory illnesses during red tide blooms. [Copyright &y& Elsevier]

There is little published literature on the efficacy of strategies to reduce exposure to residential well water arsenic. The objectives of our study were to: 1) determine if water arsenic remained a significant exposure source in households using bottled water or point-of-use treatment systems; and 2) evaluate the major sources and routes of any remaining arsenic exposure. We conducted a cross-sectional study of 167 households in Maine using one of these two strategies to prevent exposure to arsenic. Most households included one adult and at least one child. Untreated well water arsenic concentrations ranged from < 10 μg/L to 640 μg/L. Urine samples, water samples, daily diet and bathing diaries, and household dietary and water use habit surveys were collected. Generalized estimating equations were used to model the relationship between urinary arsenic and untreated well water arsenic concentration, while accounting for documented consumption of untreated water and dietary sources. If mitigation strategies were fully effective, there should be no relationship between urinary arsenic and well water arsenic. To the contrary, we found that untreated arsenic water concentration remained a significant (p ≤ 0.001) predictor of urinary arsenic levels. When untreated water arsenic concentrations were < 40 μg/L, untreated water arsenic was no longer a significant predictor of urinary arsenic. Time spent bathing (alone or in combination with water arsenic concentration) was not associated with urinary arsenic. A predictive analysis of the average study participant suggested that when untreated water arsenic ranged from 100 to 500 μg/L, elimination of any untreated water use would result in an 8%–32% reduction in urinary arsenic for young children, and a 14%-59% reduction for adults. These results demonstrate the importance of complying with a point-of-use or bottled water exposure reduction strategy. However, there remained unexplained, water-related routes of exposure. [ABSTRACT FROM AUTHOR]

Prenatal exposure to drinking water with arsenic concentrations >50 μg/L is associated with adverse birth outcomes, with inconclusive evidence for concentrations ≤50 μg/L. In a collaborative effort by public health experts, hydrologists, and geologists, we used published machine learning model estimates to characterize arsenic concentrations in private wells—federally unregulated for drinking water contaminants—and evaluated associations with birth outcomes throughout the conterminous U.S. Using several machine learning models, including boosted regression trees (BRT) and random forest classification (RFC), developed from measured groundwater arsenic concentrations of ∼20,000 private wells, we characterized the probability that arsenic concentrations occurred within specific ranges in groundwater. Probabilistic model estimates and private well usage data were linked by county to all live birth certificates from 2016 (n = 3.6 million). We evaluated associations with gestational age and term birth weight using mixed-effects models, adjusted for potential confounders and incorporated random intercepts for spatial clustering. We generally observed inverse associations with term birth weight. For instance, when using BRT estimates, a 10-percentage point increase in the probability that private well arsenic concentrations exceeded 5 μg/L was associated with a −1.83 g (95% CI: −3.30, −0.38) lower term birth weight after adjusting for covariates. Similarly, a 10-percentage point increase in the probability that private well arsenic concentrations exceeded 10 μg/L was associated with a −2.79 g (95% CI: −4.99, −0.58) lower term birth weight. Associations with gestational age were null. In this largest epidemiologic study of arsenic and birth outcomes to date, we did not observe associations of modeled arsenic estimates in private wells with gestational age and found modest inverse associations with term birth weight. Study limitations may have obscured true associations, including measurement error stemming from a lack of individual-level information on primary water sources, water arsenic concentrations, and water consumption patterns. [ABSTRACT FROM AUTHOR]

Abstract: Having demonstrated significant and persistent adverse changes in pulmonary function for asthmatics after 1h exposure to brevetoxins in Florida red tide (Karenia brevis bloom) aerosols, we assessed the possible longer term health effects in asthmatics from intermittent environmental exposure to brevetoxins over 7 years. 125 asthmatic subjects were assessed for their pulmonary function and reported symptoms before and after 1h of environmental exposure to Florida red tide aerosols for up to 11 studies over seven years. As a group, the asthmatics came to the studies with normal standardized percent predicted pulmonary function values. The 38 asthmatics who participated in only one exposure study were more reactive compared to the 36 asthmatics who participated in ≥4 exposure studies. The 36 asthmatics participating in ≥4 exposure studies demonstrated no significant change in their standardized percent predicted pre-exposure pulmonary function over the 7 years of the study. These results indicate that stable asthmatics living in areas with intermittent Florida red tides do not exhibit chronic respiratory effects from intermittent environmental exposure to aerosolized brevetoxins over a 7 year period. [Copyright &y& Elsevier]

Abstract: To enhance information sharing and garner increased support from the public for scientific research, funding agencies now typically require that research groups receiving support convey their work to stakeholders. The National Institute of Environmental Health Sciences (NIEHS) funded Aerosolized Florida Red Tide P01 research group (Florida Red Tide Research Group) has employed a variety of outreach strategies to meet this requirement. Messages developed from this project began a decade ago and have evolved from basic print material (fliers and posters) to an interactive website, to the use of video and social networking technologies, such as Facebook and Twitter. The group was able to track dissemination of these information products; however, evaluation of their effectiveness presented much larger challenges. The primary lesson learned by the Florida Red Tide Research Group is that the best ways to reach specific stakeholders are to develop unique products or services to address specific stakeholders’ needs, such as the Beach Conditions Reporting System. Based on the experience of the Group, the most productive messaging products result when scientific community engages potential stakeholders and outreach experts during the very initial phases of a project. [Copyright &y& Elsevier]

Abstract: Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1h of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide. Symptom data and spirometry data were collected before and after 1h of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24h, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1h of exposure to the Florida red tide toxin aerosols. [Copyright &y& Elsevier]

Abstract: The west coast of Florida has annual blooms of the toxin-producing dinoflagellate, Karenia brevis with Sarasota, FL considered the epicenter for these blooms. Numerous outreach materials, including Frequently Asked Question (FAQ) cards, exhibits for local museums and aquaria, public beach signs, and numerous websites have been developed to disseminate information to the public about this natural hazard. In addition, during intense onshore blooms, a great deal of media attention, primarily via newspaper (print and web) and television, is focused on red tide. However to date, the only measure of effectiveness of these outreach methods has been counts of the number of people exposed to the information, e.g., visits to a website or number of FAQ cards distributed. No formal assessment has been conducted to determine if these materials meet their goal of informing the public about Florida red tide. Also, although local residents have the opinion that they are very knowledgeable about Florida red tide, this has not been verified empirically. This study addressed these issues by creating and administering an evaluation tool for the assessment of public knowledge about Florida red tide. A focus group of Florida red tide outreach developers assisted in the creation of the evaluation tool. The location of the evaluation was the west coast of Florida, in Sarasota County. The objective was to assess the knowledge of the general public about Florida red tide. This assessment identified gaps in public knowledge regarding Florida red tides and also identified what information sources people want to use to obtain information on Florida red tide. The results from this study can be used to develop more effective outreach materials on Florida red tide. [ABSTRACT FROM AUTHOR]

Abstract: The use of enterococci as the primary fecal indicator bacteria (FIB) for the determination of recreational water safety has been questioned, particularly in sub/tropical marine waters without known point sources of sewage. Alternative FIB (such as the Bacteroidales group) and alternative measurement methods (such as rapid molecular testing) have been proposed to supplement or replace current marine water quality testing methods which require culturing enterococci. Moreover, environmental parameters have also been proposed to supplement current monitoring programs. The objective of this study was to evaluate the health risks to humans from exposure to subtropical recreational marine waters with no known point source. The study reported symptoms between one set of human subjects randomly assigned to marine water exposure with intensive environmental monitoring compared with other subjects who did not have exposure. In addition, illness outcomes among the exposed bathers were compared to levels of traditional and alternative FIB (as measured by culture-based and molecular-based methods), and compared to easily measured environmental parameters. Results demonstrated an increase in self-reported gastrointestinal, respiratory and skin illnesses among bathers vs. non-bathers. Among the bathers, a dose–response relationship by logistic regression modeling was observed for skin illness, where illness was positively related to enterococci enumeration by membrane filtration (odds ratio = 1.46 [95% confidence interval = 0.97–2.21] per increasing log10 unit of enterococci exposure) and positively related to 24 h antecedent rain fall (1.04 [1.01–1.07] per increasing millimeters of rain). Acute febrile respiratory illness was inversely related to water temperature (0.74 [0.56–0.98] per increasing degree of water temperature). There were no significant dose–response relationships between report of human illness and any of the other FIB or environmental measures. Therefore, for non-point source subtropical recreational marine waters, this study suggests that humans may be at increased risk of reported illness, and that the currently recommended and investigational FIB may not track gastrointestinal illness under these conditions; the relationship between other human illness and environmental measures is less clear. [Copyright &y& Elsevier]

Abstract: Florida red tides, an annual event off the west coast of Florida, are caused by the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins, brevetoxins, which kill fish, sea birds, and marine mammals, as well as sickening humans who consume contaminated shellfish. These toxins become part of the marine aerosol, and can also be inhaled by humans and other animals. Recent studies have demonstrated a significant increase in symptoms and decrease in lung function in asthmatics after only one hour of beach exposure during an onshore Florida red tide bloom. This study constructed a transect line placing high volume air samplers to measure brevetoxins at sites beginning at the beach, moving approximately 6.4km inland. One non-exposure and 2 exposure studies, each of 5 days duration, were conducted. No toxins were measured in the air during the non-exposure period. During the 2 exposure periods, the amount of brevetoxins varied considerably by site and by date. Nevertheless, brevetoxins were measured at least 4.2km from the beach and/or 1.6km from the coastal shoreline. Therefore, populations sensitive to brevetoxins (such as asthmatics) need to know that leaving the beach may not discontinue their environmental exposure to brevetoxin aerosols. [Copyright &y& Elsevier]

With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While many of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida''s west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting pathway for the lifeguards to minimize the amount of time away from their primary duties. Specifically, we provided a Personal Digital Assistant for each of the eight beaches. The portable unit allows the lifeguards to report from their guard tower. The data are transferred via wireless Internet to a website hosted on the Mote Marine Laboratory Sarasota Operations of the Coastal Ocean Observation Laboratories (SO COOL) server. The system has proven to be robust and well received by the public. The system has reported variability from beach to beach and has provided vital information to users to minimize their exposure to toxic marine aerosols. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to examine the distribution of brevetoxin-3 administered to pregnant dams and to determine the extent of placental transport to fetuses. Twenty-nine pregnant CD-1 mice were administered 3H-brevetoxin-3 (∼1.3μCi/animal; ∼2.8μg compound/kg) by intratracheal instillation on one of gestational days 15–18. Groups of four or five dams were killed at selected times through 48h post-dosing. Four pregnant dams were administered 3H-brevetoxin-3 on gestational day 15 or 16 via osmotic minipump to provide continuous delivery of compound (∼0.13μCi, 7.5ng compound/day) over a 72-h period. Then the dams and fetuses were killed. Brevetoxin-associated radioactivity was detected in placentas and fetuses within 0.5h of intratracheal administration. Concentrations of brevetoxin equivalents in fetuses were approximately 0.3ng/g throughout the 48-h post-dosing, resulting in a calculated dose to fetuses of 19ng/gh. Following brevetoxin infusion, concentration of brevetoxin equivalents in fetuses was 0.1ng/g, lower than that present in most maternal tissues. Results demonstrated placental transport of brevetoxin or its metabolites following maternal acute exposure and repeated low-dose exposure. The consequences of these findings for pregnant women exposed to brevetoxins by inhalation or ingestion remain to be determined. [Copyright &y& Elsevier]