Trophy hunters' willingness to pay for wildlife conservation and community benefits.

In the face of fundamental land-use changes, the potential for trophy hunting to contribute to conservation is increasingly recognized. Trophy hunting can, for example, provide economic incentives to protect wildlife populations and their habitat, but empirical studies on these relationships are few and tend to focus on the effects of benefit-sharing schemes from an ex post perspective. We investigated the conditions under which trophy hunting could facilitate wildlife conservation in Ethiopia ex ante. We used a choice experiment approach to survey international trophy hunters' (n = 224) preferences for trips to Ethiopia, here operationalized as trade-offs between different attributes of a hunting package, as expressed through choices with an associated willingness to pay. Participants expressed strong preferences and, consequently, were willing to pay substantial premiums for hunting trips to areas with abundant nontarget wildlife where domestic livestock was absent and for arrangements that offered benefit sharing with local communities. For example, within the range of percentages considered in the survey, respondents were on average willing to pay an additional $3900 for every 10 percentage points of the revenue being given to local communities. By contrast, respondents were less supportive of hunting revenue being retained by governmental bodies: Willingness to pay decreased by $1900 for every 10 percentage points of the revenue given to government. Hunters' preferences for such attributes of hunting trips differed depending on the degree to which they declared an interest in Ethiopian culture, nature conservation, or believed Ethiopia to be politically unstable. Overall, respondents thus expressly valued the outcomes of nature conservation activities--the presence of wildlife in hunting areas--and they were willing to pay for them. Our findings highlight the usefulness of insights from choice modeling for the design of wildlife management and conservation policies and suggest that trophy hunting in Ethiopia could generate substantially more financial support for conservation and be more in line with conservation objectives than is currently the case.

La Disposición de los Cazadores de Trofeos a Pagar por la Conservación de la Vida Silvestre y los Beneficios de la Comunidad Resumen De frente a los cambios fundamentales en el uso de suelo, el potencial de que la caza de trofeos contribuya a la conservación es reconocido cada vez más. Este tipo de caza puede, por ejemplo, proporcionar incentivos económicos para proteger poblaciones de vida silvestre y su hábitat, pero los estudios empíricos sobre estas relaciones son pocos y tienden a enfocarse en los efectos de los esquemas de compartir beneficios desde una perspectiva ex post. Investigamos las condiciones bajo las cuales la caza de trofeos podría facilitar la conservación de vida silvestre en Etiopía de forma ex ante. Usamos una estrategia de experimento de opciones para encuestar a cazadores internacionales de trofeos (n = 224) sobre sus preferencias por viajes a Etiopía, usados aquí como compensaciones entre los diferentes atributos de un paquete de caza, expresadas a través de opciones con una disposición asociada a pagar. Los participantes expresaron fuertes preferencias y, en consecuencia, estaban dispuestos a pagar primas sustanciales por viajes de caza a áreas con abundantes especies no cazadas y donde el ganado doméstico estaba ausente, y por arreglos que ofrecían compartir beneficios con la comunidad local. Por ejemplo, dentro del rango de porcentajes considerados en la encuesta, los respondientes estaban, en promedio, dispuestos a pagar unos $3900 adicionales por cada 10 puntos porcentuales de los ingresos que se otorgan a la comunidad local. En contraste, los respondientes no apoyaron la idea de que el gobierno retenga los ingresos: la disposición a pagar disminuyó en $1900 por cada 10 puntos porcentuales de los ingresos otorgados al gobierno. Las preferencias de los cazadores por dichos atributos de los viajes de caza difirieron dependiendo del grado al cual declararon un interés por la cultura etíope, la conservación de la naturaleza o su creencia en la inestabilidad política de Etiopía. En general, los respondientes así valoraron explícitamente los resultados de las actividades de conservación de la naturaleza - la presencia de vida silvestre en áreas de caza - y su disposición a pagar por ellos. Nuestros hallazgos resaltan la utilidad de percepción a partir del modelado de opciones para el diseño de planes de manejo de vida silvestre y políticas de conservación y sugieren que la caza de trofeos en Etiopía puede generar sustancialmente más apoyo financiero para la conservación y estar más en línea con los objetivos de conservación que los planes de manejo actuales.

Valuing the commons: An international study on the recreational benefits of the Baltic Sea.

The Baltic Sea provides benefits to all of the nine nations along its coastline, with some 85 million people living within the catchment area. Achieving improvements in water quality requires international cooperation. The likelihood of effective cooperation is known to depend on the distribution across countries of the benefits and costs of actions needed to improve water quality. In this paper, we estimate the benefits associated with recreational use of the Baltic Sea in current environmental conditions using a travel cost approach, based on data from a large, standardized survey of households in each of the 9 Baltic Sea states. Both the probability of engaging in recreation (participation) and the number of visits people make are modeled. A large variation in the number of trips and the extent of participation is found, along with large differences in current annual economic benefits from Baltic Sea recreation. The total annual recreation benefits are close to 15 billion EUR. Under a water quality improvement scenario, the proportional increases in benefits range from 7 to 18% of the current annual benefits across countries. Depending on how the costs of actions are distributed, this could imply difficulties in achieving more international cooperation to achieve such improvements.

Reduction of Baltic Sea nutrient inputs and allocation of abatement costs within the Baltic Sea catchment.

The Baltic Sea Action Plan (BSAP) requires tools to simulate effects and costs of various nutrient abatement strategies. Hierarchically connected databases and models of the entire catchment have been created to allow decision makers to view scenarios via the decision support system NEST. Increased intensity in agriculture in transient countries would result in increased nutrient loads to the Baltic Sea, particularly from Poland, the Baltic States, and Russia. Nutrient retentions are high, which means that the nutrient reduction goals of 135 000 tons N and 15 000 tons P, as formulated in the BSAP from 2007, correspond to a reduction in nutrient loadings to watersheds by 675 000 tons N and 158 000 tons P. A cost-minimization model was used to allocate nutrient reductions to measures and countries where the costs for reducing loads are low. The minimum annual cost to meet BSAP basin targets is estimated to 4.7 billion Euro.

Melt-extruded formulations of fenofibrate with various grades of hydrogenated phospholipid exhibit promising in-vitro biopharmaceutical behavior.

In the current study, it was demonstrated that three commercially available grades of hydrogenated phospholipids (HPL) differing in their content of phosphatidylcholine may be used as components for hot melt-extruded binary (HPL as sole excipient) or ternary (in combination with copovidone) solid dispersions of fenofibrate (FEN) at mass fractions between 0.5 and 20% (ternary) or 80% (binary). X-ray powder diffraction indicated complete conversion of crystalline fenofibrate into the amorphous state by hot melt extrusion for all ternary blends. In contrast, both the binary blends (HPL- and copovidone-based) contained minor remaining crystallites. Irrespectively, all solid dispersions induced during dissolution studies a supersaturated state of FEN, where the ternary ASDs showed enhanced and more complete release of FEN as compared to the binary blends and, even more pronounced, in comparison to the marketed micronized and nano-milled formulations. In terms of the cumulated amount permeated, there were marginal differences between the various formulations when combined dissolution/permeation was done using FeSSIF as donor medium; with FaSSIF as donor medium, the binary HPL-ASD containing the grade with the highest phosphatidylcholine fraction performed best in terms of permeation, even significantly better than the marketed nano-crystal formulation. Otherwise, no significant differences were seen between the various grades of HPL when FEN dissolution and permeation were analyzed for ternary solid dispersions. In conclusion, the in-vitro biopharmaceutical behaviour of hydrogenated phospholipid-containing blends manufactured by hot melt extrusion appears promising. They can be a viable formulation option for poorly water-soluble and lipophilic drug compounds like FEN.

Trade-offs in the transition to a blue economy - Mapping social acceptance of aquaculture expansion in Norway.

Aquaculture is currently the fastest growing food industry globally, and proposed expansion plans include substantial increases in production over the next decades. While this will improve global food security, contribute to the blue economy and create jobs locally, the potential negative impacts on the marine environment could be massive. The existing literature suggests that further research needs to be conducted into the dynamic nature of the social-ecological systems which host aquaculture. This paper presents the results of a choice experiment survey of Norwegian households' trade-offs between salmon production and job creation, and the detrimental impacts on the marine environment. Most respondents were at the outset neutral or supportive of plans for a substantial increase in aquaculture production. However, when informed about potential environmental impacts in terms of marine plastics and salmon lice affecting wild salmon stocks, and asked to trade these off against the positive effects, the majority opposed the plans and expressed a positive willingness-to-pay to avoid the planned expansion. Applying a hybrid mixed multinomial logit model we find that income, education and to some extent age, along with environmental attitudes, explain most of the variation in people's preferences. Support for large aquaculture expansion is higher among people who consume farmed salmon frequently and those living in areas with a high density of aquaculture farms. Hence, we do not find the so-called "not in my backyard" (NIMBY) effect. These results, which arguably contrast with previous studies of environmental impacts from aquaculture, can be useful for public planners globally as they consider expanding the blue economy.

Hydrogenated phospholipid, a promising excipient in amorphous solid dispersions of fenofibrate for oral delivery: Preparation and in-vitro biopharmaceutical characterization.

Amorphous solid dispersions (ASD) represent a viable formulation strategy to improve dissolution and bioavailability of poorly soluble drugs. Our study aimed to evaluate the feasibility and potential role of hydrogenated phospholipid (HPL) as a matrix material and solubilizing additive for binary (alone) or ternary (in combination with polymers) solid dispersions, using fenofibrate (FEN) as the model drug. FEN, incorporated within ASDs by melting or freeze-drying (up to 20% m/m), stayed amorphous during short-term stability studies. The solubility enhancing potential of HPL depended on the dissolution medium. In terms of enhancing in vitro permeation, solid dispersions with HPL were found equally or slightly more potent as compared to the polymer-based ASD. For studied ASD, in vitro permeation was found substantially enhanced as compared to a suspension of crystalline FEN and at least equal compared to marketed formulations under comparable conditions (literature data). Additionally, while the permeation of neat FEN and FEN in binary solid dispersions was affected by the dissolution medium (i.e., the "prandial state"), for ternary solid dispersions the permeation was independent of the "prandial state" (FaSSIF = FeSSIF). This suggests that ternary solid dispersions containing both polymer and HPL may represent a viable formulation strategy to mitigate fenofibrate's food effect.

Steroidogenic activity of liposomal methylated resveratrol analog 3,4,5,4'-tetramethoxystilbene (DMU-212) in human luteinized granulosa cells in a primary three-dimensional in vitro model.

PURPOSE: Steroid hormone secretion is one of the key functions of granulosa cells (GCs). Resveratrol is a natural polyphenol, known for its beneficial health effects, such as improving reproductive health. However, its application is limited due to poor bioavailability. The methoxy derivative of resveratrol (DMU-212) was demonstrated to be more lipophilic, and therefore of greater bioavailability. However, since the addition of methoxy groups to the stilbene scaffold was found to make the molecule insoluble in water, DMU-212 was loaded into liposomes. This study aimed to evaluate how the liposomal formulation of DMU-212 (lipDMU-212) alters estradiol and progesterone secretion of human ovarian GCs in a primary three-dimensional cell culture model. METHODS: DMU-212-loaded liposomes were prepared by thin film hydration followed by extrusion. Cell viability was measured after exposure of GCs spheroids to the liposomal formulation of DMU-212 using CellTiter-Glo® 3D Cell Viability Assay. The secretion of estradiol and progesterone was determined using commercial ELISA kits. RT-qPCR was conducted to analyze the expression of steroidogenesis-related genes. Finally, the western blot technique was used to analyze the effect of lipDMU-212 and FSH treatments on CYP11A1 and HSD3B1 protein levels. RESULTS: lipDMU-212 was found to significantly increase estradiol and progesterone secretion in a dose-dependent manner by enhancing the expression of CYP11A1, HSD3B1, StAR, CYP17A1, CYP19A1, and HSD17B1 genes. We have also shown that lipDMU-212, used alone and in combination with FSH, significantly increased the expression of the HSD3B1 and CYP11A1 proteins in GCs. Furthermore, our study suggests that lipDMU-212 increases FSH activity. CONCLUSIONS: This is the first study to describe the steroidogenic activity of liposomal formulation of DMU-212, possibly through increasing the StAR and CYP19A1 expression. These findings suggest that lipDMU-212 might have a beneficial effect in the treatment of disorders related to estrogen deficiency and hyperandrogenism, such as PCOS.

Municipal wastewater treatment in Poland - efficiency, costs and returns to scale.

This paper reports the costs of municipal wastewater collection and treatment in Poland. Our study provides detailed cost estimates for the collection and treatment of municipal wastewater, based on an empirical sample of 1,400 operators, who jointly collect and treat over 80% of wastewater in Poland. The unit costs of collection and treatment, and the nitrogen and phosphorus treatment efficiency were investigated, and the effects of plant capacity on unit costs (scale effects) were explored. Primary, secondary and tertiary treatment cost functions were analysed econometrically using the Box-Cox regression model, indicating high non-linearity and significant scale effects. We found that wastewater treatment costs were increasing with technology efficiency (moving from the primary, through the secondary, to the tertiary treatment), and decreasing with higher wastewater treatment plant capacity. Our results provide a comprehensive picture of municipal wastewater treatment in Poland but potentially, as the technology is fairly generic, they can also be used for applications in other countries, after accounting for capital and labour cost differences. The paper thus provides a valuable input into cost-benefit analyses of nutrient loading reduction achieved by extending or intensifying municipal wastewater treatment.

Enhanced biological activity of liposomal methylated resveratrol analog 3'-hydroxy-3,4,5,4'-tetramethoxystilbene (DMU-214) in 3D patient-derived ovarian cancer model.

3'-hydroxy-3,4,5,4'-tetramethoxystilbene (DMU-214) belongs to methoxystilbenes family and is an active metabolite of 3,4,5,4'-tetramethoxystilbene (DMU-212). In several of our previous studies, the anti-apoptotic activity of DMU-214 was significantly higher than that of the parent compound, especially in ovarian cancer cells. Due to increased lipophilicity and limited solubility, methoxystilbenes require a solubilization strategy enabling DMU-214 administration to the aqueous environment. In this study, DMU-214-loaded liposomes were developed for the first time, and its antitumor activity was tested in the ovarian cancer model.First, several liposomal formulations of DMU-214 were obtained by the thin lipid film hydration method followed by extrusion and then characterized. The diameter of the resulting vesicles was in the range of 118.0-155.5 nm, and samples presented monodisperse size distribution. The release of DMU-214 from the studied liposomes was governed by the contribution of two mechanisms, Fickian diffusion and liposome relaxation.Subsequently, in vitro activity of DMU-214 in the form of a free compound or liposome-bound was studied, including commercial cell line SK-OV-3 and patient-derived ovarian cancer cells in monolayer and spheroid cell culture models. DMU-214 liposomal formulations were found to be more potent (had lower IC50 values) than the free DMU-214 both in the monolayer and, more significantly, in both examined spheroid models. The above results, with particular emphasis on the patient-derived ovarian cancer model, indicate the importance of further development of liposomal DMU-214 as a potential anticancer formulation for ovarian cancer treatment.

Insight into theranostic nanovesicles prepared by thin lipid hydration and microfluidic method.

Liposomes are phospholipid-based self-assembled nanoparticles. Various components can be solubilized in the lipid bilayer, encapsulated in the aqueous core or attached to the surface, making liposomes attractive platforms for multimodality functionalization. Here we describe theranostic liposomes delivering a magnetic resonance contrast agent (lipid derivative of gadopentetic acid) and a hydrophobic photosensitizer (zinc phthalocyanine, ZnPc) for photodynamic therapy of cancer. For the first time, this theranostic system was prepared by the microfluidic method. Analogous formulations were produced by thin lipid film hydration (TLH) with down-sizing performed by extrusion for comparison purposes. We demonstrated double the loading capacity of ZnPc into liposomes made by microfluidics compared to TLH/extrusion. Microfluidics resulted in the theranostic nanoliposomes characterized by sizes =2.5x smaller than vesicles prepared by TLH/extrusion. Increased relaxivity was observed for liposomes manufactured by microfluidics compared to TLH, despite a slightly lower Gd chelate recovery. We attributed the improved relaxation to the increased surface area/volume ratio of vesicles and decreased phosphatidylcholine/ZnPc molar ratio, which affected water molecules' diffusion through the liposomal membrane. Finally, we showed photodynamic efficacy of ZnPc loaded into theranostic liposomes in head and neck cancer model, resulting in IC50 of 0.22 - 0.61 µM, depending on the formulation and cell line used. We demonstrate microfluidics' feasibility to be used for theranostic liposome manufacturing and co-entrapment of therapeutic and imaging components in a single-step process with a high yield.

Increasing the cost-effectiveness of nutrient reduction targets using different spatial scales.

In this paper, we investigate the potential gains in cost-effectiveness from changing the spatial scale at which nutrient reduction targets are set for the Baltic Sea, with particular focus on nutrient loadings from agriculture. The costs of achieving loading reductions are compared across five levels of spatial scale, namely the entire Baltic Sea; the marine basin level; the country level; the watershed level; and the grid square level. A novel highly-disaggregated model, which represents decreases in agricultural profits, changes in root zone N concentrations and transport to the Baltic Sea is used. The model includes 14 Baltic Sea marine basins, 14 countries, 117 watersheds and 19,023 10-by-10 km grid squares. The main result which emerges is that there is a large variation in the total cost of the program depending on the spatial scale of targeting: for example, for a 40% reduction in loads, the costs of a Baltic Sea-wide target is nearly three times lower than targets set at the smallest level of spatial scale (grid square). These results have important implications for both domestic and international policy design for achieving water quality improvements where non-point pollution is a key stressor of water quality.

Patients' Preferences and Willingness to Pay for Solid Forms of Oral Medications-Results of the Discrete Choice Experiment in Polish Outpatients.

PURPOSE: Personal preferences play an important role in the patients' decision process whether to adhere to treatment, or not. The purpose of this study is to assess Polish outpatients' preferences for solid forms of oral medications across various scenarios. METHODS: The convenience sample of 200 outpatients took part in this study. According to the discrete choice experiment (DCE) design, participants were provided with selection of tablets and capsules, in different shapes, sizes, colors, and copayment levels and were asked to state their preferences. DCE results were analyzed using mixed logit (MXL) models. RESULTS: MXL models revealed patients' willingness to pay for various solid forms of medications. The most preferred combination of drug parameters were: small yellow capsule for chronic treatment, and small yellow long tablet for short-term treatment. Study participants were happy to pay extra 6.52 PLN (≈1.63 EUR) for this drug formulation per month of antihypertensive treatment, and 14.44 PLN (≈3.61 EUR) for this drug formulation per 7-days' long course of antibiotic treatment, respectively. CONCLUSION: Results suggest that color, shape, and size of solid form of oral medications are important predictors of patients' acceptance. It can not only be expressed in monetary value, but also may serve as an important hint for companies designing new drugs, or policymakers who are happy to improve patient adherence with better prescribing, or dispensing. However, our findings are probably country-specific, and further research is necessary to better understand the relationship between solid drug characteristics, and patient's preferences across countries.

Toward the Baltic Sea Socioeconomic Action Plan.

This paper analyzes the main weaknesses and key avenues for improvement of nutrient policies in the Baltic Sea region. HELCOM's Baltic Sea Action Plan (BSAP), accepted by the Baltic Sea countries in 2007, was based on an innovative ecological modeling of the Baltic Sea environment and addressed the impact of the combination of riverine loading and transfer of nutrients on the ecological status of the sea and its sub-basins. We argue, however, that the assigned country-specific targets of nutrient loading do not reach the same level of sophistication, because they are not based on careful economic and policy analysis. We show an increasing gap between the state-of-the-art policy alternatives and the existing command-and-control-based approaches to the protection of the Baltic Sea environment and outline the most important steps for a Baltic Sea Socioeconomic Action Plan. It is time to raise the socioeconomic design of nutrient policies to the same level of sophistication as the ecological foundations of the BSAP.

Farmers' preferences for nutrient and climate-related agri-environmental schemes: A cross-country comparison.

We use data from a survey of 2439 farmers in 5 countries around the Baltic Sea (Denmark, Estonia, Finland, Poland and Sweden) to investigate their preferences for adopting agricultural practices aimed at reducing nutrient leaching and greenhouse gas emissions. The measures considered are set-aside, catch crops and reduced fertilization. Contracts vary with respect to the area enrolled, contract length, possibility of premature termination, availability of professional advice and compensation. We quantitatively describe farmers' preferences in terms of their willingness-to-accept compensation for specific attributes of these contracts, if implemented. The results vary substantially between farm types (farmers' characteristics) and between the 5 countries, and support differentiation of contract obligations and payments to improve the uptake of Agri-Environmental Schemes. The results can be readily used to improve the design of country-specific nutrient reduction policies, in accordance with the next Common Agricultural Policy.

The Baltic Sea as a time machine for the future coastal ocean.

Coastal global oceans are expected to undergo drastic changes driven by climate change and increasing anthropogenic pressures in coming decades. Predicting specific future conditions and assessing the best management strategies to maintain ecosystem integrity and sustainable resource use are difficult, because of multiple interacting pressures, uncertain projections, and a lack of test cases for management. We argue that the Baltic Sea can serve as a time machine to study consequences and mitigation of future coastal perturbations, due to its unique combination of an early history of multistressor disturbance and ecosystem deterioration and early implementation of cross-border environmental management to address these problems. The Baltic Sea also stands out in providing a strong scientific foundation and accessibility to long-term data series that provide a unique opportunity to assess the efficacy of management actions to address the breakdown of ecosystem functions. Trend reversals such as the return of top predators, recovering fish stocks, and reduced input of nutrient and harmful substances could be achieved only by implementing an international, cooperative governance structure transcending its complex multistate policy setting, with integrated management of watershed and sea. The Baltic Sea also demonstrates how rapidly progressing global pressures, particularly warming of Baltic waters and the surrounding catchment area, can offset the efficacy of current management approaches. This situation calls for management that is (i) conservative to provide a buffer against regionally unmanageable global perturbations, (ii) adaptive to react to new management challenges, and, ultimately, (iii) multisectorial and integrative to address conflicts associated with economic trade-offs.

Understanding the distribution of economic benefits from improving coastal and marine ecosystems.

The ecological status of coastal and marine waterbodies world-wide is threatened by multiple stressors, including nutrient inputs from various sources and increasing occurrences of invasive alien species. These stressors impact the environmental quality of the Baltic Sea. Each Baltic Sea country contributes to the stressors and, at the same time, is affected by their negative impacts on water quality. Knowledge about benefits from improvements in coastal and marine waters is key to assessing public support for policies aimed at achieving such changes. We propose a new approach to account for variability in benefits related to differences in socio-demographics of respondents, by using a structural model of discrete choice. Our method allows to incorporate a wide range of socio-demographics as explanatory variables in conditional multinomial logit models without the risk of collinearity; the model is estimated jointly and hence more statistically efficient than the alternative, typically used approaches. We apply this new technique to a study of the preferences of Latvian citizens towards improvements of the coastal and marine environment quality. We find that overall, Latvians are willing to pay for reducing losses of biodiversity, for improving water quality for recreation by reduced eutrophication, and for reducing new occurrences of invasive alien species. However a significant group within the sample seems not to value environmental improvements in the Baltic Sea, and, thus, is unwilling to support costly measures for achieving such improvements. The structural model of discrete choice reveals substantial heterogeneity among Latvians towards changes in the quality of coastal and marine waters of Latvia.

Valuing the benefits of improved marine environmental quality under multiple stressors.

Many marine ecosystems are under increasing pressure from multiple stressors. In the Baltic Sea, these stressors include oil and chemical spills from shipping, nutrient run-off from land and the introduction of non-indigenous species. All of these pressures have been growing over recent years. Increasing pressures lead to reductions in environmental quality, which produce negative effects on human well-being. In this paper, the choice experiment method is used to estimate the benefits to people in Estonia resulting from reductions in pressure from multiple stressors in the Baltic Sea. The main results show that, firstly, respondents have a positive, statistically-significant willingness to pay to reduce each of the three stressors analysed. Secondly, the average willingness to pay for the improvement in the quality of all Estonian marine waters to achieve Good Environmental Status is around 65 euro per household per year, with a 95% confidence interval of 48-77 euro. Thirdly, the greatest share of value of this total economic benefit is derived from the willingness to pay for reductions in the risk of large scale oil and chemical spills.

The effect of risk perception on public preferences and willingness to pay for reductions in the health risks posed by toxic cyanobacterial blooms.

Mass populations of toxin-producing cyanobacteria are an increasingly common occurrence in inland and coastal waters used for recreational purposes. These mass populations pose serious risks to human and animal health and impose potentially significant economic costs on society. In this study, we used contingent valuation (CV) methods to elicit public willingness to pay (WTP) for reductions in the morbidity risks posed by blooms of toxin-producing cyanobacteria in Loch Leven, Scotland. We found that 55% of respondents (68% excluding protest voters) were willing to pay for a reduction in the number of days per year (from 90, to either 45 or 0 days) that cyanobacteria pose a risk to human health at Loch Leven. The mean WTP for a risk reduction was UK£9.99-12.23/household/year estimated using a logistic spike model. In addition, using the spike model and a simultaneous equations model to control for endogeneity bias, we found the respondents' WTP was strongly dependent on socio-demographic characteristics, economic status and usage of the waterbody, but also individual-specific attitudes and perceptions towards health risks. This study demonstrates that anticipated health risk reductions are an important nonmarket benefit of improving water quality in recreational waters and should be accounted for in future cost-benefit analyses such as those being undertaken under the auspices of the European Union's Water Framework Directive, but also that such values depend on subjective perceptions of water-related health risks and general attitudes towards the environment.