Assessing Risks of Plant-Based Pharmaceuticals: I. Human Dietary Exposure

Protein-based drugs are the fastest growing class of drugs for the treatment of disease in humans and other animals. However, the current method of producing proteins for pharmaceutical application is predicted to fall short because of population growth and demographic trends. This study characterized human dietary risks using quantitative risk assessment techniques for three pharmaceutical proteins produced in field-grown maize. The three proteins were aprotinin, gastric lipase, and Escherichia coli heat-labile enterotoxin B subunit (LT-B). The human dietary risks from the three proteins inadvertently occurring in food were evaluated using three different exposure scenarios so that potential risks could be compared. The three exposure scenarios ranged in conservatism to evaluate the range of risk between the proteins and scenarios. Risk quotients (RQs) were calculated for all three scenarios to integrate exposure and effect (toxicity). The risk assessments revealed that the most conservative scenario produced higher RQs than the other two scenarios. The dietary risks from scenario 1 for aprotinin were three orders of magnitude greater than for scenario 2, and four orders of magnitude greater than for scenario 3. This risk assessment revealed that dietary risks will vary dramatically and depend on factors such as the specific pharmaceutical protein, protein expression, and exposure scenarios. The assessment also reinforced the need for case-by-case assessments.     

沈阳某冶炼厂废弃厂区的人类健康风险评价

以沈阳某冶炼厂废弃厂区重金属污染监测为依据,采用美国环保局最新的人类健康风险评价标准方法对沈阳某冶炼厂废弃地块污染土壤进行了评价,并且假设未来该土地利用类型为工业用地(Ⅰ)或休闲用地(Ⅱ).评价结果显示:工业用地(Ⅰ)和休闲用地(Ⅱ)的累积非致癌风险指数分别为2.65×10-2和3.67×10-2;工业用地(Ⅰ)和休闲用地(Ⅱ)由呼吸摄入Cd造成的潜在致癌风险指数分别为4.48×10-9和7.30×10-10,不会对在该地区工作和休闲的人们造成身体健康上的伤害;无论是工业用地假设还是休闲用地假设,由无机铜造成的人类健康风险在整个风险中所占的比例最大;由美国环保局的人类健康风险评价方法反推得出的冶炼厂地块未来为工业用地的土壤修复目标值均小于我国工业企业土壤环境质量风险评价基准值.     

A Quantitative Ecological Risk Assessment of the Toxicological Risks from Exxon Valdez Subsurface Oil Residues to Sea Otters at Northern Knight Island,Prince William Sound,Alaska

A comprehensive, quantitative risk assessment is presented of the toxicological risks from buried Exxon Valdez subsurface oil residues (SSOR) to a subpopulation of sea otters (Enhydra lutris) at Northern Knight Island (NKI) in Prince William Sound, Alaska, as it has been asserted that this subpopulation of sea otters may be experiencing adverse effects from the SSOR. The central questions in this study are: could the risk to NKI sea otters from exposure to polycyclic aromatic hydrocarbons (PAHs) in SSOR, as characterized in 2001–2003, result in individual health effects, and, if so, could that exposure cause subpopulation-level effects? We follow the U.S. Environmental Protection Agency (USEPA) risk paradigm by: (a) identifying potential routes of exposure to PAHs from SSOR; (b) developing a quantitative simulation model of exposures using the best available scientific information; (c) developing scenarios based on calculated probabilities of sea otter exposures to SSOR; (d) simulating exposures for 500,000 modeled sea otters and extracting the 99.9% quantile most highly exposed individuals; and (e) comparing projected exposures to chronic toxicity reference values. Results indicate that, even under conservative assumptions in the model, maximum-exposed sea otters would not receive a dose of PAHs sufficient to cause any health effects; consequently, no plausible toxicological risk exists from SSOR to the sea otter subpopulation at NKI.     

Exposure Monitoring and Health Risk Assessment of 1-Bromopropane as a Cleaning Solvent in the Workplace

This study was conducted to estimate the health risk to workers exposed to 1-bromopropane (1-BP) used as a cleaning solvent in their workplaces. Fifty samples from 10 workplaces that use 1-BP as a cleaning solvent were obtained to assess 1-BP concentrations. An exposure assessment revealed central tendency exposure (CTE) and reasonable maximum exposure (RME) levels of 82.1 and 214.8 mg/m³, respectively. For risk characterization, the 1-BP exposure concentrations for reproductive and developmental toxicities were calculated as 2.8 and 8.5 mg/m³, respectively, and compared with the reference concentrations in the workplace. The CTE and RME hazard quotients (HQ) were, respectively, 29.4 and 77.0 for reproductive toxicity and 9.6 and 25.2 for developmental toxicity. The results of our 1-BP risk assessment indicated that the CTE-HQs for both categories were higher than the acceptable risk value of 1, indicating that 1-BP may be considered as harmful to workers.     

Children's health risk assessment: incorporating a lifestage approach into the risk assessment process

This overview paper provides the historical context for the incorporation of lifestage‐specific concerns in human health risk assessment, briefly explains the process employed in a lifestage framework for risk assessment, and discusses the scientific rationale for how utilizing lifestage data will strengthen the overall risk assessment process. This risk assessment approach will add value by: (1) providing a more complete evaluation of the potential for vulnerability at different lifestages, including a focus on the underlying biological events and incorporation of mode of action information related to different critical developmental periods; (2) evaluating the potential for toxicity during all lifestages after early lifestage exposure; (3) reviewing the importance of integrating exposure information and adverse health effects across lifestages; and (4) serving as a basis to extend some aspects of the children's health risk assessment framework to all lifestages. Birth Defects Res (Part B), 2008. © 2008 Wiley‐Liss, Inc.     

Recent Developments in Nanotechnology and Risk Assessment Strategies for Addressing Public and Environmental Health Concerns

Nanotechnology is a novel emerging technology that allows the manipulation of materials at the scale comparable to the size of a single molecule (i.e., < 100 nm). There have been many new developments in this technology, resulting in complex exposure and health risk implications. Nanotechnology offers major benefits to humankind; however, there is growing concern regarding the potential adverse interactions of engineered nanoparticles at cellular or sub-cellular levels. The nanotech community is therefore experiencing growing calls for legislation to minimize or prevent exposure to nanoparticles. This article focuses on recent developments in nanotechnology including current manufacturing techniques, uses of nanoscale particles, and implications for particle toxicity and human exposure pathways. Current risk assessment methods are reviewed in the context of nanoparticle exposure routes and regulation for human and environmental health protection. This study provides a better understanding of the factors governing risks from nanoparticles and current strategies for protecting environmental and public health.     

Trends in Risk Assessment of Chemicals in the European Union

Current legislation in the European Union (EU) requires a risk assessment for industrial chemicals. The underlying procedures and paradigms of such EU risk assessment for new and existing chemicals are explained. The risk assessment is performed according to a harmonised methodology, laid down in the Technical Guidance Documents (TGD). Important new, technical risk assessment aspects covered in a recent revision round of the TGD are highlighted. The most prominent change in the environmental TGD part is the addition of the marine risk assessment, including a Persistent Bioaccumulation and Toxicity (PBT) assessment. In the human health part a significant change is the new data requirement for reproductive toxicity. The performance of both the risk assessment and the risk reduction phase of EU existing chemicals have been evaluated. An important conclusion was that our a priori knowledge on possible risks of chemicals is poor. The European Commission has recently launched a proposal (REACH) for drastically changing the risk management process of industrial chemicals in the EU. Major changes are a shift in responsibility from authorities to industry (including downstream users) for the safe use of chemicals, an acceleration of data collection for ‘non-assessed’ chemicals, and an authorization step for substances of very high concern.     

Human Health Risks of Selenium-Contaminated Fish: A Case Study for Risk Assessment of Essential Elements

A screening level human health risk assessment (HHRA) was applied to evaluate the human health implications of consuming selenium found in fish tissues collected downstream of coal mines in southeastern British Columbia, Canada. The study evaluated the potential for adverse human health effects associated with selenium, and considered known and potential benefits of selenium and fish ingestion. The results indicated that risks of selenosis due to consumption of selenium-contaminated fish in the region are negligible. Conclusions were strengthened by consideration of the potential benefits of selenium to human health, including: selenium essentiality for maintenance of good health; potential cancer prevention properties due to its role as an antioxidant; potential benefits for cardiovascular health; and other positive health benefits. The findings indicated that some aspects of the traditional framework for HHRA (e.g., application of safety factors to “err on the side of safety”) are inappropriate for the assessment of selenium-contaminated fish. Due to both deficiency and toxicity in the selenium dose-response relationship, application of compounding conservatism in risk assessment may lead to recommended intakes of fish that are contrary to the public health interest. The need for balancing risk types, for incorporating positive responses in risk assessments, and the linkage to the precautionary principle, are discussed.     

Challenges and Research Needs for Risk Assessment of Pesticides for Registration in Africa

Risk assessment is necessary for registration and risk management of new pesticides. The aim of this article is to discuss challenges that risk assessors in Africa face when conducting risk assessment of pesticides. Risk assessment requires toxicity assessment, environmental fate studies, and the use of models for occupational, dietary, residential, and environmental exposure assessments. Toxicity studies are very costly with the result that toxicity data used to register pesticides in Africa are often sourced from northern hemisphere countries. Assessors also often use exposure modeling results from the northern hemisphere. This is not an ideal approach as occupational exposure is influenced by agricultural practices, climatic conditions, and other factors. Furthermore, residential exposure models require time-location-activity information, exposure factors, and toxicokinetic rate constants for particular pesticides. Dietary exposure assessment needs accurate and comprehensive local food consumption data. Authorities in African countries should therefore generate the required data, despite these being very costly and tedious. Authorities should also provide guidance on the type of models and standard scenarios for estimating predicted environmental concentrations in various environmental compartments. It is recommended that higher educational institutions in Africa should incorporate risk assessment in general and pesticide toxicity and exposure models in particular in their curricula.     

Application of the Hazard Quotient Method in Remedial Decisions: A Comparison of Human and Ecological Risk Assessments

This paper evaluates the relative roles of the human health hazard index (HI) and the ecological risk assessment hazard quotient (HQ) in remedial decision-making. Through an analysis of HI outcomes drawn from Superfund Records of Decision, the reduced importance of the HI statistic in human health risk assessments is demonstrated, and the high visibility of the ecological risk assessment (ERA) HQ for terrestrial receptors (birds and mammals) is underscored. Three HQ method limitations common to both HHRA and ERA, deriving either from the mathematical construct of the HQ (a simple binary measure, indicating that an animal's exposure either exceeds its toxicity value or does not) or from dose-response outcomes in animal trials, are reviewed. Two additional HQ limitations unique to ERA (i.e., a propensity for the HQ to easily exceed its threshold value, and a propensity for it to assume values that are unreasonably high), and deriving from the complexities of estimating bird and mammal dietary intakes of contaminants and the availability of toxicological effects information, are also identified. The paper cautions of the potential to err in concluding that terrestrial site receptors are at risk when the HQ threshold is exceeded, and regardless of the toxicological information (NOAELs, LOAELs, etc.) used. It recognizes that because other methods of terrestrial assessment are presently unavailable, HQs are sometimes, out of necessity, used to justify a remedial action. The analysis and discussion are intended to remind ecological risk assessors that the HQ is a measure of a level of concern only and not a measure of risk     

Ecological Risk Assessment of Tebuthiuron Following Application on Tropical Australian Wetlands

The present study assessed the ecological risks of the herbicide tebuthiuron to freshwater fauna and flora of northern Australia's tropical wetlands. Effects characterization utilized acute and chronic toxicity data of tebuthiuron to local freshwater species (three animals and two plants) as well as toxicity data derived from northern hemisphere species. Species sensitivity distributions (SSDs) for four effects scenarios—plant chronic toxicity (NOEC data), plant chronic toxicity (EC/IC₅₀ data), invertebrate and vertebrate chronic toxicity (NOEC data), and vertebrate acute toxicity (LC₅₀ data)—were used to characterize effects and calculate 10, 5, and 1% hazardous concentrations (HCs). Tebuthiuron concentrations affecting 5% of species (i.e., HC₅s) for the earlier scenarios were 0.013, 0.093, 9.0, and 97 mg L^?1, respectively. Exposure characterization involved the use of historical field monitoring data of tebuthiuron concentrations following application of tebuthiuron to a large infestation of the wetland weed Mimosa pigra (Mimosa). Tebuthiuron concentrations in surface water ranged from below detection to 2.05 mg L^?1 and were still measurable up to 10 months following application. A breakpoint regression model was fitted to the field monitoring data, providing a time-dependent estimate of exposure to tebuthiuron. Risk characterization involved the comparison of the SSDs and associated HCs for each of the effects scenarios, with the time-dependent model of tebuthiuron exposure. Modeled tebuthiuron concentrations over the first 12 days post-application were in excess of concentrations required to cause major (i.e., 50% reductions in population numbers) effects to over 85% of freshwater plant species (based on data for phytoplankton and floating macrophytes). Beyond this period and up to 300 d post-application, 10–20% of species were still predicted to be affected. To quantify the probability of prolonged effects, the plant SSDs were compared to a cumulative probability distribution of tebuthiuron measured from 70 d to 293 d post-application. The probability of at least 5% of freshwater plant species experiencing chronic effects due to tebuthiruon at ≥70 d post-application was 58% based on NOEC data and 8% based on EC/IC₅₀ data. Overlap of the 95% confidence limits of the exposure distribution and plant SSDs indicated substantial uncertainty in the risk estimates. Risks of effects to freshwater invertebrates and vertebrates were generally < 1%. It was concluded that tebuthiuron appears to represent a significant and prolonged risk to native freshwater plant species, particularly phytoplankton and floating macrophytes, whereas the risks to freshwater invertebrates and vertebrates appear low. However, from a management perspective, the risks of tebuthiuron (and other herbicides) must be weighed against the known, serious environmental and economic impacts of the target weed, Mimosa. Overall, the outcomes of the risk assessment support the various management options that have been implemented with regard to the use of tebuthiuron to control Mimosa.     

Risk Assessment of Tropospheric Ozone: Human Health,Natural Resources,and Ecology

Ozone is an unusual trace gas in the atmosphere, presenting a challenge for risk assessors and risk managers. The challenge can be traced to the gas’ complex chemistry in the atmosphere (exposure), toxicology in biological systems (response), and the fledgling enterprise of risk assessment for widely distributed, highly reactive pollutants. This paper addresses the (i) co-evolution of the scientific data underlying ozone risk assessment on human health, natural resources (crops and managed forests), and unmanaged ecosystems, (ii) similarities and differences in risk assessment among these receptors, and (iii) utility of indicators in risk assessment. The scientific community has developed a sound database to underpin the ozone risk assessment, although the breadth and depth differ markedly among the three receptors. There are similarities in ozone risk assessment among human health, natural resources, and ecology, including features of exposure (e.g., temporal variation), response of plants and humans (e.g., sensitive cohorts), and integration of exposure and response (e.g., importance of peak and cumulative exposures). Equally important are the notable differences, and the more prominent are scaling of exposure-response relationships, air quality monitoring, economic valuation, and models to complement more traditional experimental approaches. Of the three receptors, the status of indicators for conducting ecological ozone risk assessment is the weakest.     

Environmental Risks at Finnish Shooting Ranges—A Case Study

We studied three Finnish shooting ranges in order to define the extent of the risks associated with elevated environmental concentrations of metals and PAHs. A scoring system revealed that lead, arsenic, and antimony were the most critical contaminants. On Site 3, the concentration of lead in groundwater exceeded the drinking water standard indicating evident health risks. For the remaining two sites we calculated Acceptable Daily Doses (ADD) based on the Reasonable Maximum Exposure (RME) approach and compared them with safe exposure levels. We also used a pharmacokinetic model to determine blood lead levels (PbBs). Risks to biota were assessed using ecological benchmarks and exposure and accumulation models. Prediction of leaching was based on laboratory tests and a distribution model. The health risk assessment for lead resulted in the maximum hazard quotient (HQ) of 1.2 whereas the HQs of As and Sb remained less than 1. Some exposure scenarios produced PbB estimates exceeding 10 μ g dl^?1 but based on the uncertainty analysis we expect the health risks to remain insignificant. However, leaching of contaminants presents a risk to groundwater quality. At site 1 the ecotoxicity-based HQs demonstrate high risks to soil biota, small mammals, terrestrial plants and aquatic organisms.     

Health Risk Assessment of Urban Surface Waters Based on Real-Time PCR Detection of Typical Pathogens

Typical enteric pathogens including enteroviruses, Salmonella typhi, Shigella spp., and Eschierichia coli were selected and monitored during a 1-year period in urban surface waters using the real-time polymerase chain reaction (PCR) method. By considering two routes of human exposure to urban surface waters (i.e., drinking water and involuntary intake), and supposing that the dose–response relation may follow either an exponential model or the Beta-Poisson model, health risk assessment was conducted to estimate the safety under a given acceptable risk level upon exposure to each water and to evaluate the required level of pathogen inactivation for safeguarding human health. As a result, it was found that human health risk due to enteroviruses is often greater than that due to bacterial pathogens, and greater removal of enteroviruses would be required for safeguarding at the same acceptable risk level.     

A Quantitative Approach for Ranking Human Health Risks from Pesticides in Irish Groundwater

This study aims to quantitatively assess the risk of pesticides (used in Irish agriculture) and their degradation products to groundwater and human health. This assessment uses a human health Monte-Carlo risk-based approach that includes the leached quantity combined with an exposure estimate and the No Observed Adverse Effect Level (NOAEL) as a toxicity ranking endpoint, resulting in a chemical intake toxicity ratio statistic (R) for each pesticide. A total of 34 active substances and their metabolites registered and used in the agricultural field were evaluated. MCPA obtained the highest rank (i.e., in order of decreasing human health risk), followed by desethly-terbuthylazine and deethylatrazine (with risk ratio values of 1.1 × 10^?5, 9.5 × 10^?6, and 5.8 × 10^?6, respectively). A sensitivity analysis revealed that the soil organic carbon content and soil sorption coefficient were the most important parameters that affected model predictions (correlation coefficient of –0.60 and –0.58, respectively), highlighting the importance of soil and pesticide properties in influencing risk estimates. The analysis highlights the importance of taking a risk-based approach when assessing pesticide risk. The model can help to prioritize pesticides, with potentially negative human health effects, for monitoring programs as opposed to traditional approaches based on pesticide leaching potential.     

Human health risk assessment of arsenic in groundwater aquifers of Lahore,Pakistan

The present study was conducted to estimate As concentration in groundwater and resulting human health risk in terms of chronic daily intake, hazard quotient (HQ), hazard index (HI), and carcinogenic risk (CR) both for oral and dermal exposure to As. Groundwater samples (n = 100) were collected from ten different towns of Lahore District (Pakistan). Arsenic concentration ranged from 2 to 111 µg L^?1 in groundwater samples of the study area, which was significantly greater than the safe limit of As (10 µg L^?1) in drinking water set by the World Health Organization. Health risk assessment of As showed that HQ (0.1–11) for oral exposure and HI (0.1–11) values also exceeded the typical toxic risk index value of 1. 9.75 × E-05–4.59 × E-03 and 5.89 × E-07–2.77 × E-05 for oral and dermal As exposure, respectively. Both CR and cancer index (CIs) values were higher than United States Environmental Protection Agency limit (10^?6), suggesting that people are at high risk of As-induced carcinogenicity from oral and dermal exposure to As in drinking water. It was concluded that As contamination of groundwater causes carcinogenic and noncarcinogenic health effects to the people; therefore, urgent management and remedial actions are required to protect people from As poisoning.     

Identification of Risks in the Life Cycle of Nanotechnology‐Based Products

In order to realize the projected market potential of nanotechnology, the environmental, health, and safety (EHS) uncertainties posed by a nano‐product (i.e., a nanotechnology‐enabled product) need to be characterized through the identification of risks and opportunities in early stages of product development. We present a methodology to identify risks from nano‐products using a scenario analysis approach that allows for expert elicitation on a set of preidentified use and disposal scenarios and what we have labeled “risk triggers” to obtain scores on their likelihood of occurrence and severity. Use and disposal scenarios describe product life‐cycle stages that could result in risk attributed to the nano‐product, whereas risk triggers are particular to nanoparticle properties. These are potential risks, as the risk assessment community is currently debating the specific risks attributed to nanotechnology. Through such a framework, our goal is to identify which products pose greater risks, where these risks occur in the product life cycle, and the impacts of these environmental risks on society. The comparison of risk triggers across nano‐products allows relative risk ranking on axes of exposure‐ and hazard‐related risk triggers. For the specific case of air fresheners, areas of acute risks resulted from bioavailability of nanoparticles in air release and water entrainment exposure scenarios; catalytic activity of nanoparticles in inhalation and air release exposure scenarios; the harmful effects due to the antibacterial property on useful bacteria particularly in susceptible populations; and, finally, risks from the lack of nanoparticle coating stability in air release scenarios.     

Initial Risk-Based Screening of Potential Brownfield Development Sites

Brownfield redevelopment is sustainable only when it is a transparent process protective of public health. The objective of the brownfield health risk screening matrix is to provide a scientifically based, transparent process to evaluate human health risks on proposed redevelopment sites as well as a framework that can be critically evaluated by both environmentalists and the community in general. Public discussion and understanding of current health risk assessment, as well as the risks specific to each brownfield redevelopment site, are essential for an effective brownfield redevelopment program.

The Brownfields Redevelopment Program was started by the EPA in 1995 and seeks to use already contaminated sites rather than contaminate even more greenfields. Two of the biggest difficulties are making redevelopment profitable and protecting human health. Traditional human health risk assessment evaluates single chemical exposures and identifies the level below which no adverse effect will occur to the most sensitive subgroups of the population. For cancer–causing chemicals the risk must be lower than 1:1,000,000. When brownfield redevelopment sites are associated with high cost, extensive time and unmanageable uncertainty, additional greenfield sites will become contaminated and the contamination on current brownfield sites will remain un-remediated.

The citizens' advisory group addressing brownfields in a southern New York county has developed a risk matrix to evaluate the uncertainty of the available data, the toxicity of the known or suspected contaminants and the likely exposure routes for each brownfield site in the county. The matrix categorizes sites as high, medium or low risk according to exposure groups. The risk matrix complements the triad approach currently being developed by EPA to identify and manage project decision uncertainties, addresses uncertainty as well as toxicity and has the potential to reduce the cost of traditional health risk assessment at brownfield redevelopment sites.     

U.S. EPA Reference Dose/Reference Concentration Methodology: Update on a Review of the Process

The U.S. Environmental Protection Agency (USEPA) has been reviewing several approaches to testing and risk assessment related to implementation of the Food Quality Protection Act (FQPA) and the Amendments to the Safe Drinking Water Act (SDWA), both signed into law in 1996. Based on recommendations from a review of issues related to children's health protection under these laws, the USEPA established the RfD Technical Panel to evaluate in depth the current reference dose (RfD) and reference concentration (RfC) process in general, and in particular with respect to how well children and other potentially sensitive subpopulations are protected. The RfD Technical Panel also was asked to consider scientific issues that have become of greater concern in RfD and RfC derivation (e.g., neurotoxicity, immunotoxicity), and to raise issues that should be explored or developed further for application in the RfD/RfC process. This paper provides the current status of the activities of the RfD Technical Panel. The Technical Panel has recommended that acute, short- term, and intermediate reference values should be set for chemicals, where possible, and that these values should be incorporated into the USEPA's Integrated Risk Information System (IRIS) Database. A review of current testing procedures is underway, including the endpoints assessed, life stages covered by exposure and outcome evaluation, and information that can be derived from current protocols on various durations of exposure. Data gaps identified for risk assessment include the types of pharmacokinetic data that should be collected, especially for developmental toxicity studies, the impact of aging on toxic responses occurring after early exposure as well as concomitant with exposure in old age, and information available on latency to response. The implications of the RfD Technical Panel's recommendations for various uncertainty factors are also being explored.     

Applying Health Risk Analysis to Assess the Chemical Quality of Water for Recreational Bathing: The Case of Tres Arroyos Creek,Buenos Aires,Argentina

The aim of the study is to assess the probabilistic non-cancer and cancer risks by recreational bathing in Tres Arroyos creeks (southeastern Buenos Aires Province, Argentina). In these waters, hazardous substances (heavy metals, pesticides) have been detected, possibly related to agricultural activities. To assess such risk, USEPA models in aggregated (exposure through accidental oral water intake and dermal contact simultaneously) and cumulative approaches (combined exposure to more than one substance) were applied, performed for bathers of 5, 10, 15, and 20 years old. The results show that chronic bathing in these waters is not harmful at the concentrations and the exposure scenarios considered. Arsenic was the riskiest substance for both non-cancer and cancer effects, affecting mainly the youngest age group, and the accidental water intake during bathing was the most relevant pathway of exposure. On the other hand, the study highlights the key role of the frequency and duration of the bath event. We discuss the results in light of a previous paper of our authorship concluding that the health risk assessment is a valid alternative to analyze recreational water quality, which, unfortunately, is unused by water management agencies in Argentina.