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Deterministic risk assessment for hydrogen installations offers an integrated solution for H 2 risk assessment, incorporating a hydrogen release model, a site-specific 3D geometry model, a Computational Fluid Dynamics (CFD) tool, and a consequence analysis methodology. Empirical engineering models expedite the preparation of source terms and harm evaluations, while CFD generates 3D contours of radiation and overpressure loads. A case study is provided by investigating a gaseous hydrogen leak of a truck in a refueling station with a large roof. The effects of leak diameters, roof configurations, and ignition locations on hydrogen dispersion, combustion, and hazard analysis are examined. Results indicate that the majority of the burnable cloud accumulates in a half-meter layer under the ceiling, diminishing within a minute. The impact of thermal radiation on individuals is insignificant, but overpressures increase the likelihood of structure failures, indirectly affecting human fatality. These findings inform the optimization of refueling station design and safety management. • CFD-based Deterministic Risk Assessment approach to assess the safety of hydrogen installations. • Addressing potential hydrogen explosions due to the current ceiling design. • Minimal injury likelihood from hydrogen flame contact or thermal radiation. • Revealing insights for optimizing ceiling design and hydrogen risk mitigation strategies. [ABSTRACT FROM AUTHOR]

Combined sewer overflows (CSOs) are a source of microbial contamination of drinking water intakes located downstream from their discharge. To safeguard the quality of the source water, it is essential to evaluate the risk levels associated with these municipal structures. This study compares two risk assessment approaches to test their applicability for assessing the risk of CSOs to drinking water intakes in a highly urbanized watershed. The first approach was based on a deterministic equation that combines the characteristics of an overflow structure allowing the risk to be rated as very low, low, medium, high, or very high. The second probabilistic risk assessment approach yielded findings that are probabilistically distributed across the five levels of risk. This approach was developed by constructing a novel Bayesian network to probabilistically link the different factors defining the exposure of water intakes to the hazards of CSOs. The comparison between the results of these two approaches highlighted the importance of simultaneously considering many scenarios for assessing the risk of contamination of source waters. It was possible to use the Bayesian network rather than the deterministic equation, which only supports one scenario at a time. It was also shown that the deterministic approach often overestimated risk levels for CSO outfalls close to the water intake. This occurred because the assessment process emphasized the distance factor between the discharge point and the water intake, while neglecting other crucial characteristics of the overflow, such as duration and frequency. In particular, the deterministic approach tended to underestimate risk for CSOs associated with low overflow frequencies as it did not support scenarios of overflow duration, unlike the probabilistic approach. The validation and sensitivity analysis of the Bayesian model revealed that the population residing in the CSO's drainage basin, along with the frequency and duration of the overflows, exerted the greatest influence on the resulting risk levels. These factors outweighed other variables utilized in the risk assessment, including vulnerability of the drinking water intake, the type of overflow recorder, pipe diameter, and variables defining the exposure of the water intake to the discharge. In the context of implementing action plans, the Bayesian network is estimated as a cost-effective technique as it prioritized overflow structures needing special attention in a highly urbanized watershed, where the same CSOs were deterministically rated as having the same risk level. The results also demonstrated the effectiveness of the Bayesian model in addressing data gaps faced by water managers and stakeholders. The Bayesian model proved capable of assessing risks with uncertainties for CSOs, even with limited input data available. These findings can assist managers in identifying problematic structures by considering various scenarios, unlike the deterministic approach, which left almost half (n = 42) of the study site's overflow structures unassessed due to data limitations.

Food consumption and tobacco smoke are the main sources of toxic trace elements (TTE) for humans. To the present, no study has been carried out that assessed human exposure to TTE (Cd, Pb, As, Ni, Cr, Cu, and Co) through the consumption of the tomatoes, rice, and tobacco crops grown in the Sancti Spiritus territory of Cuba. Accordingly, the main goal of this study was to assess which metals and crops should receive priority attention for metal pollution management in the local environment. Combining residue element analysis in crops with consumption data collected from a survey, a deterministic exposure assessment was performed. The study identified that priority attention should be focused on Ni and Cd. First, the average concentration of Ni in tomato and rice was found above their reference limits. As a consequence, the concentration of Ni represented a risk to the maximum scenario of children, adolescents, adults, and the elderly. Together with Ni, Cd, and Cu also contribute slightly to the cumulative risk. Then, Cd and Ni were quantified in tobacco smoke at a concentration that represented an equal risk to both active and passive smokers. Concentrations high enough to hazard from these toxic elements. The study helped to identify children as the highest stratum at risk of developing adverse health effects due to exposure to Ni and Cd. The results obtained from the basis for future research aimed at reducing the polluting pressure of TTE on human health and the environment. [ABSTRACT FROM AUTHOR]

Abstract One of the input parameters in food allergy risk assessment is the amount of a given food consumed at an eating occasion. There is no consensus on how to use food consumption data when assessing the risk from unintended allergen presence in food products. A sensitivity analysis was performed to establish the optimal food consumption estimate for a deterministic food allergy risk assessment. Exposure was calculated for consumption percentiles (50th percentile, P50 to maximum) using the iFAAM consumption database in conjunction with an allergen concentration range from 1 to 1000 ppm. The resulting allergen intakes were compared to the allergic population reference doses proposed by Taylor et al. (2014) for 10 major allergenic foods. Optimal consumption percentiles were defined as those which predicted an intake below the relevant reference dose and met the defined acceptable risk level confirmed by probabilistic risk assessments. Analysis showed that, for 99% of the food groups, the P50 consumption met our criteria, while the P75 did so for 100% of the food groups. We suggest that the P75 is the optimal point estimate for use in deterministic food allergy risk assessment. It meets the safety objective and is adequately conservative for a public health context. Graphical abstract Image 1 Highlights • We derived single food consumption values for food groups for deterministic allergen risk assessment. • For almost all food groups the median consumption amount fulfils the defined safety objective in the risk assessment. • With the P75 consumption, deterministic and probabilistic risk assessment have a similar conclusion for all food groups. • The sensitivity analysis developed can be applied to any ED-value chosen as a safety objective. [ABSTRACT FROM AUTHOR]

Use of glyphosate in crop production can lead to residues of the active substance and related metabolites in food. Glyphosate has never been considered acutely toxic; however, in 2015 the European Food Safety Authority (EFSA) proposed an acute reference dose (ARfD). This differs from the Joint FAO/WHO Meeting on Pesticide Residues (JMPR) who in 2016, in line with their existing position, concluded that an ARfD was not necessary for glyphosate. This paper makes a comprehensive assessment of short-term dietary exposure to glyphosate from potentially treated crops grown in the EU and imported third-country food sources. European Union and global deterministic models were used to make estimates of short-term dietary exposure (generally defined as up to 24 h). Estimates were refined using food-processing information, residues monitoring data, national dietary exposure models, and basic probabilistic approaches to estimating dietary exposure. Calculated exposures levels were compared to the ARfD, considered to be the amount of a substance that can be consumed in a single meal, or 24-h period, without appreciable health risk. Acute dietary intakes were <100% of the ARfD for all foodstuffs, except wild fungi, when calculated using the EFSA model. The model assumptions differ from those of the source model (German national model), resulting in the use of a higher variability factor. Intakes estimated with the German model represented only 18% of the ARfD. The impact of differing assumptions regarding variability and other input parameters is discussed. Probabilistic exposure estimates showed that the acute intake on no person-days exceeded 10% of the ARfD, even for the pessimistic scenario. [ABSTRACT FROM AUTHOR]

Lack of guidance regarding selection of food intake values for allergen risk assessment can lead to different outcomes for similar levels of allergens in food products. Several food consumption survey databases (United States, North-West Europe, and Netherlands) were analyzed to identify optimal food intake percentiles using a sensitivity analysis. Deterministic risk assessment scenarios using the 50th percentile up to the maximum intake per food group were compared with probabilistic risk assessment outcomes. The optimal intake percentile is the lowest percentile that results in a deterministic risk assessment outcome compliant with the predefined safety objective, i.e., the predefined risk of an objective allergic reaction at ED01, ED2.5, ED05 or ED10 doses of 14 allergenic foods. The P50 intake met these criteria in more than 99.9% of all 28,784 scenarios tested. The P50 is therefore recommended for deterministic allergen risk assessment and calculation of action levels for precautionary allergen labelling. In case a P50 value is not available, the mean is a good alternative, as analyses of the intake data showed that the mean generally is between the P50 and P65. • A sensitivity analysis provided optimal point estimates of consumption distributions. • The analysis addressed safety objectives from ED01 to ED10. • The addressed ED-range covered FAO-WHO recommended Reference Doses. • The 50th percentile of single meal consumption generally fulfilled the predefined safety objectives. • Mean single meal consumption is an alternative for use in allergen risk assessment. [ABSTRACT FROM AUTHOR]

Glyphosate is a herbicide used to control broad-leaved weeds. Some uses of glyphosate in crop production can lead to residues of the active substance and related metabolites in food. This paper uses data on residue levels, processing information and consumption patterns, to assess theoretical lifetime dietary exposure to glyphosate. Initial estimates were made assuming exposure to the highest permitted residue levels in foods. These intakes were then refined using median residue levels from trials, processing information, and monitoring data to achieve a more realistic estimate of exposure. Estimates were made using deterministic and probabilistic methods. Exposures were compared to the acceptable daily intake (ADI)—the amount of a substance that can be consumed daily without an appreciable health risk. Refined deterministic intakes for all consumers were at or below 2.1% of the ADI. Variations were due to cultural differences in consumption patterns and the level of aggregation of the dietary information in calculation models, which allows refinements for processing. Probabilistic exposure estimates ranged from 0.03% to 0.90% of the ADI, depending on whether optimistic or pessimistic assumptions were made in the calculations. Additional refinements would be possible if further data on processing and from residues monitoring programmes were available. [ABSTRACT FROM AUTHOR]

Mycotoxins are toxic metabolites produced by filamentous fungi, as Aspergillus , Penicillium and Fusarium . The first objective of this research was to study the presence of mycotoxins in 60 samples of refrigerated pizza dough, by extraction with methanol and determination by liquid chromatography associated with tandem mass spectrometry (LC-MS/MS). Then, the estimated dietary intakes (EDIs) of these mycotoxins, among the Spanish population, was calculated and the health risk assessment was performed, comparing the EDIs data with the tolerable daily intake values (TDIs). The mycotoxins detected in the analyzed samples were aflatoxin B 1 (AFB 1 ), aflatoxin B 2 (AFB 2 ), aflatoxin G 1 (AFG 1 ), zearalenone (ZEA), enniatin A (ENA), enniatin A 1 (ENA 1 ), enniatin (ENB), enniatin B 1 (ENB 1 ) and BEA (beauvericin) with average concentration of the positive samples of 4.09 μg/kg, 0.50 μg/kg, 0.79 μg/kg, 77.78 μg/kg, 14.96 μg/kg, 4.54 μg/kg, 3.37 μg/kg, 1.69 μg/kg and 22.39 μg/kg, respectively. The presence of ZEA, ENA 1 , ENB and ENB 1 was detected in 100% of the samples, AFB 2 in 32%, AFB 1 in 23%, ENA in 8% and BEA in 3%. Twelve percent of the samples contaminated with AFB 1 and 12% of the doughs contaminated with ZEA exceeded the EU legislated maximum limits. The dietary intakes were estimated considering three different age groups of population, and the EDIs calculated for the mycotoxins detected in the samples were all below the established TDI. [ABSTRACT FROM AUTHOR]

In the present study, the chronic cumulative exposure to organophosphorus (OPs), carbamates (CBs) and pyrethroid and pyrethrin (PPs) pesticides in the region of Valencia through fruit and vegetables consumption is presented. A total of 752 samples and 84 pesticides were studied of which, 52 were OPs, 23 CBs and 9 PPs. Residue data were derived from the Valencia Region monitoring program 2007–2011 and food consumption levels from a questionnaire-based dietary survey conducted in 2010 in the same area. The relative potency factor (RPFs) approach was used to estimate chronic cumulative dietary exposure to OPs, CBs and PPs using acephate, oxamyl and deltamethrin as index compounds, respectively. The exposure was estimated using a deterministic approach and two scenarios were assumed for left-censored results: the lower-bound (LB) scenario, in which unquantified results (below the limit of quantification (LOQ)) were set to zero and the upper-bound (UB) scenario, in which unquantified results were set to the LOQ. Results demonstrate that the chronic exposure of the young (<16 years) and adult (≥16 years) population to pesticides through fruits and vegetables is under control (even at high or frequent consumption of fruits and vegetables), for the three groups of pesticides. [ABSTRACT FROM AUTHOR]

Deterministic risk assessments provide a single point estimate of risk at a site of concern, while probabilistic risk assessment methods generate a range of values from probability distribution functions (PDFs). This study compares deterministic and probabilistic risk assessment methods for two different sites using uncertainty analysis and evaluates the use of toxic equivalency factors (TEFs) for polycyclic aromatic hydrocarbons (PAHs) in each method. The use of TEFs allowed more of the PAHs to be included which resulted in higher risk estimates for both adults and children at both study sites. Exposure factor variability generated greater uncertainty in risk estimates than sample heterogeneity or toxicity estimates. TEFs allowed for a more complete representation of the toxicity contributions from PAH species present at the study sites. Exposure factor distributions together with TEF estimations for toxicity of PAH species provide an assessment that can reduce and account for uncertainty. Probabilistic risk estimates provide a sensible improvement to deterministic risk estimates by generating a range of risk values, along with an average estimate and the degree of conservatism of those estimates. [ABSTRACT FROM AUTHOR]

Abstract: Deterministic and probabilistic approaches are used here to calculate the human health risk associated with trihalomethanes (THMs) in the water supply of three communities namely: St. John''s, Clarenville and Shoal Harbour located in Canada''s Newfoundland and Labrador province. Every effort is made to utilize the latest information on chloroform toxicology to quantify cancer risks through different exposures. Showering and drinking activities are identified as major sources of exposure. Chloroform is considered as the most significant THM compound during risk assessment because of its high concentrations in the chlorinated water supply and its carcinogenic characteristics. During shower, the major exposure pathways of chloroform are inhalation and dermal absorption. Inhalation pathway is due to high volatility of chloroform, which causes high concentration in confined space (shower stall) while showering with hot water. Two different deterministic approaches are used to determine the shower air concentration. The first approach is based on statistical model developed by Kar [2000, Environmental and Health Risk Assessment of Trihalomethanes in Drinking Water – A Case Study. M.Eng Dissertation. Faculty of Engineering and Applied Science, Memorial University of Newfoundland, St. John''s, NL]. The second deterministic approach is based on a transient mass balance of the air in the shower stall. For dermal exposure mode, three different approaches (i.e. traditional steady state approach, membrane approach and statistical model by Kar) are used. Ingestion is considered the major pathway to account for the drinking activity. Among the three exposure routes only the inhalation route due to shower activity has predicted risk values several times higher than the generally acceptable risk of 1 per million. Probabilistic risk assessment is also conducted to account for uncertainty and variability in the analysis. The maximum likelihood of worst consequence is also identified by probabilistic methods. [Copyright &y& Elsevier]

There is an ongoing discussion whether in the environmental risk assessment for chemicals the so called ‘deterministic’ approach using point estimates of exposure and effect concentrations is still appropriate. Instead, the more detailed and scientifically sounder probabilistic methods that have been developed over the last years are widely recommended. Here, we present the results of a probabilistic effect assessment for the aquatic environment performed for the pesticide methyl parathion and compare them with the results obtained with the common deterministic approach as described in the EU Technical Guidance Document. Methyl parathion was chosen because a sufficient data set (acute toxicity data for about 70 species) was available. The assumptions underlying the probabilistic effect assessment are discussed in the light of the results obtained for methyl parathion. Two important assumptions made by many studies are: (i) a sufficient number of ecologically relevant toxicity data is available, (ii) the toxicity data follow a certain distribution such as log-normal. Considering the scarcity of data for many industrial chemicals, we conclude that these assumptions would not be fulfilled in many cases if the probabilistic assessment was applied to the majority of industrial chemicals. Therefore, despite the well-known limitations of the deterministic approach, it should not be replaced by probabilistic methods unless the assumptions of these methods are carefully checked in each individual case, which would significantly increase the effort for the assessment procedure. [ABSTRACT FROM AUTHOR]