Upper-bound Scenario Research Articles

Comprehensive and cumulative risk evaluation of dietary exposure to aflatoxins and ochratoxin A on fermented teas worldwide by a new assessment model

Recently, mycotoxin risks in fermented tea have received high attention, but mycotoxin transfer rates from tealeaf to infusion during brewing were rarely considered. In addition, the assessment data (i.e., mycotoxin occurrences and tea consumption) in previous assessments were usually limited. Here, a comprehensive and cumulative risk assessment of aflatoxins and ochratoxin A was performed using a tea assessment model, by which mycotoxin transfer rates were included and the assessment data were collected worldwide. By 10 times of brewing, the aflatoxin transfer rate was only 2.94% and OTA was 63.65%. Besides the extreme case, hazard quotients (HQs) from all consumers were lower than the threshold of 1.0, indicating no noncarcinogenic risk; the P95 cumulative margin of exposure (1/MoET) values were 2.52E-04 (30–39 years of age) and 2.42E-04 (≥50 years of age) for two high exposure groups under the upper bound scenario, which a little higher than the carcinogenic risk threshold of 1.00E-04. Notably, the P95 cumulative 1/MoET values (3.24E-03 -7.95E-03) by food assessment model were ten times higher than those of by tea assessment model. The comparative results showed that mycotoxin dietary risks on tea consumption by food assessment model were much overestimated. The result of this study indicated that the contaminants transfer rates should be considered for risk assessment on tea consumption in future work.

Levels of organic pollutants and metals/metalloids in infant formula marketed in Brazil: Risks to early-life health

Infant formula intake is recommended to ensure comprehensive nutritional and caloric fulfillment when exclusive breastfeeding is not possible. However, similarly to breast milk, infant formulas may also contain pollutants capable of inducing endocrine-disrupting and neurotoxic effects. Thus, considering the sensitivity of their developing physiological systems and that infants have heightened susceptibility to environmental influences, this study was aimed at assessing the contents of essential elements, and inorganic and organic pollutants in infant formulas marketed in Brazil. Additionally, health risk assessments for selected contaminants were also performed. Measured contents of essential elements (Ca, Fe, Mg, Mn, Cu, Se, and Zn) were congruent with label information. Nevertheless, some toxic elements (Pb, Cd, As, Ni, and Al) were also detected. Notably, in the upper-bound scenario, Pb and Cd surpassed established threshold values when comparing the estimated daily intake (EDI) and tolerable daily intake (TDI – 3.57 and 0.36 μg/kg bw, respectively). Bisphenol P (BPP) and benzyl butyl phthalate (BBP) were frequently detected (84 % detection rate both) with elevated contents (BPP median = 4.28 ng/g and BBP median = 0.24 ng/g). Furthermore, a positive correlation (0.41) was observed between BPP and BBP, implying a potential co-occurrence within packaging materials. Methyl-paraben also correlated positively with BBP (0.57), showing a detection rate of 53 %. The cumulative PBDE contents ranged from 0.33 to 1.62 ng/g, with BDE-154 and BDE-47 the dominant congeners. When comparing EDI values with TDIs, all organic pollutants remained below the thresholds across all exposure scenarios. Moreover, non-carcinogenic risks were below the threshold (HQ > 1) when dividing the EDIs by the respective reference doses for chronic exposure. While the current findings may suggest that infant formula intake poses no immediate risk in terms of the evaluated chemicals, it remains imperative to conduct further research to safeguard the health of infants considering other chemicals, as well as their potential cumulative effects.

Estimating the Jordanian population dietary exposure to pesticides residues: An exploratory deterministic approach.

The Jordanian population's exposure to pesticides may have never been estimated. This study uses a deterministic approach as a screening method to determine the population's likelihood of daily dietary exposure to pesticide residues and identify pesticides that require further investigation. We investigated the data from surveillance programs to assess pesticide contamination in food. We also obtained data about the population's estimated consumption of different food items. The daily exposure to pesticide residues through food was estimated with two scenarios (Lu et al., 2006): the lower bound (LB) scenario and (Luo and Zhang, 2009) the upper bound (UB) scenario. The data provided the concentration of pesticides in 8085 food samples. In 15.7% of the samples, 134 pesticides were identified. The levels of quantified pesticides exceeded MRL in 41.7% of the samples. Under the LB, mean estimated daily exposures were higher than the acceptable daily intakes (ADIs) for 27 investigated residues. Using the UB scenario, which tends to overestimate exposure, the mean estimated daily exposures were above the ADIs for 111 residues. The study concludes that the population's dietary exposure to pesticide residues is noteworthy and provides a list of pesticides that could be consumed at levels higher than the relevant ADI value and thus require further assessment.

Assessment of dietary acrylamide exposure in children attending Spanish school canteens using the duplicate diet method

Acrylamide is a carcinogenic chemical contaminant formed in heat-treated foods. In this study, a duplicate diet method was used to evaluate the acrylamide content of foods/meals served at breakfast and lunch in two Spanish school canteens. The dietary acrylamide intake in students was estimated within lower bound (LB) and upper bound (UB) scenarios. Biscuits exhibited the highest acrylamide values, exceeding the benchmark level established by the European Regulation 2017/2158 (350 μg/kg), followed by main courses such as stews, side dishes and bread. In the LB scenario, breakfasts accounted for the major contributors to the daily acrylamide intake (73.3%). However, lunches were the main responsible in the UB scenario (65.4%). Acrylamide exposure was estimated for three age ranges: 3-5y pre-school children (0.59 and 0.92 μg/kg body weight/day), 6-9y children (0.43 and 0.67 μg/kg body weight/day) and 10-12y early adolescents (0.28 and 0.44 μg/kg body weight/day). Margins of exposure for neoplastic effects ranged between 144 and 1026, which is below the reference of 10,000, indicating a health concern. The findings reveal that any diet, even one that is balanced, varied and contains foods low in acrylamide, involves an additive exposure to the contaminant that should be considered when conducting acrylamide exposure risk assessments.

Non-regulated aromatic amines in clothing purchased in Spain and Brazil: Screening-level exposure and health impact assessment

The staggering amount of chemicals in clothes and their harmful effects on human health and the environment have attracted the attention of regulatory agencies and the scientific community worldwide. Azo dyes are synthetic dyestuffs with widespread use in textile industries, currently classified as emerging pollutants of great health concern to consumers. These compounds may release one or more aromatic amines (AAs) after reductive cleavage of their azo bounds. Twenty-two AAs have already been regulated due to their carcinogenic effects. However, since information on their potential toxicity is not currently available, several AAs have not been still regulated by the European Union. Considering this gap, the present study aimed to assess the levels of forty non-regulated AAs in 240 clothing items from Spain and Brazil. The potential impact on the health of vulnerable population groups after dermal exposure to those garments was also evaluated. In Brazil, at least one AA was detected in the clothes, while in samples obtained in Spain, only two of them showed values below the limit of detection for AAs. In 75 clothes, at least one of the measured AAs was higher than the hazardous threshold (30 mg/kg), which can mean risks to human health since these compounds are suspected to be mutagenic. Aniline, the most common AA, showed a high detection rate (82%) in clothes, with significantly higher concentrations in items commercialized in Brazil (0.35 vs. 0.17 mg/kg; p = 0.032). Moreover, o-aminobenzenesulfonic and p-phenylenediamine, suspected mutagenic, were found at relevant concentrations in several clothes, mainly made of synthetic fibers. In this study, the hazard index associated with exposure to AAs through clothing was low (0.006–0.13) for all the population groups of both countries in the medium-bound scenario. However, its value was close to 1 for Brazilian pregnant women (0.998) when the maximum concentration value was considered under an upper-bound scenario. The risk of exposure to non-regulated AAs may be underestimated since only dermal exposure was considered for risk assessment. Moreover, the co-occurrence of other carcinogenic and non-carcinogenic substances present in skin-contact clothes should mean an additional source of potential risk.

Dermal exposure to bisphenols in pregnant women's and baby clothes: Risk characterization

Textile manufacturing consists of a multiple-step process in which a wide range of chemicals is used, some of them remaining in the final product. Bisphenols (BPs) are non-intentionally added compounds in textiles, whose prolonged skin contact may mean a significant source of daily human exposure, especially in vulnerable groups of the population. The present study aimed to determine the levels of bisphenol A (BPA) and some BP analogs (BPB, BPF, and BPS) in 120 new clothes commercialized in Spain for pregnant women, newborns, and toddlers. In addition, exposure assessment and risk characterization were also carried out. Traces of BPA were found in all the samples, with a median concentration of 7.43 ng/g. The highest values were detected in textile samples made of polyester. Regarding natural fibers, higher concentrations of BPs were observed in garments made of conventional cotton than in those made of organic cotton, with a significant difference for BPS (1.24 vs. 0.76 ng/g, p < 0.05). Although toddlers have a larger skin-area-to-body-weight ratio, pregnant women showed higher exposure to BPs than children. Anyhow, the non-carcinogenic risks associated with BPA exposure were below the unity, even under the upper-bound scenario. However, risks could be underestimated because other exposure routes were not considered in this study. The use of BPA has been restricted in some food-related products; therefore, BPA should also be regulated in the textile industry.

Occurrence of Phenylpyrazole and Diamide Insecticides in Lactating Women and Their Health Risks for Infants.

To investigate the exposure of infants to phenylpyrazole and diamide insecticides during lactation, we collected 3467 breast milk samples of lactating women from 100 cities of 24 provinces in China and prepared 100 pooled samples together city-by-city. Among phenylpyrazole insecticides, fipronil and its metabolites (63-100%) were widely detected in breast milk, with total detection concentrations ranging from 178 to 2947 ng/L (median: 921 ng/L). Among diamide insecticides, chlorantraniliprole and flubendiamide were detected in breast milk, but their detection frequencies (20-85%) and concentration levels (nondetected to 89.9 ng/L) were far lower than those of total fipronils. The average estimated daily intake of infants exposed to total fipronils through breast milk is 209 ng/kg-bw/day by upper-bound scenario evaluation, which is higher than the acceptable daily intake (200 ng/kg-bw/day). This study indicates that infants have far higher exposure levels to fipronil than adults, while exposure levels to other types of phenylpyrazoles and diamide insecticides are low.

Projected US savings from biosimilars, 2021-2025.

Biologics account for an increasing share of US prescription drug spending. Biosimilars could lower biologic prices through competition, but barriers to increasing both supply and uptake remain. We projected US biosimilar savings from 2021 to 2025 under different scenarios. We projected US spending on biologics over a 5-year period under 3 scenarios: (1) a baseline scenario holding quarter 4 (Q4) of 2020 market conditions constant; (2) under main assumptions allowing for biosimilar market growth and entry; and (3) an upper-bound scenario assuming greater biosimilar uptake, more robust price competition, and quicker biosimilar entry. We first analyzed 2014-2020 US volume and price data from IQVIA's MIDAS database for biologics already facing biosimilar competition to inform model parameter values. We used these inputs to project biosimilar entry, biosimilar volume shares, biosimilar prices, and reference biologic prices. We calculated 2021-2025 new savings from biosimilar competition vs the Q4 2020 baseline. Estimated biosimilar savings from 2021 to 2025 under our main approach were $38.4 billion, or 5.9% of projected spending on biologics over the same period. Biologics first facing biosimilar competition from 2021 to 2025 accounted for $26.1 billion of savings, with $12.2 billion from evolving market conditions for already-marketed biosimilars. Furthermore, $24.6 billion of savings under our main approach were from downward pressure on reference biologic prices rather than lower biosimilar prices. Savings were substantially higher ($124.5 billion) under the upper-bound scenario. Biosimilar savings from 2021 to 2025 were $38.4 billion under our main assumptions. Greater savings may be feasible if managed care and other settings increase biosimilar utilization and promote competition.

Modality Attention and Sampling Enables Deep Learning with Heterogeneous Marker Combinations in Fluorescence Microscopy.

Fluorescence microscopy allows for a detailed inspection of cells, cellular networks, and anatomical landmarks by staining with a variety of carefully-selected markers visualized as color channels. Quantitative characterization of structures in acquired images often relies on automatic image analysis methods. Despite the success of deep learning methods in other vision applications, their potential for fluorescence image analysis remains underexploited. One reason lies in the considerable workload required to train accurate models, which are normally specific for a given combination of markers, and therefore applicable to a very restricted number of experimental settings. We herein propose Marker Sampling and Excite — a neural network approach with a modality sampling strategy and a novel attention module that together enable (i) flexible training with heterogeneous datasets with combinations of markers and (ii) successful utility of learned models on arbitrary subsets of markers prospectively. We show that our single neural network solution performs comparably to an upper bound scenario where an ensemble of many networks is naïvely trained for each possible marker combination separately. In addition, we demonstrate the feasibility of this framework in high-throughput biological analysis by revising a recent quantitative characterization of bone marrow vasculature in 3D confocal microscopy datasets and further confirm the validity of our approach on an additional, significantly different dataset of microvessels in fetal liver tissues. Not only can our work substantially ameliorate the use of deep learning in fluorescence microscopy analysis, but it can also be utilized in other fields with incomplete data acquisitions and missing modalities.

Total SO2 levels and risk assessment of wine and fruit wine consumed in South Korea

This study was conducted to determine the levels of total sulfur dioxide (SO2) in various fruit wines distributed across South Korea and to conduct risk assessment for SO2 exposure through wines. A total of 316 wines were analyzed in 2017, and the daily intake of wine was obtained from raw data provided in the Korea National Health and Nutrition Examination Survey conducted in 2016. In order to conduct risk assessments, we used a stochastic approach using the Monte Carlo method and presented the results in three scenarios to resolve uncertainty about SO2 non-detected (ND) data: the lower-bound scenario, which considers data below the limit of quantification (LOQ) to be 0 mg kg−1, the ½ LOQ scenario, which considers data below the LOQ as half of LOQ, and the upper-bound scenario, which considers data below the LOQ as LOQ value. During the monitoring of 316 wines, the detection range of total SO2 varied from ND to 340.06 mg kg−1, and there were no products exceeding 350 mg kg−1 total SO2, which is the regulated level in South Korea. Risk assessment revealed that most South Koreans were ingesting a safe level of SO2 through wine in terms of the acceptable daily intake (ADI, 0–0.7 mg kg−1 body weight day−1). Similar to the results of studies undertaken in other countries, only a limited percentage of South Korean individuals intake SO2 at a reasonably high amount. The regular monitoring of high levels of SO2 in wine should be a national concern, although this percentage is minimal, and we recommend that the standard be reset as appropriate.

Active learning for segmentation based on Bayesian sample queries

Segmentation of anatomical structures is a fundamental image analysis task for many applications in the medical field. Deep learning methods have been shown to perform well, but for this purpose large numbers of manual annotations are needed in the first place, which necessitate prohibitive levels of resources that are often unavailable. In an active learning framework of selecting informed samples for manual labeling, expert clinician time for manual annotation can be optimally utilized, enabling the establishment of large labeled datasets for machine learning. In this paper, we propose a novel method that combines representativeness with uncertainty in order to estimate ideal samples to be annotated, iteratively from a given dataset. Our novel representativeness metric is based on Bayesian sampling, by using information-maximizing autoencoders. We conduct experiments on a shoulder magnetic resonance imaging (MRI) dataset for the segmentation of four musculoskeletal tissue classes. Quantitative results show that the annotation of representative samples selected by our proposed querying method yields an improved segmentation performance at each active learning iteration, compared to a baseline method that also employs uncertainty and representativeness metrics. For instance, with only 10% of the dataset annotated, our method reaches within 5% of Dice score expected from the upper bound scenario of all the dataset given as annotated (an impractical scenario due to resource constraints), and this gap drops down to a mere 2% when less than a fifth of the dataset samples are annotated. Such active learning approach to selecting samples to annotate enables an optimal use of the expert clinician time, being often the bottleneck in realizing machine learning solutions in medicine.

Polybrominated diphenyl ethers in foods from the Region of Valencia: Dietary exposure and risk assessment

Dietary exposure to polybrominated diphenyl ethers (PBDEs) of the population in the Region of Valencia, Spain, was assessed. A group of 320 composite samples of different fatty foods was collected and analyzed, including the following: vegetable oils, and foods of animal origin such as (a) fish and seafood, (b) eggs, (c) milk and dairy products, and (d) meat and meat products. Two scenarios were assumed for left-censored results: lower-bound (LB) and upper-bound (UB). Vegetable oils, and fish and seafood presented the highest content of PBDEs [mean values of 503 and 464 pg g−1 wet weight (ww) for total PBDEs, respectively, in the UB]. The dominating congeners were BDE47 in the food categories of fish and seafood, meat and meat products, and vegetable oils, and BDE99 in the categories of eggs, and milk and dairy products. The dietary exposure to PBDEs through consumption of the studied foods by the population in the Region of Valencia was estimated for adults (>15 years of age) and young people (6–15 years of age). Average intake levels (UB scenario) were 1.443 and 3.456 ng kg bw−1 day−1 for adults and young people, respectively. In a risk-assessment context, the margin of exposure (MOE) for congener BDE47, -99, −153, and −209 (ranged: 30-3E6) indicate that the current dietary exposure to these substances does not pose a risk to human health.

Dietary exposure to pesticide residues and associated health risks in infants and young children – Results of the French infant total diet study

A total diet study (TDS) was undertaken to estimate the chronic dietary exposure to pesticide residues and health risks for the French infants and young children below 3 years old. As a whole, 516 pesticides and metabolites were analysed in 309 food composite samples including 219 manufactured baby foods and 90 common foods, which cover 97% of infants and young children's diet. These composite samples were prepared using 5,484 food products purchased during all seasons from 2011 to 2012 and processed as consumed. Pesticide residues were detected in 67% of the samples and quantified in 27% of the baby food samples and in 60% of the common foods. Seventy-eight different pesticides were detected and 37 of these quantified at levels ranging from 0.02 to 594 µg/kg. The most frequently detected pesticides (greater than 5% samples) were (1) the fungicides 2-phenylphenol, azoxystrobin, boscalid, captan and its metabolite tetrahydrophthalimide, carbendazim, cyprodinil, difenoconazole, dodine, imazalil, metalaxyl, tebuconazole, thiabendazole, (2) the insecticides acetamiprid, pirimiphos-methyl and thiacloprid, (3) the herbicide metribuzin and (4) the synergist piperonyl butoxide. Dietary intakes were estimated for each of the 705 individuals studied and for 431 pesticides incl. 281 with a toxicological reference value (TRV). In the lower-bound scenario, which tends to underestimate the exposure, the TRV were never exceeded. In the upper-bound scenario that overestimates exposure, the estimated intakes exceeded the TRV for dieldrin and lindane (two persistent organic pollutants) and propylene thiourea, a metabolite of propineb. For these three substances, more sensitive analyses are needed to refine the assessment. For 17 other detected and/or prioritised pesticides, the risk could not be characterised due to the lack of a valid TRV, of certain food analyses or the absence of analytical standards for their metabolites.

Investigating the Urban Air Quality Effects of Cool Walls and Cool Roofs in Southern California.

Solar reflective cool roofs and walls can be used to mitigate the urban heat island effect. While many past studies have investigated the climate impacts of adopting cool surfaces, few studies have investigated their effects on air pollution, especially on particulate matter (PM). This research for the first time investigates the influence of widespread deployment of cool walls on urban air pollutant concentrations, and systematically compares cool wall to cool roof effects. Simulations using a coupled meteorology-chemistry model (WRF-Chem) for a representative summertime period show that cool walls and roofs can reduce urban air temperatures, wind speeds, and planetary boundary heights in the Los Angeles Basin. Consequently, increasing wall (roof) albedo by 0.80, an upper bound scenario, leads to maximum daily 8-h average ozone concentration reductions of 0.35 (0.83) ppbv in Los Angeles County. However, cool walls (roofs) increase daily average PM2.5 concentrations by 0.62 (0.85) μg m-3. We investigate the competing processes driving changes in concentrations of speciated PM2.5. Increases in primary PM (elemental carbon and primary organic aerosols) concentrations can be attributed to reductions in ventilation of the Los Angeles Basin. Increases in concentrations of semivolatile species (e.g., nitrate) are mainly driven by increases in gas-to-particle conversion due to reduced atmospheric temperatures.

Dietary exposure and risk assessment of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans and dioxin-like polychlorinated biphenyls of the population in the Region of Valencia (Spain)

ABSTRACTDietary exposure of the Valencia Region population to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and PCBs was assessed in the Region of Valencia in 2010–2011. A total of 7700 food samples were collected. Occurrence data were combined with consumption data to estimate dietary exposure in adults (>15 years of age) and young people (6–15 years of age). The estimated intake was calculated by a probabilistic approach. Average intake levels (upper-bound scenario) were 1.58 and 2.76 pg toxic equivalent (TEQ) kg−1 body weight (bw) day−1 for adults and young people, respectively. These average intakes are within range of the tolerable daily intake of 1–4 pg WHO-TEQ kg−1 bw day−1 recommended by WHO, and slightly above the tolerable weekly intake (TWI) of 14 pg TEQ kg−1 bw week−1 and the Provisional tolerable monthly intake of 70 pg TEQ kg−1 bw month−1 set by the Scientific Committee on Food and the Joint FAO/WHO Expert Committee on Food, respectively. These results show that the contamination levels in food and therefore the exposure of the general population to PCDD/Fs and PCBs have declined in this region and therefore show the efficiency of the European risk-management measures. In terms of risk characterisation, the results showed that, under the upper-bound scenario, 22% of the adult and 58% of the young people population could exceed the TWI.

Risk assessment and monitoring programme of nitrates through vegetables in the Region of Valencia (Spain)

This study was carried out to determine current levels of nitrate in vegetables marketed in the Region of Valencia (Spain) and to estimate the toxicological risk associated with their intake. A total of 533 samples of seven vegetable species were studied. Nitrate levels were derived from the Valencia Region monitoring programme carried out from 2009 to 2013 and food consumption levels were taken from the first Valencia Food Consumption Survey, conducted in 2010. The exposure was estimated using a probabilistic approach and two scenarios were assumed for left-censored data: the lower-bound scenario, in which unquantified results (below the limit of quantification) were set to zero and the upper-bound scenario, in which unquantified results were set to the limit of quantification value. The exposure of the Valencia consumers to nitrate through the consumption of vegetable products appears to be relatively low. In the adult population (16–95 years) the P99.9 was 3.13 mg kg−1 body weight day−1 and 3.15 mg kg−1 body weight day−1 in the lower bound and upper bound scenario, respectively. On the other hand, for young people (6–15 years) the P99.9 of the exposure was 4.20 mg kg−1 body weight day−1 and 4.40 mg kg−1 body weight day−1 in the lower bound and upper bound scenario, respectively. The risk characterisation indicates that, under the upper bound scenario, 0.79% of adults and 1.39% of young people can exceed the Acceptable Daily Intake of nitrate. This percentage could join the vegetable extreme consumers (such as vegetarians) of vegetables. Overall, the estimated exposures to nitrate from vegetables are unlikely to result in appreciable health risks.

Chronic dietary exposure to pesticide residues and associated risk in the French ELFE cohort of pregnant women

Dietary exposure to pesticide residues may present a risk to public health, especially for sensitive populations such as pregnant women. To characterize this risk, this study assessed chronic dietary exposure to pesticide residues based on the French ELFE cohort. A self-administered food frequency questionnaire (FFQ) about the last three months of pregnancy filled in by pregnant women in 2011 was used in combination with occurrence data from French Total Diet Studies completed by the results of national monitoring programs on pesticide residues in food. The dietary intake of pesticides (μg/kg of body weight/day) was estimated for 14,099 pregnant women with a complete FFQ, for 317 substances under two occurrence scenarios to handle left-censored data: a lower-bound scenario (LB), where undetected results were set to zero, and an upper-bound scenario (UB), where undetected results were set to the detection limit if the substance was expected to be found in food and zero if it was not. The risk was assessed for 284 substances with a toxicological reference value (TRV) and a good coverage level of the diet potentially contributing to pesticide intake. The cumulative risk was also assessed for seven effects on nervous and thyroid systems using the hazard index and the Cumulative Assessment Groups defined by EFSA. Substances with the highest exposure levels under the LB scenario were, in decreasing order, imazalil, piperonyl butoxide, chlorpropham, thiabendazole, iprodione and propargite. Under the LB scenario, only for lindane did women have a statistically significant probability of exceeding the TRV (2.4%). Under the UB scenario, risk could not be excluded for nine other substances. A better management of left-censored data and more sensitive analyses of the main food contributors might help to refine the UB exposure and risk assessments. A statistically significant cumulative risk was found for neurochemical effects related to high intake levels of three organophosphate insecticides (chlorpyrifos, pirimiphos-methyl and dimethoate) mainly detected in fruits and cereals.

A mycotoxin-dedicated total diet study in the Netherlands in 2013: Part III – exposure and risk assessment

In a mycotoxin-dedicated total diet study (mTDS) performed in the autumn and winter of 2013 in the Netherlands, 48 mycotoxins, including patulin, aflatoxins, ochratoxin A, fumonisins, zearalenone, trichothecenes, ergot alkaloids,Alternaria toxins, beauvericin and enniatins, were quantified. Analyses were performed in 88 composite samples representative for the consumption pattern of the Dutch population. This article presents the results of the exposure assessment and subsequent risk assessment of these mycotoxins. Exposure was assessed by combining individual food consumption data obtained from the Dutch National Food Consumption Surveys (DNFCS) for young children aged 2-6 years and the population aged 7-69 years with the analytical results of the mTDS, using a lower bound and an upper bound scenario for levels below the limit of detection. Wherever possible, exposure estimates were compared with toxicological reference values, including health-based guidance values. The high level of exposure (95th percentile) exceeded the toxicological reference value regardless of the substitution scenario for ochratoxin A in the population aged 7-69 years, for the sum of T-2 and HT-2 toxins for children aged 2-6 years and for alternariol and alternariol monomethyl ether in both examined populations. The margin of exposure was too small for aflatoxin B1. For the remaining 23 mycotoxins with a toxicological reference value, the estimated exposure was below this level.

Dietary exposure to benzoates (E210–E213), parabens (E214–E219), nitrites (E249–E250), nitrates (E251–E252), BHA (E320), BHT (E321) and aspartame (E951) in children less than 3 years old in France

This study aimed to estimate the exposure to seven additives (benzoates, parabens, nitrites, nitrates, BHA, BHT and aspartame) in children aged less than 3 years old in France. A conservative approach, combining individual consumption data with maximum permitted levels, was carried out for all the additives. More refined estimates using occurrence data obtained from products’ labels (collected by the French Observatory of Food Quality) were conducted for those additives that exceeded the acceptable daily intake (ADI). Information on additives’ occurrence was obtained from the food labels. When the ADI was still exceeded, the exposure estimate was further refined using measured concentration data, if available. When using the maximum permitted level (MPL), the ADI was exceeded for benzoates (1.94 mg kg–1 bw day–1), nitrites (0.09 mg kg–1 bw day–1) and BHA (0.39 mg kg–1 bw day–1) in 25%, 54% and 20% of the entire study population respectively. The main food contributors identified with this approach were current foods as these additives are not authorised in specific infant food: vegetable soups and broths for both benzoates and BHA, delicatessen and meat for nitrites. The exposure estimate was significantly reduced when using occurrence data, but in the upper-bound scenario the ADI was still exceeded significantly by the age group 13–36 months for benzoates (2%) and BHA (1%), and by the age group 7–12 months (16%) and 13–36 months (58%) for nitrites. Measured concentration data were available exclusively for nitrites and the results obtained using these data showed that the nitrites’ intake was below the ADI for all the population considered in this study. These results suggest that refinement of exposure, based on the assessment of food levels, is needed to estimate the exposure of children to BHA and benzoates for which the risk of exceeding the ADI cannot be excluded when using occurrence data.

Stochastic dynamic itinerary interception refueling location problem with queue delay for electric taxi charging stations

A new facility location model and a solution algorithm are proposed that feature (1) itinerary-interception instead of flow-interception; (2) stochastic demand as dynamic service requests; and (3) queueing delay. These features are essential to analyze battery-powered electric shared-ride taxis operating in a connected, centralized dispatch manner. The model and solution method are based on a bi-level, simulation–optimization framework that combines an upper level multiple-server allocation model with queueing delay and a lower level dispatch simulation based on earlier work by Jung and Jayakrishnan. The solution algorithm is tested on a fleet of 600 shared-taxis in Seoul, Korea, spanning 603km2, a budget of 100 charging stations, and up to 22 candidate charging locations, against a benchmark “naïve” genetic algorithm that does not consider cyclic interactions between the taxi charging demand and the charger allocations with queue delay. Results show not only that the proposed model is capable of locating charging stations with stochastic dynamic itinerary-interception and queue delay, but that the bi-level solution method improves upon the benchmark algorithm in terms of realized queue delay, total time of operation of taxi service, and service request rejections. Furthermore, we show how much additional benefit in level of service is possible in the upper-bound scenario when the number of charging stations is unbounded.