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Ying-Fei Yang,1 Yi-Jun Lin,2 Shu-Han You,3 Tien-Hsuan Lu,4 Chi-Yun Chen,5,6 Wei-Min Wang,1 Min-Pei Ling,7 Szu-Chieh Chen,8,9 Chung-Min Liao1 1Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, 10617, Taiwan; 2Institute of Food Safety and Health Risk Assessment, National Yang Ming Chiao Tung University, Taipei, 11230, Taiwan; 3Institute of Food Safety and Risk Management, National Taiwan Ocean University, Keelung City, 20224, Taiwan; 4Department of Science Education and Application, National Taichung University of Education, Taichung, 403514, Taiwan; 5Department of Environmental and Global Health, College of Public Health and Health Professions, University of Florida, Gainesville, FL, 32610, USA; 6Center for Environmental and Human Toxicology, University of Florida, Gainesville, FL, 32608, USA; 7Department of Food Science, National Taiwan Ocean University, Keelung City, 20224, Taiwan; 8Department of Public Health, Chung Shan Medical University, Taichung, 40201, Taiwan; 9Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, 40201, TaiwanCorrespondence: Chung-Min Liao, Department of Bioenvironmental Systems Engineering, National Taiwan University, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan, Email cmliao@ntu.edu.twBackground: The emergence and progression of highly divergent SARS-CoV-2 variants have posed increased risks to global public health, triggering the significant impacts on countermeasures since 2020. However, in addition to vaccination, the effectiveness of non-pharmaceutical interventions, such as social distancing, masking, or hand washing, on different variants of concern (VOC) remains largely unknown.Objective: This study provides a mechanistic approach by implementing a control measure model and a risk assessment framework to quantify the impacts of control measure combinations on the transmissions of five VOC (Alpha, Beta, Delta, Gamma, and Omicron), along with a different perspective of risk assessment application.Materials and Methods: We applied uncontrollable ratios as an indicator by adopting basic reproduction number (R0) data collected from a regional-scale survey. A risk assessment strategy was established by constructing VOC-specific dose-response profiles to implicate practical uses in risk characterization when exposure data are available.Results: We found that social distancing alone was ineffective without vaccination in almost all countries and VOC when the median R0 was greater than two. Our results indicated that Omicron could not be contained, even when all control measure combinations were applied, due to its low threshold of infectivity (~3× 10− 4 plague-forming unit (PFU) mL− 1).Conclusion: To facilitate better decision-making in future interventions, we provide a comprehensive evaluation of how combined control measures impact on different countries and various VOC. Our findings indicate the potential application of threshold estimates of infectivity in the context of risk communication and policymaking for controlling future emerging SARS-CoV-2 variant infections.Keywords: SARS-CoV-2, variants of concern, basic reproduction number, modeling, non-pharmaceutical interventions, infection risk

Yi-Jun Lin,1 Hsing-Chieh Lin,2 Ying-Fei Yang,2 Chi-Yun Chen,2 Min-Pei Ling,3 Szu-Chieh Chen,4,5 Wei-Yu Chen,6,7 Shu-Han You,8 Tien-Hsuan Lu,2 Chung-Min Liao2 1Institute of Food Safety and Health Risk Assessment, National Yang-Ming University, Taipei, Taiwan; 2Department of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan; 3Department of Food Science, National Taiwan Ocean University, Keelung City, Taiwan; 4Department of Public Health, Chung Shan Medical University, Taichung, Taiwan; 5Department of Family and Community Medicine, Chung Shan Medical University Hospital, Taichung, Taiwan; 6Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, Kaohsiung, Taiwan; 7Research Center for Environmental Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan; 8Institute of Food Safety and Risk Management, National Taiwan Ocean University, Keelung City, TaiwanCorrespondence: Chung-Min LiaoDepartment of Bioenvironmental Systems Engineering, National Taiwan University, Taipei, Taiwan, ROCTel +886 2 3366 3475Email cmliao@ntu.edu.twBackground: Broad-scale evidence has shown the significant association between ambient air pollutants and the development of tuberculosis (TB). However, the impact of air quality on the risk of TB in Taiwan is still poorly understood.Objective: To develop a probabilistic integrated population-level risk assessment approach for evaluating the contribution of ambient air pollution exposure to the risk of TB development among different regions of Taiwan.Materials and methods: A Bayesian-based probabilistic risk assessment model was implemented to link exposure concentrations of various air pollutants quantified in a probabilistic manner with the population-based exposure-response models developed by using an epidemiological investigation.Results: The increment of the risk of TB occurred in a region with a higher level of air pollution, indicating a strong relationship between ambient air pollution exposures and TB incidences. Carbon monoxide (CO) exposure showed the highest population attributable fraction (PAF), followed by nitrogen oxides (NOX) and nitrogen dioxide (NO2) exposures. In a region with higher ambient air pollution, it is most likely (80% risk probability) that the contributions of CO exposure to development of TB were 1.6–12.2% (range of median PAFs), whereas NOX and NO2 exposures contributed 1.2–9.8% to developing TB.Conclusion: Our findings provide strong empirical support for the hypothesis and observations from the literature that poor air quality is highly likely to link aetiologically to the risk of TB. Therefore, substantial reductions in CO, NOX, and NO2 exposures are predicted to have health benefits to susceptible and latently infected individuals that provide complementary mitigation efforts in reducing the burden of TB. Considering that people continue to be exposed to both TB bacilli and ambient air pollutants, our approach can be applied for different countries/regions to identify which air pollutants contribute to a higher risk of TB in order to develop potential mitigation programs.Keywords: tuberculosis, ambient air pollution, exposure-response function, probabilistic risk assessment, population attributable fraction

The aim of the study is to develop Salmonella spp. Quantitative microbial risk assessments (QMRA) and to evaluate the risk of Salmonellosis illness in the Taiwanese population after consumption of Taiwanese salty chicken (TSC). We assume that Salmonella spp. May contaminate the fresh raw chicken used in TSC. After transport to the diner, fresh raw chicken is received, cleaned, and surface-washed by diner staff. The TSC is then cooked and sold to consumers. We set four different cross-contamination scenarios to evaluate the contamination level of Salmonella spp. In TSC. We used a Monte Carlo simulation method, a probabilistic analysis method, and exceedance risk to evaluate the risk of Salmonellosis illness. When the exceedance risk was 5 %, and taking the Taiwanese population above 19 years old as an example, the rate of contracting Salmonellosis from the consumption of TSC will be 2.94 % (2.94 million per 100 million people) if the chef does not clean their hands, knives, or cutting boards. However, if the chef washes their hands, knives, and cutting boards with cold water and soap, the illness rate of Salmonellosis from consuming TSC will be 1.93E-04 % (193 per 100 million people). Sensitivity analysis indicates that the most important risk factor in the QMRAs of TSC is the temperature of the fresh raw chicken during transportation, following which were the Salmonella spp. Residual. If the staff of the diner separates the cooking tools used for raw ingredients and those for cooked food, the illness risk of Salmonellosis will be very low., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors. Published by Elsevier Ltd.)

This paper carries out probabilistic approach to quantify the benefit-risk analysis for foods (BRAFO) of omega-3 polyunsaturated fatty acid and methylmercury (MeHg) for the people who eat the mercury-contaminated fish in Taiwan. We applied the hazard quotient (HQ) model to assess the risk of developmental neuropsychological impairment effect and the desirable dose index (DI) model to quantify the health benefits. Besides, we also applied the disability adjusted life years (DALY) model to assess the number of years lost by incidence of affected infants' intelligence quotient (IQ) and coronary heart disease (CHD) or Stroke for adult. The results of this study show that although the risk of cod and scad are higher, Taiwan residents do not need to reduce intake rate based on benefit considerations. Furthermore, according to the benefits of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), this study suggests that more intake of saury and salmon., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background: Naturally existing and human-produced heavy metals are released into the environment and cannot be completely decomposed by microorganisms, but they continue to accumulate in water and sediments, causing organisms to be exposed to heavy metals., Results: This study designs and proposes heavy metal hazard decision trees for aquatic products, which are divided into seven categories including pelagic fishes, inshore fishes, other fishes, crustaceans, shellfish, cephalopods, and algae. Based on these classifications, representative fresh and processed seafood products are at the root of the heavy metal hazard decision trees. This study uses 2,107 cases of eating 556 cooked fresh or processed seafood product samples. The constructions of the proposed decision trees consist of 12 heavy metals, which include inorganic arsenic (iAs), cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), strontium (Sr), thallium (Tl), and zinc (Zn). The heavy metal concentrations in cooked fresh and processed seafood product samples are subjected to a food safety risk assessment., Conclusions: The results indicate the relationships among the seven categories of aquatic products, the relationships among 12 heavy metals in aquatic products, and the relationships among potential human health risks. Finally, the proposed heavy metal hazard decision trees for aquatic products can be used as a reference model for researchers and engineers., (© 2022. The Author(s).)

This paper examines the health risks of exposure to methylmercury (MeHg) through the consumption of mercury-contaminated seafood in Taiwan, based on the total diet study (TDS) method. Samples of seafood ( n = 140) were purchased at fishing harbors or supermarkets and classified into seven categories (pelagic fish, inshore fish, farmed fish, shellfish, cephalopods, crustaceans, and algae). For each sample, we analyzed raw and cooked versions and compared the concentration difference. Total mercury (THg) was detected at the highest rate and in the highest concentrations in pelagic fish, followed by inshore fish and other farmed fish. The average concentration of THg was higher after cooking. In a 75th percentile scenario, the hazard indices for children aged 1 to 3 years and children aged 4 to 6 years were higher than 100% of the provisional tolerable weekly intake. Taking into consideration the risk assessment results, MeHg concentrations, and the nutritional composition of fish, we have provided weekly consumption advisories for children aged 1 to 3 years, children aged 4 to 6 years, and childbearing women aged 19 to 49 years. The weekly consumption advisories for childbearing women are 35 g/week of pelagic fish and 245 g/week of inshore fish based on the risk results from MeHg and the potential benefits from eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake.

Cadmium (Cd) is a toxic pollutant that is widely spread through industrial production and agricultural practices. Epidemiological data has revealed that lifetime exposure to environmentally relevant levels of Cd increases the risk of developing various organ diseases, including chronic kidney, heart, and lung diseases, as well as nervous tissue disorders. This study assessed Cd levels in rice to determine the health risks associated with rice consumption in various age-gender subgroups in Taiwan. The distribution of Cd concentration, the lifetime average daily dose (LADD), and the hazard index (HI) were estimated by Monte Carlo simulation. In the general population, the 50th percentile LADD of Cd for male rice consumers between the ages of 19-65 years was 0.06 μg/kg body weight per day, and the hazard index (HI) 50th, 90th, and 95th percentiles were 0.16, 0.69, and 1.54, respectively. According to the HI heat map for the exposure of the general population to Cd from rice in Taiwan, the highest exposure to Cd was noted in the Yilan area (HI 0.64). Therefore, rice production in the Yilan area should be further monitored to evaluate the levels of Cd contamination.

Phosphorus and calcium are essential nutrients for the human body. However, excessive intake of phosphates and a low calcium:phosphorus ratio can lead to disorders in calcium-phosphorus metabolism, kidney disease, or osteoporosis. In this study, a total diet study (TDS) was used. The total phosphorus concentrations of foods were combined with the average dietary consumption to calculate the estimated daily intake, which was compared with the maximum tolerable daily intake (MTDI) to assess the resulting health risk of total phosphorus exposure. The calcium concentration in food and total calcium intake were also analyzed and estimated to calculate the calcium:phosphorus ratio. In conclusion, the phosphate exposure risks for the Taiwanese population are acceptable. However, the calcium:phosphorus ratio in the Taiwanese population (0.51-0.63) is lower than the reference calcium:phosphorus ratio (1.25).

Background: In Taiwan, nearly 90% of apples and raw ingredients for apple-based products are imported. Apple juices (137 samples) and apple-containing beverages (35 samples) were collected in Taiwan from imported food and analyzed for patulin content., Results: The results revealed that the incidence levels of patulin for apple juice and apple-containing beverages are 5.84% and 5.71%. The mean contamination levels were 1.7 and 1.4 μg kg -1 for apple juice and apple-containing beverages. One sample exceeded 50 μg kg -1 , the maximum permissible limit according to the Taiwan Sanitation Standard for the Tolerance of Mycotoxins in Foods. The estimated intake of patulin for consumers ranged from 5.4 to 18.0 ng kg -1 body weight per day for apple juice and between 6.1 and 11.2 ng kg -1 body weight for apple-containing beverages. The highest average patulin intake was observed among infants aged 0-3 years, followed by children aged 4-12 years old. Finally, the hazard index (HI) for the 50th, 90th, and 95th percentiles are 0.0186, 0.1201, and 0.2048, respectively, for infants aged 0-3 years., Conclusion: The dietary intake of patulin from imported apple juices and apple-containing beverages is well below the safety levels and does not present a risk for adult and children consumers. However, it is important to point out that we only analyzed imported apple juices and apple-containing beverages. More studies are necessary to establish if the HI for patulin will still remain below 1 when other foods and beverages are included in the risk calculations. © 2020 Society of Chemical Industry., (© 2020 Society of Chemical Industry.)

Outbreaks of foodborne illness caused by pathogenic Escherichia coli ( E. coli ) O157:H7, which are attributable to the consumption of undercooked beef, have occurred in many countries. In Taiwan, the production of domestic beef accounts for only 5% of the total amount of beef sold. Therefore, we applied different contextual assumptions to develop a quantitative microbial risk assessment of E. coli O157:H7 and evaluated the risk of illness in the Taiwanese population consuming beef imported from the United States of America. The probability distribution showed that, in males aged 19-65 years in the Taiwanese population, for example, when rare beef was consumed 100 servings, there was a 90% probability of randomly intaking seven colony forming units of E. coli O157:H7. When medium beef was consumed 10,000 servings, there was a 90% probability of randomly intaking two colony forming units of E. coli O157:H7. When the exceedance risk was 5%, the rate of foodborne illnesses caused by consuming rare beef contaminated with E. coli O157:H7 was 10-28 cases per 1 million individuals. For medium beef, this rate was 6-13 per 100 million individuals. Sensitivity analyses indicated that the amount of E. coli O157:H7 remaining in beef products after cooking was the most important risk factor, followed by the amount of beef products consumed. Proper cooking of imported beef consumed by the Taiwanese public reduces the incidence of foodborne disease to almost zero, without risk of harm to health., Competing Interests: The author declares no conflict of interest.

Neonicotinoids (NEOs) are a class of pesticides widely used worldwide. This study analyzed post-cooking residues of NEO pesticides and assessed their potential health risks for preschool children (0-6 years old) by conducting a total diet study (TDS). It involved food sampling, preparation, analysis of pesticide residues, estimation of food consumption data, and assessment of food safety risks. Food sampling was conducted between March and June 2015. A total of 128 food samples were obtained from 4 parts of Taiwan. After the food had been prepared, the 128 samples were aggregated into 32 composite food items and the NEO residues analyzed. Acetamiprid had the highest detection rate of the NEO residues (59.4%), and the concentrations ranged from not detected to 80.5 μg/kg. The estimated daily intake (EDI) of NEO residues among preschool children was found to be lower than the adjusted acceptable daily intake (ADI) even for highly exposed groups. The results showed that NEO pesticides were primarily detected in preserved fruits, cherry tomato, rape, bell fruit, and baby bok choy. The main health risk posed by detected NEO residues at high consumption rates for preschool children was attributed to acetamiprid (34.20 %ADI) and imidacloprid (23.69 %ADI), respectively. Therefore, this research implicates that the present level of NEO residues in the diets for preschool children in Taiwan does not exceed 100 %ADI.

Aflatoxin is a fungal secondary metabolite with high toxicity that is capable of contaminating various types of food crops. It has been identified as a Group 1 human carcinogen by the International Agency for Research on Cancer. Chronic aflatoxin exposure has caused worldwide concern as a matter of public food safety. Peanuts and peanut products are the major sources of aflatoxin exposure. Therefore, some reduction interventions have been developed to minimize contamination throughout the peanut production chain. The purpose of this study is to estimate the efficacy of interventions in reducing the health impact of hepatocellular carcinoma caused by aflatoxin contamination in peanuts. The estimated total Disability-Adjusted Life Years (DALYs) were calculated using FDA-iRISK software. Six aflatoxin reduction strategies were evaluated, including good agricultural practice (GAP), biocontrol, Purdue Improved Crop Storage packaging, basic processing, ozonolysis, and ultraviolet irradiation. The results indicated that basic processing could prevent huge public health loss of 4,079.7-21,833 total DALYs per year. In addition, GAP and biocontrol were both found to be effective strategies in the farm field. Meanwhile, the other three interventions had limited effectiveness in reducing total DALYs. In conclusion, this study could help farmers, processing plants, and government policy makers to alleviate aflatoxin contamination issues in the peanut production chain., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Aflatoxins are highly toxic and cause disease in livestock and humans. In order to assess Taiwan population exposure to aflatoxin from peanuts and peanut products, a total of 1089 samples of peanut candy, peanut butter, and peanuts etc. were collected in the period from 2011 to 2017 and analyzed using a liquid chromatography/tandem mass spectrometer. The overall mean contamination levels of aflatoxin in peanuts and peanut products were 2.40 μg/kg of aflatoxin B1, 0.41 μg/kg of aflatoxin B2, 0.19 μg/kg of aflatoxin G1, and 0.03 μg/kg of aflatoxin G2. We use margin of exposure (MOE) as a tool to improve food safety management. According to MOE levels of aflatoxins in peanuts and peanut products from China, Indonesia, Thailand, the United States, and the Philippines were above the safe lower limit of 10,000, indicating an absence of public health or safety risk for the majority of the population. However, products from Vietnam were under the MOE safe lower limit, suggesting that regulatory actions must be continued to avoid excessive consumer exposure.

Flowers of Tabernaemontana divaricata (L.) R. Br., (Apocynaceae) are used in traditional medicine for analgesic property. The present study was performed to isolate the active principles and investigate the mechanisms involved in the anti-nociception caused by T. divaricata flower methanolic extract (TDFME). The extract in the doses of 125, 250 and 500 mg/kg, p.o was subjected to various assays in acetic acid induced abdominal writhing and formalin induced paw licking test models. Naloxone, L-Arginine, Glibenclamide and Glutamate were used as inducers while Morphine, L-NAME, Methylene blue and Aspirin served as standard drugs. The phytochemical analysis led to the isolation of three indole alkaloids namely Voacangine, Catharanthine and O-acetyl Vallesamine. The anti-nociception produced by TDFME was attenuated significantly (p< 0.001) by the intra-peritoneal pretreatment of naloxone, L-Arginine and glibenclamide. The nociception produced by glutamate was inhibited by TDFME. TDFME also enhanced the antinociceptive activity of L-NAME when given in combination. However TDFME co-administration did not produce significant results with methylene blue indicating lack of cGMP involvement. These results indicate that TDFME produces anti-nociception action mediated by opioid, nitric oxide, K+-ATP and glutamate mechanisms and the effect is largely related to the indole alkaloids., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Background: Retinal degeneration is a condition ensued by various ocular disorders such as artery occlusion, diabetic retinopathy, retrolental fibroplasia and retinitis pigmentosa which cause abnormal loss of photoreceptor cells and lead to eventual vision impairment. No efficient treatment has yet been found, however, the use of stem cell therapy such as bone marrow and embryonic stem cells has opened a new treatment modality for retinal degenerative diseases. The major goal of this study is to analyze the potential of endothelial progenitor cells derived from bone marrow to differentiate into retinal neural cells for regenerative medicine purposes., Methods: In this study, endothelial progenitor cells were induced in-vitro with photoreceptor growth factor (taurine) for 21 days. Subsequently, the morphology and gene expression of CRX and RHO of the photoreceptors-induced EPCs were examined through immunostaining assay., Findings: The results indicated that the induced endothelial progenitor cells demonstrated positive gene expression of CRX and RHO. Our findings suggested that EPC cells may have a high advantage in cell replacement therapy for treating eye disease, in addition to other neural diseases, and may be a suitable cell source in regenerative medicine for eye disorders., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Mycobacterium tuberculosis has a remarkable ability of long-term persistence despite vigorous host immunity and prolonged therapy. The bacteria persist in secure niches such as the mesenchymal stem cells in the bone marrow and reactivate the disease, leading to therapeutic failure. Many bacterial cells can remain latent within a diseased tissue so that their genetic material can be incorporated into the genetic material of the host tissue. This incorporated genetic material reproduces in a manner similar to that of cellular DNA. After the cell division, the incorporated gene is reproduced normally and distributed proportionately between the two progeny. This inherent adoption of long-term persistence and incorporating the bacterial genetic material into that of the host tissue remains and is considered imperative for microbial advancement and chemotherapeutic resistance; moreover, new evidence indicates that the bacteria might pass on genetic material to the host DNA sequence. Several studies focused on the survival mechanism of M. tuberculosis in the host immune system with the aim of helping the efforts to discover new drugs and vaccines against tuberculosis. This review explored the mechanisms through which this bacterium affects the expression of human genes. The first part of the review summarizes the current knowledge about the interactions between microbes and host microenvironment, with special reference to the M. tuberculosis neglected persistence in immune cells and stem cells. Then, we focused on how bacteria can affect human genes and their expression. Furthermore, we analyzed the literature base on the process of cell death during tuberculosis infection, giving particular emphasis to gene methylation as an inherited process in the neutralization of possibly injurious gene components in the genome. The final section discusses recent advances related to the M. tuberculosis interaction with host epigenetic circuitry., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Leptospirosis is a widespread zoonotic disease caused by pathogenic Leptospira species (Leptospiraceae). LipL32 is an abundant lipoprotein from the outer membrane proteins (OMPs) group, highly conserved among pathogenic and intermediate Leptospira species. Several studies used LipL32 as a specific gene to identify the presence of leptospires. This research was aimed to study the characteristics of LipL32 protein gene code, to fill the knowledge gap concerning the most appropriate gene that can be used as antigen to detect the Leptospira. Here, we investigated the features of LipL32 in fourteen Leptospira pathogenic strains based on comparative analyses of their primary, secondary structures and 3D modeling using a bioinformatics approach. Furthermore, the physicochemical properties of LipL32 in different strains were studied, shedding light on the identity of signal peptides, as well as on the secondary and tertiary structure of the LipL32 protein, supported by 3D modelling assays. The results showed that the LipL32 gene was present in all the fourteen pathogenic Leptospira strains used in this study, with limited diversity in terms of sequence conservation, hydrophobic group, hydrophilic group and number of turns (random coil). Overall, these results add basic knowledge to the characteristics of LipL32 protein, contributing to the identification of potential antigen candidates in future research, in order to ensure prompt and reliable detection of pathogenic Leptospira species., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Immuno-pathogenesis of leptospirosis can be recounted well by following its trail path from entry to exit, while inducing disastrous damages in various tissues of the host. Dysregulated, inappropriate and excessive immune responses are unanimously blamed in fatal leptospirosis. The inherent abilities of the pathogen and inabilities of the host were debated targeting the severity of the disease. Hemorrhagic manifestation through various mechanisms leading to a fatal end is observed when this disease is unattended. The similar vascular destructions and hemorrhage manifestations are noted in infections with different microbes in endemic areas. The simultaneous infection in a host with more than one pathogen or parasite is referred as the coinfection. Notably, common endemic infections such as leptospirosis, dengue, chikungunya, and malaria, harbor favorable environments to flourish in similar climates, which is aggregated with stagnated water and aggravated with the poor personal and environmental hygiene of the inhabitants. These factors aid the spread of pathogens and parasites to humans and potential vectors, eventually leading to outbreaks of public health relevance. Malaria, dengue and chikungunya need mosquitoes as vectors, in contrast with leptospirosis, which directly invades human, although the environmental bacterial load is maintained through other mammals, such as rodents. The more complicating issue is that infections by different pathogens exhibiting similar symptoms but require different treatment management. The current review explores different pathogens expressing specific surface proteins and their ability to bind with array of host proteins with or without immune response to enter into the host tissues and their ability to evade the host immune responses to invade and their affinity to certain tissues leading to the common squeal of hemorrhage. Furthermore, at the host level, the increased susceptibility and inability of the host to arrest the pathogens' and parasites' spread in different tissues, various cytokines accumulated to eradicate the microorganisms and their cellular interactions, the antibody dependent defense and the susceptibility of individual organs bringing the manifestation of the diseases were explored. Lastly, we provided a discussion on the immune trail path of pathogenesis from entry to exit to narrate the similarities and dissimilarities among various hemorrhagic fevers mentioned above, in order to outline future possibilities of prevention, diagnosis, and treatment of coinfections, with special reference to endemic areas., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Dengue virus (DENV) has emerged as a major economic concern in developing countries, with 2.5 billion people believed to be at risk. Vascular endothelial cells (ECs) lining the circulatory system from heart to end vessels perform crucial functions in the human body, by aiding gas exchange in lungs, gaseous, nutritional and its waste exchange in all tissues, including the blood brain barrier, filtration of fluid in the glomeruli, neutrophil recruitment, hormone trafficking, as well as maintenance of blood vessel tone and hemostasis. These functions can be deregulated during DENV infection. In this study, BALB/c mice infected with DENV serotype 2 were analyzed histologically for changes in major blood vessels in response to DENV infection. In the uninfected mouse model, blood vessels showed normal architecture with intact endothelial monolayer, tunica media, and tunica adventitia. In the infected mouse model, DENV distorted the endothelium lining and disturbed the smooth muscle, elastic laminae and their supporting tissues causing vascular structural disarrangement. This may explain the severe pathological illness in DENV-infected individuals. The overall DENV-induced damages on the endothelial and it's supporting tissues and the dysregulated immune reactions initiated by the host were discussed., (Copyright © 2017. Published by Elsevier B.V.)

Human health risks associated with the consumption of metal-contaminated fish over extended periods have become a concern particularly in Taiwan, where fish is consumed on a large scale. This study applied the interaction-based hazard index (HI) to assess the mixture health risks for fishers and non-fishers who consume the arsenic (As), copper (Cu), and zinc (Zn) contaminated milkfish from As-contaminated coastal areas in Taiwan, taking into account joint toxic actions and potential toxic interactions. We showed that the interactions of As-Zn and Cu-Zn were antagonistic, whereas As-Cu interaction was additive. We found that HI estimates without interactions considered were 1.3-1.6 times higher than interactive HIs. Probability distributions of HI estimates for non-fishers were less than 1, whereas all 97.5%-tile HI estimates for fishers were >1. Analytical results revealed that the level of inorganic As in milkfish was the main contributor to HIs, indicating a health risk posed to consumers of fish farmed in As-contaminated areas. However, we found that Zn supplementation could significantly decrease As-induced risk of hematological effect by activating a Zn-dependent enzyme. In order to improve the accuracy of health risk due to exposure to multiple metals, further toxicological data, regular environmental monitoring, dietary survey, and refinement approaches for interactive risk assessment are warranted.

In this research, we characterized the histopathological impact of dengue virus (serotype DENV-2) infection in livers of BALB/c mice. The mice were infected with different doses of DENV-2 via intraperitoneal injection and liver tissues were processed for histological analyses and variation was documented. In the BALB/c mouse model, typical liver tissues showed regular hepatocyte architecture, with normal endothelial cells surrounding sinusoid capillary. Based on histopathological observations, the liver sections of BALB/c mice infected by DENV-2 exhibited a loss of cell integrity, with a widening of the sinusoidal spaces. There were marked increases in the infiltration of mononuclear cells. The areas of hemorrhage and micro- and macrovesicular steatosis were noted. Necrosis and apoptosis were abundantly present. The hallmark of viral infection, i.e., cytopathic effects, included intracellular edema and vacuole formation, cumulatively led to sinusoidal and lobular collapse in the liver. The histopathological studies on autopsy specimens of fatal human DENV cases are important to shed light on tissue damage for preventive and treatment modalities, in order to manage future DENV infections. In this framework, the method present here on BALB/c mouse model may be used to study not only the effects of infections by other DENV serotypes, but also to investigate the effects of novel drugs, such as recently developed nano-formulations, and the relative recovery ability with intact immune functions of host., (Copyright © 2016 Elsevier Ltd. All rights reserved.)

Melamine contamination of food has become a major food safety issue because of incidents of infant disease caused by exposure to this chemical. This study was aimed at establishing a safety limit in Taiwan for the degree of melamine migration from food containers. Health risk assessment was performed for three exposure groups (preschool children, individuals who dine out, and elderly residents of nursing homes). Selected values of tolerable daily intake (TDI) for melamine were used to calculate the reference migration concentration limit (RMCL) or reference specific migration limit (RSML) for melamine food containers. The only existing values of these limits for international standards today are 1.2 mg/L (0.2 mg/dm 2 ) in China and 30 mg/L (5 mg/dm 2 ) in the European Union. The factors used in the calculations included the specific surface area of food containers, daily food consumption rate, body weight, TDI, and the percentile of the population protected at a given migration concentration limit (MCL). The results indicate that children are indeed at higher risk of melamine exposure at toxic levels than are other groups and that the 95th percentile of MCL (specific surface area = 5) for children aged 1-6 years should be the RMCL (0.07 mg/dm 2 ) for protecting the sensitive and general population., (© 2016 Society for Risk Analysis.)

The purpose of this study was to assess the health risk associated with dietary intake of sulfites for Taiwanese general consumers by conducting a total diet study (TDS). We evaluated the exposure of Taiwanese to sulfites in the diet and its associated health risk. This study used a list of 128 food items representing 83% of the total daily diet. Among the 128 food items, 59 items may contain sulfites. Samples of the 59 food items were collected and subjected to chemical analysis to determine the sulfur dioxide concentration. Health risk was assessed by calculating the ratio of exposure level to the acceptable daily intake (ADI) level of the analyte. For high-intake consumers, the HI of sulfites was 19.7% ADI for males over the age of three years at the 95th percentile; whereas for females over the age of 66, the HI was 17.8% ADI. The HI for high-intake consumers was above 10% ADI. This suggests that regulatory actions must be continued and that consumers should be advised to be aware of processed foods with relatively high contamination to avoid excessive exposure.

The purpose was to assess the health risk to general consumers in Taiwan associated with dietary intake of benzoic acid and sorbic acid by conducting a total diet study (TDS). The hazard index (HI) in percent acceptable daily intake (%ADI) of benzoic acid and sorbic acid for eight exposure groups classified by age were calculated. In high-intake consumers, the highest HI of benzoic acid was 54.1%ADI for males aged 1-2 years old at the 95th percentile, whereas for females, the HI was 61.7%ADI for aged over 66 years old. The highest HI of sorbic acid for male and female consumers aged 3-6 years old at the 95th percentile were 14.0%ADI and 12.2%ADI, respectively. These results indicate that the use of benzoic acid and sorbic acid as preservatives at the current level of use in the Taiwanese diet does not constitute a public health and safety concern.

Geogenic arsenic (As) contamination of groundwater is a major ecological and human health problem in southwestern and northeastern coastal areas of Taiwan. Here, we present a probabilistic framework for assessing the human health risks from consuming raw and cooked fish that were cultured in groundwater As-contaminated ponds in Taiwan by linking a physiologically based pharmacokinetics model and a Weibull dose-response model. Results indicate that As levels in baked, fried, and grilled fish were higher than those of raw fish. Frying resulted in the greatest increase in As concentration, followed by grilling, with baking affecting the As concentration the least. Simulation results show that, following consumption of baked As-contaminated fish, the health risk to humans is <10(-6) excess bladder cancer risk level for lifetime exposure; as the incidence ratios of liver and lung cancers are generally acceptable at risk ranging from 10(-6) to 10(-4), the consumption of baked As-contaminated fish is unlikely to pose a significant risk to human health. However, contaminated fish cooked by frying resulted in significant health risks, showing the highest cumulative incidence ratios of liver cancer. We also show that males have higher cumulative incidence ratio of liver cancer than females. We found that although cooking resulted in an increase for As levels in As-contaminated fish, the risk to human health of consuming baked fish is nevertheless acceptable. We suggest the adoption of baking as a cooking method and warn against frying As-contaminated fish. We conclude that the concentration of contaminants after cooking should be taken into consideration when assessing the risk to human health.

There were many studies that reported the concentrations of trace elements in fish and assessed the human health risk through consumption of contaminated fish. However, fish species with different feeding habits may accumulate toxic elements differentially in their muscle. In this study, we conducted a field survey to analyze concentrations of ten trace elements in water, sediment, artificial feed, and different part of muscles either with or without skin of two species of fish, tilapia and milkfish. The results of this study showed that the ventral and dorsal muscles with skin contained higher concentrations of metals than those without skin for both species of fish. Tilapia lives in the bottom layer, the ventral part therefore contacts closely with sediment. A higher metal concentration in ventral muscle was obtained in this study when compared to dorsal muscle for tilapia. The estimated Metal Pollution Index (MPI) of tilapia is higher than that of milkfish. Our results indicated that metal concentrations in muscle of tilapia are mainly originated from sediment. However, sources of metal concentrations in muscle of milkfish can be from sediment and artificial feed., (Copyright © 2012 Elsevier Inc. All rights reserved.)

In recent years, many engineered nanomaterials (NMs) have been produced, but increasing research has revealed that these may have toxicities far greater than conventional materials and cause significant adverse health effects. At present, there is insufficient data to determine the permissible concentrations of NMs in the workplace. There is also a lack of toxicity data and environmental monitoring results relating to complete health risk assessment. In view of this, we believe that workers in the NMs industry should be provided with simple and practical risk management strategy to ensure occupational health and safety. In this study, we developed a risk management strategy based on the precautionary risk management (PRM). The risk of the engineered NMs manufacturing plants can be divided into three levels based on aspect identification, solubility tests, dermal absorption, and cytotoxic analyses. The risk management strategies include aspects relating to technology control, engineering control, personal protective equipment, and monitoring of the working environment for each level. Here we report the first case in which a simple and practical risk management strategy applying in specific engineered NMs manufacturing plants. We are confident that our risk management strategy can be effectively reduced engineered NM industries risks for workers., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The purpose of this study was to examine tuberculosis (TB) population dynamics and to assess potential infection risk in Taiwan. A well-established mathematical model of TB transmission built on previous models was adopted to study the potential impact of TB transmission. A probabilistic risk model was also developed to estimate site-specific risks of developing disease soon after recent primary infection, exogenous reinfection, or through endogenous reactivation (latently infected TB) among Taiwan regions. Here, we showed that the proportion of endogenous reactivation (53-67%) was larger than that of exogenous reinfection (32-47%). Our simulations showed that as epidemic reaches a steady state, age distribution of cases would finally shift toward older age groups dominated by latently infected TB cases as a result of endogenous reactivation. A comparison of age-weighted TB incidence data with our model simulation output with 95% credible intervals revealed that the predictions were in an apparent agreement with observed data. The median value of overall basic reproduction number (R₀) in eastern Taiwan ranged from 1.65 to 1.72, whereas northern Taiwan had the lowest R₀ estimate of 1.50. We found that total TB incidences in eastern Taiwan had 25-27% probabilities of total proportion of infected population exceeding 90%, whereas there were 36-66% probabilities having exceeded 20% of total proportion of infected population attributed to latently infected TB. We suggested that our Taiwan-based analysis can be extended to the context of developing countries, where TB remains a substantial cause of elderly morbidity and mortality., (© 2012 Society for Risk Analysis.)

The manufacture of large quantities of engineered nanomaterials (NMs) may lead to unintended contamination of aquatic ecosystems. Biologically based monitoring techniques need to be developed to detect these emerging NMs. The purpose of this study was to develop a risk-based probability model to predict the potential hazards of nanoecotoxicity toward aquatic organisms posed by waterborne copper and silver nanoparticles (Cu/Ag NPs). Published experimental evidence based on Cu/Ag NP-zebrafish (Danio rerio) systems was adopted as the study data. A Hill model was used to reconstruct a concentration-mortality response profile. A cumulative Weibull predictive model was employed to estimate exposure thresholds. The derived probabilistic model can predict the potential risk of environmentally relevant Cu/Ag NPs for major Taiwanese rivers with predicted environmental concentrations of 0.06 (95% confidence interval (CI): 0.01-0.92) mgL(-1) for Cu NPs and 0.04 (0.01-0.11) mgL(-1) for Ag NPs. The results indicated that estimated thresholds were 0.10-0.48mgL(-1) (95% CI) for Cu NPs and 2.69-2.73mgL(-1) for Ag NPs. The probabilities of a risk quotient (RQ) of >1 ranged 17%-81% for zebrafish exposed to Cu NPs. This study found that Ag NP exposure scenarios posed no significant risks to zebrafish (RQ≪0.1)., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Background: Variety of environmental and individual factors can cause tuberculosis (TB) incidence change. The purpose of this study was to assess the characteristics of TB trends in the period 2004 - 2008 in Taiwan by month, year, gender, age, temperature, seasonality, and aborigines., Methods: The generalized regression models were used to examine the potential predictors for the monthly TB incidence in regional and national scales., Results: We found that (i) in Taiwan the average TB incidence was 68 per 100,000 population with mortality rate of 0.036 person-1 yr-1, (ii) the highest TB incidence rate was found in eastern Taiwan (116 per 100,000 population) with the largest proportion of TB relapse cases (8.17%), (iii) seasonality, aborigines, gender, and age had a consistent and dominant role in constructing TB incidence patterns in Taiwan, and (iv) gender, time trend, and 2-month lag maximum temperature showed strong association with TB trends in aboriginal subpopulations., Conclusions: The proposed Poisson regression model is capable of forecasting patterns of TB incidence at regional and national scales. This study suggested that assessment of TB trends in eastern Taiwan presents an important opportunity for understanding the time-series dynamics and control of TB infections, given that this is the typical host demography in regions where these infections remain major public health problems.

Background: We linked viral titers and respiratory symptom scores for seasonal influenza to estimate the effective contact rate among schoolchildren., Methods: We analyzed 274 diary-based questionnaires. In addition, 2 sets of influenza data from published studies were used to investigate the relationship between viral titer, total symptom score, and normalized contact rate in children., Results: The mean number (SD) of contacts for children in grades 7 to 9 ranged from 9.44 ± 8.68 to 11.18 ± 7.98 person⁻¹ day⁻¹; contact behavior was similar across school grades. The mean number of contacts was 5.66 ± 6.23 person⁻¹ day⁻¹ (range, 0 to 44 person⁻¹ day⁻¹) for the age group of 13 to 19 years. Estimated contact age, household size, contact duration, and contact frequency were the variables most strongly associated with total number of contacts. We also found that a reduction in total respiratory symptom scores among infected individuals had a positive correlation with an increase in the normalized contact rate., Conclusions: The relationship between daily virus titer and respiratory symptom score can be used to estimate the effective contact rate in explaining the spread of an airborne transmissible disease. The present findings can be incorporated into population-dynamic models of influenza transmission among schoolchildren.

Kinmen is located in the southwest of Mainland China. Groundwater supplies 50% of the domestic water use on the island. Residents of Kinmen drink groundwater over the long term because surface water resources are limited. Nitrate-N pollution is found and distributed primarily in the western part of groundwater aquifer whereas saline groundwater is distributed to the northeastern Kinmen. This work applied the DRASTIC model to construct the vulnerability map of Kinmen groundwater. MT3D was then used to evaluate the contamination potential of nitrate-N. The health risk associated with the ingestion of nitrate-N contaminated groundwater is also assessed. The results from DRASTIC model showed that the upland crop and grass land have high contamination potential, whereas the forest, reservoir and housing land have low contamination potential. The calibrated MT3D model inversely determined the high strength sources (0.09-2.74 kg/m(2)/year) of nitrate contaminant located in the west to the north west area and required 2-5 years travel time to reach the monitoring wells. Simulated results of MT3D also showed that both the continuous and instantaneous contaminant sources of nitrate-N release may cause serious to moderate nitrate contamination in the western Kinmen and jeopardize the domestic use of groundwater. The chronic health hazard quotient (HQ) associated with the potential non-carcinogenic risk of drinking nitrate-N contaminated groundwater showed that the assessed 95th percentile of HQ is 2.74, indicating that exposure to waterborne nitrate poses a potential non-cancer risk to the residents of the island. Corrective measures, including protecting groundwater recharge zones and reducing the number of agricultural and non-agricultural nitrogen sources that enters the aquifer, should be implemented especially in the western part of Kinmen to assure a sustainable use of groundwater resources.

Purpose: This study assessed the potential exposure risks for workers in the workplace exposed to airborne titanium dioxide nanoparticles (TiO(2)-NPs) and carbon black nanoparticles (CB-NPs). The risk management control strategies were also developed for the NP engineering workplace., Methods: The method used in this study was based on the integrated multiple-path particle dosimetry model to estimate the cumulative dose of nanoparticles (NPs) in the human lung. The study then analyzed toxicological effects such as pulmonary cytotoxicity and inflammation and evaluated the health risk associated with exposure to NPs in the workplace. Risk control measures such as the use of ventilating systems and N95 respirator protection are also discussed., Results and Discussion: This study found that: (1) the cumulative dose of CB-NPs was greater than that of TiO(2)-NPs in human lungs; (2) there is a potential health risk to workers exposed to TiO(2)-NPs and CB-NPs in the absence of control measures in the workplace, with higher health risks associated with CB-NPs than TiO(2)-NPs; and (3) the use of a ventilating system and an N95 respirator offers greater protection in the workplace and significantly reduces the health risks associated with NP exposure., Conclusion: The present risk management control strategy suggests that the most effective way to reduce airborne NPs is to incorporate the use of a ventilating system combined with N95 respirator protection. This will enable the concentrations of TiO(2)-NPs and CB-NPs to be reduced to acceptable exposure levels.

Exposures to carcinogenic polycyclic aromatic hydrocarbons (PAHs) have been linked to human lung cancer. The purpose of this study was to assess lung cancer risk caused by inhalation exposure to nano/ultrafine particle-bound PAHs at the population level in Taiwan appraised with recent published data. A human respiratory tract model was linked with a physiologically based pharmacokinetic model to estimate deposition fraction and internal organic-specific PAHs doses. A probabilistic risk assessment framework was developed to estimate potential lung cancer risk. We reanalyzed particle size distribution, total-PAHs, particle-bound benzo(a)pyrene (B[a]P) and PM concentrations. A dose-response profile describing the relationships between external B[a]P concentration and lung cancer risk response was constructed based on population attributable fraction (PAF). We found that 90% probability lung cancer risks ranged from 10(-5) to 10(-4) for traffic-related nano and ultrafine particle-bound PAHs, indicating a potential lung cancer risk. The particle size-specific PAF-based excess annual lung cancer incidence rate due to PAHs exposure was estimated to be less than 1 per 100,000 population, indicating a mild risk factor for lung cancer. We concluded that probabilistic risk assessment linked PAF for limiting cumulative PAHs emissions to reduce lung cancer risk plays a prominent role in future government risk assessment program., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Taiwan is a small island nation, and many aquaculture sites are located near industrial parks. Anthropogenic activities may contaminate fish ponds. Therefore, we investigated the concentrations of eight metal elements in tilapia tissues (muscle and scale) at two fisheries. We compared the difference in metal content in tilapia at these two fisheries with that in non-contaminated fish at the Fisheries Research Institute. Probabilistic risk analysis was carried out to assess the health risk for people who eat contaminated tilapia. The predicted 95th percentiles of the hazard quotient and excess lifetime cancer risk for residents consuming contaminated tilapia were found to be in the range of 3.1-9.2 and 1.03 x 10(-5)-1.85 x 10(-5), respectively.

The purpose of this study was to develop a biologically based risk assessment model for human health through consumption of arsenic (As) contaminated farmed tilapia (Oreochromis mossambicus) from blackfoot disease (BFD)-endemic area in Taiwan for estimating the consumption advice. We linked a physiologically based pharmacokinetic (PBPK) and a pharmacodynamic (PD) model to account for the exposure and dose-response profiles of As in human. Risk analysis indicates that consumption of farmed tilapia poses no significant threat from As-induced lung and bladder cancers. The predicted risk-based median consumption advice was no more than 5-17 meals month(-1) (or 2-6 g day(-1)).

Bisphenol A (BPA) is a weakly estrogenic monomer used to produce polymers for food contact and other applications, so there is potential for oral exposure of humans to trace amounts via ingestion. To date, no physiologically based pharmacokinetic (PBPK) model has been located for BPA in pregnant mice with or without fetuses. An estimate by a mathematical model is essential since information on humans is difficult to obtain experimentally. The PBPK model was constructed based on the pharmacokinetic data of our experiment following single oral administration of BPA to pregnant mice. The risk assessment of bisphenol A (BPA) on the development of human offspring is an important issue. There have been limited data on the exposure level of human fetuses to BPA (e.g. BPA concentration in cord blood) and no information is available on the pharmacokinetics of BPA in humans with or without fetuses. In the present study, we developed a physiologically based pharmacokinetic (PBPK) model describing the pharmacokinetics of BPA in a pregnant mouse with the prospect of future extrapolation to humans. The PBPK model was constructed based on the pharmacokinetic data of an experiment we executed on pregnant mice following single oral administration of BPA. The model could describe the rapid transfer of BPA through the placenta to the fetus and the slow disappearance from fetuses. The simulated time courses after three-time repeated oral administrations of BPA by the constructed model fitted well with the experimental data, and the simulation for the 10 times lower dose was also consistent with the experiment. This suggested that the PBPK model for BPA in pregnant mice was successfully verified and is highly promising for extrapolation to humans who are expected to be exposed more chronically to lower doses.

This paper examines the age-specific human health risks exposed to inorganic arsenic through arsenic-contaminated farmed fish/shrimp and groundwater consumptions in arseniasis-endemic areas of blackfoot disease (BFD)-endemic area and Lanyang Plain in Taiwan, based on an probabilistic integrated risk assessment framework. We employ an age-dependent predictive physiologically-based pharmacokinetic model to account for arsenic concentrations in target organs. We reconstruct age-specific dose-response profiles for arsenicosis and arsenic-induced cancers by best fitting a pharmacodynamics-based three-parameter Hill equation model to published epidemiological data from West Bengal and Taiwan. The predicted median arsenic concentrations in age group-specific skin, lung, and bladder ranged from 2.24-5.70, 3.76-9.46, and 5.11-20.71 micro g g(-1) in BFD-endemic area, whereas 4.98-12.04, 8.23-19.92, and 11.07-43.45 micro g g(-1) in Lanyang Plain, respectively. Risk analysis indicates that consumption of arsenic-contaminated farmed fish/shrimp and groundwater in arseniasis-endemic areas may increase threat to prevalence of arsenicosis for all age groups, whereas adults may undergo potential risks of arsenic-induced skin, lung and bladder cancers. We show that peoples in Lanyang Plain are more readily associated with higher morbidities for arsenicosis and skin cancer as well as fatalities for lung and bladder cancers than that of peoples in BFD-endemic area. Here we report the first case in which theoretical human health risks for consuming As-contaminated farmed fish/shrimp and groundwater in the arseniasis-endemic areas are alarming under a conservative condition based on a probabilistic risk assessment framework.

A biologically based risk-assessment model of arsenic (As) exposure evaluated farmed tilapia (Orechromis mossambicus) and human health during tilapia consumption in an area of southwestern Taiwan where blackfoot disease (BFD) occurs. The risk assessment addressed exposures to city residents who lived in Taipei, Taichung, and Kaohsiung, as well as subsistence fishers living in the BFD area who consumed tilapia. The models implemented included a physiologically based toxicokinetic and toxicodynamic (PBTK/TD) model to account for As exposure and dose-response profiles in tilapia and a human health exposure/risk model that accounts for target lifetime risk (TR) and hazard quotient (HQ) for humans consuming farmed tilapia. Results demonstrated that 90th percentiles of TR ranged from 1.53 x 10(-8) to 1.62 x 10(-6) for city residents with farmed tilapia consumption rates of 0.41 to 1.37 g/d. The 90th percentiles ranged from 2.07 x 10(-6) to 7.89 x 10(-5) for subsistence fishers in the BFD area with farmed tilapia consumption rates of 16.80 to 59.15 g/d. All predicted 90th percentiles of HQ were less than 1 for city residents and subsistence fishers in the BFD area, indicating small contributions from farmed tilapia consumption. Critical variables included whole-fish body weight, water As content, and As level in tilapia muscle. Although bioaccumulation of As seems unlikely to result in toxicity to farmed tilapia and humans consuming tilapia, the theoretical human health risks in the BFD area are alarming, using a probabilistic risk-assessment model based on conservative assumptions.

We appraised organ-specific toxicokinetics and dose responses of arsenic burdens in tilapia Oreochromis mossambicus. We kinetically linked an Area-under-the-curve (AUC)-based acute toxicity model and a pharmacodynamic model to derive dose-response relationships between equilibrium organ-specific arsenic concentrations and mortality effects. The AUC-based acute toxicity model was also used to derive organ-specific internal effect concentration (IEC)-time-response relationships, which can also be applied to predict a time-mortality profile. We conducted a 7-day exposure experiment to obtain toxicokinetic parameters, whereas the AUC-based acute toxicity model was verified with LC50(t) data obtained from a 7-day acute toxicity bioassay. Our results demonstrated that 96-hour LC50 and incipient LC50 for tilapia exposed to arsenic are 28.68 (95% confidence interval to 24.92 to 32.44) and 25.55 mg L(-1), respectively. Dose-response relationships followed the Hill equation, which could be expressed as organ-specific bioconcentration factors and incipient LC50. Organ-specific dose-response relationships showed that muscle, gill, and liver have a relatively steep sigmoid dose-response profile in that IEC50 were 26.6, 62.5, and 78.5 microg g(-1) dry wt (dw), respectively. Organ-specific arsenic internal lethal burdens were the highest in the gill and the lowest in the muscle in waterborne-exposed tilapia. The IEC and target-organ concentrations derived in this study can be used in site-specific risk assessment.

This paper describes a risk assessment approach that integrates predicted tissue concentrations of zinc (Zn) with a concentration-response relationship and leads to predictions of survival risk for pond abalone Haliotis diversicolor supertexta as well as to the uncertainties associated with these predictions. The models implemented include a probabilistic bioaccumulation model, which linking biokinetic and consumer-resource models, accounts for Zn exposure profile and a modified Hill model for reconstructing a dose-response profile for abalone exposed to waterborne Zn. The growth risk is assessed by hazard quotients characterized by measured water level and chronic no-observed effect concentration. Our risk analyses for H. diversicolor supertexta reared near Toucheng, Kouhu, and Anping, respectively, in north, central, and south Taiwan region indicate a relatively low likelihood that survival is being affected by waterborne Zn. Expected risks of mortality for abalone were estimated as 0.46 (Toucheng), 0.36 (Kouhu), and 0.29 (Anping). The predicted 90th-percentiles of hazard quotient for potential growth risk were estimated as 1.94 (Toucheng), 0.47 (Kouhu), and 0.51 (Anping). These findings indicate that waterborne Zn exposure poses no significant risk to pond abalone in Kouhu and Anping, yet a relative high growth risk in Toucheng is alarming. Because of a scarcity of toxicity and exposure data, the probabilistic risk assessment was based on very conservative assumptions.

This paper carries out probabilistic risk analysis methods to quantify arsenic (As) bioaccumulation in cultured fish of tilapia (Orechromis mossambicus) and large-scale mullet (Liza macrolepis) at blackfoot disease (BFD) area in Taiwan and to assess the range of exposures for the people who eat the contaminated fish. The models implemented include a probabilistic bioaccumulation model to account for As accumulation in fish and a human health exposure and risk model that accounts for hazard quotient and lifetime risk for humans consuming contaminated fish. Results demonstrate that the ninety-fifth percentile of hazard quotient for inorganic As ranged from 0.77-2.35 for Taipei city residents with fish consumption rates of 10-70 g/d, whereas it ranged 1.86-6.09 for subsistence fishers in the BFD area with 48-143 g/d, consumption rates. The highest ninety-fifth percentile of potential health risk for inorganic As ranged from 1.92 x 10(-4)-5.25 x 10(-4) for Taipei city residents eating tilapia harvested from Hsuehchia fish farms, with consumption rates of 10-70 g/d, whereas for subsistence fishers it was 7.36 x 10(-4)-1.12 x 10(-3) with 48-143 g/d consumption rates. These findings indicate that As exposure poses risks to residents and subsistence fishers, yet these results occur under highly conservative conditions. We calculate the maximum allowable inorganic As residues associated to a standard unit risk, resulting in the maximum target residues, are 0.0019-0.0175 and 0.0023-0.0053 microg/g dry weight for tilapia and large-scale mullet, respectively, with consumption rates of 70-10 g/d, or 0.0009-0.0029 and 0.0011-0.0013 microg/g dry weight for consumption rates of 169-48 g/d.

Although trisomy 8 is the single most common numerical abnormality in acute myeloid leukemia (AML), relatively few cases with acute lymphoblastic leukemia (ALL) and trisomy 8 have been reported. We report the clinical and laboratory features of seven children with ALL and trisomy 8 as the sole cytogenetic abnormality and review nine similar cases from the literature. Among the children studied by the Pediatric Oncology Group (POG) with newly diagnosed ALL, only 0.3% had trisomy 8 as the sole abnormality. Four of our patients had T-cell ALL and three had early pre-B ALL. Presenting clinical features were typical for the respective immunophenotypes. Six of the seven children achieved complete remission. Our study suggest that trisomy 8 is an infrequent, recurring abnormality among children with ALL, which appears to be associated with a T-cell immunophenotype.