• Nutrition Research and Practice
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• v.15 no.1
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• pp.1-11
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• 2021

BACKGROUND/OBJECTIVES: It is difficult to consistently demonstrate the health effects of soy isoflavones owing to the multitude of factors contributing to their bioavailability. To accurately verify these health effects, dietary isoflavone intake should be measured using a biologically active dose rather than an intake dose. This concept has been expanded to the development of new exposure biomarkers in nutrition research. This review aims to provide an overview of the development of exposure biomarkers and suggest a novel research strategy for identifying the health effects of soy isoflavone intake. MATERIALS/METHODS: We cover recent studies on the health effects of soy isoflavones focusing on isoflavone metabolites as exposure biomarkers. RESULTS: Compared to non-fermented soy foods, fermented soy foods cause an increased concentration of isoflavones in the biofluid immediately following ingestion. The correlation between exposure biomarkers in blood and urine and the food frequency questionnaire was slightly lower than that of corresponding 24-h dietary recalls. Urinary and blood isoflavone levels did not show a consistent association with chronic disease and cancer risk. CONCLUSION: It is crucial to understand the variable bioavailabilities of soy isoflavones, which may affect evaluations of soy isoflavone intake in health and disease. Further studies on the development of valid exposure biomarkers are needed to thoroughly investigate the health effects of isoflavone.

• Journal of Environmental Science International
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• v.14 no.2
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• pp.121-128
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• 2005

Hexachlorobenzene (HCB) was analyzed in various marine organisms of Korea. HCB was detected in all organism samples with residual concentrations from 0.51 to 222 pg/g wet weight. HCB residue was the highest content in crustacean, and followed by bivalves, fish, cephalopods and gastropods. The residues were comparable to or lower than those in marine organisms of other countries. Daily dietary intake of HCB from seafood was estimated to be 13.4 pg/kg body weight/day. The relative contribution of taxonomic group to the total dietary intake of HCB were in the order of crustaceans $(40.1\%)$, bivalves $(34.2\%)$, fish $(23.1\%)$, cephalopods $(2.22\%)$, and gastropods $(0.38\%)$. Daily dietary intake of HCB expressed as toxic equivalent (TEQ) value was estimated to be $1.34\times10^{-3}pg$ TEQ/kg body weight/day. This value did not exceed tolerable daily intake (TDI) proposed by the WHO, the UK toxicity committee and the KFDA. Cancer risk and target hazard quotient (THQ) due to the consumption of the marine organism in Korean adult population were evaluated using the exposure equation of food ingestion. This result suggests that dietary intake of HCB by the consumption of Korean seafood seems to be safe for human health with negligible cancer and non-cancer risks so far.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.2 no.3
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• pp.210-218
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• 2021

Recently, pest-resistant living modified (LM) crops developed using RNA interference (RNAi) technology have been imported into South Korea. However, the potential adverse effects of unintentionally released RNAi-based LM crops on non-target species have not yet been reported. Coccinella septempunctata, which feeds on aphids, is an important natural enemy insect which can be exposed to the double-stranded RNA (dsRNA) produced by RNAi-based LM plants. To assess the risk of ingestion of Snf7 dsRNA by C. septempunctata, we first identified the species through morphological analysis of collected insects. A method for species identification at the gene level was developed using a specific C. septempunctata 12S rRNA. Furthermore, an experimental model was devised to assess the risk of Snf7 dsRNA ingestion in C. septempunctata. Snf7 dsRNA was mass-purified using an effective dsRNA synthesis method and its presence in C. septempunctata was confirmed after treatment with purified Snf7 dsRNA. Finally, the survival rate, development time, and dry weight of Snf7 dsRNA-treated C. septempunctata were compared with those of GFP and vATPase A dsRNA control treatments, and no risk was found. This study illustrates an effective Snf7 dsRNA synthesis method, as well as a high-concentration domestic insect risk assessment method which uses dsRNA to assess the risk of unintentional released of LM organisms against non-target species.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.4
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• pp.21-29
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• 2015

Safety of reclaimed wastewater irrigation needs to be evaluated to promote public health. Quantitative microbial and toxic risk assessment was conducted to identify the level of risk for farmland workers who use reclaimed wastewater and groundwater in Jeju island. Microbial risk through inhalation and ingestion exposure was below acceptable level (less than $10^{-3}$) of $7.07{\times}10^{-6}$ for reclaimed wastewater and $9.99{\times}10^{-8}$ for groundwater irrigation worker. Aggregate exposure risk of Ni, As and Cu was most contributable to overall risk in both reclaimed wastewater and groundwater irrigation plot. High cumulative exposure risk was estimated through non-dietary soil ingestion and dermal contact of soil, due to the high concentration of As, Cu and Ni in farmland soil. Overall toxic risk was $2.68{\times}10^{-4}$ for reclaimed water and $2.39{\times}10^{-4}$ for groundwater irrigation, which could not meet acceptable toxic risk level of $10^{-6}$. Further efforts, such as provide personal protective equipments or public health education, need to be implicated to reduce adverse health risk.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.17-26
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• 2014

Background: Despite children's unique characteristics that distinguish them from adults, relatively few attempts have been made to measure exposure factors for characterization of children's exposure to hazardous chemicals in child-specific products (CSP). This study was conducted to establish the child-specific exposure factors for exposure and risk assessment of hazardous substances in CSP. Methods: We investigated the exposure factors (e.g., time use of child-products, time and frequency of object-to-body contact, time and frequency of object-to-mouth contact) influencing children's exposure to CSP (e.g., toys, playmats, oil pastels, etc.) in 650 children through a parent-completed questionnaire using a web-based survey. Participants were recruited in five age groups, <1, 1-2, 2-3, 3-6, and 6-12 years of age. Results: The child-specific exposure factors were presented as the mean, median, $95^{th}$ percentile, minimum, and maximum values. Time activity for play mats was the longest among CSP and infants spent more time on them than did elder age groups (189.3-224.7 min/day for <1-2 years vs. 91.2 min/day for 6-12 years). It is apparent that time and frequency of toy block- and plastic toy-to-mouth contact significantly decreased as a function of age. When the variation of CSP use patterns was compared by gender, the only variable that was statistically different between genders was time activity in child-products exposure space. Conclusion: We believe the five child-specific exposure factors suggested in the present study will be valuable for reducing uncertainty in the estimation of chemical exposure during risk assessment of CSP and furthermore, in the appropriate regulations to protect children's health.

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.11
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• pp.1436-1444
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• 2010

The objectives of this study were to determine the highest inclusion of licury (Syagrus coronate) cake in the diet of growing Boer goats without adverse effects on intake and digestibility and to determine its effects on ingestive behavior and physiological responses. Twenty entire, one year old 3/4 Boer goats, 18.1 kg (DS = 2.2) average body weight (BW), were allocated to dietary treatments in a completely randomized design. Each animal was confined in a $1.0\;m^2$ pen with a suspended floor and given ad libitum access to clean, fresh water. Diets were formulated to meet NRC (2007) requirements and the ingredients were: 50% of Tifton-85 (Cynodon sp.) hay, corn meal, soybean meal, mineral and vitamin premix, and licury cake. The treatments were: i) no addition of licury cake to the diet, ii) 15% (DM basis) addition of licury cake, iii) 30% licury cake and, iv) 45% licury cake. The experiment lasted for 17 days; the first 10 days were used to adapt the animals to the diets and facilities. The inclusion of licury cake increased the fiber concentration of the diets; however, there was no effect on either dry matter (DM) or organic matter (OM) intake. There was a linear increase (p<0.05) in the EE content of the diet as the addition of licury cake increased; however, EE intake did not differ (p>0.05) between treatments. The digestibility of non-fibrous carbohydrates (NFC) decreased with increasing inclusion of licury cake, as did NFC intake. The efficiency of ingestion of DM and NDF presented a negative quadratic effect with the inclusion of licury cake. Results from this study indicate that licury cake can be fed to goats at up to 45% of the diet without adverse effects on either intake or digestibility.

• Journal of the Korea Society of Computer and Information
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• v.23 no.6
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• pp.51-58
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• 2018

This study was conducted to investigate the relationship between drinking, smoking, meat intake, and exercise. The participants were 1,060 males and females who voluntarily responded to the survey by visiting the health promotion booth at the H Festival held in C city in 2014. Research data were collected in interview form using questionnaires on alcohol use, smoking, exercise, and meat intake. The data were analyzed by descriptive analysis, cross tabulation analysis, multinominal logistic regression after stratification of gender using the SPSS 24 program. The results of the study are as follows: Smokers had a significantly higher frequency of drinking ($x^2=163.33$, p<.001) than non-smokers. Meat intake was high when alcohol use was high ($x^2=35.13$, p<.001). The risk rates for smoking, meat consumption, and exercise related to alcohol use are as follows. The smoking was higher as the frequency of drinking increased. For men, smoking OR(odd ratio) was 6.26 (p=.001) and for women, smoking risk OR was 16.82 (p=.002). Meats intake showed a higher OR as the alcohol use increased. The OR of almost daily ingestion of meat at frequent drinking days was 4.40 (p=.002) for males and 4.52(p=.009) for females. As the frequency of drinking increased, the OR of days of exercise tended to decrease. In men, the OR was 0.36 (p=.003), the lowest in the probability of exercising more than 5 days when drinking high. In the case of women drinking less than once a week, the OR was 0.43 (p=.027), which was the lowest for exercise for 5 days or more. In conclusion, the higher the frequency of drinking, the higher the smoking and meat intake, and the less exercise. If drinking, smoking, and meat intake are high but there is a lack of exercise, a chronic disease can occur and cause premature death unless there is a change in the new health behavior. The results of this study suggest researches to understand the motives related to alcohol abstinence, smoking cessation, dietary control and exercise, and to develop programs.

• Journal of Environmental Health Sciences
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• v.43 no.5
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• pp.438-445
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• 2017

Objectives: The purpose of this study was to develop exposure factor data for the Korean child population, with a specific focus on behavior characteristics such as hand-to-mouth and object-to-mouth and an analysis of influential factors. Methods: We divided environments into two places, which were house/indoor and nursery. A total of 400 children (house/indoor) and a total of 162 children (nursery) were recruited from the cities of Seoul, Incheon, Daegu, and Gwangju. The children were divided into two groups. We conducted direct measurement by using one hour of videotaping alongside questionnaire surveys. This was performed to calculate behavior rates, such as how many children perform hand-to-mouth and object-to-mouth behaviors. Results: The respective average frequencies of hand-to-mouth and object-to-mouth were $0.8{\pm}2.23$ and $0.82{\pm}2.64contacts/hr$ for house/indoor. The respective average frequencies of hand-to-mouth and object-to-mouth were $2.87{\pm}4.63$ and $1.47{\pm}3.84contacts/hr$ in the nursery group. For the mouthing participants, the average frequencies of hand-to-mouth and object-to-mouth were 3.31 and 3.20 contacts/hr in house, and 4.80 and 3.26 in nursery. Compared to other countries such as the USA, the frequencies of hand-to-mouth and object-to-mouth behaviors found in this study were relatively lower. Conclusions: Children have the potential for exposure to toxic substances through non-dietary ingestion pathways by mouthing objects or their fingers. In this study, the mouthing frequency was relatively lower than that found in Western countries. This can be explained that mouthing behaviour may be affected by culture and lifestyle characteristics.

• Journal of Food Hygiene and Safety
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• v.35 no.6
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• pp.587-601
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• 2020

Exposure to hazardous substances occurs through multiple pathways. Aggregated risk assessment, which includes all potential exposure pathways to a single toxicant, is necessary to prevent exposure to harmful substances. We aimed to estimate cadmium and lead exposure through various media, such as food, water, air, smoking, cosmetics, and female hygiene products. This study covered 10,733 subjects from the Seventh Korea National Health and Nutrition Examination Survey(2016, 2017). Dietary exposure was estimated using 24-hour recall data. For water and inhalational exposure, regional variations were considered. Water was classified as tap, bottled, and public water. Inhalational exposure was estimated using the '2014 Time Use Survey' based on daily lifestyle and social status. The frequency and volume of cosmetic usage were randomly approximated by sex and age. Post-menarcheal and premenopausal women were assumed to use feminine hygiene products. Non-carcinogenic aggregated risks were estimated using the Aggregate Risk Index from EPAs and the Total Exposure Hazard Index from Korean government guidelines. For carcinogenic risk assessment, excessive cancer risk was estimated. Ingestion, especially food, was the major route for both cadmium and lead exposure. Smoking was also associated with high cadmium exposure. Exposure to lead from cosmetics was remarkable but not critical. In aggregate risk assessments, median cadmium and lead exposure did not exceed the reference value. Sex, age, smoking status, and income affected exposure levels, unlike to regional variations.