Captive breeding and reintroduction are crucial strategies for conserving endangered species populations. However, fish raised in predator-free environments, show a lack of recognition of predationrelated stimuli such as chemical and visual signals. It is critical to recognize chemical signals from injured conspecifics, also known as alarm signals, and the order or shape of predators to indicate the spread of predation risk in the habitat. We conducted a laboratory experiment to determine and adjust the optimal exposure period to induce appropriate anti-predator behavior response to different types of stimuli (Chemical, Visual and Chemical+Visual) for the endangered species Microphysogobio rapidus. Our results demonstrate that predator avoidance behavior varies depending on the types of stimuli and the duration of predation risk exposure. First, the results showed captive-breed M. rapidus show lack of response against conspecific alarm signal (Chemical cue) before the predation risk exposure period and tend to increase response over predation risk exposure time. Second, response to predator (visual cue) tend to peak at 48 hours cumulative exposure, but show dramatic decrease after 72 hours cumulative exposure. Finally, response to the mixed cue (Chemical+visual) tend to peak prior to the predation risk exposure period and show reduced response during subsequent exposure periods. This experiment confirms the lack of responsiveness to conspecific alarm signals in captive-bred M. rapidus and the need for an optimal nature behavior enhancement program prior to release of endangered species. Furthermore, responsiveness to predator visual signal peak at 48 hours cumulative exposure, suggest an optimal predation risk exposure period of up to 48 hours. Key words: predator cognition, captive breeding, chemical signal, visual signal, endangered

Vulnerable populations in healthcare facilities are more sensitive to exposure to indoor air pollutants, and therefore are more affected by such pollutants than the general population. This was the underlying reason why studies of indoor air pollutant concentration distribution and health risk assessment have been conducted targeting facilities, such as daycare centers, medical facilities, elderly care facilities, and postnatal care centers. However, previous studies have mainly focused on daycare and medical facilities for their research, and relatively speaking, studies conducted on the other venues are lacking. Therefore, this study aims to present the current status of indoor air quality and perform a health risk assessment in regard to Formaldehyde exposure at postnatal care centers and elderly care facilities. Here, the study focused on facilities that had undergone pollution level inspections from January 2017 to December 2021. A total of 81 postnatal care centers and 48 elderly care facilities were selected as the subject of the study. Then, the study utilized concentrations of five elements (CO2, HCHO, PM10, PM2.5, TBC) to determine the status of indoor air quality of both postnatal care centers and elderly care facilities. For health risk assessment, HCHO concentration was used. The investigation demonstrated that the yearly average concentration of the five elements stood within the indoor air quality maintenance standards, and the ratio of PM2.5 to PM10 in the two types of facilities was distributed as high as about 70%. In addition, the study showed that HCHO and TBC demonstrated a positive correlation when the relationship between indoor temperature and humidity with the five elements was examined. The health risk assessment showed that the cancer risk level of postnatal care center users stood below 10-6, below the level that is perceived as an acceptable risk. The cancer risk of workers from both postnatal care centers and elderly care facilities and elderly care facility users exceeded the acceptable risk level of 10-6, but was shown to be below 10-4, the maximum acceptable risk.

국내외적으로 유해물질의 통합 노출에 대한 관심은 높아지고 있다. 이러한 흐름에 따라 다양한 경로를 통해 노출될 수 있는 중금속에 대한 통합 노출 연구가 필요하다. 카드뮴과 납은 각각 신장 독성과 인지 장애 등 다양한 독성을 나타낼 수 있으며 또한 발암 물질로 알려져있다. 따라서 본 연구에서는 카드뮴과 납의 노출량 추정 및 통합 위해성 평가를 진행하였다. 2016, 2017년의 7기 국민건강 영양조사에 참여한 10,733명의 식품, 물, 흡연과 간접흡연, 호흡, 화장품, 여성용 위생용품을 통한 중금속 노출 추정량을 계산하였다. 결과적으로 카드뮴과 납 모두 식품을 통한 노출이 제일 높게 나타났다. 이외에도 흡연은 카드뮴의 주요한 노출원이었으며, 납은 화장품을 통해 높은 농도로 노출되었다. 통합 위해평가에서도 식품이 가장 큰 영향을 미쳤다. 지역적 특성의 차이는 노출 추정량의 차이를 보이지 못하였으나, 연령 별, 성별 간 노출 추정량은 큰 차이를 보였다. 특히, 월경 중인 성인 여성의 경우 카드뮴, 월경 중이지 않은 여성은 납의 노출 추정량이 더 높으며 신체 대사를 고려하였을 때, 그 위험성이 더 클 수 있음을 암시하였다. 결론적으로 노출량 추정 및 통합 위해평가 모두 식품이 주요 노출원이었다. 다만, 잠재적 위험을 방지하기 위해 다른 경로에 대한 노출량 추정 및 위해평가가 요구된다.

In the manufacturing industry, sparks occur during operation due to collisions of metals, and strong sparks and arcs are generated even during welding works. X-rays are generated when high-speed electrons from outside collide with electrons in a metal. Thus, the objective of this study proposes the risk of sparks and arcs that can generate X-rays. We developed the spark generator using the electrostatic principle and constructed the arc generating device using the high voltage. The X-rays are measured when sparks and arcs are continuously generated between the anode metal target and the cathode metal. The measured X-rays were found to be harmful to humans when exposed for a long period. Therefore, workers exposed to workplaces with frequent sparks and arcs need to protect themselves.

In this study, 40 residents of the Gwangyang and Yeosu areas were assessed for their level of exposure to heavy metals (As, Cd, Ni) from April 2017 to June 2018. The aim was to understand the differences in levels of indoor exposure to heavy metals (As, Cd, Ni), and a health risk assessment was conducted to determine whether there was any fatal cause from carcinogenic elements. The mean concentrations of PM10 particles indoors were As 0.24 μg/m3, Cd 0.07 μg/m3, and Ni 0.89 μg/m3. The health risk assessment for the arsenic, cadmium, and nickel in indoor air confirmed that the mean values exceeded the cancer risk tolerances specified by the U.S. EPA, for As (males 3.07 × 10−4, females 3.35 × 10−4), Cd (males 3.83 × 10−5, females 4.18 × 10−5), and Ni (males 6.36 × 10−5, females 6.95 × 10−5).

도시림, 생활림, 가로수, 도시공원 등 국민들의 일상생활을 하는 구역이나 장소에 위치한 생활권 수목 식재지에서의 농약 살포는 농약 살포자의 농약 노출 문제뿐만 아니라 농약의 살포 후 생활권 수목과 접촉하는 불특정 시민들도 지속적인 농약 노출이 문제가 될 수 있다. 본 연구에서는 생활권 수목의 관리를 위해 관행적으로 가장 많이 사용 살포되는 살충제인 Fenitrothion을 회양목에 살포하고 일정시간별로 손 노출량, 잎 잔류량, 호흡 노출량을 측정 한 뒤, 위해성 평가 수식(MOS; margin of safety)을 이용하여 체중별 안전 노출시간을 분석하였다. 그 결과, 살포된 Fenitrothion의 손을 통한 전이량이 급격하게 떨어지고 호흡노출량이 측정되지 않는 48시간 이전 까지는 농약노출에 대한 주의가 필요할 것으로 판단되었다.

This study measured and analyzed the heavy metal (Cd, As) content of fine dust in the city of Gwangyang, Jeonnam from September 19 to September 22, 2016. For cadmium, the arithmetic average was 0.21 ng/m3 (0.12~0.49 ng/ m3), which did not exceed the WHO's recommended level. The average of arsenic was 2.41 ng/m3 (0.30~142.08 ng/ m3) and the geometric mean was 11.18 ng/m3, which exceeded the WHO's recommended standard in 16 out of 24 measurements. In the case of cadmium, the CTE of male was 9.22 × 10−8 RME 1.91 × 10−7 and the female CTE was 9.44 × 10−8 RME 1.92 × 10−7, which did not exceed the EPA limit of CTE 2.18 × 10−5 RME 1.51 × 10−4 for men and CTE 2.23 × 10−5 RME 1.51 × 10−4 For women, CTE 2.23 × 10−5 RME 1.51 × 10−4 results were obtained, which exceeded the EPA's recommended limit and also exceeded the maximum allowable limit of 10-4.

This study was conducted to compare the value of the working environment measurement with the expected exposure value drawn by using a program, thereby going to investigate whether it is available to the risk assessment of domestic workplace. We used the ECETOC TRA program which is one of the exposure predictive models. Four kinds of substances were measured in two workplace which was exposed to organic solvents and one kind of substance was measured in three workplace which was exposed to dusts and then an exposure assessment of chemical risk factors was conducted. The result value of the working environment measurement, solid substance exceeded standard in one site, and it was found that the other solid and liquid substances were within the standard. The value of the exposure assessment program showd the same result; it was higher than the value of the working environment measurement, suggesting that due to its nature, the exposure assessment program is run only on the worst situation. Therefore, it was found that when the exposure assesment program is used, variables should be substituted only after accurately assessing the workplace and it is a good idea to assess the risk beforehand with the exposure assessment program in the case of the workplace which employs no more than 5 people and where it is hard to assess the working environment.

The objective of the present study was to estimate the health risk level for children exposed to phthalate and identify the pathways including indoor floor dust, surface wipe and hand wipe in elementary-schools and institutes. The samples of indoor place were collected at children's facilities (50 elementary-schools and 46 academies) in summer (Aug ~ Sept, 2008), winter (Dec 2008 ~ Feb, 2009) and Spring (Mar ~ Apr, 2009) periods. Hazard Index (HI) were estimated for the non-carcinogens and the examined phthalate were diethylhexyl phthalate (DEHP), dibutyl-n-butyl phthalate (DnBP), butylbenzyl phthalate (BBzP). Risk analysis indicates that did not exceed 0.01 (HI) for all subjects in all facilities it's 50^th % and 95^th % value. For DEHP, DnBP and BBzP their detection rates through multi-pathways were high and their risk based on health risk assessment was also observed to be acceptable.

The aim of this study was to calculate the health risks which children were exposed to trace metals through several pathways including air, floor dust, wipe and hand wipes in elementary-schools and academies. The samples were collected at children's facilities (50 elementary-schools and 46 academies) in summer (Aug ~ Sept, 2008), winter (Dec 2008 ~ Feb, 2009) and Spring (Mar ~ Apr, 2009) periods. The lifetime Excess Cancer Risks (ECRs) were estimated for carcinogen trace elements such as As, Cd, and Cr. For carcinogens, the Excess Cancer Risk (ECR) was calculated by considering the process of deciding Cancer Potency Factor (CPF) and Age Dependent Adjust Factor (ADAF) of the data of adults. Hazard Quotients (HQs) were estimated for the non-carcinogens trace metals like Cd, Cr, Hg and Pb. The average ECRs for young children were 1×10^-9~1×10^-8 (50%th percentile) level in all facilities. Non-carcinogens did not exceed 0.1 for all subjects in all facilities. For trace metals their risk based on health risk assessment was also observed to be acceptable.

The purpose of this study was to investigate the health risk and management of childhood exposure to indoor aldehydes in elementary-schools and academies. The samples were collected at children's facilities (50 elementary-schools and 46 academies) in summer (Aug ~ Sept, 2008), winter (Dec 2008 ~ Feb, 2009) and Spring (Mar ~ Apr, 2009) periods. The overall mean concentration of formaldehyde was 68.3 ㎍ /m³ and 27.2% of exceeded the 100 ㎍/m³ by the school health guideline. The concentration ratio of Indoor air and outdoor air (I/O) of aldehydes exceeds 1.0. The level of indoor air contamination did appear to be high, and 24.6% of the academies evaluated had exceeded the formaldehyde level specified by the public health act (120㎍ /m³). We estimated the lifetime excess cancer risks (ECRs) of formaldehyde, and the hazard quotients (HQs) of non-carcinogens (acetaldehyde and benzaldehyde). In addition, for carcinogens, the excess cancer risk (ECR) was calculated by considering the process of deciding cancer potency factor (CPF) and age dependent adjust Factor (ADAF) of the data of adults. The average ECRs of formaldehyde for young children were 1×10^-6~1×10^-5 level in all facilities. HQs of formaldehyde did exceed 0.1 for all subjects in elementary school.

This study assessed the health risk of trace elements in indoor children-facilities by multi-pathway measurements (Air, Dust, Wipe, Hand washing). The samples of indoor place were collected at various children's facilities (40 day-care houses, 42 child-care centers, 44 kindergartens, and 42 indoor playgrounds) in summer (Jul~Sep, 2007) and winter (Jan~Feb, 2008) periods, and analyzed by ICP-MS. The lifetime Excess Cancer Risks (ECRs) were estimated for carcinogen trace elements such as As, Cd, Cr and Ni. For carcinogens, the Excess Cancer Risk (ECR) was calculated by considering the process of deciding Cancer Potency Factor (CPF) and Age Dependent Adjust Factor (ADAF) of the data of adults. Both Hazard Quotients (HQs) and Hazard Index (HI) were estimated for the non-carcinogens and children sensitivity trace elements like Cd, Cu, and Cr. The average ECRs for young children were 1×10^-10~1×10^-6 (50%th percentile) level in all facilities. Non-carcinogens and Children's sensitivity materials did not exceed 1.0 (HQs, HI) for all subjects in all facilities. For trace elements their detection rates through multi-pathways were not high and their risk based on health risk assessment was also observed to be acceptable. In addition, through education on the risk of multi-pathway exposure of trace elements for managers of facilities as well as for users the risk control of exposure of children.

Domestic studies for identification of causality between children exposure to toxic chemicals, such as arsenic (As) and resulted hazardous effects were not implemented. This study was conducted to probabilistically estimate dietary As intake and health risk assessment for young children and all age-specific populations from the consumption of As-contaminated rice of Korea. Arsenic intakes for young children (1 to 6 years old) from As-contaminated rice were higher than other age-specific groups, based on a dose-per-body weight basis. Based on the current EPA cancer slope factor for As, estimated cancer risks (to the skin cancer) associated with dietary intake of As-contaminated rice for 1 to 2 years old group and 3 to years old group are 1.76 per 10,000 and 3.16 per 10,000, respectively, at the 50th percentile. Based on possible reference levels (0.005 mg/kg/day) for children, mean and 95th percentile value of HQ from rice for young children are very below 1.0, which is a regulatory limit of non-carcinogenic risks for human.

This study was performed to investigate the concentration of indoor aldehydes in children’s facilities. The samples were collected from various children's facilities (40 playrooms, 42 day-care centers, 44 kindergartens, and 42 indoor playgrounds) in summer (Jul~Sep, 2007), winter (Jan~Feb, 2008) and spring (Mar~Apr, 2008). The ratio of Indoor and outdoor (I/O) of aldehydes exceeds 1.0 and the formaldehyde levels in each child-care facilities were significantly different. We evaluated the lifetime cancer and non-cancer risk of young children due to indoor aldehyde exposure. We estimated the lifetime excess cancer risks (ECRs) of formaldehyde, acetaldehyde and the hazard quotients (HQs) of non-carcinogens (benzaldehyde and formaldehyde). Formaldehyde was evaluated for both carcinogenic and non-carcinogenic risk. The average ECRs of formaldehyde for young children were 1×10^-4~1×10^-5 level in all facilities. HQs of four non-carcinogens did not exceed 1.0 for all subjects in all facilities.

In this paper the lifetime risk assessment of exposure to airborne volatile organic compounds (VOCs) in environmental atmosphere was carried out in one of the Korean industrial city, Gumi based on their measurements of VOCs at five representative outdoor monitoring sites. According to this study toluene, trichloroethylene, and dichloromethane are three main VOCs in Gumi. The carcinogenic risks 5the carcinogenic VOC are greater than the benchmark concentration (1.0E-6) in all five designated sites. Particularly, the Lifetime Cancer Risk in industrial complex 1 and 2 reached 9.64E-5 and 1.32E-4, respectively, both of which are far higher than the benchmark risks. The components of predominant risk in industrial areas are found as chloroform, benzene and trichloroethylene, while those of other sites are benzene and chloroform. It was estimated that the contributions of those componentsto cancer risk are not less than 90%. For non carcinogenic VOCs, the total hazard indices in 5 monitored sites are less than 1. The hazard index in industry complex No. 2 recorded the highest among 5 sites up to 0.663 due to the dominant contribution of 1, 2-dichloropropane by up to 50% (0.335). Based on this analysis, effective emission reduction for chloroform, benzene, trichloroethylene, and 1,2-dichloropropane will rapidly I the cancer risks and hazard indices in Gumi.

The aim of this study was to determine exposure assessment of pathogenic bacteria in edible ices by using the monitoring data from the previous study. According to the results of exposure assessment of edible ices contaminated with S. aureus, the contamination level of S. aureus in raw materials was higher than other foodborne pathogens, and the contamination level of S. aureus in mixed samples increased much before sterilization. The most significant reduction in contamination level was observed in mixed samples after sterilization, thus, the contamination levels in frozen final products was less than that of raw materials. Overall, the possibility for the infection of foodborne bacteria from the intake of edible ices per person per day was ranged from minimum 5.89 × 10-7 to maximum 5.01 × 10-5. For more realistic estimates, consumption of edible ices and dose-response model must be studied further.

This study performed and re-analysed the articles of exposure assessment for the indoor environment of houses in many environment-related journals published. in Korea since 1990. Based on this comparative study, we estimated the unit health risk on indoor environment. The objective of this study was to offer scientific data for decision-making policy for improvement and management of indoor air quality on Korean house in. The pooled concentrations for the critical air pollutants in the house were 13.93±13.91㎍/m3 (PM10), 680±226 ppm for (CO2), 1.9±1.6 ppm (CO), 419±158 CFU/m3 (bacteria), 0.036 ± 0.002 ppm (NO2), and 104.935 ± 16.424 Bq/m3 (Rn), The pooled concentrations for the volatile organic compounds were 6.9±6.7㎍ /m3 (benzene), 39.3±55.1㎍/m3 (toluene), 4.2±4.0㎍/m3 (ethylbenzene), 11.4±8.3㎍/m3 (m, p-xylene), 4.2 ±1.5㎍/m3 (styrene) and 6.3±4.5㎍/m3 (o-xylene). The unit cancer risk for men and women by inhalation of benzene was 3.7 × 10-5 and 4.8 × 10-6, respectively. In additio

Indoor air quality tends to be the dominant contributor to personal exposure, because most people spend over 80% of their time indoors. In this study, indoor and outdoor NO2 concentrations were measured simultaneously with personal exposures of 30 university students in weekday and weekend in Daegu, Korea. House characteristics and subject's activity pattern were used to determine the effects on personal exposure. Since university students spent most of their times indoor, their NO2 exposure was associated with indoor NO2 level during both weekday and weekend in spite of different time activity. Using a time-weighted average model, NO2 exposures of university students were estimated by NO2 measurements in indoor home, indoor school, and outdoor home. In conclusion, major personal exposure to NO2 resulted from air quality of indoor environment at house.