Potential health risks to disinfection workers from exposure to active substances in COVID-19 biocidal products.

The importance of disinfection has recently been emphasized due to the increasing risk of the spread of infections such as coronavirus disease-2019 (COVID-19). In addition, disinfection for preventing the spread of COVID-19 is highly recommended. The increased use of biocidal products raises concerns regarding the potential health risks from exposure among disinfection workers. This study aimed to assess these exposure and health risks using questionnaires targeting disinfection workers who were exposed to the active substances in biocidal products used for disinfection during the COVID-19 pandemic. A follow-up survey was conducted among 271 disinfection workers for 10 working days within two weeks, and exposure factors with reference to disinfection were evaluated through interview-administered questionnaires. An exposure algorithm was used to evaluate the exposure of disinfection workers during disinfection. The hazard index (HI) was calculated by dividing the inhalation concentration obtained using the exposure algorithm and the dermal dose according to occupational exposure limits (OEL). A sensitivity analysis was conducted to identify the exposure factors with the greatest impact on the inhalation and dermal exposure algorithms. A logistic regression analysis was performed to verify the relationship with health effects and sociodemographic and exposure characteristics. The average number of disinfections performed during 10 working days was 17.5 ± 12.3 times. The type of disinfection work was divided into 2806 cases of COVID-19 prevention and disinfection and 1956 cases of regular pesticide application to prevent and remove any pests. The HI was ≥1, indicating a potential health risk, with the use of ethanol (6.50E+00), quaternary ammonium compounds (QACs; 1.49E+01), and benzalkonium chloride (BKC; 1.73E+00). Dermal exposure was more hazardous than inhalation exposure for 6 of the 11 active substances in biocidal products. The weight fraction and exposure time were the factors that most significantly influenced the inhalation and dermal exposure algorithms in the sensitivity analysis. Higher exposure concentrations were more likely to affect health (AOR: 3.239, 95% CI: 1.155-9.082). This study provides valuable information regarding the exposure and risk of disinfection workers to 11 biocidal active substances included in common disinfectants. Our results suggest that the use of ethanol, BKC, and QACs has potential health risks to disinfection workers, with a higher possibility of negative health impacts with increasing exposure concentration.

Exposures to humidifier disinfectant and various health conditions in Korean based on personal exposure assessment data of claimants for compensation.

BACKGROUND: Humidifier disinfectants (HDs) were commonly used household chemicals to prevent microbial growth in a humidifier water tank in South Korea. A growing body of evidence has indicated that its airborne exposure can induce severe lung injury. However, there has been low awareness of other health outcomes in HD users. This study aimed to evaluate health conditions appealed by claimants for compensation in relation with an increased exposure to HD. METHODS: From survey data of personal HD exposure assessment of claimants for compensation in Korea, we included a total of 4,179 subjects [cases in each dataset were defined by nine reported health conditions, i.e., pneumonia, asthma, cardiovascular disease, respiratory disease, otorhinolaryngologic disease, brain disease (including cerebrovascular disease), dermatological disease, lung cancer, and all cancers]. HD exposures was considered as the following exposure criteria: exposure duration, exposure proximity, exposure direction, chemical type, cumulative exposure time, indoor air concentration, and cumulative exposure level. Logistic regression models were used to evaluate the associations between HD exposure and health conditions. RESULTS: After adjusting for sociodemographic and health behavioral factors and other chemical exposures (households, environmental, and occupational exposures), an increase in cumulative HD exposure time was significantly associated with risks of all nine diseases (all p-trends < 0.05). An increase in HD exposure duration was associated with asthma, respiratory disease, otorhinolaryngologic disease, dermatological disease, all cancers, and lung cancer (p-trends < 0.05). Indoor HD concentration was associated with only pneumonia (p-trend = 0.015). CONCLUSIONS: Our findings suggest that cumulative exposures to airborne HD might potentially increase the risk of various reported health outcomes.

Proposal of a Methodology for Prediction of Indoor PM2.5 Concentration Using Sensor-Based Residential Environments Monitoring Data and Time-Divided Multiple Linear Regression Model.

This study aims to propose an indoor air quality prediction method that can be easily utilized and reflects temporal characteristics using indoor and outdoor input data measured near the indoor target point as input to calculate indoor PM2.5 concentration through a multiple linear regression model. The atmospheric conditions and air pollution detected in one-minute intervals using sensor-based monitoring equipment (Dust Mon, Sentry Co Ltd., Seoul, Korea) inside and outside houses from May 2019 to April 2021 were used to develop the prediction model. By dividing the multiple linear regression model into one-hour increments, we attempted to overcome the limitation of not representing the multiple linear regression model's characteristics over time and limited input variables. The multiple linear regression (MLR) model classified by time unit showed an improvement in explanatory power by up to 9% compared to the existing model, and some hourly models had an explanatory power of 0.30. These results indicated that the model needs to be subdivided by time period to more accurately predict indoor PM2.5 concentrations.

Effect of PM concentration on anemia blood indicators reduced by air purifiers.

Housewives perform daily household chores, which directly expose them to indoor particulate matter (PM). Indoor PM exposure is a potential factor that increases systemic inflammation and affects hematopoietic action. This study investigated the decrease in indoor PM concentration by air purifiers on indicators of anemia, such as hemoglobin, mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC). We analyzed the data of 40 housewives who were subjected to an air purifier intervention in Seoul and Ulsan, Republic of Korea. Indoor exposure levels of PM2.5 and PM10 were analyzed with sensor adjusted and gravimetric measurement. We also investigated the same anemia indicators before and after the installation of an air purifier for three months (short-term: one month, long-term: three months). Statistical analysis was performed by a multiple linear model and a linear mixed model. The indoor PM exposure levels and air purifier use were related to anemia indicators (hemoglobin and MCHC). The increase in indoor PM2.5 level was associated with a decrease in MCHC (ß: 0.034, P = 0.031) and hemoglobin (ß: 0.013, P = 0.04). The decrease in indoor PM2.5 concentration by air purifier was associated with an increase in MCHC (ß: 0.204, P = 0.087) and hemoglobin (ß: 0.190, P = 0.039). In particular, after air purifier intervention, the amounts of MCHC and hemoglobin significantly increased. Our results suggest that indoor air purifier use could decrease indoor PM level and the risk of anemia to housewives. Because the effect on anemia is subacute, it was confirmed three months after air purifier operation. In conclusion, anemia indicators can be improved by PM reduction management.

New-Onset and Exacerbation of Lung Diseases after Short-Term Exposures to Humidifier Disinfectant during Hospitalization.

(1) Background: Humidifier disinfectant (HD) is a biocidal chemical to keep the water tank inside a humidifier clean. Thousands of Koreans have experienced HD-related lung injuries. Of them, 6.9% were exposed to HD in hospitals. (2) Methods: This study investigated changes of diseases in patients (or caregivers) who experienced HD exposures during hospitalization and also investigated characteristics of hospital exposure using data from all HD-related lung injury enrollment in Korea. (3) Results: Of a total of 162 subjects, 139 subjects were hospitalized for non-lung diseases, and 23 people were hospitalized for lung diseases at the time of hospitalization. During hospital exposure, 99 (71.2%) of those hospitalized with non-lung disease experienced a new-onset of lung disease, and 15 (65.2%) of those hospitalized with lung diseases experienced exacerbation of their existing lung diseases. When we compared their exposure characteristics, those exposed in hospitals (vs. non-hospital, mostly home) were exposed for shorter periods, at closer distances, at higher HD indoor concentrations, constantly all day, and directly in the facial direction. (4) Conclusion: In conclusion, HD exposures in hospital with a high intensity even for a short term were associated with new-onset or exacerbation of lung diseases. Our findings suggest that acute exposures to HD can cause lung diseases.

Updated general exposure factors for risk assessment in the Korean population.

BACKGROUND: There has been an increasing need to update the recommended values of Korean exposure factors for adults aged 19 and older, as using exposure factors developed over a decade ago could reduce risk assessment reliability. OBJECTIVE: Exposure factor data have been compiled and standardized using the latest national statistical reports and academic literature, as well as studies conducted from 2016 to 2018. METHODS: The updated data contained anthropometric parameters, inhalation rates, food and drinking water ingestion rates, and time-activity patterns and provided technical information on Koreans' exposure factors classified by sex, age group, per capita and general population, and doer-only for various exposure assessments. RESULTS: Although the average life expectancy, body weight, body surface area, and inhalation rate increased slightly compared to the 2007 Korean Exposure Factor Handbook, differences various in food consumption were remarkable. Because of Asians' similar food preferences, the intake rate of grain products and vegetables in Koreans, Chinese, and Japanese contributed much toward total intake. Koreans spent half their times outdoors compared to Americans and Chinese. SIGNIFICANCE: This study provided the currently updated exposure factor information for Koreans and could be compared with recommendations provided by exposure factor resources in various countries. IMPACT STATEMENT: Exposure to environmental pollutants may significantly vary depending on the exposure factors related to human behaviors and characteristics. Therefore the exposure factors need to be continuously updated along with more extensive survey areas and improved measurement methods. We utilized the existing data with the aim to develop general exposure factors for risk assessment in Korean aged ≥19 years. Measurements and questionnaire surveys were also performed if there were no existing data. This study provided the currently updated exposure factor information for Koreans and could be compared to those of other countries.

Risk Assessment of Indoor Air Quality and Its Association with Subjective Symptoms among Office Workers in Korea.

The 2014 Time-Use Survey of Statistics Korea revealed that office workers are increasingly spending more than eight hours at work. This study conducted an exposure assessment for office workers in Korea. Indoor and outdoor air pollutants were measured in offices. A self-administered questionnaire was employed to determine work information, indoor air quality (IAQ) awareness, and subjective symptoms for 328 workers. Indoor air concentrations for measured air pollutants were below IAQ guideline values. The average concentrations of target air pollutants did not show significant differences except for benzene, which had relatively a higher concentration in national industrial complexes. The indoor benzene, ethylbenzene, and acetaldehyde concentrations were higher in offices where workers were having dry eye, ophthalmitis, and headache symptoms. This study provides reference values to manage IAQ in offices, suggesting that if the benzene concentration exceeds 4.23 µg/m3 in offices, it could cause dry eye symptoms. Considering the increasing working hours for office workers and health effects, workers' exposure to indoor pollutants should be reduced. In addition, the IAQ was heavily influenced by outdoor air levels and various indoor sources. Therefore, in areas with relatively high air pollution, greater monitoring and management is required considering the influence of outdoor air quality.

Direct and Indirect Effects of Indoor Particulate Matter on Blood Indicators Related to Anemia.

Exposure to indoor particulate matter (PM) is a potential risk factor that increases systemic inflammation and affects erythropoiesis. This study investigated the association between exposure to indoor PM and blood indicators related to anemia (BIRA) in housewives. Indoor PM and blood folate status are important factors in the risk of anemia. This was a housewife cohort study; we recruited 284 housewives in Seoul and Ulsan, Republic of Korea. Indoor exposure to PM2.5 and PM10 was measured by gravimetric analysis and sensors. We investigated the BIRA, such as hemoglobin (Hb), hematocrit, mean corpuscular volume (MCV), mean corpuscular Hb (MCH), and mean corpuscular Hb concentration (MCHC). Statistical analysis was performed by multiple linear regression model and mediation analysis. The association between BIRA and PM was assessed by multiple linear regression models fitted by mediation analyses. The increase in the level of indoor PM2.5 was associated with a decrease in MCV (Beta coefficient (B): -0.069, Standard error (SE): 0.022) and MCH (B: -0.019, SE: 0.009) in gravimetric measurements. The increase in the level of indoor PM2.5 was associated with a decrease in Hb (B: -0.024, SE: 0.011), hematocrit (B: -0.059, SE: 0.033), and MCV (B: -0.081, SE: 0.037) and MCH (B: -0.037, SE: 0.012) in sensor measurements (PM2.5-Lag10). Further, we identified a serum folate-mediated PM effect. The indoor PM exposure was significantly associated with decreased Hb, MCV, and MCH in housewives. Taken together, our data show that exposure to indoor PM is a risk factor for anemia in housewives. Blood folate concentration can be a mediating factor in the effect of indoor PM on BIRA. Therefore, folate intake should be recommended to prevent anemia in housewives. Moreover, indoor PM exposure should be managed.

Psychological Changes and Cancer Occurrence in Seoul Citizens Due to Changes in Fine Dust Concentration before Seoul Fine Dust Policy.

BACKGROUND: Particulate matter and urban air pollution affect the human body and can lead to death. Epidemiological studies should consider exposure to pollutants and the diverse responses of individuals, depending on their sensitivity to the pollutants. METHODS: In this study, air pollution measurements were obtained hourly at measuring stations operated by national and local governments to increase the reliability of the measured values. A ß-ray absorption method was used to analyze the measurements of fine dust and determine the particulate matter content. RESULTS: The air pollution data were log-linear, thereby enabling a comparison of data from different time periods. The comparison was made by focusing on the period of the implementation of Seoul's fine dust policy. It was observed that the cancer incidence rate decreased after the implementation of the policy. The data on individual characteristics were obtained from a survey of Seoul citizens conducted from 2015 to 2016 using indicators such as quality of life and the social trust of Seoul citizens. CONCLUSION: The survey on the living environment and residence indicated that 80% of the heads of households were men. Women had a greater dissatisfaction than men with their residential, economic, and social environments. The survey questions on well-being were related to elements of internal and external environments, such as air pollution, noise, and fine dust.

Missing Value Imputation of Time-Series Air-Quality Data via Deep Neural Networks.

To prevent severe air pollution, it is important to analyze time-series air quality data, but this is often challenging as the time-series data is usually partially missing, especially when it is collected from multiple locations simultaneously. To solve this problem, various deep-learning-based missing value imputation models have been proposed. However, often they are barely interpretable, which makes it difficult to analyze the imputed data. Thus, we propose a novel deep learning-based imputation model that achieves high interpretability as well as shows great performance in missing value imputation for spatio-temporal data. We verify the effectiveness of our method through quantitative and qualitative results on a publicly available air-quality dataset.

Misclassification and characterization of exposure to humidifier disinfectants using a questionnaire.

BACKGROUND: Lung disease caused by exposure to chemical substances such as polyhexamethylene guanidine (PHMG) used in humidifier disinfectants (HDs) has been identified in Korea. Several researchers reported that exposure classification using a questionnaire might not correlate with the clinical severity classes determined through clinical diagnosis. It was asserted that the lack of correlation was due to misclassification in the exposure assessment due to recall bias. We identified the cause of uncertainty to recognize the limitations of differences between exposure assessment and clinical outcomes assumed to be true value. Therefore, it was intended to check the availability of survey using questionnaires and required to reduce misclassification error/bias in exposure assessment. METHODS: HDs exposure assessment was conducted as a face-to-face interview, using a questionnaire. A total of 5245 applicants participated in the exposure assessment survey. The questionnaire included information on sociodemographic and exposure characteristics such as the period, frequency, and daily usage amount of HDs. Based on clinical diagnosis, a 4 × 4 cross-tabulation of exposure and clinical classification was constructed. When the values of the exposure rating minus the clinical class were ≥ 2 and ≤ - 2, we assigned the cases to the overestimation and underestimation groups, respectively. RESULTS: The sex ratio was similar in the overestimation and underestimation groups. In terms of age, in the overestimation group, 90 subjects (24.7%) were under the age of 10, followed by 52 subjects (14.2%) in their 50s. In the underestimation group, 195 subjects (56.7%) were under the age of 10, followed by 80 subjects (23.3%) in their 30s. The overestimation group may have already recovered and responded excessively due to psychological anxiety or to receive compensation. However, relatively high mortality rates and surrogate responses observed among those under 10 years of age may have resulted in inaccurate exposure in the underestimation group. CONCLUSIONS: HDs exposure assessment using a questionnaire might not correlate with adverse health effects due to recall bias and various other causes such as recovery of injury and psychological anxiety. This study revealed exposure misclassification and characteristics affected by HDs and proposed a questionnaire-based exposure assessment methodology to overcome the limitations of past exposure assessment.

Humidifier Disinfectant Consumption and Humidifier Disinfectant-Associated Lung Injury in South Korea: A Nationwide Population-Based Study.

Humidifier disinfectant (HD) is a household biocidal product used in humidifier water tanks to prevent the growth of microorganisms. In 2011, a series of lung injury cases of unknown causes emerged in children and pregnant women who had used HD in Korea. This study investigated changes in the nationwide number of cases of humidifier disinfectant-associated lung injury (HDLI) in concordance with nationwide HD consumption using data covering the entire Korean population. More than 25 kinds of HD products were sold between 1994 and 2011. The number of diagnosed HDLI, assessed by S27.3 (other injuries of lungs) of the Korea National Health Insurance Service (NHIS) data, sharply increased by 2005, subsequently decreased after 2005, and almost disappeared after 2011 in concordance with the annual number of HD sales. The number of self-reported HDLIs, assessed using data from all suspected HDLI cases registered in the Korea Ministry of Environment, changed with the annual number of HD sales, with a delay pattern, potentially induced by the late awareness of lung injury diseases. The present study suggests that changes in the nationwide annual consumption of HD products were consistent with changes in the annual number of HDLI cases in Korea.

Indoor particulate matter and blood heavy metals in housewives: A repeated measured study.

BACKGROUND: Particulate matter (PM) less than 2.5 µm in diameter and 10 µm (PM10) contains heavy metals, but whether exposure to PM is significantly associated with the burden of heavy metal exposure in the population is unknown. We investigated the association between exposure to PM and blood concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in Korean housewives. MATERIALS & METHODS: From July 2017 to January 2020, we recruited 115 housewives in Ulsan, Republic of Korea. After excluding participants with missing information, we finally included 88 Korean housewives in our study. We measured the concentrations of indoor PM using a gravimetric method 24 h before blood sampling and the concentrations of Cd, Pb, and Hg in blood, twice at a 1-year interval. We used a linear mixed effect model to estimate the associations between indoor PM and blood heavy metals. RESULTS: Exposure to PM10 was significantly associated with blood concentrations of Cd among Korean housewives. A 10 µg/m3 increase of PM10 the previous day was associated with a 2.8% (95% confidence interval (CI) = 1.1%, 4.6%) and a 1.5% (95% CI = -0.1%, 3.1%) increase in blood concentrations of Cd and Pb in the linear mixed effect model, respectively. CONCLUSION: There was a significant association between indoor PM exposure and blood Cd concentrations among Korean housewives. This result suggests that the body burden of heavy metals is significantly associated with air pollution.

Environmental Health Surveillance System for a Population Using Advanced Exposure Assessment.

Human exposure to air pollution is a major public health concern. Environmental policymakers have been implementing various strategies to reduce exposure, including the 10th-day-no-driving system. To assess exposure of an entire population of a community in a highly polluted area, pollutant concentrations in microenvironments and population time-activity patterns are required. To date, population exposure to air pollutants has been assessed using air monitoring data from fixed atmospheric monitoring stations, atmospheric dispersion modeling, or spatial interpolation techniques for pollutant concentrations. This is coupled with census data, administrative registers, and data on the patterns of the time-based activities at the individual scale. Recent technologies such as sensors, the Internet of Things (IoT), communications technology, and artificial intelligence enable the accurate evaluation of air pollution exposure for a population in an environmental health context. In this study, the latest trends in published papers on the assessment of population exposure to air pollution were reviewed. Subsequently, this study proposes a methodology that will enable policymakers to develop an environmental health surveillance system that evaluates the distribution of air pollution exposure for a population within a target area and establish countermeasures based on advanced exposure assessment.

Development of General Exposure Factors for Risk Assessment in Korean Children.

There has been an increasing need for the risk assessment of external environmental hazards in children because they are more sensitive to hazardous chemical exposure than adults. Therefore, the development of general exposure factors is required for appropriate risk assessment in Korean children. This study aimed to determine the general exposure factors among Korean children aged ≤18 years. We developed the recommended exposure factors across five categories: physiological variables, inhalation rates, food and drinking water intake, time-activity patterns, and soil and dust ingestion. National databases were used, and direct measurements and questionnaire surveys of representative samples were performed to calculate the inhalation rate, water intake, and soil ingestion rate. With regard to the time-activity patterns, the daily inhalation rates ranged from 9.49 m3/day for children aged 0-2 years to 14.98 m3/day for those aged 16-18 years. This study found that Korean children spent an average of 22.64 h indoors, 0.63 h outdoors, and 0.73 h in-transit on weekdays. The general exposure factors of Korean children were studied for the first time, and these results could be used to assess children's exposure and risk. They also suggest the differences compared with the results of international results.

Consumer exposure and risk assessment to selected chemicals of mold stain remover use in Korea.

Mold stain remover (MSR) is used to clean mold and mildew spots from surfaces and contains a variety of chemical substances. In this study, we estimated the inhalation and dermal exposures associated with the use of trigger spray MSRs, and performed screening-level risk assessments for the use of this type of product in Korea. Inhalation and dermal exposures were estimated using exposure algorithms based on exposure factors obtained from a nationwide survey of 10,000 participants and chemical analyses of the four most popular trigger spray MSRs. The hazard quotients (HQs) for noncancer risk and excess cancer risk (ECR) were calculated for each chemical. The mean inhalation exposure estimates for formaldehyde, benzene, chloroform, and carbon tetrachloride were 6.9 × 10-7, 1.7 × 10-7, 5.4 × 10-6, and 2.7 × 10-5 mg/kg/day, respectively. Dermal exposures of the chemicals were 5.7-6.5 times higher than inhalation exposures. The HQs for total exposure were all below 1, which indicated little noncancer risk from the use of MSRs. The safe ECR value of 1 × 10-6, was exceed in one subject for inhalation exposure of benzene and four subjects for dermal exposure of formaldehyde, while 19.8% for dermal exposure of benzene were above this value. Therefore, use of trigger spray MSRs in Korea should require more detailed exposure and risk assessment, especially for benzene.

Characteristics of exposure factors and inhalation exposure to selected spray consumer products in Korean population.

Many consumer spray products are sold for various purposes. Use of spray products can cause adverse health effects. This study evaluated exposure factors for consumer spray products and assessed the particle inhalation exposure. Six consumer spray products were evaluated: an automobile interior cleaner, car deodorizing spray, anti-static spray, waterproofing spray, microorganism deodorizer, and disinfectant spray. The exposure factors were based on 10,000 respondents over 15 years old. Inhalation dose was calculated from the concentration released into the room air and time used. The use rates of the spray products ranged from 0.4 to 11% and differed significantly by gender (p < 0.001). Aerosol types had a higher mass per use and longer duration of usage than trigger types. The median concentration of the trigger type ranged from 17.35 to 373.38 mg/m3, while that of the aerosol type ranged from 36.66 to 1601.97 mg/m3. The median inhalation dose of the trigger and aerosol types ranged from 2.04 × 10-3 to 0.20 and 2.60 × 10-3 to 1.71 mg/kg/day, respectively. The inhalation dose of the disinfectant spray increased with the level of education (p < 0.001), while the inhalation doses of the other spray products were not significantly associated with gender, age, income, or education.

Health risk assessment of volatile organic compounds exposure near Daegu dyeing industrial complex in South Korea.

BACKGROUND: Studying human health in areas with industrial contamination is a serious and complex issue. In recent years, attention has increasingly focused on the health implications of large industrial complexes. A variety of potential toxic chemicals have been produced during manufacturing processes and activities in industrial complexes in South Korea. A large number of dyeing industries gathered together in Daegu dyeing industrial complex. The residents near the industrial complex could be often exposed to volatile organic compounds. This study aimed to evaluate VOCs levels in the ambient air of DDIC, to assess the impact on human health risks, and to find more convincing evidences to prove these VOCs emitted from DDIC. METHODS: According to deterministic risk assessment, inhalation was the most important route. Residential indoor, outdoor and personal exposure air VOCs were measured by passive samplers in exposed area and controlled area in different seasons. Satisfaction with ambient environments and self-reported diseases were also obtained by questionnaire survey. The VOCs concentrations in exposed area and controlled area was compared by t-test. The relationships among every VOC were tested by correlation. The values of hazard quotient (HQ) and life cancer risk were estimated. RESULTS: The concentrations of measured VOCs were presented, moreover, the variety of concentrations according the distances from the residential settings to the industrial complex site in exposed area. The residential indoor, outdoor, and personal exposure concentrations of toluene, DMF and chloroform in exposed area were significantly higher than the corresponding concentrations in controlled area both in summer and autumn. Toluene, DMF, chloroform and MEK had significantly positive correlations with each other in indoor and outdoor, and even in personal exposure. The HQ for DMF exceeded 1, and the life cancer risk of chloroform was greater than 10- 4 in exposed area. The prevalence of respiratory diseases, anaphylactic diseases and cardiovascular diseases in exposed area were significantly higher than in controlled area. CONCLUSIONS: This study showed that adverse cancer and non-cancer health effects may occur by VOCs emitted from DDIC, and some risk managements are needed. Moreover, this study provides a convenient preliminarily method for pollutants source characteristics.

Towards smoke-free cars in the Republic of Korea: Evidence from environmental and biochemical monitoring of third-hand smoke exposure in taxis.

INTRODUCTION: To evaluate the level of tobacco smoke exposure in taxis in Korea using tobacco specific environmental markers. METHODS: From June to September 2012, cross-sectional measurements of air nicotine levels and dust nicotine-derived nitrosamine ketone (NNK) concentrations were conducted in 17 taxis in Goyang, Korea. Field investigators completed an observational questionnaire on building characteristics, smoking policies and evidence of smoking. Descriptive statistics including geometric means (GMs) ± standard deviations were produced for air nicotine levels and dust NNK concentrations. RESULTS: There was no evidence of active smoking in the 17 taxis monitored, despite the fact that 10 drivers were current smokers. The overall GMs of air nicotine and dust NNK concentration were 0.42 µg/m3 and 6.78 pg/mg, respectively. These levels were 3.4-fold and 2.6-fold higher in taxis whose drivers were current smokers compared to the taxis of nonsmokers (GM of air nicotine: 0.65 µg/m3 vs 0.19 µg/m3; GM of dust NNK: 10.07 pg/mg vs 3.85 pg/mg). CONCLUSIONS: The present study shows that air nicotine and dust NNK were detected in all taxis regardless of whether the taxi driver was smoking or not, which indicates the potential for exposure to SHS or THS. It suggests that an appreciable level of SHS and TSH exposure might occur if the environment is not completely smoke-free and enforcement is lacking. ABBREVIATIONS: THS: third-hand smoke, SHS: second-hand smoke, FCTC: Framework Convention Alliance for Tobacco Control, NNK: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone, LOD: limit of detection, GM: geometric mean, GSD: geometric standard deviation.

Psychological effects of a disastrous hydrogen fluoride spillage on the local community.

BACKGROUND: On September 27, 2012, at 3:43 pm, a hydrogen fluoride spill occurred in a manufacturing plant located at the 4th complex of the Gumi National Industrial Complex in Gumi City, South Korea. The present study aimed to evaluate the psychological effects of the hydrogen fluoride spill on the members of the community and to investigate their relationships with physical symptoms and changes in psychological effects occurring as time passed after the accident. METHODS: The 1st phase involved a survey of 1359 individuals that was conducted 1 month after the spill, and the 2nd phase involved a survey of 711 individuals that was conducted 7 months after the accident. The questionnaires included items for assessing demographic characteristics, hydrogen fluoride exposure level, physical symptoms, and psychological status. Physical symptoms were assessed to determine the persistence of irritations. Psychological status was assessed to investigate the impact of event level using the Impact of Event Scale - Revised Korean version (IES-R-K), and the anxiety level was assessed using the Beck Anxiety Inventory (BAI). RESULTS: As the hydrogen fluoride exposure level increased, the impact of event and anxiety levels increased significantly both 1 and 7 months after the accident (p < 0.05). The mean score of the impact of event levels decreased significantly from 33.33 ± 14.64 at 1 month after the accident to 28.68 ± 11.80 at 7 months after the accident (p < 0.05). The mean score of the anxiety levels increased significantly from 5.16 ± 6.59 at 1 month after the accident to 6.79 ± 8.41 at 7 months after the accident (p < 0.05). The risk of persistent physical symptoms at 7 months after the accident was significantly higher in females. The risk of persistent physical symptoms also increased significantly, with increasing age, hydrogen fluoride exposure, and impact of event levels (p < 0.05). CONCLUSIONS: The present study found that the impact of event level and anxiety level increased with increasing hydrogen fluoride exposure. Anxiety levels persisted even after time passed. The risk of persistent physical symptoms at 7 months after the accident was higher in females, and it increased with increasing age, hydrogen fluoride exposure level, and impact of event levels.