Evidence integration on health damage for humidifier disinfectant exposure and legal presumption of causation.

OBJECTIVES: Inhalation exposure to humidifier disinfectants has resulted to various types of health damages in Korea. To determine the epidemiological correlation necessary for presuming the legal causation, we aimed to develop a method to synthesize the entire evidence. METHODS: Epidemiological and toxicological studies are systematically reviewed. Target health problems are selected by criteria such as frequent complaints of claimants. Relevant epidemiologic studies are reviewed and the risk of bias and confidence level of the total evidence are evaluated. Toxicological literature reviews are conducted on three lines of evidence including hazard information, animal studies, and mechanistic studies, considering the source-to-exposure-to-outcome continuum. The confidence level of the body of evidence is then translated into the toxicological evidence levels for the causality between humidifier disinfectant exposure and health effects. Finally, the levels of epidemiological and toxicological evidence are synthesized. RESULTS: Under the Special Act revised in 2020, if the history of exposure and the disease occurred/worsened after exposure were approved, and the epidemiological correlation between the exposure and disease was verified, the legal causation is presumed unless the company proves the evidence against it. The epidemiological correlation can be verified through epidemiological investigations, health monitoring, cohort investigations and/or toxicological studies. It is not simply as statistical association as understood in judicial precedents, but a general causation established by the evidence as a whole, i.e., through weight-of-the-evidence approach. CONCLUSIONS: The weight-of-the-evidence approach differs from the conclusive single study approach and this systematic evidence integration can be used in presumption of causation.

Association between Peak Expiratory Flow Rate and Exposure Level to Indoor PM2.5 in Asthmatic Children, Using Data from the Escort Intervention Study.

Various studies have indicated that particulate matter <2.5 µm (PM2.5) could cause adverse health effects on pulmonary functions in susceptible groups, especially asthmatic children. Although the impact of ambient PM2.5 on children's lower respiratory health has been well-established, information regarding the associations between indoor PM2.5 levels and respiratory symptoms in asthmatic children is relatively limited. This randomized, crossover intervention study was conducted among 26 asthmatic children's homes located in Incheon metropolitan city, Korea. We aimed to evaluate the effects of indoor PM2.5 on children's peak expiratory flow rate (PEFR), with a daily intervention of air purifiers with filter on, compared with those groups with filter off. Children aged between 6-12 years diagnosed with asthma were enrolled and randomly allocated into two groups. During a crossover intervention period of seven weeks, we observed that, in the filter-on group, indoor PM2.5 levels significantly decreased by up to 43%. (p < 0.001). We also found that the daily or weekly unit (1 µg/m3) increase in indoor PM2.5 levels could significantly decrease PEFR by 0.2% (95% confidence interval (CI) = 0.1 to 0.5) or PEFR by 1.2% (95% CI = 0.1 to 2.7) in asthmatic children, respectively. The use of in-home air filtration could be considered as an intervention strategy for indoor air quality control in asthmatic children's homes.

Association between the Ratio of FEV1 to FVC and the Exposure Level to Air Pollution in Neversmoking Adult Refractory Asthmatics Using Data Clustered by Patient in the Soonchunhyang Asthma Cohort Database.

Using real-world cases, asthma-related clinical data were clustered by patient; 5% of all asthmatics were found to have refractory asthma (RA) with a relatively low lung function (forced expiratory volume in 1 s/forced vital capacity (FEV1/FVC) less than 80%). Using a multilevel study design for clustered spirometry data observed between 2005 and 2014, we evaluated the association between changes in the ratio of FEV1 to FVC and variations in acute exposure to air pollution. We analyzed 2310 episodes of RA from 214 neversmoking patients. In spring, a 1 µg/m³ increase in concentration of particles ≤10 µm (PM10) on Lag 1 significantly reduced the ratio by 0.4% (95% confidence interval (CI): 0.1⁻0.7%) after adjusting for sex, age, body mass index (BMI), and total Immunoglobulin E (IgE) level. Unit (ppb) increase in SO2 concentration on Lag 3 and 4 in fall and on Lag 6 in winter significantly reduced the ratio by 2 to 3% (p < 0.05). We found that acute exposure to PM10 in spring or SO2 in fall or winter were positively associated with lung function drop indicating necessity of control strategies of target air pollutant source by season to protect susceptible population.

Smoking Topography among Korean Smokers: Intensive Smoking Behavior with Larger Puff Volume and Shorter Interpuff Interval.

The difference of smoker's topography has been found to be a function many factors, including sex, personality, nicotine yield, cigarette type (i.e., flavored versus non-flavored) and ethnicity. We evaluated the puffing behaviors of Korean smokers and its association with smoking-related biomarker levels. A sample of 300 participants was randomly recruited from metropolitan areas in South Korea. Topography measures during a 24-hour period were obtained using a CReSS pocket device. Korean male smokers smoked two puffs less per cigarette compared to female smokers (15.0 (13.0⁻19.0) vs. 17.5 (15.0⁻21.0) as the median (Interquartile range)), but had a significantly larger puff volume (62.7 (52.7⁻75.5) mL vs. 53.5 (42.0⁻64.2) mL); p = 0.012). The interpuff interval was similar between men and women (8.9 (6.5⁻11.2) s vs. 8.3 (6.2⁻11.0) s; p = 0.122) but much shorter than other study results. A dose-response association (p = 0.0011) was observed between daily total puff volumes and urinary cotinine concentrations, after controlling for sex, age, household income level and nicotine addiction level. An understanding of the difference of topography measures, particularly the larger puff volume and shorter interpuff interval of Korean smokers, may help to overcome a potential underestimation of internal doses of hazardous byproducts of smoking.

Needs assessment survey for simulation-based training for gastrointestinal endoscopy nurses.

The optimal performance of gastrointestinal (GI) endoscopy nurses is required for patient safety and quality improvement. The aim of the present study was to assess the educational needs for simulation-based training for Korean GI endoscopy nurses using importance-performance analysis. A cross-sectional survey was conducted with 238 Korean nurses from 25 endoscopy units. The educational needs of these nurses were identified using the 35 item clinical competence importance-performance scale. Exploratory factor analysis of the scale identified the following eight factors: emergency care, patient monitoring, evidence-based practice, documentation and referral, patient safety, nursing process, patient assessment, and infection control. A significant overall mean difference was identified between importance and performance for all eight factors, with emergency care showing the largest difference. It was also ranked the highest priority for continuing education in the importance-performance analysis matrix. Therefore, simulation-based training should focus on enhancing emergency care competence for GI endoscopy nurses to improve patient safety and quality of care.

Spatiotemporal Association of Real-Time Concentrations of Black Carbon (BC) with Fine Particulate Matters (PM2.5) in Urban Hotspots of South Korea.

We evaluated the spatiotemporal distributions of black carbon (BC) and particulate matters with aerodynamic diameters of less than 2.5 m (PM2.5) concentrations at urban diesel engine emission (DEE) hotspots of South Korea. Concentrations of BC and PM2.5 were measured at the entrance gate of two diesel bus terminals and a train station, in 2014. Measurements were conducted simultaneously at the hotspot (Site 1) and at its adjacent, randomly selected, residential areas, apartment complex near major roadways, located with the same direction of 300 m (Site 2) and 500 m (Site 3) away from Site 1 on 4 different days over the season, thrice per day; morning (n = 120 measurements for each day and site), evening (n = 120), and noon (n = 120). The median (interquartile range) PM2.5 ranged from 12.6 (11.3-14.3) to 60.1 (47.0-76.0) µg/m³ while those of BC concentrations ranged from 2.6 (1.9-3.7) to 6.3 (4.2-10.3) µg/m³. We observed a strong relationship of PM2.5 concentrations between sites (slopes 0.89-0.9, the coefficient of determination 0.89-0.96) while the relationship for BC concentrations between sites was relatively weak (slopes 0.76-0.85, the coefficient of determination 0.54-0.72). PM2.5 concentrations were changed from 4% to 140% by unit increase of BC concentration, depending on site and time while likely supporting the necessity of monitoring of BC as well as PM2.5, especially at urban DEE related hotspot areas.

Evaluation of Potential Average Daily Doses (ADDs) of PM2.5 for Homemakers Conducting Pan-Frying Inside Ordinary Homes under Four Ventilation Conditions.

Several studies reported that commercial barbecue restaurants likely contribute to the indoor emission of particulate matters with a diameter of 2.5 micrometers or less (PM2.5) while pan-frying meat. However, there is inadequate knowledge of exposure level to indoor PM2.5 in homes and the contribution of a typical indoor pan-frying event. We measured the indoor PM2.5 concentration and, using Monte-Carlo simulation, estimated potential average daily dose (ADD) of PM2.5 for homemakers pan-frying a piece of pork inside ordinary homes. Convenience-based sampling at 13 homes was conducted over four consecutive days in June 2013 (n = 52). Although we pan-fried 100 g pork for only 9 min, the median (interquartile range, IQR) value was 4.5 (2.2-5.6) mg/m³ for no ventilation and 0.5 (0.1-1.3) mg/m³ with an active stove hood ventilation system over a 2 h sampling interval. The probabilities that the ADDs from inhalation of indoor PM2.5 would be higher than the ADD from inhalation of PM2.5 on an outdoor roadside (4.6 µg/kg·day) were 99.44%, 97.51%, 93.64%, and 67.23%, depending on the ventilation conditions: (1) no window open; (2) one window open in the kitchen; (3) two windows open, one each in the kitchen and living room; and (4) operating a forced-air stove hood, respectively.

The interactive association of smoking and drinking levels with presence of periodontitis in South Korean adults.

BACKGROUND: Periodontitis is a chronic and long-lasting low-grade inflammatory disease. Numerous studies have shown that the severity of periodontitis rose when there was an increase in the amount of smoking or alcohol consumption. However, as periodontitis known as a chronic disease, it is important to consider not only the amount but "duration" with frequency i.e., rates, of smoking or drinking. This study assessed impacts of the amount and duration of smoking and drinking on periodontal health in Korean adults. We also investigated whether or not there is an interactive effect of smoking and drinking on periodontal health. METHODS: Under a cross-sectional study design, we used data from the fourth and fifth the Korean National Health and Nutrition Examination Survey (KNHANES) sessions (2008-2010). A total of 18,488 subjects (over 19 years) answered both smoking and drinking status and were given the periodontal examination. Periodontal health status was determined by the community periodontal index (CPI) developed by the World Health Organization (WHO). According to the WHO guidelines, if a participant's CPI was 3 or larger, we classified the person as a case of periodontitis. Participants with a CPI < 3 were assigned to the control group. RESULTS: Prevalence of periodontitis for self-reported smokers or drinkers in South Korea was 35.0 or 28.0 %, respectively. We observed 1.20 (0.93~1.56) of odds ratio (95 % CI) for prevalence (POR) of periodontitis for those smoked <13 pack-year (PY) and drank ≥6.8 glass-year (GY). And we had POR of 1.91 (1.34~2.73) for those smoked ≥13 PY and drank <6.8 GY, compared to those nonsmoking nondrinkers. The observed POR of 2.41 (95 % CI: 1.94-3.00), for those smoked ≥13 PY and drank ≥6.8 GY, was higher than a multiplicative effect estimated, i.e., 1.20 (0.93~1.56) [those smoked <13 PY and drank ≥6.8 GY] × 1.91 (1.34~2.73) [those smoked ≥13 PY and drank <6.8 GY], or 2.29. CONCLUSIONS: We observed a multiplicative interactive effect of smoking and drinking on periodontal status among Korean adults.

Short-Term Impact of a Comprehensive Smoke-Free Law Following a Partial Smoke-Free Law on PM2.5 Concentration Levels at Hospitality Venues on the Peripheries of College Campuses.

Tobacco-free policies on college campuses are spreading in Korea. However, the impact of the smoking ban legislation at venues on the boundary of a college campus is still limited. This study aimed to assess short-term changes in PM2.5 concentrations before and after the enactment of the smoking ban legislation to evaluate the impact. In this cross-sectional study, PM2.5 measurements (pre-ban: n = 99, post-ban: n = 64) were conducted in randomly selected billiards, pubs, and computer game rooms on the peripheries of college campuses in October 2013, prior to implementation of the smoking ban, and in May 2014, after the ban. The median (interquartile range, IQR) of the PM2.5 concentration for all venues was 31 µg/m³ (0-80 µg/m³) in the pre-ban period and 11 µg/m³ (0-36 µg/m³) in the post-ban period implying indoor PM2.5 concentration levels of the peripheries of college campuses likely decreased one year after implementation of the ban. However, the differences were not significant yet. The results support the introduction of more rigorous monitoring of SHS exposure levels toward the ultimate goal of encouraging a complete smoking ban in hospitality venues, including billiards, pubs, and computer game rooms located on the peripheries of college campuses.

Variations in label information and nicotine levels in electronic cigarette refill liquids in South Korea: regulation challenges.

BACKGROUND: In South Korea, the consumption of liquid nicotine used in electronic cigarettes has dramatically increased from 4310 L in 2012 to 7220 L in 2013. This study aimed to examine the level of heterogeneity of contents of the labels and discrepancy of the nicotine content between that indicated on the label and the actual values for electronic cigarette liquid refill products in South Korea. METHODS: We purchased 32 electronic cigarette liquid refill products (17 Korean domestic, 15 imported ones) and one pure nicotine product at six different electronic cigarette retail stores in Seoul between May and June 2014. The actual nicotine concentrations of each product were measured by a blinded analyst at Roswell Park Cancer Institute, Buffalo, NY, USA. RESULTS: Three out of 15 imported liquid refill products provided manufacturing dates, while expiration dates were available on eight products. The range of nicotine concentration was from "not detected" to 17.5 mg/mL. Labeling discrepancies of the concentrations ranged from -32.2% to 3.3% among electronic cigarette liquid refill products. The highest concentration (150.3 ± 7.9 mg/mL) was found in a sample labeled as "pure nicotine". CONCLUSIONS: There is no standardization of labelling among electronic cigarette liquids sampled from retail stores and the labels did not accurately reflect the content. One product labeled "pure nicotine" raises concerns, since it may be poisonous to consumers, especially to children. This study revealed the urgent need for the development of product regulations in South Korea.