While hair samples are easier to collect and less expensive to store and transport than biological fluids, and hair nicotine characterizes tobacco exposure over a longer time period than blood or urine cotinine, information on its utility, compared with salivary cotinine, is still limited. We conducted a cross-sectional study with 289 participants (107 active smokers, 105 passive smokers with self-reported secondhand smoke (SHS) exposure, and 77 non-smokers with no SHS exposure) in Baltimore (Maryland, USA). A subset of the study participants (n = 52) were followed longitudinally over a two-month interval. Median baseline hair nicotine concentrations for active, passive and non-smokers were 16.2, 0.36, and 0.23 ng/mg, respectively, while those for salivary cotinine were 181.0, 0.27, and 0.27 ng/mL, respectively. Hair nicotine concentrations for 10% of passive or non-smokers were higher than the 25th percentile value for active smokers while all corresponding salivary cotinine concentrations for them were lower than the value for active smokers. This study showed that hair nicotine concentration values could be used to distinguish active or heavy passive adult smokers from non-SHS exposed non-smokers. Our results indicate that hair nicotine is a useful biomarker for the assessment of long-term exposure to tobacco smoke.

Objectives:This study aimed to evaluate the association between presence of depression symptoms and the exposure level to insecticides among aged population in rural area, determined via measured levels of urinary 3-phenoxybenzoic acid (3-PBA), after controlling for socioeconomic confounding factors. Methods:Using a cross-sectional study design, we randomly recruited participants for our study (161 male and 239 female) from rural areas of Asan, Chungnam, Korea. Environmental risk factor exposure was assessed using a questionnaire, and gas chromatography- mass spectrometry was used to analyze urinary 3-PBA levels. We used a logistic regression analysis to assess the association of urinary 3-PBA levels with the presence of self-reported depression symptoms. Results:After controlling for creatinine levels, the median (interquartile range) concentration of 3-PBA was approximately 1.5 times (p<0.05) higher among female (1.54 [0.90 to 2.35]) μg/g) than among male (1.06 [0.64 to 1.81] μg/g). Our study found that among female participants, the unit increase in 3-PBA levels exhibited a likely positive association (odds ratio, 1.12; 95% confidence interval, 1.00 to 1.25) with an increased risk of presence of self-reported depression symptoms, after adjusting for socioeconomic insurance type, daily physical condition, marital status, smoking status, and age. Conclusions:Given our finding of a potential association between the presence of selfreported depression symptoms and 3-PBA levels, precautions should be considered to minimize exposure to insecticides and thus protect the health of aged residents in rural areas.

Background: In South Korea, young adults' smoking prevalence is relatively higher than that of other age groups. Although most hospitality venues are subject to regulations mandating a complete indoor smoking ban pursuant to Article 7 of the Enforcement Rules of the National Health Promotion Act, information is still limited on university students' potential exposure level to secondhand smoke in hospitality venues. This study evaluated indoor secondhand smoke levels at various venues in campus towns. Methods: Using a portable real-time PM 2.5 monitor, we measured indoor PM 2.5 concentration at various venues as an indicator of secondhand smoke exposure. On weekdays, we conducted measurement inside of campus buildings (from 12:00 to 2:00 pm) and in hospitality venues (e.g., PC-rooms, billiard-rooms, and pubs) from 6:00 pm to 8:30 pm. On weekends, we performed the measurement at clubs and bars, which are recognized as trendy venues among young university students. Results: The median of PM 2.5 concentrations was 9.0, 180.4, 41.2, and 44.3 g/m3 in campus buildings, PC-rooms, billiard-rooms, and pubs, respectively. The levels at clubs, nightclubs, and hookah-bars were as high as 982.0, 134.9, and 227.5 g/m3, indicating that PM 2.5 concentrations in these places were 4 to 19 times higher than the 24 hour exposure guideline for outdoor PM 2.5 (50 g/m 3) that will be implemented in South Korea after January 1, 2015. Conclusion: Our study provides evidence for the introduction of more rigorous policy initiatives aimed at encouraging a complete smoking ban in venues, particularly clubs and bars as well as PC-rooms, billiard-rooms and pubs.

This study investigated the association between PM2.5 concentrations obtained with portable real-time monitors and those obtained with gravimetric methods in national urban air-quality monitoring sites in Seoul, South Korea. We used the SidePak AM510 Personal Aerosol Monitor (TSI Inc., 500 Cardigan Road Shoreview, MN) and DustTrak DRX 8533 (TSI Inc., 500 Cardigan Road Shoreview, MN) as portable real-time monitors for measuring PM2.5 concentrations and compared these values with those measured with the PMS-103 or SEQ 47/50 models operated by Federal Reference Method (FRM) or the European Committee for Standardization(ECS), respectively, in national urban air-quality monitoring sites in Seoul. Measurements were conducted every other day in the winter and spring seasons of 2014. The estimated daily mean concentrations of PM2.5 ranged between 13.4 and 161.9 µg/m 3 using AM 510 and between 22.0 and 156.0 µg/m 3 using DustTrak. The Spearman correlation coefficient for PM2.5 concentrations between AM 510 and gravimetric results was 0.99, and the correlation between DustTrak and gravimetric results was 0.87. The correction factor suggested was 0.42 and 0.29 for AM 510 and DustTrak, respectively. We found that PM2.5 concentrations measured with real-time monitors could overestimate true PM2.5 concentrations and therefore the application of a correction factor (0.43) is strongly suggested for quantification when Real-time monitors were operated of PM2.5 levels at urban atmospheric environment 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.