Association between ambient air pollution and perceived stress in pregnant women.

Air pollution may influence prenatal maternal stress, but research evidence is scarce. Using data from a prospective cohort study conducted on pregnant women (n = 2153), we explored the association between air pollution and perceived stress, which was assessed using the 14-item Perceived Stress Scale (PSS), among pregnant women. Average exposures to particulate matter with an aerodynamic diameter of < 2.5 µm (PM2.5) or < 10 µm (PM10), nitrogen dioxide (NO2), and ozone (O3) for each trimester and the entire pregnancy were estimated at maternal residential addresses using land-use regression models. Linear regression models were applied to estimate associations between PSS scores and exposures to each air pollutant. After adjustment for potential confounders, interquartile-range (IQR) increases in whole pregnancy exposures to PM2.5, PM10, and O3 in the third trimester were associated with 0.37 (95% confidence interval [CI] 0.01, 0.74), 0.54 (95% CI 0.11, 0.97), and 0.30 (95% CI 0.07, 0.54) point increases in prenatal PSS scores, respectively. Furthermore, these associations were more evident in women with child-bearing age and a lower level of education. Also, the association between PSS scores and PM10 was stronger in the spring. Our findings support the relationship between air pollution and prenatal maternal stress.

Association of ambient air pollution with depressive and anxiety symptoms in pregnant women: A prospective cohort study.

BACKGROUND: Air pollution is associated with depressive and anxiety symptoms in the general population. However, this relationship among pregnant women remains largely unknown. OBJECTIVE: To evaluate the association between pregnancy air pollution exposure and maternal depressive and anxiety symptoms during the third trimester assessed using the Center for Epidemiologic Studies-Depression and State-Trait Anxiety Inventory scales, respectively. METHODS: We analyzed 1481 pregnant women from a cohort study in Seoul. Maternal exposure to particulate matter with an aerodynamic diameter <2.5 µm (PM2.5) and <10 µm (PM10), as well as to nitrogen dioxide (NO2) and ozone (O3) for each trimester and the entire pregnancy was assessed at participant's residential address by land use regression models. We estimated the relative risk (RR) and corresponding confidence interval (CI) of the depressive and anxiety symptoms associated with an interquartile range (IQR) increase in PM2.5, PM10, NO2, and O3 using modified Poisson regression. RESULTS: In single-pollutant models, an IQR increase in PM2.5, PM10, and NO2 during the second trimester was associated with an increased risk of depressive symptoms (PM2.5 RR = 1.15, 95% CI: 1.04, 1.27; PM10 RR = 1.13, 95% CI: 1.04, 1.23; NO2 RR = 1.15, 95% CI: 1.03, 1.29) after adjusting for relevant covariates. Similarly, an IQR increase in O3 during the third trimester was associated with an increased risk of depressive symptoms (RR = 1.09, 95% CI: 1.01, 1.18), while the IQR increase in O3 during the first trimester was associated with a decreased risk (RR = 0.89, 95% CI: 0.82, 0.96). Exposure to PM2.5, PM10, and NO2 during the second trimester was significantly associated with anxiety symptoms. The associations with PM2.5 and O3 in single-and multi-pollutant models were consistent. CONCLUSIONS: Our findings indicate that increased levels of particulate matter, NO2, and O3 during pregnancy may elevate the risk of depression or anxiety in pregnant women.

Air pollution exposure during pregnancy and ultrasound and birth measures of fetal growth: A prospective cohort study in Korea.

Few studies have examined the effects of air pollution on fetal growth based on ultrasound measures during pregnancy. More data is needed to evaluate the windows of special vulnerability. Our aim was to investigate the association of ambient air pollution during pregnancy with fetal and neonatal characteristics in a cohort of Korean women. Maternal exposure to particulate matter with an aerodynamic diameter<10µm (PM10) and nitrogen dioxide (NO2) was estimated using land-use regression models based on residential address. The biparietal diameter (BPD), abdominal circumference (AC), femur length (FL), and estimated fetal weight (EFW) were evaluated via ultrasonography, and birth weight (BW), birth length (BL), and head circumference at birth (BHC) were obtained from medical records. The multiple linear regression model was used to adjust for confounders, and the mixed-effect model was used to evaluate longitudinal effect. The negative effects for NO2 and PM10 were estimated; in the adjusted analyses the decreases of BPD were -0.26mm (95% confidence interval [CI]=-0.41 to -0.11, with a 10µg/m3 increase) in the second trimester for NO2, and -0.30mm (95% CI=-0.59 to -0.03, with a 10µg/m3 increase) in the third trimester for PM10. Both NO2 and PM10 levels (10µg/m3) during third trimester were inversely associated with BHC, and NO2 level was inversely associated with BL in all exposure windows. No significant associations for AC, FL, and EFW were observed. The longitudinal analyses showed inverse association of NO2 exposure with head and length growth (P<0.001). Our findings suggest that ambient air pollution is associated with impaired fetal head size from mid-gestation onwards.

Effects of traffic-related air pollution on susceptibility to infantile bronchiolitis and childhood asthma: A cohort study in Korea.

OBJECTIVE: This study examined the role of exposure to traffic-related air pollution (TRAP) on susceptibility to asthma in children with past episodes of bronchiolitis. METHODS: The baseline data included 2,627 school children aged 6-14 years who had participated in the longitudinal follow-up survey of the Children's Health and Environmental Research of Korea. Lifetime wheezing, past episodes of bronchiolitis, and doctor-diagnosed asthma were evaluated using an International Study of Asthma and Allergies in Childhood questionnaire. We used generalized linear regression with binomial distribution to calculate the relative risk (RR) between TRAP, assessed by proximity to a main road and the total length of roads, and asthma. RESULTS: Compared with the subjects who had less than 100 m of road length within 200-m radius from their home, those with more than 500 m of road length had significantly increased odds for infantile bronchiolitis (adjusted OR [aOR]: 1.57, 95% confidence interval [CI]: 1.01-2.42). Positive exposure-response relationships were found between residential proximity to the main road and asthma (aOR: 1.79, 95% CI: 1.05-3.06; <75 m vs. >700 m from a main road, P for the trend = 0.02). Closer residential proximity to the main road (<75 m) and bronchiolitis combined increased the risks of newly diagnosed asthma (adjusted RR: 3.62, 95% CI: 1.07-12.26) compared with those without bronchiolitis and living ≥ 75 m away from the main road. CONCLUSIONS: TRAP appeared to be associated with an increased asthma among children with bronchiolitis, indicating the importance of modifying effects of bronchiolitis in asthma pathogenesis.

Impact of prenatal exposure to polycyclic aromatic hydrocarbons from maternal diet on birth outcomes: a birth cohort study in Korea.

OBJECTIVE: Polycyclic aromatic hydrocarbons (PAH) are common dietary exposures that cross the human placenta and are classified as a probable human carcinogen. The aim of the present study was to investigate the potential impact of exposure to PAH-containing meat consumed during pregnancy on birth outcomes. DESIGN: Prospective birth cohort study. Only non-smoking women with singleton pregnancies, who were free from chronic disease such as diabetes and hypertension, were included in the study. Maternal consumption of PAH-rich meat was estimated through FFQ. Multiple linear regression was used to assess factors related to higher intake and the association between dietary PAH and birth outcomes. SETTING: Republic of Korea, 2006-2011. SUBJECTS: Pregnant women (n 778) at 12-28 weeks of gestation enrolled in the Mothers and Children's Environmental Health (MOCEH) study. RESULTS: The multivariable regression model showed a significant reduction in birth weight associated with higher consumption level of foods rich in PAH, such as grilled or roasted meat, during pregnancy (ß=-17·48 g, P<0·05 for every 1 point higher in meat score). Further adjusting for biomarkers of airborne PAH did not alter this association. There was no evidence that higher consumption level of PAH-rich meat shortens the duration of gestation (P=0·561). Regression models performed for birth length and head circumference produced negative effects that were not statistically significant. CONCLUSIONS: Consumption of higher levels of barbecued, fried, roasted and smoked meats during pregnancy was associated with reduced birth weight. Dietary risk of PAH exposure in Korean women is of concern.

Psychosocial factors and psychological well-being: a study from a nationally representative sample of Korean workers.

This study was conducted to examine how each psychosocial factor on working conditions is related to a worker's well-being. Data from the 2011 Korean Working Conditions Survey were analyzed for 33,569 employed workers aged ≥15 years. Well-being was evaluated through the WHO-5 questionnaire and variables about occupational psychosocial factors were classified into eight categories. The prevalence ratios were estimated using Poisson regression model. Overall, 44.3% of men and 57.4% of women were in a low well-being group. In a univariate analysis, most of the psychosocial factors on working conditions are significantly related with a worker's low well-being, except for insufficient job autonomy in both genders and job insecurity for males only. After adjusting for sociodemographic and structural factors on working conditions, job dissatisfaction, lack of reward, lack of social support, violence and discrimination at work still showed a statistically significant association with a worker's low well-being for both genders. We found that psychosocial working conditions were associated with the workers' well-being.

Job stress as a risk factor for absences among manual workers: a 12-month follow-up study.

This study was conducted to evaluate the impact of job stress on absence from work caused by illnesses and accidents through a prospective research design. A total of 2,349 manual workers were included in this analysis. In the first survey, job stress was determined using the Korean Occupational Stress Scale-Short Form. In the second survey, information on absence due to accidents or illnesses during the past one year was obtained through a questionnaire. The relationship was analyzed using a logistic regression model with multiple imputation. After adjusting for confounding variables for males, absence due to accidents was statistically associated with high job demand, insufficient job control, inadequate social support, and organizational injustice. In addition, high job demands and organizational injustice were related to increased absence due to illnesses in both genders. A lack of reward was associated with increased absence due to illnesses among female workers. We found that job stress was associated with a higher risk of absence caused by accidents or illnesses of manual workers.

Association of active and passive smoking with occupational injury in manual workers: a cross-sectional study of the 2011 Korean working conditions survey.

This study was conducted to investigate the relationship of active and passive smoking with occupational injury among manual workers. Data from the 2011 Korean Working Conditions Survey were analyzed for 12,507 manual workers aged ≥15 yr. Overall, 60.4% of men and 5.8% of women were current smokers. The prevalence of injury was higher among never smokers who were exposed to secondhand smoke (SHS) (7.7% in men and 8.1% in women) than current smokers (4.2% in men and 4.1% in women). After controlling for potential confounders, in men, compared to those who never smoked and were not exposed to SHS, people who never smoked and were exposed to SHS (adjusted odds ratio (aOR)=3.7, 2.2-6.4) and current smokers (aOR=2.5, 1.6-3.8) were more likely to experience injury. Among women, the aORs of occupational injury were 8.4 (4.2-16.7) for never smoking women with occasional exposure to SHS and 3.5 (95% CI: 1.4-8.7) for current smokers, in comparison to never smoking women who were never exposed to SHS at work (reference group). The present study suggests that exposure to SHS is a possible risk factor of occupational injury for never smoking men and women.

Effect of Traffic-Related Air Pollution on Allergic Disease: Results of the Children's Health and Environmental Research.

PURPOSE: This study evaluated the relationship of living near to main roads to allergic diseases, airway hyperresponsiveness (AHR), allergic sensitization, and lung function in Korean children. METHODS: A total of 5,443 children aged 6-14 years from 33 elementary schools in 10 cities during 2005-2006 were included in a baseline survey of the Children's Health and Environmental Research. We assessed association of traffic-related air pollution (TAP) exposure with the distance to the nearest main road, total road length of main roads and the proportion of the main road area within the 200-m home area. RESULTS: Positive exposure-response relationships were found between the length of the main road within the 200-m home area and lifetime wheeze (adjusted prevalence ratio [PR] for comparison of the longest to the shortest length categories=1.24; 95% CIs, 1.04-1.47; P for trend=0.022) and diagnosed asthma (PR=1.42; 95% CIs, 1.08-1.86; P for trend=0.011). Living less than 75 m from the main road was significantly associated with lifetime allergic rhinitis (AR), past-year AR symptoms, diagnosed AR, and treated AR. The distance to the main road (P for trend=0.001), the length of the main road (P for trend=0.041), and the proportion of the main road area (P for trend=0.006) had an exposure-response relationship with allergic sensitization. A strong inverse association was observed between residential proximity to the main load and lung function, especially FEV1, FEV1/FVC, and FEF25₋75. The length of the main road and the proportion of the main road area were associated with reduced FEV1 in schoolchildren. CONCLUSIONS: The results of this study suggest that exposure to traffic-related air pollution may be associated with increased risk of asthma, AR, and allergic sensitization, and with reduced lung function in schoolchildren.

Association among Working Hours, Occupational Stress, and Presenteeism among Wage Workers: Results from the Second Korean Working Conditions Survey.

OBJECTIVES: The purpose of the present study was to identify the association between presenteeism and long working hours, shiftwork, and occupational stress using representative national survey data on Korean workers. METHODS: We analyzed data from the second Korean Working Conditions Survey (KWCS), which was conducted in 2010, in which a total of 6,220 wage workers were analyzed. The study population included the economically active population aged above 15 years, and living in the Republic of Korea. We used the chi-squared test and multivariate logistic regression to test the statistical association between presenteeism and working hours, shiftwork, and occupational stress. RESULTS: Approximately 19% of the workers experienced presenteeism during the previous 12 months. Women had higher rates of presenteeism than men. We found a statistically significant dose-response relationship between working hours and presenteeism. Shift workers had a slightly higher rate of presenteeism than non-shift workers, but the difference was not statistically significant. Occupational stress, such as high job demand, lack of rewards, and inadequate social support, had a significant association with presenteeism. CONCLUSIONS: The present study suggests that long working hours and occupational stress are significantly related to presenteeism.

Depressive symptoms as a risk factor for the common cold among employees: a 4-month follow-up study.

OBJECTIVE: The purpose of this study was to investigate the correlation between symptoms of depression in workers and the common cold. METHODS: A follow-up survey of workers at 44 small- to medium-sized companies was conducted; 1350 questionnaires were used in the final analysis. The first survey requested information regarding personal information, work characteristics and symptoms of depression (Center for Epidemiologic Studies Depression Scale); the second survey queried participants who answered the first survey about manifestations of the common cold during the previous four months. Odds ratios (ORs) were calculated using a logistic regression model, which was adjusted for potential confounders. All analyses were stratified according to gender separately. RESULTS: The ORs for reporting symptoms of the common cold were 1.36 (95% confidence interval [CI]: 1.01-1.83) and 2.27 (95% CI: 1.49-3.45) in males and females, respectively. When adjusted for age, marital status, educational level, smoking habits, alcohol consumption, exercise, sleep duration and job type, the ORs remained significant for both genders (male: 1.38; 95% CI: 1.01-1.89; female: 2.08; 95% CI: 1.32-3.23). CONCLUSIONS: The risk of self-reported manifestations of the common cold was higher in workers who reported symptoms of depression.