Jae Wook Choi

Influence of GSTM1 genotype on association between aromatic DNA adducts and urinary PAH metabolites in incineration workers.

Waste incinerating workers are exposed to various pyrolysis products including polycyclic aromatic hydrocarbons (PAHs). We examined their PAH exposure by assessing urinary 1-hydroxypyrene glucuronide (1-OHPG), as a measure of internal dose, and aromatic DNA adducts in peripheral white blood cells (WBCs), as a measure of biological effect dose. The potential effect of genetic polymorphisms of three enzymes involved in PAH metabolisms (i.e., CYP1A1, GSTM1, and GSTT1) on these exposure markers was also investigated.Twenty-nine employees including workers incinerating industrial wastes and 21 non-exposed on-site controls were recruited from a company handling industrial wastes in South Korea. Sixteen ambient PAHs were determined by GC/MSD (NIOSH method) from personal breathing zone samples of nine subjects working near incinerators. Urinary 1-OHPG was assayed by synchronous fluorescence spectroscopy (SFS) after immunoaffinity purification using monoclonal antibody 8E11. Aromatic DNA adducts in peripheral WBC were measured by the nuclease P1-enhanced post-labelling assay. Genotypes were assessed by PCR-based methods. Information on smoking habits and use of personal protective equipment were collected by self-administered questionnaire. Urinary 1-OHPG levels were significantly higher in workers handling industrial wastes than in those with presumed lower exposure to PAHs (P=0.006, by Kruskal-Wallis test). A statistically significant dose-response increase in 1-OHPG levels was seen with the number of cigarettes consumed per day (r=0.686, P<0.001). Smoking and GSTM1 genotype were significant predictors for log-transformed 1-OHPG by multiple regression analysis (overall model R(2)=0.565, P<0.001), whereas smoking was the only significant predictor for log-transformed aromatic DNA adducts (overall model R(2)=0.249, P=0.201). Aromatic DNA adducts were significantly correlated with log-transformed urinary 1-OHPG level (r=0.31, P=0.04). However, the partial correlation coefficient adjusting for age, sex, and cigarette consumption was not significant (r=0.15, P=0.17). The significant association exists only in individuals with the GSTM1 null genotype (Pearsons correlation coefficient, r=0.52, P=0.01; partial correlation coefficient adjusting for age, sex, and cigarette consumption, r=0.36, P=0.04). Our results suggest that the significant increase in urinary 1-OHPG in the exposed workers is due to higher prevalence of smokers among them, and that the association between urinary PAH metabolites and aromatic DNA adducts in workers of industrial waste handling may be modulated by GSTM1 genotype. These results remain to be confirmed in future larger studies.

Cameroon public health sector: shortage and inequalities in geographic distribution of health personnel

IntroductionCameroon is classified by the World Health Organization (WHO) as having a critical shortage of health personnel. This is further complicated by the geographic distributional inequalities of the national health workforce. This shortfall impedes Cameroons’ progress of improving the human resources for health (HRH) to meet up with the Millennium Development Goals (MDGs) by 2015. However, it is unknown whether the health workforce of Cameroon is distributed equally across geographic regions. Additionally, indicators other than population levels have not been used to measure health care needs. This study aimed to assess the adequacy, evenness of distribution and challenges faced by the health workforce across the different regions of Cameroon.MethodsNational health personnel availability and distribution were assessed by use of end-of-year census data for 2011 obtained from the MoPH data base. The inequalities and distribution of the workforce were estimated using Gini coefficient and Lorenz curve and linear regression was used to determine the relation between health personnel density and selected health outcomes. Alternative indicators to determine health care needs were illustrated using concentration curves.ResultsSignificant geographic inequalities in the availability of health workforce exist in Cameroon. Some regions have a higher number of physicians (per person) than others leading to poor health outcomes across the regions. 70 % of regions have a density of health personnel-to-population per 1,000 that is less than 1.5, implying acute shortage of health personnel. Poor working and living conditions, coupled with limited opportunities for career progress accounted for some documented 232 physicians and 205 nurses that migrated from the public sector. Significant distributional inequality was noticed when under-five infant mortality and malaria prevalence rate were used as indicators to measure health care needs.ConclusionOur results show an absolute shortage of public health personnel in Cameroon that is further complicated by the geographic distributional inequalities across the regions of the nation. Cameroon aims to achieve universal health coverage by 2035; to realize this objective, policies targeting training, recruitment, retention and effective deployment of motivated and supported health workforce as well as the development and improvement of health infrastructures remain the major challenge.

INFLUENCE OF POLYMORPHISM OF GSTM1 GENE ON ASSOCIATION BETWEEN GLYCOPHORIN A MUTANT FREQUENCY AND URINARY PAH METABOLITES IN INCINERATION WORKERS

The association between urinary 1-hydroxypyrene glucuronide (1-OHPG) levels, as an internal measure of polycyclic aromatic hydrocarbon (PAH) exposure, and glycophorin A (GPA) mutation frequency, as an early biologic effect indicator, was determined to establish whether genetic polymorphisms of glutathione S -transferase (GST) isoforms GSTM1 and GSTT1 play a role. Eighty-one workers including 38 employees directly involved in incinerating industry wastes were recruited from a company located in South Korea. Urinary 1-OHPG levels were measured by synchronous fluorescence spectroscopy after immunoaffinity purification using monoclonal antibody 8E11. Erythrocyte GPA variant frequency (NN or NO) was assessed in MN heterozygotes with a flow cytometric assay. The GSTM1 and GSTT1 genotypes were assessed by a multiplex polymerase chain reaction (PCR) method. Urinary 1-OHPG levels were higher in workers handling industrial wastes than in those with presumed lower exposure to PAHs. An increase was seen in GPA variant frequency levels with increase in urinary 1-OHPG levels. When this association was evaluated by GSTM1 genotype status, the association between GPA mutation and urinary 1-OHPG levels was stronger in individuals with GSTM1 genotype. These results suggest that the association between urinary 1-OHPG and GPA mutation might be modulated by the GSTM1 genotype.

Risk perception and public concerns of electromagnetic waves from cellular phones in Korea.

In this study, the difference between the risk perception of electromagnetic waves from cellular phones and the risk perception of other factors such as environment and food was analyzed. The cause of the difference in the psychological and social factors that affect the group with high risk perception of electromagnetic waves was also analyzed. A questionnaire survey on the risk perception of electromagnetic waves from cellular phones was carried out on 1001 subjects (men and women) over the age of 20. In the group with high risk perception of electromagnetic waves from cellular phones, women had higher risk perception than men. Logistic regression analysis, where the group with high risk perception of electromagnetic waves and the group with low risk perception were used as dependent variables, indicated that the risk perception of electromagnetic waves in women was 1.815 times statistically significantly higher than the risk perception of men (95% CI: 1.340-2.457). Also, high risk perception of electromagnetic waves from cellular phones was observed when the subjects considered that they had more personal knowledge (OR: 1.416, 95% CI: 1.216-1.648), that the seriousness of the risk to future generations was high (OR: 1.410, 95% CI: 1.234-1.611), and their outrage for the occurrence of accidents related to electromagnetic waves was high (OR: 1.460, 95% CI: 1.264-1.686). The results of this study need to be sufficiently considered and reflected in designing the risk communication strategies and communication methods for the preventive measures and advice on electromagnetic waves from cellular phones.

A study on the risk perception of light pollution and the process of social amplification of risk in Korea

In this study, the risk perception level of each light pollution type was analyzed, and the effects of the variables (e.g., psychometric paradigm factor, trust in the government, etc.) on the process of the increase in the risk perception were analyzed. For the sample population (1096 persons) in Korea, the risk perception levels of each light pollution type and other environmental and health risk factors were compared, and the relative magnitude was examined. In addition, to test which variables affect the group with high-risk perception of each light pollution type, a logistic regression analysis was performed. For the group with highest risk perception of light pollution, the odds ratios (OR) of all psychometric paradigms (excluding controllability) increased compared to those of the group with low-risk perception. Additionally, the level showing the acquisition of information from the media and the recollection level of media criticism on each light pollution type showed a statistically significant increase. Especially, the risk perception of light trespass increased as trust in the government decreased. The significance of this study includes the finding that the public’s risk perception of light pollution was significantly affected by the psychometric paradigm factors. Moreover, this study analyzed the differences of the variables that affect the increase in the risk perception of each light pollution type and provided a theoretical framework that can practically reflect the strategy for the risk communication of light pollution.

A nationwide study of patients hospitalised for poisoning in Korea based on Korea National Hospital Discharge In-Depth Injury Survey data from 2005 to 2009

Objectives In light of the need to develop an integrated database on poisoning incidents in Korea, this study seeks to determine the characteristics of poisoning incidents in Korea by age, gender, location of incident, causative substance and patient prognosis. Data sources The Korea National Hospital Discharge In-Depth Injury Survey results (2005–2009) from the Korea Centers for Disease Control and Prevention were used. Participants 3826 participants in the survey who had been hospitalised for poisoning incidents. Results The poisoning hospitalisation rate per 100 000 population was higher in women (1.735) than in men (1.372) and increased with age: the rate was 0.458 among individuals aged ≤9 years, 0.481 among those aged 10–19 years, 1.584 among those aged 20–64 years and 4.053 among those aged ≥65 years. The intentional poisoning hospitalisation rate differed by gender and age group. Women aged ≤19 years and 20–64 years showed a higher hospitalisation rate than men, while men aged ≥65 years showed a higher hospitalisation rate than women in the same age group. The most common poisoning substance was pesticides (33.6%), while antiepileptic, sedative-hypnotic and antiparkinsonism drugs and psychotropic drugs, not elsewhere classified were also very common. Poisoning in those aged ≤9 years usually involved other drugs, while pesticides were the most common substances in those aged 20–64 years and ≥65 years. Conclusions This study analysed poisoning incidents in Korea from 2005 to 2009, by age and gender, causative substance, and characteristics. The results of this study may serve as evidence for new strategies in Korea to prevent poisoning.

High Incidence of Breast Cancer in Light-Polluted Areas with Spatial Effects in Korea

We have reported a high prevalence of breast cancer in light-polluted areas in Korea. However, it is necessary to analyze the spatial effects of light polluted areas on breast cancer because light pollution levels are correlated with region proximity to central urbanized areas in studied cities. In this study, we applied a spatial regression method (an intrinsic conditional autoregressive [iCAR] model) to analyze the relationship between the incidence of breast cancer and artificial light at night (ALAN) levels in 25 regions including central city, urbanized, and rural areas. By Poisson regression analysis, there was a significant correlation between ALAN, alcohol consumption rates, and the incidence of breast cancer. We also found significant spatial effects between ALAN and the incidence of breast cancer, with an increase in the deviance information criterion (DIC) from 374.3 to 348.6 and an increase in R2 from 0.574 to 0.667. Therefore, spatial analysis (an iCAR model) is more appropriate for assessing ALAN effects on breast cancer. To our knowledge, this study is the first to show spatial effects of light pollution on breast cancer, despite the limitations of an ecological study. We suggest that a decrease in ALAN could reduce breast cancer more than expected because of spatial effects.

The correlations between oxidative stress markers and indoor volatile organic compounds among the general population in Ansan and Incheon cities, Korea

Indoor VOC and aldehydes may increase oxidative stress for home dwellers. Our study aim was to determine the correlations between oxidative stress markers in subjects and exposure to VOC and aldehydes in homes. Among ninety five control subjects in Ansan and Incheon (South Korea), blood samples were collected for evaluation of total antioxidant capacity, malondialdehyde (MDA) in plasma, protein carbonyl, and DNA damage of lymphocytes. Indoor VOC and aldehydes were measured in the homes of the subjects. A partial correlation analysis was performed to assess the association between oxidative stress markers and VOC/aldehydes with adjustment for formaldehyde levels. There were significant correlations between the total antioxidant capacity and some chemicals, including heptanes, α-pinene, β-pinene, and decanal in the young age (10–19 years) group. The many correlations between VOC/aldehydes and DNA damage expressed as the Olive tail moment showed statistically significant in the middle (20–39 years) and older age (40–59 years) groups, but not in the young age group. These correlation could not account for the exposure to specific chemicals being related to an increase in DNA damage because most VOC/aldehydes were highly correlate exac other except some chemicals. In conclusion, we found that DNA damage of T- and B-lymphocytes evaluated by the Comet assay could be sensitive oxidative stress markers to evaluate the human response to VOC/ aldehydes exposure in middle and older age groups. Our study also showed that age affected the association between VOC/aldehydes exposure and oxidative stress markers including DNA damage and antioxidants. However, further studies are needed to confirm these correlations in a larger number of subjects because of limitations of this study, including a lack of personal exposure.

A cross-sectional study of the association between mobile phone use and symptoms of ill health

Objectives This study analyzed the associations between mobile phone call frequency and duration with non-specific symptoms. Methods This study was conducted with a population group including 532 non-patient adults established by the Korean Genome and Epidemiology Study. The pattern of phone call using a mobile phone was investigated through face-to-face interview. Structured methods applied to quantitatively assess health effects are Headache Impact Test-6 (HIT-6), Psychosocial Well-being Index-Short Form, Beck Depression Inventory, Korean-Instrumental Activities of Daily Living, Perceived Stress Scale (PSS), Pittsburgh Sleep Quality Index, and 12-item Short Form Health Survey where a higher score represents a higher greater health effect. Results The average daily phone call frequency showed a significant correlation with the PSS score in female subjects. Increases in the average duration of one phone call were significantly correlated with increases in the severity of headaches in both sexes. The mean (standard deviation) HIT-6 score in the subgroup of subjects whose average duration of one phone call was five minutes or longer was 45.98 (8.15), as compared with 42.48 (7.20) in those whose average duration of one phone call was <5 minutes. The severity of headaches was divided into three levels according to the HIT-6 score (little or no impact/moderate impact/substantial or severe impact), and a logistic regression analysis was performed to investigate the association between an increased phone call duration and the headache severity. When the average duration of one phone call was five minutes or longer, the odds ratio (ORs) and the 95% confidence intervals (CIs) for the moderate impact group were 2.22 and 1.18 to 4.19, respectively. The OR and 95% CI for the substantial or severe impact group were 4.44 and 2.11 to 8.90, respectively. Conclusions Mobile phone call duration was not significantly associated with stress, sleep, cognitive function, or depression, but was associated with the severity of headaches.

A follow-up study of the association between mobile phone use and symptoms of ill health

The duration and frequency of mobile phone calls, and their relationship with various health effects, have been investigated in our previous cross-sectional study. This 2-year period follow-up study aimed to assess the changes in these variables of same subjects. The study population comprised 532 non-patient adult subjects sampled from the Korean Genome Epidemiology Study. The subjects underwent a medical examination at a hospital in 2012/2013 and revisited the same hospital in 2014/2015 to have the same examination for the characteristics of mobile phone use performed. In addition, to evaluate the effects on health, the Headache Impact Test-6 (HIT-6), Psychosocial Well-being Index-Short Form, Beck Depression Inventory, Korean-Instrumental Activities of Daily Living, Perceived Stress Scale, Pittsburgh Sleep Quality Index, and 12-item Short Form Health Survey were analyzed. For all these tests, the higher the score, the greater the effect on health. Variances between scores in all the indices in the baseline and follow-up surveys were calculated, and correlations of each index were analyzed. The average duration per call and HIT-6 score of the subjects decreased significantly compared with those recorded two years ago. The results showed a slight but significant correlation between call duration changes and HIT-6 score changes for female subjects, but not for males. HIT-6 scores in the follow-up survey significantly decreased compared to those in the baseline survey, but long-time call users (subjects whose call duration was ≥5 minutes in both the baseline and follow-up surveys) had no statistically significant reduction in HIT-6 scores. This study suggests that increased call duration is a greater risk factor for increases in headache than any other type of adverse health effect, and that this effect can be chronic.