Ji Young Ryu

Chronic Obstructive Pulmonary Disease (COPD) and Vapors, Gases, Dusts, or Fumes (VGDF): A Meta-analysis

Abstract To evaluate the association between the risk of chronic obstructive pulmonary disease (COPD) and exposure to vapors, gases, dusts, or fumes (VGDF), we conducted a meta-analysis of epidemiological studies. We searched for studies investigating the relationship between COPD and occupational exposure to VGDF in the adult population. The bibliographic search was conducted in databases (PubMed and Google Scholar). Eleven studies that met predetermined inclusion criteria were included in the meta-analysis. We calculated the pooled odds ratio (OR) with its 95% confidence interval (CI) of COPD for exposure to VGDF using a random-effects model. The presence of publication bias was explored. There was moderate heterogeneity among the included studies (I2 = 54.3%). In a random-effects model meta-analysis, the pooled OR for exposure to VGDF was 1.43 for COPD (95% CI: 1.19–1.73) compared with no exposure to VGDF. Publication bias was not observed in this study. Our study suggests that exposure to VGDF is associated with a higher risk of COPD. Further prospective cohort studies are needed to confirm this association.

Relationship between housing characteristics, lifestyle factors and phthalates exposure: the first Korean National Environmental Health Survey (2009-2011).

Background Phthalates, the esters of phthalic acid, are widely used as plasticizers in many consumer products. Phthalate plasticizers are mainly used in the polyvinyl Chloride (PVC) products including plastic containers, toys, or flooring materials, and comprise 10 to 60 % of plastic products by weight [1]. Phthalates are also utilized as solvents of cosmetics, liquid soaps, or pesticides. About 6 million tons of phthalates were produced worldwide in 2004, of which Di (2-ethylhexyl) phthalate (DEHP) accounted for half of the entire production [2]. Phthalates are easily released from products into the environment or food by leaching, migration, evaporation or natural degradation [3]. Most phthalates are absorbed through ingestion, while low molecular weight phthalates such as Dibutyl Phthalate (DBP) can be absorbed by dermal exposure or inhalation [4]. Once absorbed, phthalates usually undergo a phase I hydrolysis to form the primary metabolites such as Mono-2-ethylhexyl phthalate (MEHP) or Mono-n-butyl phthalate (MnBP), and may proceed to further hydroxylation and oxidation or phase II conjugation before they are excreted in urine and feces [5]. Since most metabolites are excreted through urine, the urinary metabolites of phthalates are useful indices for the evaluation of phthalate exposure. MnBP, the primary metabolite of DBP, could be an appropriate biomarker for DBP exposure, since 84 % of absorbed DBP is excreted as MnBP in urine within 24 h of intake [6]. As to DEHP, secondary metabolites such as Mono (2-ethyl-5-oxohexyl) phthalate (MEOHP) and Mono (2-ethyl-5-hydroxylhexyl) phthalate (MEHHP) have been used to predict DEHP exposure [7, 8]. Many investigations have been performed regarding in vivo effects of phthalate exposure since 1970s. An animal study reported testicular atrophy and decrease of reproductive ability in mice exposed to phthalates [9]. An epidemiologic study of human indicated that exposure to phthalates in male during gestation and infancy is related to the decrease of anogenital index and testosterone levels suggesting a possible anti-androgenic effect [10]. Thus, the exposure in pregnant or lactating women and boys has been considered relatively important. However, endocrine disrupting effects of phthalates in adults also have been reported in recent studies. One study showed that phthalate exposure and testosterone levels are negatively correlated in male and female adults aged over 40 years [11]. Other study has suggested that it not only affected reproductive function, but also influenced on insulin-resistance and obesity [12]. Moreover, several studies showed that the prevalence of diseases such as asthma or ADHD has a positive correlation with phthalate exposure and relevant research is still ongoing [13–15]. The effect of phthalates on the human body is not fully investigated yet and the mechanisms involved also remain unclear. There are various products containing phthalates and most people are exposed to these products in daily living. Especially, the inside structures of a building such as flooring materials, wall paper, or window frames are thought to be important sources of phthalate exposure. Larsson et al. reported higher urinary concentrations of * Correspondence: kimdh@paik.ac.kr Department of Occupational and Environmental Medicine, Inje University Haeundae Paik Hospital, 875 Heaundae-ro, Haeundae-Gu, Busan 612-862, South Korea Full list of author information is available at the end of the article

Obstructive Pulmonary Function Impairment among Korean Male Workers Exposed to Organic Solvents, Iron Oxide Dust, and Welding Fumes

We evaluated spirometric obstructive pulmonary function impairment among workers who were occupationally exposed to organic solvents, iron oxide dust, or welding fumes. Data were collected from records of periodic health examinations of workers. In total, 448 Korean male workers were enrolled and classified into three exposure groups: exposure to organic solvents, iron oxide dust, or welding fumes. Logistic regression analysis was performed to evaluate the association between occupational exposure and pulmonary function. Compared to exposure to organic solvents, exposure to iron oxide dust was significantly associated with obstructive pulmonary function impairment (odds ratio [OR], 9.61; 95% confidence interval [CI], 2.20–41.97). The group exposed to welding fumes did not show a significantly higher OR compare to those exposed to organic solvents (OR, 2.83; 95% CI, 0.74–10.8). These results suggest that exposure to iron oxide dust has a greater association with obstructive pulmonary function impairment than exposure to organic solvents or welding fumes.

Pre-immigration Screening for Tuberculosis in South Korea: A Comparison of Smear- and Culture-Based Protocols

Background Tuberculosis (TB) is the most important disease screened for upon patient history review during preimmigration medical examinations as performed in South Korea in prospective immigrants to certain Western countries. In 2007, the U.S. Centers for Disease Control and Prevention (CDC) changed the TB screening protocol from a smear-based test to the complete Culture and Directly Observed Therapy Tuberculosis Technical Instructions (CDOT TB TI) for reducing the incidence of TB in foreign-born immigrants. Methods This study evaluated the effect of the revised (as compared with the old) protocol in South Korea. Results Of the 40,558 visa applicants, 365 exhibited chest radiographic results suggestive of active or inactive TB, and 351 underwent sputum tests (acid-fast bacilli smear and Mycobacterium tuberculosis culture). To this end, using the CDOT TB TI, 36 subjects (88.8 per 105 of the population) were found to have TB, compared with only seven using the older U.S. CDC technical instruction (TI) (p<0.001). In addition, there were six drug-resistant cases which were identified (16.7 per 105 of the population), two of whom had multidrug-resistance (5.6 per 105 of the population). Conclusion The culture-based 2007 TI identified a great deal of TB cases current to the individuals tested, as compared to older U.S. CDC TI.

Relationship between concealment of emotions at work and musculoskeletal symptoms: results from the third Korean Working Conditions Survey

In this study, we explored the relationship between concealing emotions at work and musculoskeletal symptoms in Korean workers using data from a national, population-based survey. Data were obtained from the third Korean Working Conditions Survey in 2011. We investigated the prevalence of three musculoskeletal symptoms (“back pain”, “pain in the upper extremities”, and “pain in the lower extremities”). Multiple logistic regression analysis was also performed to determine odds ratios (ORs) for musculoskeletal symptoms according to concealing emotions at work, adjusting for socioeconomic factors. In both sexes, the emotion-concealing group showed a significantly higher prevalence of “pain in the upper extremities” and “pain in the lower extremities” than the non-emotion-concealing group. For back pain, male—but not female—workers who concealed their emotions showed a higher prevalence than their non-emotion-concealing counterparts; the difference was statistically significant. Adjusted ORs for musculoskeletal symptoms (excluding “back pain” for female workers) in the emotion-concealing group were significantly higher. Our study suggests that concealment of emotions is closely associated with musculoskeletal symptoms, and the work environment should operate in consideration not only of the physical health work condition of workers but also of their emotional efforts including concealing emotion at work.

Perception of and attitude toward ethical issues among Korean occupational physicians

BackgroundOccupational physicians (OPs) have complex relationships with employees, employers, and the general public. OPs may have simultaneous obligations towards third parties, which can lead to variable conflicts of interests. Among the various studies of ethical issues related to OPs, few have focused on the Korean OPs. The aim of the present survey was to investigate the ethical contexts, the practical resolutions, and the ethical principles for the Korean OPs.MethodsAn email with a self-administered questionnaire was sent to members of the Korean Society of Occupational and Environmental Medicine, comprising 150 specialists and 130 residents. The questionnaire was also distributed to 52 specialists and 46 residents who attended the annual meeting of the Korean Association of Occupational and Environmental Clinics in October 2015, and to 240 specialists by uploading the questionnaire to the online community ‘oem-doctors’ in February 2016. The responses to each question (perception of general ethical conflicts, recognition of various ethical codes for OPs, core professional values in ethics of occupational medicine, and a mock case study) were compared between specialists and residents by the chi-squared test and Fisher’s exact test.ResultsResponses were received from 80 specialists and 71 residents. Most participants had experienced ethical conflicts at work and felt the need for systematic education and training. OPs suffered the most ethical conflicts in decisions regarding occupational health examination and evaluation for work relatedness. Over 60% of total participants were unaware of the ethical codes of other countries. Participants thought ‘consideration of worker’s health and safety’ (26.0%) and ‘neutrality’ (24.7%) as the prominent ethical values in professionality ofoccupational medicine. In mock cases, participants chose beneficence and justice for fitness for work and confidential information acquired while on duty, and beneficence and respect for autonomy in pre-placement examinations.ConclusionsThis study evaluated the current perception of and attitude toward ethical issues among the Korean OPs. These findings will facilitate the development of a code of ethics and the ethical decision-making program forthe Korean OPs.