Development of a multipotent diagnostic tool for chest X-rays by multi-object detection method.

The computer-aided diagnosis (CAD) for chest X-rays was developed more than 50 years ago. However, there are still unmet needs for its versatile use in our medical fields. We planned this study to develop a multipotent CAD model suitable for general use including in primary care areas. We planned this study to solve the problem by using computed tomography (CT) scan with its one-to-one matched chest X-ray dataset. The data was extracted and preprocessed by pulmonology experts by using the bounding boxes to locate lesions of interest. For detecting multiple lesions, multi-object detection by faster R-CNN and by RetinaNet was adopted and compared. A total of twelve diagnostic labels were defined as the followings: pleural effusion, atelectasis, pulmonary nodule, cardiomegaly, consolidation, emphysema, pneumothorax, chemo-port, bronchial wall thickening, reticular opacity, pleural thickening, and bronchiectasis. The Faster R-CNN model showed higher overall sensitivity than RetinaNet, nevertheless the values of specificity were opposite. Some values such as cardiomegaly and chemo-port showed excellent sensitivity (100.0%, both). Others showed that the unique results such as bronchial wall thickening, reticular opacity, and pleural thickening can be described in the chest area. As far as we know, this is the first study to develop an object detection model for chest X-rays based on chest area defined by CT scans in one-to-one matched manner, preprocessed and conducted by a group of experts in pulmonology. Our model can be a potential tool for detecting the whole chest area with multiple diagnoses from a simple X-ray that is routinely taken in most clinics and hospitals on daily basis.

Characteristics of particulate matter generated while handling municipal household waste.

OBJECTIVES: This study was conducted to assess the size characteristics of particulate matter (PM) generated during waste collection and sorting, and to assess the effect of the type of waste-handling activity on levels of coarse and fine PM. METHODS: A portable aerosol spectrometer calibrated to 1.2 //min was used to monitor PM generated during four types of waste-handling activities. The types of PM measured included inhalable particulate matter (IPM), PM10, respirable particulate matter (RPM), PM2.5 and PM1. Twenty-eight data sets with 3,071 subsets recorded every 6 sec were categorized according to occupational and environmen¬tal classifications, including type of waste-handling activity. An ANOVA was used to compare PM levels characterized by size. Significant variables with p-values <0.25 were included in a multiple regression model for predicting levels of each PM. RESULTS: The average levels of PM10 and PM2.5 greatly exceeded the air-quality levels enforced by the Korean Ministry of the Environment. The highest PM2.5 fine-particle levels monitored were during waste-transfer work, while the highest IPM and PM10 coarse-particle levels monitored were during waste-sorting work. The type of waste-collection activity was the only factor that significantly affected both PM25 and IPM, accounting for 36% (p=0.0034) and 40% (p=0.0049), respectively, of the observed variations. None of the factors affected PM10 or RPM levels. CONCLUSIONS: Waste-collection and Waste-transfer work may be associated with the generation of high levels of fine PM, which can be influenced by environ Workmental conditions such as traffic levels and the type of waste transport vehicle.

Corrigendum: Necessity for a National Carcinogen List in Korea, Based on International Harmonization.

[This corrects the article on p. e2013008 in vol. 28, PMID: 23882448.].

Necessity for a national carcinogen list in Korea, based on international harmonization.

Cancer has been the leading cause of death in Korea for the last 30 years. Cancer patients' 5-year survival rate between 2005 and 2009 was 62.0%, representing a highly advanced standard of care, as much as developed countries in the EU and the US. The Korean government formulated its first 10-year plan for cancer control in 1996 and has been carrying out a second 10-year plan for cancer control since 2006. But despite the Korean government's efforts, the cancer burden in Korea continues to increase. Many separate laws have gone into effect concerning the management of carcinogen exposure. However, there are no integrated regulatory laws or management systems against carcinogen exposure in Korea. Dead zones remain where carcinogen exposure cannot be controlled properly in Korea. In this paper, we suggest the need to establish a national carcinogen list based on international harmonization as a prerequisite for a paradigm shift in cancer control policy from treatment to primary prevention.

Airborne bacteria and fungi associated with waste-handling work.

BACKGROUND: Municipal workers handling household waste are potentially exposed to a variety of toxic and pathogenic substances, in particular airborne bacteria, gram-negative bacteria (GNB), and fungi. However, relatively little is known about the conditions under which exposure is facilitated. METHODS: This study assessed levels of airborne bacteria, GNB, and fungi, and examined these in relation to the type of waste-handling activity (collection, transfer, transport, and sorting at the waste preprocessing plant), as well as a variety of other environmental and occupational factors. Airborne microorganisms were sampled using an Andersen single-stage sampler equipped with agar plates containing the appropriate nutritional medium and then cultured to determine airborne levels. Samples were taken during collection, transfer, transport, and sorting of household waste. Multiple regression analysis was used to identify environmental and occupational factors that significantly affect airborne microorganism levels during waste-handling activities. RESULTS: The "type of waste-handling activity" was the only factor that significantly affected airborne levels of bacteria and GNB, accounting for 38% (P = 0.029) and 50% (P = 0.0002) of the variation observed in bacteria and GNB levels, respectively. In terms of fungi, the type of waste-handling activity (R2 = 0.76) and whether collection had also occurred on the day prior to sampling (P < 0.0001, R2 = 0.78) explained most of the observed variation. Given that the type of waste-handling activity was significantly correlated with levels of bacteria, GNB, and fungi, we suggest that various engineering, administrative, and regulatory measures should be considered to reduce the occupational exposure to airborne microorganisms in the waste-handling industry.

The "Chair Campaign" in Korea: an alternative approach in occupational health and safety for service workers.

In spite of the increasing number of service workers in Korea, their occupational health and safety concerns have largely been neglected. It is in this context that the Chair Campaign, which lasted four months, was launched as an alternative occupational health approach for service workers. The campaign succeeded in getting wide public support, bringing about a special inspection by the Ministry of Labor. Finally, chairs were provided for workers at checkout counters in 71 department stores and 449 large discount stores. However, there are still many workplaces where workers cannot sit, whether chairs are provided or not. Although there is still much to be done, this campaign raised social awareness that service workers, mainly women, have the right to work in healthy and safe conditions. This paper will review the campaign and evaluate its achievements and limitations.

An assessment of dust, endotoxin, and microorganism exposure during waste collection and sorting.

This study was conducted to assess inhalation exposure to dust, endotoxin, and microorganisms (including viable bacteria, Gram-negative bacteria [GNB], and fungi) during waste collection and sorting; to identify factors affecting this exposure; and to estimate the gastrointestinal exposure to microorganisms. A total of 48 or 49 workers involved in collecting and sorting waste from households or the street were studied. Each worker carried two personal samplers in which filters were placed in the breathing zone for estimation of inhalation exposure. To assess the possibility of gastrointestinal exposure, microorganisms on the workers' faces were collected before and after work and compared with those collected from office workers. Inhalation exposure levels were categorized according to job title, waste type handled, and working conditions and were compared using analysis of variance. Multiple regression models were developed to identify those factors that substantially affected inhalation exposure. The average exposure level to total dust was 0.9 mg/m3 (range = 0.05 to 4.51 mg/m3), and the average exposure to endotoxin was 1123 EU/m3. The average respective exposure levels to bacteria, GNB, and fungi each exceeded 10(4) colony forming units (CFU)/m3. The multiple regression models found several factors that significantly explained the variation in levels of inhalation exposure to endotoxin and microorganisms; namely, sex (dust, bacteria, and GNB), job title (GNB and fungi), collection day (dust, bacteria, and GNB), temperature (endotoxin and GNB), humidity (endotoxin and fungi), and region (endotoxin) were significantly associated with exposure to these agents. In addition, the workers' faces were highly contaminated with microorganisms. In conclusion, inhalation exposure to endotoxin and microorganisms was high during waste collection and sorting, which may place workers at risk of developing various health problems, including respiratory complaints.

Vaporization and Conversion of Ethanolamines used in Metalworking Operations.

OBJECTIVES: This study examined how ethanolamines (EAs) with the same functional alcohol group (HOCH(2)CH(2)), such as mono-EA (MEA), di-EA (DEA), and tri-EA (TEA), in water-based metalworking fluids (wbMWFs) are vaporized, condensed, and transformed by heat generated during metalworking. METHODS: Two types of experimental apparatus were manufactured to achieve these objectives. RESULTS: Vaporization tests using a water bath showed that the vaporization rate increased markedly from 0.19 mg/m(2)·min at 23.5℃ to 8.04 mg/m(2)·min at 60℃. Chamber tests with a heat bulb revealed that "spiked" MEA was fully recovered, while only 13.32% of DEA and no TEA were recovered. Interestingly, non-spiked types of EAs were detected, indicating that heat could convert EAs with more alcohol groups (TEA or DEA) into other EAs with fewer group(s) (DEA or MEA). The EA composition in fresh fluid was 4% DEA, 66% TEA, and 30% MEA, and in used fluids (n = 5) was 12.4% DEA, 68% TEA, and 23% MEA. Conversion from TEA into DEA may therefore contribute to the DEA increment. Airborne TEA was not detected in 13 samples taken from the central coolant system and near a conveyor belt where no machining work was performed. The DEA concentration was 0.45 mg/m(3) in the only two samples from those locations. In contrast, airborne MEA was found in all samples (n = 53) regardless of the operation type. CONCLUSION: MEAs easily evaporated even when MWFs were applied, cleaned, refilled, and when they were in fluid storage tanks without any metalworking being performed. The conversion of TEA to DEA and MEA was found in the machining operations.

Exposure assessment to suggest the cause of sinusitis developed in grinding operations utilizing soluble metalworking fluids.

A worker who ground the inner parts of camshafts for automobile engines using water-soluble metalworking fluid (MWF) for 14 yr was diagnosed with sinusitis. We postulated that the cause of sinusitis might be associated with exposure to microbes contaminating the water-soluble MWF used in the grinding operation. To uncover responsible agents for this case of sinusitis, a quantitative exposure assessment for chemical and biological agents was made and prevalence of work-related respiratory symptoms was investigated by questionnaire. The exposure ranges of MWF mist (0.59 mg/m(3) to 2.12 mg/m(3)) measured during grinding exceeded 0.5 mg/m(3) of the recommended exposure limit (REL). Grinders' exposures to bacteria, fungi and endotoxins were also generally higher than not only the proposed standards, but also those reported by several studies investigating the causes of respiratory effects. Statistical tests indicated that the prevalence rate of reported symptoms related to nasal cavities showed no significant differences among the operations. Evaluation of grinding operation characteristics and the quantitative exposure assessment indicated that repeated exposure to MWF mist, including water-soluble MWF contaminated with microbes may cause respiratory diseases like sinusitis or at least increase susceptibility to the development of sinusitis. Further study is underway to identify environmental risk factors for sinusitis by analyzing the relationship between medical examination results and plant characteristics including exposure data.

Loss of straight metalworking fluid samples from evaporation during sampling and desiccation.

Straight metalworking fluids (MWFs) were used to evaluate the potential for the loss of MWF mass from filters. Two methods were used to study the stability of MWF mass on filter media. The first was to spike known amounts of MWF onto polyvinyl chloride (PVC) filters, store the filters over silica gel desiccant, and take repeated gravimetric measurements of the filters at intervals of 1, 2, and 3 days. An MWF aerosol mist was generated in a test chamber and collected on PVC filters for the second experimental method. Additional clean air was drawn through a subset of filters (range 0.02-0.48 m(3)), which were then stored over silica gel prior to weighing. Losses due to desiccation were found in filters that had not been exposed to airflow, as well as for filters after aspiration. The losses occurring in spiked filters (range of mean 2.6-15.2%) were higher than those in collected filters (range 0.7-8.1%). The MWF aerosol mass collected on PVC filters decreased with the increasing volume of clean air passing through the filter. In a multiple regression model, to predict the loss of collected MWF due to desiccation, loading mass, fresh MWF, and air passing time of 10 min were significant predictors (p=.0001, R(2)=.374). In particular, only air passage of 10 min was significantly higher (2.13%) than the reference air passage (p=.0054). The investigators concluded that MWF aerosol collected on PVC filters may be lost to evaporation under conditions typical of shipment, storage, and desiccation of sample filters, and with airflow through the filter.