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Journal: Environmental health and toxicology

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Radon, the primary constituent of natural radiation, is the second leading environmental cause of lung cancer after smoking. To confirm a relationship between indoor radon exposure and lung cancer, estimating cumulative levels of exposure to indoor radon for an individual or population is necessary. This study sought to develop a model for estimate indoor radon concentrations in Korea. Especially, our model and method may have wider application to other residences, not to specific site, and can be used in situations where actual measurements for input variables are lacking.

Concepts: Cancer staging, Background radiation, Mathematics, Tobacco smoking, Ionizing radiation, Cancer, Lung cancer, Radon

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The purpose of this study is to introduce the establishment process, policy target, and projects for “Chungnam’s master plan on environmental health policy (2017-2020)” as the local government’s role in addressing local environmental health challenges. We first analyzed existing studies and social issues on the media related to “Chungnam’s master plan” to understand Chungnam’s environmental health status and discussed domestic and international policy trends and related plans. An environmental health perception questionnaire survey and a Delphi expert questionnaire survey were conducted among provincial residents to collect various actors' opinions on Chungnam’s environmental health issues and policy. An expert advisory panel was launched, and a residents' voice workshop and cities-and-guns-policy-suggestion workshop were held. The vision of Chungnam’s environmental health policy is minimizing environmental hazards. We finally selected “Pleasant environment, healthy people, happy Chungnam” to represent the will to shape a pleasant environment and prevent and manage health damages for a happy Chungnam. We selected five strategies based on status analysis and a review of domestic and international policy trends and related plans and identified 2 targets (policy objectives) to accomplish the strategies. The strategies to achieve the first target, “Leader in environmental health policy: Chungnam,” include “Empowering active provincial capabilities,” “Setting up province-specific systems for environmental health surveys and research,” and “Preventing and managing newly emerging pollutants.” The strategies for the second target, “Everyone is healthy: Chungnam,” include “Relieving health inequalities among vulnerable regions and residents” and “Enlarging the resident-friendly environmental health policy.” We developed 29 projects in total, according to these strategies. The establishment of “Chungnam’s master plan” is highly valuable; we developed it through discussion involving diverse actors to address environmental health challenges together. It is necessary to continue to strengthen participation, communication, and cooperation among actors to develop an environmental health policy model for the future.

Concepts: Population health, Government, Health care, Health economics, Medicine, Target Corporation, Health, Plan

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This study utilized the Community Multi-scale Air Quality (CMAQ) model to simulate the spatial distribution of benzene, toluene, and xylene (BTX) concentrations in Ulsan metropolitan region (UMR), where large national industrial complexes (IC) are located. Through controlling the pollutant emissions in major IC, this study has performed a quantitative analysis on the influence of pollutant emissions from the IC on the BTX concentrations in surrounding urban areas. The seasonal modeling results indicated that the average BTX concentrations were high around the petrochemical complexes, with higher concentrations in the surrounding urban areas during the summer. The results of the emission control modeling in major IC showed that approximately 40% of the annual average BTX concentrations of nearby urban grids were directly influenced by pollutant emissions from the IC. While all three of the BTX pollutants showed similar seasonal differences, their contributions were highest during July. Daily contributions differed significantly throughout the modeling period, with some values reaching a maximum of 80% during July; overall, when the urban areas were located downwind of the IC, the contributions rose. Moreover, this study compared the differences in BTX contributions at each measurement point within the IC and urban areas, which indicated that the influence of the IC emissions decreased significantly with distance. The spatial distribution and the direct influence of the IC on the BTX concentrations in the UMR identified through this study could be used for basic data in environmental epidemiological studies.

Concepts: Ethylbenzene, Urban area, City, Metropolitan area, Soil contamination, Xylene, Toluene, Benzene

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The role of infectious agents in the etiology of inflammatory diseases once believed to be non-infectious is increasingly being recognized. Many bacterial components in the indoor dust can evoke inflammatory lung diseases. Bacteria secrete nanometer-sized vesicles into the extracellular milieu, so-called extracellular vesicles (EVs). which are pathophysiologically related to inflammatory diseases. Microbiota compositions in the indoor dust revealed the presence of both gram-negative and gram-positive bacteria. Escherichia coli is a model organism of gram-negative Enterobacteriaceae. The repeated inhalation of E. coli-derived EVs caused neutrophilic inflammation and emphysema in a dose-dependent manner. The emphysema induced by E. coli-derived EVs was partially eliminated by the absence of IFN-gamma or IL-17, suggesting that Th1 and/or Th17 cell responses are important in the emphysema development. Meanwhile, the repeated inhalation of Staphylococcus aureus-derived EVs did not induce emphysema, although they induced neutrophilic inflammation in the lung. In terms of microbial EV compositions in the indoor dust, genera Pseudomonas, Acinetobacter, Enterobacter, and Staphylococcus were dominant. As for the clinical significance of sensitization to EVs in the indoor dust, EV sensitization was closely associated with asthma, COPD, and lung cancer. These data indicate that biological ultrafine particles in the indoor dust, which are mainly composed of microbial EVs, are important in the pathogenesis of chronic lung diseases associated with neutrophilic inflammation. Taken together, microbial EVs in the indoor dust are an important diagnostic and therapeutic target for the control of chronic lung diseases, such as asthma, COPD, and lung cancer.

Concepts: Microbiology, Chronic obstructive pulmonary disease, Infection, Pneumonia, Immune system, Escherichia coli, Asthma, Bacteria

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In this economic evaluation of environmental epidemiological monitoring projects, we analyzed the economic feasibility of these projects by determining the social cost and benefit of these projects and conducting a cost/benefit analysis. Here, the social cost was evaluated by converting annual budgets for these research and survey projects into present values. Meanwhile, the societal benefit of these projects was evaluated by using the contingent valuation method to estimate the willingness to pay of residents living in or near industrial complexes. In addition, the extent to which these projects reduced negative health effects (i.e., excess disease and premature death) was evaluated through expert surveys, and the analysis was conducted to reflect the unit of economic value, based on the cost of illness and benefit transfer method. The results were then used to calculate the benefit of these projects in terms of the decrease in negative health effects. For residents living near industrial complexes, the benefit/cost ratio was 1.44 in the analysis based on resident surveys and 5.17 in the analysis based on expert surveys. Thus, whichever method was used for the economic analysis, the economic feasibility of these projects was confirmed.

Concepts: Contingent valuation, Value, Cost-benefit analysis, Costs, Sociology

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The objective of this study was to verify a change in the longitudinal trend of blood lead levels for the Korean population, before and after the regulation of leaded gasoline-which occurred between 1987 and 1993 in Korea. A total of 77 general Korean population blood lead level reports from between 1981 and 2014 were selected, and the results were summarized to have the variables of year, number of subjects,the subjects' range in age, sex and blood lead concentrations (arithmetic mean). The annual average lead levels for four major cities, i.e., Seoul, Busan, Daegu and Gwangju were collected from The Air Pollution Monitoring Database from 1991, and pilot studies from 1985 to 1990 before the national air quality monitoring system was launched in 1991. Furthermore, blood lead levels were visualized in a bubble plot in which the size of each bubble represented the sample size of each study, and the annual average concentrations in ambient air were depicted on line graphs. Blood lead levels in the Korean population tended to gradually increase from the early 1980s (approximately 15-20 ug/dL) until 1990-1992 (20-25 ug/dL). Blood lead levels then began to rapidly decrease until 2014 (<2 ug/dL). Similar patterns were observed for both adults (≥9 years) and younger children/adolescents. The same longitudinal trend was observed in annual average air lead concentration, which suggests a significant correlation between air lead concentration and blood lead concentration in the general population. The regulation of leaded gasoline has significantly contributed to the rapid change in blood lead concentrations. Consequently, the regulation of other sources of lead exposure should be considered to further decrease blood lead levels in the Korean population.

Concepts: Korea, Gasoline, Blood lead level, South Korea, Seoul, Arithmetic mean, Lead, Lead poisoning

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The rapidly increasing annual global volume of e-waste, and of its inherently valuable fraction, has created an opportunity for individuals in Agbogbloshie, Accra, Ghana to make a living by using unconventional, uncontrolled, primitive and crude procedures to recycle and recover valuable metals from this waste. The current form of recycling procedures releases hazardous fractions, such as heavy metals, into the soil, posing a significant risk to the environment and human health. Using a handheld GPS, 132 soil samples based on 100 m grid intervals were collected and analysed for cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn). Using geostatistical techniques and sediment quality guidelines, this research seeks to assess the potential risk these heavy metals posed to the proposed Korle Ecological Restoration Zone by informal e-waste processing site in Agbogbloshie, Accra, Ghana. Analysis of heavy metals revealed concentrations exceeded the regulatory limits of both Dutch and Canadian soil quality and guidance values, and that the ecological risk posed by the heavy metals extended beyond the main burning and dismantling sites of the informal recyclers to the school, residential, recreational, clinic, farm and worship areas. The heavy metals Cr, Cu, Pb and Zn had normal distribution, spatial variability, and spatial autocorrelation. Further analysis revealed the decreasing order of toxicity, Hg > Cd > Pb > Cu> Zn > Cr, of contributing significantly to the potential ecological risk in the study area.

Concepts: Metal, Copper, Cadmium, Soil, Recycling, Heavy metal music, Lead, Zinc

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Humidifier disinfectant damage was terrible chemical damage caused by household goods that happened in only South Korea, but it is still very little known in humidifier disinfectant damage. Up to now, previous research tried to focus on interstitial fibrosis on terminal bronchiole and alveoli because it is specific finding, compared with other diseases. To figure out overall effects from HDs, many epidemiologic and toxicologic research is underway. Humidifier disinfectants showed to give rise to typical toxicologic effects on various target organs, such as skin, conjunctiva, naval mucosa, bronchial mucosa, alveoli and so on, which were sharing common toxicological responses. On specific target, specific toxicologic effects existed. Diverse diseases along exposure pathways can occur at the same time with common toxicologic mechanism and cause of humidifier disinfectants, which can be called as humidifier disinfectants syndrome. To gain more strong scientific evidence about it, further epidemiological and toxicological studies should be applied.

Concepts: Research, Demography, Cancer, Bronchiole, Scientific method, Infectious disease, Disease, Epidemiology

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Inferring causality is necessary to achieve the goal of epidemiology, elucidating the cause of disease. Causal inference is conducted in three steps; evaluation of validity of the study, inference of general causality and inference of individual causality. To evaluate validity of the study, we proposed a checklist which focuses on biases and generalizability. For general causal inference, Hill’s 9 viewpoints can be used. Individual causality can be inferred based on the general causality and evidence of exposure. Additional considerations may be needed for social or legal purposes; however, these additional considerations should be based on the scientific truth elucidated by the causal inference described in the present article.

Concepts: Reasoning, Epidemiology, Inference, Causality, Logic

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Carcinogenesis is a complex process involving in genotoxic and non-genotoxic pathways. Carcinogenic potential of AgNPs has been predicted by genotoxic effects using several in vitro and in vivo models. However, there is no little information on non-genotoxic effects of AgNPs for carcinogenesis. In vitro cell transformation assay (CTA) can provide specific and sensitive evidence to predict the tumorigenic potential of a chemical, which cannot be supplied by genotoxicity testing. Therefore, we carried out CTA in Balb/c 3T3 A31-1-1 cells to evaluate the carcinogenic potential of silver nanoparticle (AgNPs). Colony forming efficiency (CFE) assay, and crystal violet (CV) assay were carried out to find cytotoxicity of AgNPs. Cytokinesis-block micronucleus assay (CBMN) and CTA in Balb/c 3T3 A31-1-1 cells were performed to predict in vitro carcinogenic potential of AgNPs. In CBMN assay, AgNPs (10.6 ug/mL) induced a significant increase of the micronucleus formation indicating that AgNPs had genotoxicity and could be an initiator for carcinogenesis. In CTA assay to assess carcinogenic potential of AgNPs, cells exposed to AgNPs for 72 h significantly induced morphological neoplastic transformation at all treated doses (0.17, 0.66, 2.65, 5.3, and 10.6 ug/mL) and Tf (transformation frequency) showed a significant increase in a dose-dependent manner. These results indicated that short-term exposure (72 h) to AgNPs had in vitro carcinogenetic potency in Balb/c 3T3 A31-1-1 cells.

Concepts: Toxicology, Cancer, Nanotechnology, Carcinogenesis, In vivo, In vitro, Mutagen, Oncology