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Journal: Environmental health and toxicology

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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

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In this study, the associations between mercury exposure and cholesterol profiles were analyzed, and increased mercury levels and cholesterol profiles according to the amount of fish consumption were evaluated.

Concepts: According to Jim, Health, Mercury, Nutrition

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Complexity and heterogeneity of soil samples have often implied the inclusion of purification steps in conventional DNA extraction for PCR assays. Unfortunately the purification steps are also time and labor intensive. Therefore the necessity of DNA purification was re-visited and investigated for a variety of environmental soil samples that contained various amounts of PCR inhibitors.

Concepts: Gene expression, Labor, Soil, Laboratory techniques, Archaea, Polymerase chain reaction, Molecular biology, DNA

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The purpose of this study is to examine whether water and air pollutants have a relationship with an increase in the genetic disorders Turner syndrome and Down syndrome, which are caused by congenital chromosomal abnormalities, and to generate a hypothesis about the genetic health effects of environmental pollutants. A panel regression based on random effect was conducted on South Korea’s metropolitan councils from 2012 to 2014. The dependent variable was the number of Turner syndrome and Down syndrome cases, and the main independent variables were those regarding the water and air pollution. Air pollutants did not have a significant impact on the number of Turner syndrome and Down syndrome cases; however, the increase in number of wastewater discharge companies did have a significant relationship with the number of cases. The more the number of wastewater discharge companies, the more the number Turner syndrome and Down syndrome cases were observed. Therefore, scientific investigation on water and air pollutants in relation with genetic health effects needs to be performed.

Concepts: Aneuploidy, Biofilter, Acid rain, Environmentalism, Cruise ship pollution, Scientific method, Genetic disorders, Pollution

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The rapidly increasing annual global volumes and the inherently valuable fractions of e-waste have created an avenue for individuals in Agbogbloshie, Accra, Ghana to make a living by utilizing unconventional, uncontrolled, primitive and crude procedures to recycle and recover valuable metals from these wastes. The current form of recycling procedures releases hazardous fractions such as heavy metals into the soils posing a significant risk to ecology and human health. 132 soil samples based on 100 m grid intervals were collected using handheld GPS and analyzed for Cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) heavy metals. Using geostatistical techniques and sediment quality guidelines (SQGs), 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. Cr, Cu, Pb and Zn heavy metals reveal normal distribution, spatial variability and spatial autocorrelation. Further analysis reveals, Hg>Cd>Pb>Cu>Zn>Cr decreasing toxicity order to contribute significantly to the potential ecological risk in the study area.

Concepts: Waste management, Chromium, Cadmium, Copper, Recycling, Heavy metal music, Zinc, Lead

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It is widely accepted that relatively small parts of chronic diseases can be explained by genetic factors alone. Although environmental exposures are important to evaluate chronic diseases comprehensively, they are not assessed with sufficient comprehensiveness and accuracy in contrast to genome. To emphasize the importance of more complete evaluation of environmental exposure, the concept of exposome, which indicates the entirety of environmental exposure from conception onwards, was introduced in 2005. Since 2010s, several epidemiological studies, such as the Human Early-Life Exposome (HELIX) project, have applied the exposome concept. The exposome consists of three overlapping domains: a general external, specific external, and internal environment. General external factors include broader socioeconomic environment, and specific external factors include lifestyles, occupation, and pollutant exposure. Internal factors include biological effects and response. Because the exposome covers exposures from conception to death, birth cohort is an important part of the exposome study. Although there is no established consensus in selecting what, when, and where to measure exposome yet, use of omics analyses, especially metabolome, should be considered to implement the exposome concept in the birth cohort. The exposome needs to be measured repeatedly in certain important phases of life stage, such as during pregnancy and infancy. To perform exposome-informed epidemiologic study, untargeted data-driven approach with dimension reduction techniques needs to be developed and refined. The exposome concept has a potential to make a breakthrough in the limitations of conventional epidemiology. National and international consorted efforts are required for future exposome studies.

Concepts: Demography, Epidemiological study, Public health, Biology, Biostatistics, Disease, Infectious disease, Epidemiology