Mercury exists naturally and as a man-made contaminant. The release of processed mercury can lead to a progressive increase in the amount of atmospheric mercury, which enters the atmospheric-soil-water distribution cycles where it can remain in circulation for years. Mercury poisoning is the result of exposure to mercury or mercury compounds resulting in various toxic effects depend on its chemical form and route of exposure. The major route of human exposure to methylmercury (MeHg) is largely through eating contaminated fish, seafood, and wildlife which have been exposed to mercury through ingestion of contaminated lower organisms. MeHg toxicity is associated with nervous system damage in adults and impaired neurological development in infants and children. Ingested mercury may undergo bioaccumulation leading to progressive increases in body burdens. This review addresses the systemic pathophysiology of individual organ systems associated with mercury poisoning. Mercury has profound cellular, cardiovascular, hematological, pulmonary, renal, immunological, neurological, endocrine, reproductive, and embryonic toxicological effects.
Body Burden ; *Environmental Exposure ; Environmental Pollutants/*toxicity ; Humans ; Methylmercury Compounds/*toxicity ; Nervous System/*drug effects ; Seafood/analysis

No abstract available.

No abstract available.
Humans ; *Public Health

No abstract available.
Humans ; *Public Health

OBJECTIVES: Season of birth, an exogenous indicator of early life environment, has been related to higher risk of adverse psychiatric outcomes but the findings for Alzheimer's disease (AD) have been inconsistent. We investigated whether the month or season of birth are associated with AD. METHODS: A nationwide nested case-control study including all community-dwellers with clinically verified AD diagnosed in 2005 to 2012 (n=70 719) and up to four age- sex- and region of residence-matched controls (n=282 862) residing in Finland. Associations between month and season of birth and AD were studied with conditional logistic regression. RESULTS: Month of birth was not associated with AD (p=0.09). No strong associations were observed with season (p=0.13), although in comparison to winter births (December-February) summer births (June-August) were associated with higher odds of AD (odds ratio, 1.03; 95% confidence interval, 1.00 to 1.05). However, the absolute difference in prevalence in winter births was only 0.5% (prevalence of those born in winter were 31.7% and 32.2% for cases and controls, respectively). CONCLUSIONS: Although our findings do not support the hypothesis that season of birth is related to AD/dementia risk, they do not invalidate the developmental origins of health and disease hypothesis in late-life cognition. It is possible that season does not adequately capture the early life circumstances, or that other (postnatal) risk factors such as lifestyle or socioeconomic factors overrule the impact of prenatal and perinatal factors.
Adult ; Aged ; Aged, 80 and over ; Alzheimer Disease/*diagnosis/epidemiology ; Case-Control Studies ; Finland ; Humans ; Logistic Models ; Middle Aged ; Odds Ratio ; Risk Factors ; Seasons

OBJECTIVES: The systematic review (SR) is a research methodology that aims to synthesize related evidence. Updating previously conducted SRs is necessary when new evidence has been produced, but no consensus has yet emerged on the appropriate update methodology. The authors have developed a new SR update method called 'adaptive meta-analysis' (AMA) using the 'cited by', 'similar articles', and 'related articles' citation discovery tools in the PubMed and Scopus databases. This study evaluates the usefulness of these citation discovery tools for updating SRs. METHODS: Lists were constructed by applying the citation discovery tools in the two databases to the articles analyzed by a published SR. The degree of overlap between the lists and distribution of excluded results were evaluated. RESULTS: The articles ultimately selected for the SR update meta-analysis were found in the lists obtained from the 'cited by' and 'similar' tools in PubMed. Most of the selected articles appeared in both the 'cited by' lists in Scopus and PubMed. The Scopus 'related' tool did not identify the appropriate articles. CONCLUSIONS: The AMA, which involves using both citation discovery tools in PubMed, and optionally, the 'related' tool in Scopus, was found to be useful for updating an SR.
Databases, Factual ; Meta-Analysis as Topic ; *Peer Review, Research ; *Research Design

OBJECTIVES: The purposes of this study were to examine the status of children and adolescents with regard to enrollment in private medical insurance (PMI) and to investigate its influence on their utilization of medical services. METHODS: The present study assessed 2973 subjects younger than 19 years of age who participated in five consecutive Korea Health Panel surveys from 2009 to 2012. RESULTS: At the initial assessment, less than 20% of the study population had not enrolled in any PMI program, but this proportion decreased over time. Additionally, the number of subjects with more than two policies increased, the proportions of holders of indemnity-type only ('I'-only) and of fixed amount+indemnity-type ('F+I') increased, whereas the proportion of holders with fixed amount-type only ('F'-only) decreased. Compared with subjects without private insurance, PMI policyholders were more likely to use outpatient and emergency services, and the number of policies was proportionately related to inpatient service utilization. Regarding out-patient care, subjects with 'F'-only PMI used these services more often than did uninsured subjects (odds ratio [OR], 1.69), whereas subjects with 'I'-only PMI or 'F+I' PMI utilized a broad range of inpatient, outpatient, and emergency services relative to uninsured subjects (ORs for 'I'-only: 1.39, 1.63, and 1.38, respectively; ORs for 'F+I': 1.67, 2.09, and 1.37, respectively). CONCLUSIONS: The findings suggest public policy approaches to standardizing PMI contracts, reform in calculation of premiums in PMI, re-examination regarding indemnity insurance products, and mutual control mechanisms to mediate between national health insurance services and private insurers are required.
Adolescent ; Ambulatory Care/*utilization ; Child ; Child, Preschool ; Female ; Health Surveys ; Humans ; Income ; Infant ; Infant, Newborn ; Insurance, Health/economics/*statistics & numerical data ; Male ; Medically Uninsured ; Odds Ratio ; Republic of Korea

OBJECTIVES: Smoking is known to be associated with nephropathy in patients with diabetes. The distinct effects of smoking before and after diabetes has been diagnosed, however, are not well characterized. We evaluated the association of cigarette smoking before and after a diagnosis of diabetes with the presence of diabetic nephropathy. METHODS: We analyzed data from the 2011-2013 editions of the Korea National Health and Nutrition Examination Survey. A total of 629 male patients diagnosed with diabetes were classified as non-smokers (90 patients), former smokers (225 patients), or continuing smokers (314 patients). A "former smoker" was a patient who smoked only before receiving his diagnosis of diabetes. A "continuing smoker" was a patient who smoked at any time after his diabetes had been diagnosed. Diabetic nephropathy was defined as the presence of albuminuria (spot urine albumin/creatinine ratio ≥30 mg/g) or low estimated glomerular filtration rate (<60 mL/min/1.73 m2). Multiple logistic regression models were used to assess the independent association after adjusting for age, duration of diabetes, hemoglobin A1c, body mass index, systolic blood pressure, medication for hypertension, and medication for dyslipidemia. Female patients were excluded from the study due to the small proportion of females in the survey who smoked. RESULTS: Compared to non-smokers, continuing smokers had significantly higher odds ratio ([OR], 2.17; 95% confidence interval [CI], 1.23 to 3.83) of suffering from diabetic nephropathy. The corresponding OR (95% CI) for former smokers was 1.26 (0.70 to 2.29). CONCLUSIONS: Smoking after diagnosis of diabetes is significantly associated with the presence of diabetic nephropathy in the Korean male population.
Aged ; Albumins/analysis ; Asian Continental Ancestry Group ; Blood Pressure ; Body Mass Index ; Creatinine/urine ; Diabetes Mellitus, Type 2/complications/*diagnosis ; Diabetic Nephropathies/epidemiology/*etiology ; Female ; Glomerular Filtration Rate ; Hemoglobin A, Glycosylated/analysis ; Humans ; Logistic Models ; Male ; Middle Aged ; Nutrition Surveys ; Odds Ratio ; Prevalence ; Republic of Korea ; Smoking/*adverse effects

OBJECTIVES: Research on how the risk of gastric cancer increases with Epstein-Barr virus (EBV) infection is lacking. In a systematic review that investigated studies published until September 2014, the authors did not calculate the summary odds ratio (SOR) due to heterogeneity across studies. Therefore, we include here additional studies published until October 2015 and conduct a meta-analysis with meta-regression that controls for the heterogeneity among studies. METHODS: Using the studies selected in the previously published systematic review, we formulated lists of references, cited articles, and related articles provided by PubMed. From the lists, only case-control studies that detected EBV in tissue samples were selected. In order to control for the heterogeneity among studies, subgroup analysis and meta-regression were performed. RESULTS: In the 33 case-control results with adjacent non-cancer tissue, the total number of test samples in the case and control groups was 5280 and 4962, respectively. In the 14 case-control results with normal tissue, the total number of test samples in case and control groups was 1393 and 945, respectively. Upon meta-regression, the type of control tissue was found to be a statistically significant variable with regard to heterogeneity. When the control tissue was normal tissue of healthy individuals, the SOR was 3.41 (95% CI, 1.78 to 6.51; I-squared, 65.5%). CONCLUSIONS: The results of the present study support the argument that EBV infection increases the risk of gastric cancer. In the future, age-matched and sex-matched case-control studies should be conducted.
Case-Control Studies ; DNA, Viral/analysis/metabolism ; Databases, Factual ; Epstein-Barr Virus Infections/*pathology/virology ; Herpesvirus 4, Human/genetics/isolation & purification/*pathogenicity ; Humans ; Odds Ratio ; Stomach Neoplasms/*pathology/virology

Recently, a series of lawsuits were filed in Korea claiming tort liability against tobacco companies. The Supreme Court has already issued decisions in some cases, while others are still pending. The primary issue in these cases is whether the epidemiological evidence submitted by the plaintiffs clearly proves the causal relationship between smoking and disease as required by civil law. Proving causation is difficult in tobacco lawsuits because factors other than smoking are involved in the development of a disease, and also because of the lapse of time between smoking and the manifestation of the disease. The Supreme Court (Supreme Court Decision, 2011Da22092, April 10, 2014) has imposed some limitations on using epidemiological evidence to prove causation in tobacco lawsuits filed by smokers and their family members, but these limitations should be reconsidered. First, the Court stated that a disease can be categorized as specific or non-specific, and for each disease type, causation can be proven by different types of evidence. However, the concept of specific diseases is not compatible with multifactor theory, which is generally accepted in the field of public health. Second, when the epidemiological association between the disease and the risk factor is proven to be significant, imposing additional burdens of proof on the plaintiff may considerably limit the plaintiff's right to recovery, but the Court required the plaintiffs to provide additional information such as health condition and lifestyle. Third, the Supreme Court is not giving greater weight to the evidential value of epidemiological study results because the Court focuses on the fact that these studies were group-level, not individual-level. However, group-level studies could still offer valuable information about individual members of the group, e.g., probability of causation.
Chloracne/epidemiology/etiology ; Humans ; *Liability, Legal ; Life Style ; Lung Neoplasms/epidemiology/etiology ; Public Health ; Republic of Korea ; Risk Factors ; *Smoking/adverse effects