Environmental and Body Concentrations of Heavy Metals at Sites Near and Distant from Industrial Complexes in Ulsan, Korea

BACKGROUND: Industrial pollution may affect the heavy metal body burden of people living near industrial complexes. We determined the average concentrations of atmospheric heavy metals in areas close to and distant from industrial complexes in Korea, and the body concentrations of these heavy metals in residents living near and distant from these facilities. METHODS: The atmospheric data of heavy metals (lead and cadmium) were from the Regional Air Monitoring Network in Ulsan. We recruited 1,148 participants, 872 who lived near an industrial complex (“exposed” group) and 276 who lived distant from industrial complexes (“non-exposed” group), and measured their concentrations of blood lead, urinary cadmium, and urinary total mercury. RESULTS: The results showed that atmospheric and human concentrations of heavy metals were higher in areas near industrial complexes. In addition, residents living near industrial complexes had higher individual and combined concentrations (cadmium + lead + mercury) of heavy metals. CONCLUSION: We conclude that residents living near industrial complexes are exposed to high concentrations of heavy metals, and should be carefully monitored.

Cost analysis of different cervical cancer screening strategies in Mexico / Análisis de costos de distintas estrategias de tamizaje para cáncer cervical en México

Objective. To compare the costs and number of undetected cases of four cervical cancer screening strategies (CCSS) in Mexico. Materials and methods. We estimated the costs and outcomes of the following CCSS: a) conventional Papanicolaou smear (Pap) alone; b) high-risk human papilloma virus testing (HR-HPV) as primary screening with Pap as reflex triage; c) HR-HPV as primary screening with HPV-16/18 typing, liquid-based cytology (LBC) and immunostaining for p16/Ki67 testing as reflex triage, and d) co-testing with HR-HPV and LBC with HPV-16/18 typing and immunostaining for p16/Ki67 as reflex triage. The outcome of interest was high-grade cervical lesions or cervical cancer. Results. HR-HPV testing, HPV typing, LBC testing and immunostaining is the best alternative because it is the least expensive option with an acceptable number of missed cases. Conclusions. The opportunity costs of a poor quality CCSS is many false negatives. Combining multiple tests may be a more cost-effective way to screen for cervical cancer in Mexico.

Objetivo. Comparar los costos y los casos no detectados de cuatro estrategias de tamizaje de cáncer cervical (ETCC) en México. Material y métodos. Se estimaron los costos y resultados en salud de las siguientes ETCC: a) citología convencional como único procedimiento de tamizaje; b) detección de virus del papiloma humano de alto riesgo (VPH-AR) como tamizaje primario y citología convencional como procedimiento de triage; c) detección de VPH-AR como tamizaje primario y tipificación de VPH-16/18, citología en base líquida e inmunotinción para p16/Ki67 como procedimientos de triage, y d) evaluación conjunta con VPH-AR y citología en base líquida como tamizaje primario y tipificación de VPH-16/18 e inmunotinción para p16/Ki67 como procedimientos de triage. El resultado en salud analizado fueron los casos de neoplasia intraepitelial cervical (CIN 2/3) o cáncer cervical detectados. Resultados. La ETCC basada en la detección de VPH-AR como prueba primaria y seguida de la tipificación de VPH-16/18, la citología en base líquida y la inmunotinción para p16/Ki67 como procedimientos de triage es la mejor alternativa, ya que es la menos costosa y la que tuvo un nivel aceptable de casos perdidos. Conclusiones. El costo de oportunidad de una ETCC de mala calidad es un alto número de falsos negativos. La combinación seriada de varias pruebas de tamizaje y triage puede ser una alternativa costo-efectiva para la detección oportuna de cáncer cervical en México.

Environmental Mercury and Its Toxic Effects / 예방의학회지

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.

The human body burden of polychlorinated dibenzo-p-dioxins and dibenzofurans and dioxin-like polychlorinated biphenyls in residents' human breast milk from Beijing in 2007 / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate contamination levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (dl-PCBs) in human breast milk from Beijing residents, and evaluate the human body burden of PCDD/Fs and dl-PCBs of general population.</p><p><b>METHODS</b>A total of 110 human milk samples were collected from 11 regions in Beijing in 2007. After 11 pooled samples were made, concentrations of PCDD/Fs and dl-PCBs in breast milk pooled samples were measured by a high resolution gas chromatography - high resolution mass spectrometry (HRCG-HRMS) with isotope dilution.</p><p><b>RESULTS</b>For congeners of PCDD/Fs and dl-PCBs in human breast milk from Beijing, the highest content of congeners was octachlorodibenzo-p-dioxin (OCDD), polychlorinated biphenyl (PCB)-118, and PCB-105 with the median of 20.6 pg/g fat, 4.07 ng/g fat and 1.63 ng/g fat, respectively. The concentration median of total dioxins in 11 pooled human milk samples from Beijing was 7.4 pg TEQ/g fat. The highest was 13.5 pg TEQ/g fat from Tongzhou, and the lowest was 4.3 pg TEQ/g fat from Pinggu.</p><p><b>CONCLUSION</b>The contamination level of PCDD/Fs and dl-PCBs in human milk from Beijing is relatively low. However, with the rapid industrialization in China, the human body burden of PCDD/Fs and dl-PCBs will be likely to rise. Thus, further studies should be conducted to continuously monitor the trend of contamination level.</p>

Human Exposure and Health Effects of Inorganic and Elemental Mercury / 예방의학회지

Mercury is a toxic and non-essential metal in the human body. Mercury is ubiquitously distributed in the environment, present in natural products, and exists extensively in items encountered in daily life. There are three forms of mercury, i.e., elemental (or metallic) mercury, inorganic mercury compounds, and organic mercury compounds. This review examines the toxicity of elemental mercury and inorganic mercury compounds. Inorganic mercury compounds are water soluble with a bioavailability of 7% to 15% after ingestion; they are also irritants and cause gastrointestinal symptoms. Upon entering the body, inorganic mercury compounds are accumulated mainly in the kidneys and produce kidney damage. In contrast, human exposure to elemental mercury is mainly by inhalation, followed by rapid absorption and distribution in all major organs. Elemental mercury from ingestion is poorly absorbed with a bioavailability of less than 0.01%. The primary target organs of elemental mercury are the brain and kidney. Elemental mercury is lipid soluble and can cross the blood-brain barrier, while inorganic mercury compounds are not lipid soluble, rendering them unable to cross the blood-brain barrier. Elemental mercury may also enter the brain from the nasal cavity through the olfactory pathway. The blood mercury is a useful biomarker after short-term and high-level exposure, whereas the urine mercury is the ideal biomarker for long-term exposure to both elemental and inorganic mercury, and also as a good indicator of body burden. This review discusses the common sources of mercury exposure, skin lightening products containing mercury and mercury release from dental amalgam filling, two issues that happen in daily life, bear significant public health importance, and yet undergo extensive debate on their safety.

Comparison of calculation precision of photon dose between the two algorithms for the situation with air cavity and small fields / 生物医学工程学杂志

In order to evaluate the calculation precision of the pencil beam (PB) algorithm and convolution-superposition(CS) algorithm for the situation with air cavity and small fields, we built a water phantom with an air cavity slab, in which the depth dose (DD) and off-axis ratio (OAR) for field 1cm x 1cm to field 7cm x 7cm were calculated by PB algorithms, CS algorithms and Monte Carlo (MC) simulation. The evaluation of algorithms by MC simulation was achieved by comparisons of DD with the spread penumbras of OAR curve self-defined as the width between isodose lines of 10% and 90%. It was shown that PB algorithm and CS algorithm both overestimated the DD but the degree overestimated by PB algorithm was more serious. The CS algorithm showed a better agreement with the MC simulation for the OARs, which spread to both laterals, while that was not predicted accurately by PB algorithm. It was indicated that PB algorithm and CS algorithm do not have high calculation precision whereas CS algorithms is relatively better for the situation with air cavity and small fields.

Occupational Health Management in the Lead Industry: The Korean Experience

In 1967, the problem of occupational lead exposure came to public attention in Korea. Since then, regular progress has been made in lowering workplace lead exposures, instituting new workplace controls, and implementing health examinations of exposed workers. Past serious lead poisoning episodes made it possible to introduce biological monitoring programs on a voluntary basis in high-lead-exposure facilities in Korea. Industry-specific occupational health services for lead workers in Korea during the last 22 years can be categorized into three phases. During the first phase (1988-1993), efforts were directed at increasing awareness among workers about the hazards of lead exposure, biological monitoring of blood zinc protoporphyrin began, and a respiratory protection program was introduced. During the second phase (1994-1997), a computerized health management system for lead workers was developed, blood-lead measurement was added to biologic monitoring, and engineering controls were introduced in the workplace to lower air-lead levels to comply with air-lead regulations. Finally, during the third phase (1998-present), a new biomarker, bone-lead measurement by X-ray fluorescence, was introduced. Bone-lead measurement proved to be useful for assessing body burden and to demonstrate past lead exposure in retired workers. Occupational health service practice for lead workers, including the industry-specific group occupational health system, has brought considerable success in the prevention of lead poisoning and in reducing the lead burden in Korean lead workers during the last several decades. The successful achievement of prevention of lead poisoning in Korea was a result of the combined efforts of lead workers, employers, relevant government agencies, and academic institutes.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice

Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 µg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean ± SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 ± 0.032 and 0.040 ± 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.

As unhas têm sido consideradas um biomarcador para a exposição ao flúor (F), mas não há consenso se é um indicador confiável para exposição ao F a partir do dentifrício. Vinte e três crianças, com idade entre 1 a 3 anos, moradoras de Piracicaba (0,72 ppm F na água), Brasil, foram submetidas a duas fases de diferentes exposição ao F: fase A (1a a 11a semanas), as crianças foram expostas à combinação de F a partir da dieta (sólidos e líquidos) e dentifrício (1500 µg F/g como MFP); e na fase B (12ª a 29ª semanas), apenas ao F da dieta, uma vez que usaram dentifrício não fluoretado. As unhas das mãos foram coletadas semanalmente durante 35 semanas para determinação de F. A exposição ao F a partir da dieta e dentifrício foi também determinada. Ambas análises foram feitas com eletrodo específico para F. A exposição ao F foi significativamente maior (p<0,001) quando as crianças foram expostas ao F da dieta + dentifrício que ao F da dieta (0,086 ± 0,032 e 0,040 ± 0,009 mg F/kg corpóreo/dia, respectivamente). Entretanto, a concentração de F nas unhas coletadas durante todo o período experimental não diminuiu após a interrupção da ingestão do F a partir do dentifrício. Os resultados sugerem que as unhas das mãos não são um biomarcador confiável para refletir a exposição ao F pelo dentifrício.

Health Effects of Manganese and Some Recent Issues in Manganese Neurotoxicity Research / 대한산업의학회지

INTRODUCTION: This article reviews the health effects of manganese (Mn) and introduces readers to recent issues in Mn neurotoxicity research. METHODS: An extensive Medline search that covered publications up to December 2008 was conducted and the relevant papers and their references were evaluated for review. RESULTS AND DISCUSSION: Exposure to excess levels of the essential trace element Mn produces cognitive, psychiatric, and motor abnormalities. The lungs and the gastrointestinal tract both absorb Mn, but homeostatic mechanisms limit the absorption of Mn by the gastrointestinal tract. Elimination of Mn occurs primarily by excretion into the bile. Average Mn levels in the blood reflect the total body burden on a group basis, but not on an individual basis. Previous studies have shown that blood Mn contributes to a high pallidal signal in a T1-weighted brain MRI and that the high signal is an effective predictor of neurobehavioral performance. Thus, a high pallidal signal on an MRI may offer clues concerning the target organ dose from Mn exposure in the spectrum of Mn symptomatology. Neuroimaging as well as a clinical evaluation with exposure history is very important in a differential diagnosis that can distinguish manganism from Parkinson disease (PD). Recent research on Mn neurotoxicity has focused on several issues. First, concerns about the interaction between manganism and PD have been raised, but further research is needed. Second, epidemiological studies on non-occupational Mn exposure have suggested that environmentally induced neurotoxicities may have features that are different from the classic features of occupational manganism, but, again, this requires further research. Third, liver cirrhosis could be used as a model of manganism. Finally, functional neuroimaging such as magnetic resonance spectroscopy, functional MRI, or diffusion tensor imaging appears to have promising applications in Mn research. CONCLUSION: Reviewing the health effects of Mn and recent issues in Mn neurotoxicity research provides us with important suggestions for how to pursue other lines of toxicological research as well as for how best to develop a systematic understanding of Mn symptomatology.

Cadmium-exposed population in Mae Sot District, Tak Province: 1. Prevalence of high urinary cadmium levels in the adults.

BACKGROUND: In Mae Sot District, Tak Province, Thailand, the paddy fields receiving irrigation from the two creeks and crops grown in the areas were found to contain markedly elevated cadmium levels during the surveys in 2001-2004. OBJECTIVE: The present report carried out a survey in 2004 to determine urinary cadmium, a good index of excessive cadmium exposure and body burden, among the exposed residents aged 15 years and older in these contaminated areas. MATERIAL AND METHOD: Morning urine samples were collected from the subjects and then kept frozen until cadmium analysis. Urinary cadmium was determined using the atomic absorption spectrometry and urinary creatinine was determined using a method of reaction with picric acid at alkaline pH and colorimetry. RESULTS: Of the 7,697 persons surveyed, only 45.6% had urinary cadmium levels < 2 microg/g creatinine. About 4.9% were between 5 and 10 microg/g creatinine and 2.3% had cadmium concentrations > 10. The urinary cadmium level was greater among women than men and increased with increasing age. Smokers were more likely to have high urinary cadmium than non-smokers. Persons who mainly consumed rice grown locally in the contaminated areas had higher urinary cadmium than those who did not. CONCLUSION: Persons who had high urinary cadmium levels and might have cadmium-induced toxic effects should be screened for early detection of chronic cadmium toxicity. Smoking cessation programs should be one component of preventive action beneficial for the study population. The production of rice and other crops for human consumption should be prohibited to prevent further accumulation of cadmium in the body of the exposed population.

Elemental contents in organs and tissues of Chinese adult men / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To provide basis of reference values for relevant parameters of Chinese Reference Man.</p><p><b>METHODS</b>Eighteen kinds of major organ or tissue samples, including muscle, rib, liver, and so on, were obtained from 4 areas (Hebei, Shanxi, Jiangsu, and Sichuan provinces) with different dietary patterns in China in autopsy of 16 healthy adult men, who had just encountered sudden deaths. At the same time, whole blood samples were collected from 10 volunteers living in each of these areas. The concentrations of 56 elements in these samples were detected by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS), Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES), and Graphite Furnace Atomic Absorption Spectrometry (GF-AAS) techniques. Based on obtained concentrations and reference values of these organ or tissue weights for Chinese Reference Man, the relative elemental burdens in these organs or tissues as well whole body were also estimated.</p><p><b>RESULTS</b>The concentrations of 56 elements in 18 main organs or tissues were determined all together and their elemental organ or tissue and whole body burdens were estimated. Furthermore, the distributions of important elements for radiation protection in these organs or tissues were emphatically discussed.</p><p><b>CONCLUSION</b>By summing with past related results, the total results obtained from the series of research may provide more reliable and better representative basis of these reference values for Chinese Reference Man than before.</p>

Activities of Daily Living of The Elderly with a Chronic Disease and Burden on Family Care-givers / 간호학회지

PURPOSE: The purpose of this study was to help families decrease and alleviate the burden on family care-givers taking care of elderly patients. METHOD: Data was collected by a questionnaire from 100 family members who were registered in the department of home health care nursing at 4 hospitals of H University Medical Center from September 20 to October 25, 2005. The collected data was analyzed using Mean and Standard Deviation, Pearson Correlation Coefficient, t-test and One-Way ANOVA with the Duncan's test, and Stepwise multiple regression. RESULT: The average burden on family care-givers of elderly patients with chronic diseases was 3.31. The social burden was the highest(M=3.68), the lowest was the emotional burden (M=2.95). In ADL of elderly patients with chronic diseases, all 10 questions showed an average point above 2.50. The dependency level of going up and down the stairs was the highest (M=2.88). CONCLUSION: This research is necessary for the application of a plan in the social support system in order to reduce the burden on family care-givers who are taking care of elderly patients with a chronic disease.

Integrated assessment of environment and health: America's children and the environment

There is a need for systematic approaches to assessment of environmental factors most relevant to health, health outcomes most influenced by the environment, and relationships between them, as well as for approaches to representing results of such assessments in policy deliberations. As a step in the development of such methods, we used findings and data from environmental protection and public health sectors to develop a set of measures representing topics relevant to children's environmental health. We used a definition of the environment that emphasized contaminants and a process that involved both analytic and deliberative elements. The steps in this process were to: a) develop a conceptual framework to depict relationships between environment and health with relevant types of data and information, b) select topic areas of significance for children, c) identify best available data sources and devise measures, d) assess possible surrogate data sources and measures when needed, e) design and implement metrics for computation of measures; f) select graphical representations of measures, g) identify related measures, and h) identify data gaps. Representatives of policy and stakeholder audiences participated in this process.

No momento atual do conhecimento sobre o tema, existe a necessidade de avaliações sistemáticas a respeito dos fatores que mais contribuem para a saúde, das contribuições mais relevantes do setor saúde para o ambiente e das relações entre ambos os campos, assim como de abordagens sobre resultados das deliberações políticas sobre resultados dos estudos. Neste artigo, apresentamos achados e dados a respeito da proteção ambiental e de saúde visando desenvolver propostas a favor da saúde ambiental das crianças. Usamos uma definição de ambiente que enfatiza contaminantes e processos e envolvem elementos analíticos e deliberativos. As etapas do estudo foram: a) desenvolver um marco conceitual que retratasse relações entre saúde e ambiente por meio de relevantes tipos de dados e informações; b) selecionar tópicos de significância para a saúde das crianças; c) identificar as melhores fontes e tópicos para medição; d) avaliar possíveis medidas e fontes adicionais se necessário; e) desenhar e implementar métrica para medidas de computação; f) selecionar representações gráficas das medidas; g) identificar medidas relacionadas e h) identificar lacunas de dados. Gestores e financiadores participaram do processo.

An eight-year study report on arsenic contamination in groundwater and health effects in Eruani village, Bangladesh and an approach for its mitigation.

Based on several surveys during 1997-2005 and visits of a medical team to Eruani village, Laksham upazila, Comilla district, Bangladesh, the arsenic contamination situation and consequent clinical manifestations of arsenicosis among the villagers, including dermatology, neuropathy, and obstetric outcome, are reported here. Analysis of biological samples from patients and non-patients showed high body burden of arsenic. Even after eight years of known exposure, village children were still drinking arsenic-contaminated water, and many of them had arsenical skin lesions. There were social problems due to the symptoms of arsenicosis. The last survey established that there is a lack of proper awareness among villagers about different aspects of arsenic toxicity. The viability of different options of safe water, such as dugwells, deep tubewells, rainwater harvesting, and surface water with watershed management in the village, was studied. Finally, based on 19 years of field experience, it was felt that, for any successful mitigation programme, emphasis should be given to creating awareness among villagers about the arsenic problem, role of arsenic-free water, better nutrition from local fruits and vegetables, and, above all, active participation of women along with others in the struggle against the arsenic menace.

Effect of Cumulative Blood Lead and Cumulative Blood ZPP as Lead Body Burden on Renal Lead Biomarkers / 대한산업의학회지

OBJECTIVE: To evaluate the possibility of cumulative blood lead and blood ZPP as surrogates of lead body burden and to investigate their association with renal function as an index of lead body burden. METHODS: The study subjects comprised 678 lead workers with past blood lead and blood ZPP data from their employment. Cumulative blood and ZPP were calculated by accumulating the every year mean value of both indices from the new employment since 1983. To assess the cumulative data of lead workers who started their lead work before 1983, the years before 1983 were simulated with the first available data from 1983. Study variables for lead body burden were tibia bone lead and DMSA chelatable lead, whereas those for current lead biomarkers were blood lead and blood ZPP. BUN and serum creatinine were selected as clinical renal biomarkers, while NAG (N-acetyl-D-glucosamine) and RBP (Retinol binding protein) were selected as early renal biomarkers. RESULTS: The association between cumulative blood lead and blood ZPP with tibia bone lead was statistically significant with determinant coefficients (r(2)) of 0.72 and 0.567, respectively, and their relationships were better explained by the curvilinear regression model. In multiple regression analysis of current lead biomarkers on the renal biomarkers after controlling for possible confounders (age, sex, job duration, smoking and drinking status), blood lead was associated only with log-transformed NAG, whereas blood ZPP was associated with 3 other renal biomarkers. On the other hand, in multiple regression analysis of biomarkers of lead body burden on renal biomarkers after controlling for possible confounders (age, sex, job duration, smoking and drinking status), cumulative blood ZPP and tibia bone lead were associated with all 4 renal function biomarkers, whereas cumulative blood lead and DMSA chelatable lead were associated with 3 renal biomarkers except BUN. CONCLUSION: Cumulative blood and ZPP were demonstrated to be good surrogates of lead burden. Furthermore, the cumulative blood ZPP was confirmed to have a better association than the cumulative blood lead.

Influence of Blood Lead Concentration on the Nerve Conduction Velocity in Patients with End-Stage Renal Disease

Diseases of the peripheral nervous system are the most prevalent in patients with end-stage renal disease (ESRD). Although increased blood levels of lead in ESRD have been reported, the role of lead remains to be elucidated. The purpose of this study was to determine the connection of blood lead concentration with peripheral nerve conduction velocity. One hundred ninety-eight healthy subjects (control group) and 68 patients with ESRD undergoing hemodialysis (ESRD group) were enrolled. Nerve conduction was measured within two hours after hemodialysis. Orthodromic sensory nerve action potentials and compound muscle action potentials were recorded on the median, ulnar, and radial nerves. Hemoglobin-corrected blood lead was significantly higher in ESRD patients than in controls (9.1+/-2.8 microgram/dL vs. 5.9+/-2.3 microgram/dL, p0.05). Our result suggested that even though the blood lead levels were high in ESRD, they were not associated with the decline of peripheral nerve function. Diabetes mellitus is a primary independent risk of neuropathy in ESRD patients.

Long-term Chelation Therapy in Patients with Chronic Lead Nephropathy by Excessive Body Lead Burden / 대한신장학회잡지

BACKGROUND: Although chelation therapy with calcium disodium ethylenediamine tetraacetic acid (CaNa2EDTA) reduces body burden of lead and improves clinical side effects from lead, it is unclear whether long-term repeated chelation is safe for chronic lead poisoning with nephropathy. We described the consequential changes of renal function and clinicopathological findings during one to two years of monthly administration of CaNa2EDTA in patients with chronic lead nephropathy and excessive body lead burden. METHODS: Three patients diagnosed as chronic lead nephropathy received 1 g/day of intravenous CaNa2EDTA for a 3-5 day/cycle. A total of 48-86 g CaNa2EDTA was administered. Midtibial bone lead, chelatable lead, and blood lead levels were assessed. Renal function was determined in each chelation, and renal biopsies before and after chelation were conducted and compared for microscopic and immunofluorescence changes. RESULTS: Cortical bone lead levels showed a high burden of lead (>200 microgram Pb/g bone mineral). During CaNa2EDTA treatment, blood lead level and renal function were in steady state. No evidence of progression of renal pathology was observed in both renal biopsies, showing similar interstitial fibrosis and glomerular sclerosis. CONCLUSION: Our results suggest that long-term repeated chelation therapy with CaNa2EDTA is safe and effective for patients who have suffered from severe chronic lead poisoning, even though renal pathologic change has started.

A 20-year follow-up study on the effects of long-term exposure to thorium dust / 中华医学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate the possible effects of long-term exposure to dust containing thorium and thoron progeny on dust-exposed miners.</p><p><b>METHODS</b>A negative, high voltage, exhaled thoron progeny measurement system was used to estimate the miners' thorium lung burden.</p><p><b>RESULTS</b>The highest thorium lung burden of 638 miners was 11.11 Bq. The incidence of stage 0(+) pneumoconiosis was higher among dust-exposed miners. Lung cancer mortality of the dust-exposed miners was significantly higher than that of controls (P < 0.005).</p><p><b>CONCLUSION</b>There is a difference in cancer rates between those who have long-term exposure to dust containing thorium (in which carcinogenic ThO(2) and SiO(2) exist) and thoron progeny and those who have not.</p>

Exposure Assessment of PCDD/Fs and Monitoring of Health Effects on Workers and Residents near the Waste Incinerators in Korea / 예방의학회지

OBJECTIVES: In this study, the exposure status of the hazardous substances from incinerators, such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs), were studied, and the relationship between the exposure of these hazardous substances and their heath effects on the workers and residents near municipal solid waste (MSW) incinerators and an industrial incinerator investigated. METHODS: Between July 2001 and June 2002, 13 workers at two MSW incinerators, 16 residents from the area around the two MSW incinerators, 6 residents from the control area, and further 10 residents near an industrial incinerator, estimated to emit higher levels of hazardous substances, were interviewed. Information, including sociodemographic information, personal habits, and work history, detailed gynecologic and other medical history were collected through interviews. Blood samples were also collected from 45 subjects, and analyzed for PCDD/DFs, by high resolution gas chromatography - high resolution mass spectrometry, using the US EPA 1613 method. In addition to the questionnaire survey, urinary concentrations of 8-hydroxydeoxyguanosine (8-OH-dG) and malondialdehyde (MDA) were measured as oxidative injury biomarkers. The urinary concentrations of 8-OH-dG were determined by in vitro ELISA, and the MDA by HPLC, using an adduct with thiobarbituric acid. RESULTS: The PCDD/DFs concentrations in the residents near the industrial incinerator were higher than those in the controls, workers and residents near the MSW incinerators. The average TEQ (Toxic Equivalencies) concentrations of the PCDD/DFs in residents near the industrial incinerator were 53.4pg I-TEQs/g lipid. The estimated daily intakes were within the tolerable daily intake range (1-4 pg I-TEQ/Kg bw/day) suggested by WHO (1997) in only 30% to the people near the industrial incinerator. Animal studies have already shown that even a low body burden of PCDD/DFs, such as 10ng TEQ/kg bw, can cause oxidative damage in laboratory animals. Our study also showed that the same body burden of PCDD/DFs can cause oxidative damage to humans. CONCLUSIONS: The exposures to PCDD/DFs and the oxidative stress of residents near the industrial incinerator, were higher than those in the controls, workers and residents near the MSW incinerators. Proper protection strategies against these hazardous chemicals are needed. Because a lower body burden of PCDD/Fs, such as 10ng TEQ/kg bw, can cause oxidative damage, the tolerable daily intake range should be restrictedly limited to 1pg I-TEQ/kg bw/day.