Correction to: Guidelines for recognition of occupational cancers in Korea: the results of scientific review by Korean Society of Occupational and Environmental Medicine (2013-2016).

[This corrects the article DOI: 10.1186/s40557-018-0223-2.].

Guidelines for recognition of occupational cancers in Korea: the results of scientific review by Korean Society of Occupational and Environmental Medicine (2013-2016).

This thematic collection includes the articles to review eleven occupational cancer related risks or working conditions and to propose the guidelines of S. Korea.

Medication use associated with exposure to manganese in two Ohio towns.

This report describes the use of medications as a proxy when medical record reviews are unavailable, to study the health effects of residents environmentally exposed to air-manganese (n = 185) compared to unexposed residents (n = 90). Participants' current medication lists and medication questionnaire responses were collected in clinical interviews and categorized into 13 domains. Exposed participants reported fewer hours of sleep than controls (6.6 vs. 7.0). The exposed used significantly more medications than unexposed participants (82.2 % vs. 67.8 %) and, when adjusting for age, education, and personal income, also for pain (aOR = 2.40) and hypothyroidism (aOR = 7.03). Exposed participants with higher air-Mn concentrations, monitored for 10 years by the U.S. Environmental Protection Agency, were 1.5 times more likely to take pain medications. The exposed participants take significantly more medications than unexposed participants in the categories of hypothyroidism, pain, supplements, and total medications.

Iron Deficiency is Not Associated with Increased Blood Cadmium in Infants.

OBJECTIVES: To determine whether blood cadmium concentration is elevated in iron-deficient infants. METHODS: Blood cadmium and serum ferritin concentrations, serum iron/total iron-binding capacity (Fe/TIBC) and complete blood counts were measured in 31 iron deficient and 36 control infants, aged 6-24 months. All 31 iron-deficient infants received iron supplementation for 1-6 months. RESULTS: Blood cadmium concentrations were measured again in 19 of the iron deficient infants after their ferritin levels returned to the normal range. The mean blood cadmium concentration did not differ significantly in iron deficient and control infants. The mean blood cadmium concentration in the 19 iron-deficient infants was not significantly altered by ferric hydroxide treatment, while their hemoglobin, ferritin, and Fe/TIBC (%) concentrations were significantly higher after than before treatment. CONCLUSION: These findings indicate that iron deficiency does not increase blood cadmium concentrations in infants, in contrast with the effects of iron deficiency on manganese and lead concentrations.

Effects of iron therapy on blood lead concentrations in infants.

To determine whether blood lead concentration is elevated in iron-deficient infants, blood lead and serum ferritin concentrations, serum iron/transferring iron-binding capacity (Fe/TIBC) and complete blood counts were measured in 30 iron deficient and 35 control infants, aged 6-24 months. All 30 iron-deficient infants received iron supplementation (ferric hydroxide-polymaltose complex, 6mg/kg Fe(3+)/day) for 1-6 months. Blood lead concentrations were measured in 18 of the iron deficient infants after their ferritin levels returned to the normal range. The geometric mean blood lead concentration was higher in iron deficient than in control infants (1.846 vs. 1.416µg/dL). After iron therapy, the blood lead levels of iron-deficient infants decreased significantly compared with pre-treatment levels (1.785 vs. 2.386µg/dL), and the hemoglobin and ferritin concentrations increased significantly. These findings indicate that iron deficiency increases blood lead concentrations in infants with very low blood lead concentrations.

Blood manganese concentration is elevated in infants with iron deficiency.

The present study was done to determine whether blood Mn concentration is elevated in iron-deficient infants. Thirty-one infants with iron deficiency and thirty-six control subjects (6-24 months of age) were tested for blood Mn concentration, complete blood counts, serum ferritin, and serum iron/transferring iron-binding capacity (Fe/TIBC). All the 31 iron-deficient infants were treated with iron supplement; however, 19 of them underwent blood Mn checkup again in compliance with follow-up schedule when their ferritin levels returned to the normal range. Iron therapies were done for 1-6 months (mean, 2.8; standard deviation, 1.6) using ferric hydroxide-polymaltose complex (6 mg/kg Fe(3+) daily). Infants with iron deficiency had a higher mean blood Mn concentration than controls (2.550 vs. 1.499 µg/dL, respectively). After iron therapy, the blood Mn levels of iron-deficient infants significantly decreased compared to their pre-therapy levels (2.045 vs. 2.971 µg/dL, respectively), and their hemoglobin and ferritin levels significantly increased. After adjustment for covariates (e.g., age and breast-feeding), multiple linear regression models showed that increased blood Mn levels were significantly associated with low serum ferritin and hemoglobin levels, whereas with Fe/TIBC there was only a tendency. Our results indicate that iron deficiency increases blood Mn levels in infants, presumably by increasing Mn absorption.

Maternal iron intake at mid-pregnancy is associated with reduced fetal growth: results from Mothers and Children's Environmental Health (MOCEH) study.

BACKGROUND: Iron supplementation is a common recommendation for pregnant women to prevent iron deficiency during pregnancy. There is an increasing concern about excessive iron consumption as a general iron prophylaxis by pregnant women without any due consideration about their dietary iron intake or iron status. Our present study investigated the association between total iron intake from diet and supplements and fetal growth in 337 pregnant women at mid-pregnancy in South Korea. METHODS: Iron intake from diet and supplements was examined by a 24-hour recall method. Subjects were divided into three groups based on tertiles of total iron intake levels. Fetal biometry was assessed by ultrasonography at mid-pregnancy. RESULTS: About 99% of the non-supplement users had iron intake below the recommended nutrient intake (RNI) for pregnant women (24 mg), whereas 64.9% of supplement users had iron intake above the upper level (UL) (45 mg). In the babies of mothers in the third tertile of iron intake (>17.04 mg), biparietal diameter, abdominal circumference, and femur length were lower by 0.41 cm (P =0.019), 0.41 cm (P = 0.027), and 0.07 cm (P = 0.051), respectively, than the babies of mothers in the second tertile of iron intake (11.49 ~ 17.04 mg). CONCLUSION: These results suggest that excessive maternal iron intake at mid-pregnancy is associated with reduced fetal growth. Iron supplementation for pregnant women should be individualized according to their iron status. Appropriate diet education is needed for pregnant women so that they can consume adequate amounts of iron from food and supplements.

Relationship between maternal sodium intake and blood lead concentration during pregnancy.

Pb is released from bone stores during pregnancy, which constitutes a period of increased bone resorption. A high Na intake has been found to be negatively associated with Ca and adversely associated with bone metabolism. It is possible that a high Na intake during pregnancy increases the blood Pb concentration; however, no previous study has reported on the relationship between Na intake and blood Pb concentration. We thus have investigated this relationship between Na intake and blood Pb concentrations, and examined whether this relationship differs with Ca intake in pregnant Korean women. Blood Pb concentrations were analysed in 1090 pregnant women at mid-pregnancy. Dietary intakes during mid-pregnancy were estimated by a 24 h recall method covering the use of dietary supplements. Blood Pb concentrations in whole-blood samples were analysed using graphite furnace atomic absorption spectrophotometry. Multiple regression analysis performed after adjustment for covariates revealed that maternal Na intake was positively associated with blood Pb concentration during pregnancy, but only when Ca intake was below the estimated average requirement for pregnant Korean women (P= 0·001). The findings of the present study suggest that blood Pb concentration during pregnancy could be minimised by dietary recommendations that include decreased Na and increased Ca intakes.

Birth weight of Korean infants is affected by the interaction of maternal iron intake and GSTM1 polymorphism.

Excessive iron consumption during pregnancy can lead to increased oxidative stress in the maternal body, which may result in adverse pregnancy outcomes. Glutathione S-transferases (GSTs) originate from a superfamily of detoxifying enzymes that play a role in reducing xenobiotic compounds and oxidative stress. The aim of this study was to determine the relationship among GST gene expression, maternal iron intake during pregnancy, and neonatal birth weight. The study participants were 1087 Korean gravidas and their newborns recruited for the Mothers and Children's Environmental Health study between 2006 and 2010. A 24-h dietary recall interview was conducted to estimate iron intake; additional intake through nutritional supplements was thoroughly investigated. Deletion polymorphisms of GSTM1 and GSTT1 were genotyped using PCR. Dietary iron consumption during pregnancy was positively associated with birth weight in pregnant women who were GSTM1-present after adjustment for the following covariates: maternal age, prepregnancy BMI, mother's education level, log-transformed urinary cotinine level, infant gender, gestational age at term, log-transformed energy intake, parity, and the use of folic acid supplements (P < 0.05). There were interactions between the GSTM1 genotype and iron intakes from animal foods (P < 0.05), diet (P < 0.05), and diet with supplements (P < 0.05). No relationship was found between maternal iron intake and birth weight for the GSTT1 polymorphism. This study demonstrates that increased iron consumption during pregnancy may improve infant birth weight for mothers who are GSTM1-present, but it might not be beneficial for mothers with the GSTM1-null genotype.

A Guillain-Barré syndrome-like neuropathy associated with arsenic exposure.

OBJECTIVES: We report on a patient presenting with an isolated polyneuropathy mimicking Guillain-Barré syndrome (GBS) associated with arsenic exposure. CASE: A 43-year-old man visited our emergency room complaining of progressive quadriparesis over the prior 5 days. His clinical course with laboratory data was typical of GBS. However, because of his recent use of herbal medication, we screened for the presence of several heavy metals. Serial analyses of urinary inorganic arsenic concentrations confirmed exposure to arsenic. He was diagnosed as arsenic neuropathy mimicking GBS without any systemic manifestation of arsenic intoxication. CONCLUSIONS: The present case study emphasizes the need to consider arsenic intoxication in patients presenting with acute demyelinating neuropathies and histories of herbal medication use.

Neuroplastic changes within the brains of manganese-exposed welders: recruiting additional neural resources for successful motor performance.

BACKGROUND: In a previous study, regional delivery of manganese (Mn)ions within the brain revealed that the metal accumulates in the basal ganglia, where it induces degeneration of the globus pallidus. Degeneration of the basal ganglia impairs motor ability by compromising an important neural circuit involved in the regulation of motor control. Therefore, much research has been devoted to identifying a sensitive and non-invasive imaging marker to evaluate the functional correlates of Mn-related brain dysfunction. METHODS: We performed the first-ever sequential finger-tapping functional MRI (fMRI) experiment to investigate the behavioural significance of additionally recruited brain regions in welders with chronic Mn exposure. RESULTS: During the finger tapping task, activation of the bilateral primary sensorimotor cortex (SM1), bilateral supplementary motor area (SMA), bilateral dorsolateral premotor cortex, bilateral superior parietal cortex and ipsilateral dentate nucleus was higher in the welding group (42 welders) than in the control group (26 controls). The pallidal index correlated with the activation observed in the contralateral SM1 for the finger tapping task of the left hand. The fMRI variables correlated with motor behaviour. Grooved Pegboard performances (right hand) correlated with activation, as seen in the ipsilateral and contralateral SMAs obtained during the finger tapping task of the right hand. CONCLUSION: Our findings suggest that increased brain activation results from the compensational activation of ancillary cortical pathways, which ensures adequate motor function.

A case of generalized argyria after ingestion of colloidal silver solution.

A 58-year-old woman was referred to our hospital due to progressive skin darkening, which began 5 months previously. The patient had strikingly diffuse blue-gray discoloration of the skin, most prominent in sun-exposed areas, especially her face and hands. The oral mucosa, tongue, gums, eye conjunctiva, ears, nail beds, and trunk were also involved. Bluish-gray discoloration of all nails was aggravated by cold weather. She had ingested 1 L of colloidal silver solution daily for approximately 16 months as a traditional remedy. Her serum silver concentration was 381 ng/ml which was a very high (reference level: <15 ng/ml). Light microscopic examination of a punch biopsy specimen from her nose revealed fine, minute, round, and brown-black granules deposited in the basement membrane of hair follicular epithelium. Scanning electron microscopic examination showed electron-dense granules deposited in the intercellular space of sweat glands. Energy disperse X-ray spectrometry analysis demonstrated peaks for silver and sulfur in the dense black deposits. The ingestion of colloidal silver appears to be an increasing practice among patients using alternative health practices. All silver-containing products including colloidal silver should be labeled with a clear warning to prevent argyria, especially in alternative health practices.

CDNA array analysis of gene expression profiles in brain of mice exposed to manganese.

This study is performed to detect changes of gene expression in substantia nigra (SN) and striatum in manganese (Mn)-exposed mice brain. The cDNA array is a recently developed molecular biological method that can detect the differential expression of several hundreds of genes simultaneously and is therefore advantageous in the study of trace metal intoxication effect at the genetic level. Using this technology, we discovered 5 genes in the mouse striatum and 9 genes in SN changed by more than 50% following Mn exposure. Depression were observed in two genes (neural cell adhesion protein BIG2, heavy neurofilament subunit genes) in striatum and three genes (light neurofilament subunit, brain acyl-CoA synthetase II, heavy neurofilament subunit genes) in the SN. However three genes (N-acetylglucosaminyltransferase I, S100beta, and synaptonemal complex protein I genes) in striatum and six genes (noggin, striatin, Ost oncogene, S100beta, calcium/calmodulin-dependent protein kinase kinase beta, and N-acetylglucosaminyltransferase I genes) in SN were elevated following Mn exposure. Immunohistochemical study revealed that protein levels of S100beta also increased following Mn treatment. Activated astrocytes overexpressing S100beta are invariably and intimately associated with decreased expression of heavy and light neurofilament subunits which is a distinguishing feature of neurodegeneration by Mn exposure. All our findings suggested that neuronal degenerations occur in SN as well as striatum of mice exposed to Mn.

Neurologic sequela of hydrogen sulfide poisoning.

A 25-year-old man, a field operator in a petroleum refinery was found unconscious. He was exposed to hydrogen sulfide and presented with Glasgow Coma Score of 5, severe hypoxemia on arterial blood gas analysis, normal chest radiography, and normal blood pressure. On hospital day 7, his mental state became clear, and neurologic examination showed quadriparesis, profound spasticity, increased tendon reflexes, abnormal Babinski response, and bradykinesia. He was also found to have decreased memory, attention deficits and blunted affect, which suggested general cognitive dysfunction, but which improved soon. MRI scan showed abnormal signals in both basal ganglia and motor cortex, compatible with clinical findings of motor dysfunction.

Calcification mimicking manganese-induced increased signal intensities in T1-weighted MR images in a patient taking herbal medicine: case report.

Characteristic high signal intensities confined to the globus pallidus on T1-weighted magnetic resonance image (MRI) can be observed in manganese (Mn)-exposed workers, however, these high signals should be differentiated from those due to other causes such as fat, hemoglobin breakdown products, melanoma, neurofibromatosis, and calcification. A 39-year-old woman was admitted with mutism and involuntary movements which had developed the day before. She had ingested two packs of liquid herbal medicine containing 0.53 mg of Mn daily for 4 months prior to visiting our hospital. Her MRI showed high signals, confined mainly to the globus pallidus on T1-weighted images. Follow-up brain MRI at an interval of 11 months showed no interval change. Brain computed tomography (CT) at the time of the second MRI showed symmetric calcification on both globus pallidus. Blood levels of liver function tests, calcium, phosphorus, and parathyroid hormone were within normal ranges. The increased signals, which were first presumed to be induced by Mn, were concluded to be due to calcification based on the following reasons. First, follow-up brain MRI at an interval of 11 months did not show any interval change. Second, the ingested amount of 1.06 mg Mn daily for 4 months is even less than that added to mineral supplements for adults. Third, Mn-induced high signals in T1-weighted MRI do not show any abnormal findings in brain CT. The present case report suggests that brain CT should be performed to rule out symmetric calcification on basal ganglia in patients showing increased signals in T1-weighted MRI, but who do not have a significant exposure history to Mn. The present report also showed that the amount of 1.06 mg Mn daily ingested for 4 months did not cause the high signal in brain MRI.