We have reviewed epidemiological studies examining the association between residential exposure to extremely low frequency electric and magnetic fields (ELF-EMF) and childhood leukemia. We have excluded studies focusing on electrical appliances, because it is difficult to consolidate transient exposure from multiple sources and equally difficult to control information bias. We have identified 24 studies of residential exposure to ELF-EMF and childhood leukemia. About half of these studies were reported as positive and the remaining as null. For each of the studies reported as positive, however, one or more sources of bias could not be confidently excluded. Moreover, studies which were methodologically more sound, or benefited from high quality registry data, were more frequently null than other investigations. We conclude that the empirical evidence in support of an association between ELF-EMF and childhood leukemia is weak.

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Isocyanates are among the most frequent causes of occupational asthma in industrialized countries. Early diagnosis of diisocyanate asthma followed by prompt termination of chemical exposure can prevent chronic morbidity due to persistent asthma. Chronic exposure to isocyanates also induces hypersensitivity pneumonitis (HP). The accurate diagnosis of diisocynate asthma requires a systematic approach that combines information obtained from the occupational history, immunologic tests and physiologic studies. The prevention of health problems from toluene diisocyanate (TDI), 4,4’-methylenediphenyl diisocyanate (MDI) and 1,6’-hexamethylene diisocyanate (HDI) is essential for all those handling the chemicals. Regulatory exposure limits should be observed. However, wheezing, coughing or even asthmatic attacks may occur after exposure much below the regulatory exposure limits especially in sensitive individuals. Preventing or minimizing exposure is of prime importance and should be supported by the installation of engineering controls, by education of the workforce, by regular monitoring of the workplace exposure and by medical surveillance. To prevent such asthma it is suggested that workers should be tested airway sensitivity and should avoid working in areas that have dust containing specific-IgE. Such tests must be periodically performed after working. Symptoms induced by isocyanate need earlier discover and early isolation of the associated individuals.

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Chronic inhalation of cigarette smoke is a major risk factor for the development of lung cancer. It has been suggested that genetic susceptibility may contribute to the risk, because only a small portion of smokers develops the disease. Several polymorphisms that involve the metabolic activation or detoxification of carcinogens derived from cigarette smoke have been found to be associated with lung cancer risk. Many studies have focused on the relation between the distribution of polymorphic variants of different forms of the metabolic enzymes and lung cancer susceptibility. In this respect two groups of genetic polymorphisms of enzymes involved in xenobiotic metabolism, cytochrome P450 (CYP) and glutathione S-transferases (GSTs), have been discussed. CYP multigene superfamily consists of 10 subfamilies (CYP1-CYP10). A positive association between development of lung cancer and the mutant homozygous genotype of CYP1A1 gene has been reported in several Japanese populations but such an association has not been observed in either Caucasians or African-Americans. The relation between CYP2D6 and lung cancer remains conflicting and inconclusive. Several polymorphisms have been identified at the CYP2E1 locus. No definitive link between the polymorphisms of CYP2E1 and the risk of lung cancer has, however, been identified. The role of other CYP2 isoforms in lung carcinogenesis has not been sufficiently investigated. GSTs form a superfamily of genes consisting of five distinct families, named GSTA, GSTM, GSTP, GSTT and GSTS. The role of GSTM, GSTT1 or GSTP1 polymorphism in modifying the lung cancer risk may be more limited than has been so far anticipated.
Although some genetic polymorphisms discussed here have not shown significant increases/decreases in risk, individuals with differing genotypes may have different susceptibilities to lung cancer. Hopefully, in future studies it will be possible to screen for lung cancer using specific biomarkers.

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Objective: To clarify the seasonal differences of the trace element excretion in sweat, the trace element concentrations in sweat and their loss during exercise were compared between summer and winter.
Methods: Sweat samples were collected from ten healthy adult males. Bicycle ergometer exercise was conducted by each subject at a heart rate of 140 beats/min for 1 hour, in summer and in winter. Sweat was collected by the arm bag method.
Results: Concentrations of major (Na, K, Ca, and Mg) and trace elements (Zn, Cu, Fe, Ni, Mn, and Cr) in sweat tended to be lower in summer than in winter, and significantly lower concentrations of Mg (p<0.01), Na, Cu, and Mn (p<0.05) were found in summer. The sweat volume in summer (0.90 L) was 1.7-fold larger than that in winter (0.52 L) (p<0.01). The amount of loss of each element to sweat calculated from the concentrations in sweat and sweat volume showed no significant difference between summer and winter.
Conclusions: It is suggested that there was no significant difference in the amount of loss of trace elements in sweat due to exercise between summer and winter.

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Objective: Phytoestrogen isoflavones (IFs) are considered to suppress estrogen-related cancers through their antiestrogenic activity. The antioxidant effect of IFs, however, has not been confirmed in an in vivo system, so suppression of hydroperoxide formation and resultant DNA adduct formation were studied.
Metheds: The antioxidant effects of the soya-hypocotyl tea (SHT), which contained daidzein (14+/−1.5 mg/l) and genistein (3+/−0.5 mg/l), were examined in Wistar rats fed the AIN-76 control diet or iron deficient diet (FeD) for 4 weeks. The intake amount of the diet and IFs were measured daily. Urinary excretion of IFs was measured for 3 days before sacrifice. In addition to the serum lipid analyses, phosphatidylcholine hydroperoxide (PCOOH), and phosphatidylethanolamine hydroperoxide (PEOOH) production in red blood cells and the liver were measured as a biomarker of oxidants. Production of DNA adducts by oxidative stress was measured by the amount of 8-hydroxy-2’-deoxyguanosine (oh⁸dG) in the liver and kidney, and urine. Histological changes were checked by H&E staining and immunohistochemistry for oh⁸dG.
Results: FeD rats showed anemia, growth retardation, hyperlipidemia. IFs only lowered the triacylglycerol level and did not change the cholesterol level. Rats fed the normal diet did not show suppression of PCOOH and PEOOH production in either red blood cells or the liver, while groups administered SHT showed suppressed production of PCOOH and PEOOH in the liver. The cumulative intake of daidzein, genistein and the total amount of IFs showed significant inverse associations with urinary excretion of oh⁸dG. oh⁸dG in the kidney showed an inverse association with the amount of oh ⁸dG in the urine. Enzyme-histochemically, a strong localization of oh⁸dG was found in the epithelial cells of the bile canaliculi and proximal tubules of the kidney.
Conclusion: IFs and SHT showed antioxidant effects at physiological concentrations in an in vivo system. The antioxidant effects of IFs decreased oxidation stress to the nuclear DNA, which was shown by the decreased oh⁸dG production. It is suggested that to prevent various cancers, in addition to the known antiestrogenic, antityrosin kinase, and other effects. IFs appeared to promote excretion of oh⁸dG.

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This study focuses on the predictability of two alternative questionnaires for nicotine dependence, i.e., the Fagerstrom Tolerance Questionnaire (FTQ) and the Tobacco Dependence Screener (TDS), each of which represents a different aspect of dependence, among patients with coronary heart disease (CHD). Twenty-nine male inpatients that had been newly diagnosed as CHD were followed up for 30 weeks after hospital discharge. The baseline information included age, number of cigarettes per day, years of smoking, disease type (angina pectoris [AP] or acute myocardial infarction [AMI]), whether they had received a briefing on smoking cessation, the FTQ, and the TDS. At 30 weeks after hospital discharge, 19 (66%) were abstainers. The group with a high TDS score (of 6 or greater) was significantly less likely to quit smoking than the group with a low TDS score (p=0.046). The FTQ score was not significantly different between the abstainers and non-abstainers. The subjects with AP were significantly less likely to quit smoking than those with AMI (p=0.021). Multiple logistic regression analysis showed that belonging to the high-TDS group and being diagnosed as AP were significantly associated with failure in smoking cessation (p<0.05). The present study suggests that the TDS may have higher predictability than the FTQ concerning smoking cessation among CHD inpatients.

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Objectives: To examine the effective preventive strategy for hypertension in a Japanese male population, based on attributable risk measures.
Methods: A 7-year follow-up study of hypertension among 6,306 middle-aged male office workers in a Japanese telecommunication company.
Results: In terms of population attributable risk percentage (PAR%), regular alcohol intake and physical inactivity showed great contributions to the development of hypertension in the population no less than obesity. The PAR% of each risk factor varied by age group, and the total PAR% of the three modifiable risk factors was considerably higher in the 30−39 year old group (71%) than in the older groups.
Conclusions: Reduced alcohol intake and increased physical activity, as well as weight control, may have a larger impact on prevention of hypertension in younger groups than in older groups.

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