Jun Kagawa

Photochemical air pollution. Its effects on respiratory function of elementary school children.

The effects of photochemical air pollution on respiratory function of Tokyo elementary school children were investigated. Nine types of environmental factors were continuously recorded. Seven categories of respiratory function tests were performed on 20 normal 11-year-old children once a week from June to December 1972, as a general rule. The correlation coefficients between respiratory function measurements and each of the environmental factors were calculated. The maximum expiratory flow rate (V max) showed high correlation with the largest number of environmental factors. Among environmental factors, temperature highly affected various respiratory function tests. The O3 was significantly associated with airway resistance (Raw) or specific airway conductance (Gaw/Vtg), NO or NO2 with V max, and temperature with Raw, Gaw/Vtg, and V max. Two subjects among all subjects were considered as the reactors to the environmental factors.

Effects of ozone and brief exercise on specific airway conductance in man

Four normal male subjects were exposed to 0.9 ppm ozone with exercise for five minutes. Specific airway conductance (Gaw/Vtg) was increased by exercise and decreased by inhalation of ozone in most subjects, but these effects were small. Ozone inhalation with exercise resulted in a highly significant decrease of Gaw/Vtg. It would seem that a peak concentration of 0.9 ppm of ozone for five minutes produces adverse effects when the subject undertakes exxercise in it.

Relation between Cotinine in the Urine and Indices Based on Self-Declared Smoking Habits

ObjectivesThe reliability of surveys on smoking habits based on questionnaires was investigated, using the urinary cotinine content as an objective index.MethodsThe subjects tested were 2,849 office workers of middle age, who responded to questions concerning their smoking status, and also their urinary cotinine was measured by the HPLC method.ResultsThe boundary value between smokers and non-smokers, determined by the histogram independent of the questionnaire, was 63.1 and 79.4 ng/mg of creatinine for males and females, respectively. The rate of misclassification of the non-smokers and former smokers as smokers was 1.3% for males and 1.8% for females, whereas that of current smokers as non-smokers was 6.3% and 2.1%. We also assessed the effect of smoke inhalation on the urinary cotinine value, and found a significant difference for males in the cotinine value by the presence of inhalation and also its depth.ConclusionsThe rate of misclassification in this study was considered to be comparatively low. Several studies have also assessed the reliability of the questionnaire on smoking habits, and found different misclassification rates, indicating the dependence on the race and number of subjects tested. To our knowledge, there were only a few surveys on smoking among large groups, particularly in Japan, such as this one, therefore the results obtained in this study are meaningful.

Between- and within-subject variability of pulmonary function.

Maximal forced expiration of 326 adult males 30 to 55 yr of age was measured four times during a follow-up of 4 yr. Acceptable results were obtained in 270 subjects three times or more. Forced vital capacity (FVC), forced expiratory volume in one second, maximal expiratory flows at 50% and 25% FVC divided by squared height (CFVC, CFEV1, CVmax50, and CVmax25, respectively) were analyzed. Between- and within-subject variance were estimated by a linear model, including the effects of individual and age as explanatory variables. The goodness of fit of the model was satisfactory, since the coefficients of determination of the model were more than 0.96 for CFVC and CFEV1 and around 0.91 for CVmax50 and CVmax25. Estimated between-subject variance was far larger than within-subject variance, being more than ten times for CFVC and CFEV1, about eight times for CVmax50, and five times for CVmax25. At the same time, annual decline of pulmonary function determined cross-sectionally was significantly larger than that determined longitudinally. These results indicated the superiority of longitudinal analysis to cross-sectional analysis in evaluating relatively small effects on pulmonary function especially in the case of chronic exposure of toxic substances in low doses.

ACUTE MERCURY VAPOR POISONING

Four cases of atypical elemental mercury poisoning are reported each of which showing a sudden increase of urinary mercury excretion, which lasted for about 6 months, after 18th month from the exposure, although urinary mercury concentrations had been gradually decreased until 17th month after the mercury vapor exposure. The characteristic features such as tremor and kidney symptoms usually seen in elemental mercury poisoning were not observed in our four cases. Some patients showed concentric constriction of visual fields, hearing damage in high frequencies, ataxia and peripheral neuropathy which were frequently seen in the alkyl mercury poisoning. But, these signs were considered to be related to mercury vapor exposure, although some other agents might have produced such unusual symptoms. The reason for the sudden increase of urinary mercury for many months after the exposure was not explained in the present study.