Effects of SO2 on respiratory system of adult Miyakejima resident 2 years after returning to the island.

BACKGROUND: Mt. Oyama in Miyakejima Island erupted in June, 2000. All Miyake villagers were forced to evacuate from the island in September, 2000, due to continuous eruptions and emissions of unsafe amounts of volcanic gas, mainly SO2. From February, 2005, Miyake villagers returned to the island despite volcanic gas still being emitted. OBJECTIVES: This study examines the 2-yr changes in Miyake residents' respiratory systems from autumn 2004 to November 2006. METHODS: The study population was 823 Miyake adult residents who participated in the health check-up in 2006. Respiratory effects were evaluated by a questionnaire for respiratory symptoms and spirometry. SO2 has been continuously monitored at 7 sampling points of the inhabited area. The mean SO2 concentration from February 2005 to November 2006 was 0.031 ppm. The area was categorized into 4 areas by SO2 concentration, namely, areas L, H-1, H-2 and H-3, where average SO2 concentrations were 0.019, 0.026, 0.032, and 0.045 ppm, respectively. RESULTS: The study subjects showed no deterioration in lung function. Prevalence of cough and phlegm among all participants were significantly higher in 2006 than in 2004, and age-, sex- and smoking-adjusted odds ratios of cough and phlegm were 1.75 (95%CI 1.33-2.30) and 1.44 (1.12-1.87). Prevalence of chronic bronchitis-like symptoms among normosusceptive subjects in 2006 was 4.1% which was significantly higher than that of 2.1% in 2004 (p=0.035). Compared to area L, the frequencies of phlegm and irritation of the nose were significantly increased in areas H-2 and H-3. CONCLUSION: SO2 exposure-related respiratory symptoms were observed in adult Miyakejima residents after returning to the island.

Visceral fat thickness in overweight men correlates with alterations in serum fatty acid composition.

BACKGROUND: We examined relationships between visceral fat amount and alterations in serum fatty acid composition, both of which represent critical factors in the development of metabolic syndrome. METHODS: Correlations were analyzed between visceral fat thickness as measured by ultrasonography and proportions of individual fatty acids in 21 normal-weight and 24 overweight Japanese men. RESULTS: Significant associations were identified in overweight subjects. Visceral fat thickness displayed positive correlations to levels of palmitic acid and saturated fatty acids (r=0.475, P<0.05 and r=0.545, P<0.01, respectively); and negative correlations to levels of linoleic acid and polyunsaturated fatty acids (r=-0.513, P<0.05 and r=-0.428, P<0.05, respectively). Visceral fat thickness was also correlated with estimated desaturase activities, with positive correlations to Delta9- and Delta6-desaturase activities and negative correlations to Delta5-desaturase activity (r=0.580, P<0.01, r=0.669, P<0.01 and r=-0.559, P<0.01, respectively). No significant associations were identified in normal-weight subjects. CONCLUSIONS: Significant associations between visceral fat amount and alterations in serum fatty acid composition were identified, but only in overweight individuals.

Lack of relationship between occupational exposure to carbon disulfide and endocrine dysfunction: a six-year cohort study of the Japanese rayon workers.

OBJECTIVES: A six-year prospective cohort study was conducted to clarify whether the current carbon disulfide (CS2) exposure level is low enough to prevent subclinical health impairment and/or to ameliorate health effects due to previous high exposure. This paper describes the follow-up results, exposure assessment, and effects on the endocrine system. METHODS: The study subjects were 432 male workers exposed to CS2 at one of the 11 rayon factories in Japan and 402 referent workers from the same factories, all of whom were examined in 1992-93. 251 CS2-exposed, 140 former-exposed and 359 referent workers participated in the follow-up survey (follow-up rate 89.9%) in 1998-99. Urinary 2-thiothiazolidine-4-carboxylic acid (TTCA) at the end of a shift as internal exposure index and the time-weighted average CS2 concentration as external exposure index were measured twice a year from 1992-1993. By using various blood indices, we evaluated effects on thyroid, hypophysis, and gonad function, as well as effects on glucose metabolism. Information on potential confounding factors, such as age, smoking and alcohol drinking, were collected and adjusted for. RESULTS: When the individual exposure level was represented by arithmetic mean for TTCA and CS2 concentration, geometric means (SD) of CS2 workers were 1.61 (1.91) mg/g.crea and 5.02 (1.84) ppm, respectively. There were no exposure-related differences in glucose metabolism or any of the endocrinological indices. CONCLUSIONS: No biologically significant effects of CS2 were found on endocrine function in Japanese rayon manufacturing workers when the average internal and external exposure levels were maintained below the current occupational exposure limit.

Uptake of cadmium in meals from the digestive tract of young non-smoking Japanese female volunteers.

OBJECTIVES: To estimate rates of cadmium (Cd) uptake from the digestive tract and changes in Cd in biological specimens after intake of Cd mainly in rice. METHODS: Twenty-five young non-smoking Japanese female volunteers (20-23 in age) were recruited and a 20-d experimental study was conducted. With polished rice containing 0.004 ppm and 0.340 ppm of Cd, Meal L and Meal H were prepared. Approximately 12% of total Cd in Meal L and 92% of total Cd in Meal H originated in rice. The volunteers ate Meal L for 11 d to achieve a stable intake-output balance of Cd. Fifteen of the 25 volunteers ate Meal H on the 12(th) day (Group D1), and the remaining 10 ate Meal H on the 12(th), 13(th) and 14(th) day (Group D3). All 25 subjects then resumed the consumption of Meal L to the end of the study (20(th) day). All meals, feces and urine were collected during the study, and Cd intake from the daily meals (Cd-I), Cd in feces (Cd-F) and Cd in urine (Cd-U) were determined. For measurement of Cd in blood (Cd-B), venous blood was collected from all volunteers on the day before the study and again on the 12(th) and 20(th) day; venous blood was also collected from 4-8 volunteers at additional time points. RESULTS: Mean Cd-I was 4.51 microg/d (range: 1.85-6.93) or 48.48 microg/d (range: 27.98-56.27) when they ate Meal L or Meal H. Cd-F and Cd-B exhibited faster responses to the change in Cd-I than did Cd-U. The Cd(uptake) rate, defined as (1-Cd-F(excess) /Cd-I(excess)) (Fig. 1), was 47.2% (range: -9.4-83.3%) in Group D1 and 36.6% (range: -9.2-73.5%) in Group D3, and the Cd(balance) rate, defined as (1-Cd-F(output) /Cd-I(intake)), was 23.9% (range: -4.0-37.7%) in Group D1 and 23.7% (range: -8.2-56.9%) in Group D3. CONCLUSIONS: Cd-F and Cd-B are better biological monitoring parameters for assessing change in Cd-I than Cd-U. The Cd(uptake) and Cd(balance) rates appeared to be higher than those in previous papers when ingested Cd mainly originated in rice.