Fumihiko Jitsunari

Migration of surrogate contaminants in paper and paperboard into water through polyethylene coating layer

The migration of five surrogate contaminants, anthracene, benzophenone, dimethyl phthalate, methyl stearate and pentachlorophenol, from paper and paperboard into water through a polyethylene (PE) coating layer was investigated. Virgin paper and paperboard coated with PE films of 0.012 and 0.030mm thickness were spiked evenly with standard 1-ml solutions containing 5mg of each surrogate. The spiked papers were placed in contact with the PE coating layer at 10 and 24°C for 21 days. The resulting surrogate migration through the PE layer into 100ml water was measured by an analytical method developed here that used gas chromatography equipped with a flame ionization detector. Non-polar surrogates of anthracene and methyl stearate did not show any significant migration. In the case of the thin layer coating of 0.012mm, polar water-soluble contaminants of benzophenone, dimethyl phthalate and pentachlorophenol showed an equilibrated or maximized migration after 1 day, even at a refrigerated temperature of 10 °C. A thick PE coating of 0.030mm thickness delayed the progress of contaminant migration, which was also slower at lower temperature. Our results indicate that polyethylene coatings should not be seen as a complete barrier against possible contaminants in paper packaging materials under chilled or ambient conditions. Several variables such as coating thickness, temperature and suspected contaminants need to be considered to control the possible contamination risk from recycled or printed paper.

Migration of styrene monomer, dimers and trimers from polystyrene to food simulants

Migration experiments with polystyrene were performed in two-sided contact with n-heptane and distilled water as the food simulants at temperatures of 10, 24 and 40, and 40, 60 and 90°C, respectively. The surface/volume ratios in the migration cell were set at 8.04 and 10.05 dm2 l−1 for n-heptane and distilled water, respectively. Styrene monomer, styrene dimers and styrene trimers migrating to the food simulants were determined by GC-FID analysis. Heptane fully extracted the styrene monomer and the oligomers from the polystyrene sheet, whereas in the distilled water only the migrated styrene trimers could be detected. To determine the apparent diffusion coefficient, the migration process was analysed based on Ficks law. The higher the molecular weight of the oligomers, the more significant the reduction in the diffusion coefficient. Higher molecular weight oligomers also had lower activation energy of diffusion when the temperature dependence of diffusivity was analysed by the Arrhenius equation. The diffusion coefficient of the trimers was much higher for heptane contact than for water. The activation energy of the diffusion of trimers for water contact was higher than that for heptane.

Association between interpersonal relationship among high-school students and mental health.

ObjectivesAdolescents have many anxieties, and having someone to consult is important for them to maintain their mental health. This study examines: whether students have someone to consult; if they have, whether there are differences in their depressive state and in their degree of satisfaction with their school lives depending on whom they consult; and how their mental health is affected by their human relations.MethodsPersons whom high-school students consult about their worries, Depression Self-Rating Scale for Children (DSRS-C), and satisfaction of high-school students with their school lives were surveyed in 2,646 students of public high schools in A Prefecture, and the persons selected for consultation were classified into four groups (“no one,” “friends,” “adults,” and “friends and adults”) and analyzed.ResultsIn terms of whom they consult we found that high-school students, especially girls, frequently consult “friends and adults.” Mean DSRS-C score was significantly higher for those who consulted “no one” than for those who consulted “friends” or “friends and adults.” Regarding hopelessness, the mean score of those who consulted “no one” was significantly higher than for those who consulted “friends and adults.” Those who consulted “no one” had significantly lower mean score for satisfaction with school life than did those who consulted “friends and adults.”ConclusionsMost of the students selected “friends and adults” for persons to consult, but boys were more likely to have “no one” to consult. Students (boys and girls) having no one to consult are likely to be more depressive and less satisfied with their school lives.

Investigation of Indoor Air Pollution by Chlorpyrifos : Determination of Chlorpyrifos in Indoor Air and 3,5,6-Trichloro-2-pyridinol in Residents' Urine as an Exposure Index

ObjectsWe carried out an investigation to clarify the real state of indoor air pollution by chlorpyrifos (termiticide) and exposure to chlorpyrifos of residents by measuring its urinary metabolite 3,5,6-trichloro-2-pyridinol (TCP) as an exposure index, such as biological monitoring.MethodsThe investigation was conducted in 43 individual houses with termiticide application (whether the termiticide was chlorpyrifos is uncertain) and 3 control houses without any termiticide application in Kagawa, Japan. Urine samples were collected from 46 healthy adult residents of the aforementioned houses.ResultsChlorpyrifos in indoor air in the control houses was not detected (ND<1 ng/m3, n=3), while 41 of 43 houses with termiticide application showed 1–350 ng/m3. Although the chlorpyrifos concentrations in these 41 houses did not exceeded the indoor air quality guideline of 1000 ng/m3, but 3 houses were higher than the guideline 100 ng/m3 for children in Japan. Urinary TCP concentrations of 0.1–7.8 ng/mg·creatinine were detected in 41 residents from the 41 houses where chlorpyrifos had been detected. The chlorpyrifos concentration and the urinary TCP revealed a positive correlation (r=0.5468, p<0.01, n=41).ConclusionsThe immediate health hazard from air born chlorpyrifos in the examined houses was negligible, but the findings suggest that it is necessary to monitor chemicals which may contaminate indoor air and to assess the risk of prolonged exposure to such chemicals. The measuring of urinary metabolite TCP of chlorpyrifos via biological monitoring would be useful, allowing comprehensive evaluation of the exposure to chlorpyrifos in indoor air.

A Method for On-Site Analysis of Urinary Benzene by Means of a Portable Gas-Chromatograph

Benzene is one of the toxic air pollutants released from automobile fuel, exhaust, tobacco smoke etc., and is commonly found in both indoor and outdoor air. Since benzene is a carcinogenic substance classified into group 1 (carcinogenic to humans) by the International Agency for Research on Cancer (IARC), it is important to assess the human health risk posed by exposure to environmental or occupational benzene. The analytical trials were performed to determine blood and urinary unchanged benzene as a specific index for low benzene exposure. But these methods require sophisticated and expensive instruments such as a gas chromatograph-mass spectrometer which can be used only in a laboratory. Moreover, benzene in biological fluids is volatilized so easily that it may cause the loss of samples during collection, transportation and preservation which is the most common cause of uncertainties. Therefore, the development of simple and specific methods to perceive benzene exposure are expected. In this study, we developed a method for on-site analysis of benzene in urine by head space-gas chromatography (HS-GC) employing a field portable GC, since on-site analysis can provide rapid data without time-consuming and loss-inducing processes such as transportation and preservation.

Impact of Health Professionals on Health Promotion Activities in Japanese Worksites

Impact of Health Professionals on Health Promotion Activities in Japanese Worksites: Tomohiro Hirao, et al. Department of Hygiene & Public Health, Faculty of Medicine, Kagawa Medical University—We tried to assess the impact of health staff on health promotion activities in Japanese worksites. We surveyed all worksites with 50 or more employees in Kagawa Prefecture, western Japan through self‐administered questionnaires. We constructed a general linear model that contained three health professions, occupational physicians, health supervisors and occupational health nurses, which are common in the Japanese workplace as co‐regressors, and fourteen health promotion activities as dependent variables. The impact of occupational physicians was small. The impact of health supervisors was considered high in workplace defined activities. The impact of occupational health nurses was considered high in person‐to‐person services and life‐style related activities. Through assessing the impact, the strengths and weaknesses of each health professional were clarified.

Analysis of beta3 adrenergic receptor gene polymorphism using noninvasive samples obtained at scheduled infant health checkups.

Obesity is a risk factor for life-style-related diseases, and is based on three factors: genetic, environmental, and life-style. In adults, it is difficult to achieve and maintain normal body weight, so it is more effective to intervene from infancy to establish weight control. Legally required health checkups in infants of 18 and 36 months present important opportunities for obesity prevention. We consider genetic analysis to be a very important factor for obesity prevention in infancy. However, since health checkups don’t involve the collection of blood, genetic analysis is considered difficult. In this study, we attempted the typing of beta3 adrenergic receptor gene polymorphism as a genetic factor from non-invasively obtained samples, buccal mucosa, hair and cerumen in 96 infants at their 18- and 36-month health checkups. Sampling buccal mucosa, hair and cerumen instead of blood caused almost no anxiety to the child or parent, so 94.1% cooperation with sampling was obtained. From buccal mucosa, about 76% of the samples could be used for the typing of polymorphism (81% by enzyme method, 59% by kit method). From hair, about 44% of the samples permitted typing of polymorphism, but from cerumen only about 4% of the samples could be used. Results from buccal mucosa and hair typed about 90% of infant polymorphism. These results suggest that this method would be practical at periodic health checkups, and would probably be applicable to mass screenings for genetic factor analysis for other diseases.

Study on biological monitoring of fenpropathrin exposure in application by utilizing urinary 3-phenoxybenzoic acid level

To estimate pesticide exposure faced by applicators, an investigation of exposure-absorption was conducted on two applicators under routine working conditions and using regular procedures during pesticide spraying of greenhouse strawberries with fenpropathrin. The authors hypothesized that 3-phenoxybenzoic acid (3-PBA) is a urinary excreted metabolite of fenpropathrin, a synthetic pyrethroid pesticide with 3-phenoxybenzyl moiety, and its determination would help to improve the assessment of fenpropathrin exposure-absorption in applicators. The extent of exposure-absorption was evaluated by the determination of urinary level of 3-PBA (biological monitoring), the amount of the chemical adhered to clothes and permeated to the skin surface, and its concentration in the air of the greenhouse. The results showed that the fenpropathrin concentration in the air was less than 0.1 μg/m3. The amount of adhesion was less than 0.001 to 10.25 μg/cm2, and there was very little permeation. However, the urinary 3-PBA concentration by biological monitoring appeared to be approximately twice that of pre-exposure levels in both applicators. This finding demonstrates that the applicators were exposed to fenpropathrin and absorbed it during spraying. We conclude that the fenpropathrin exposure-absorption in application could be estimated by the determination of urinary 3-PBA. This method of biological monitoring may be more useful indicator to accurately evaluate the working conditions in application.

Aging Exacerbates Restraint Stress-Induced Inhibition of Antigen-Specific Antibody Production in Mice

BACKGROUND We have recently found that exposure to acute restraint stress suppresses antigen-specific antibody production, including IgE, in a murine model of allergic rhinitis. Although age-related alterations in immune responses are known, it remains unclear whether aging modulates the antibody production under stressful conditions. In this study, we set out to determine the effects of aging on antibody production under acute restraint stress in mice. METHODS Both young and aged CBA/J mice were repeatedly sensitized intranasally with phospholipase A2 (PLA2) without adjuvants. Restraint stress was applied using uniform cylinders once a week for a continuous 8h period, on 5 occasions in total. Blood samples were taken at 0, 20 and 30 days after primary sensitization, and production of PLA2-specific antibodies and levels of IL-4, IFN-gamma, IL-10 and IL-1 beta in sera were determined by ELISA. RESULTS Repeated intranasal sensitization with PLA2 induced PLA2-specific IgE, IgG1 and IgG2a production in aged mice. We found that exposure to restraint stress significantly inhibited production of PLA2-specific IgE, IgG1 and IgG2a in aged mice. In addition, antibody production under restraint stress decreased significantly in aged mice when compared with young mice. No IL-4, IFN-gamma, IL-10 or IL-1 beta were detected in sera from non-stressed or stressed aged mice. CONCLUSIONS Aging exacerbates the immunosuppressive role of acute restraint stress in antigen-specific antibody production in mice.

Protective effect of D-psicose against testicular atrophy induced by di(2-ethylhexyl) phthalate

The pollutant di(2-ethylhexyl) phthalate (DEHP) is a suspected reproductive toxicant. To clarify the protective effect of D-psicose on DEHP-induced testicular atrophy, we exposed rats to 1% DEHP via their diet while receiving D-psicose supplementation. A significant negative correlation was found between plasma mono(2-ethylhexyl) phthalate (MEHP) concentrations and relative testicular weight in rats given the 1% DEHP-containing diet for seven days. There was, however, no significant difference in testicular weight compared with control in rats given the 1% DEHP-containing diet plus 2% D-psicose-supplemented water. Rats given the 1% DEHP-containing diet for 14 days showed severe testicular atrophy. Conversely, those given the diet plus 2 or 4% D-psicose-supplemented water did not develop testicular atrophy and exhibited complete spermatogenesis. Testicular weight was also restored almost completely by D-psicose. But, incomplete but significant protection was noted in rats receiving a 2% DEHP-containing diet plus 4% D-psicose-supplemented water for 14 days. The present study shows the almost complete protective effect of D-psicose against DEHP-induced testicular atrophy. Although the reproductive toxicity of DEHP in human beings remains unclear, D-psicose may act as a protective agent against oxidant-mediated testicular injury in mammals, including human beings.