Based on a survey of airborne Japanese cedar pollen carried out in Hyogo prefecture over 10 years (1998-2007), we performed a comparative study of yearly, weekly and daily changes in Japanese cedar pollen counts in the large metropolitan areas of Kyoto, Osaka and Kobe in the Kansai region. Airborne pollen counts were found to have a bi-annual cycle in each of the cities. Fluctuations in the quantity of male cedar flowers and temperatures during the previous summer season are thought to have an effect. Pollen scattering tended to begin earlier in Kobe than in Kyoto. Weekly and daily changes in pollen counts were found to follow the same rise and fall patterns in all three cities at certain times; but to vary between the cities at other times. The position and distance of cedar trees, forest flowering stages and wind speed and direction are also thought to have an effect.
Food labeling is an important information source for consumers when selecting foods. However, we often hear news about mislabeling of foods. To ensure fair labeling, it is necessary to establish scientifically sound methods for classifying foods and to check the labeling. The polymerase chain reaction (PCR) method, which amplifies a specific region of DNA, is very useful for food classification, particularly in cultivar identification. The PCR method makes it possible to detect material of animal origin in meats and meat products and to identify the cultivar of agricultural products.
An investigation was made of high-performance photocatalyst synthesis by low-temperature heating of amorphous TiO2 treated with hydroxyl peroxide. Peroxo titanic acid seems to be formed after the reaction of amorphous TiO2 with hydroxyl peroxide. The high-performance photocatalyst is fabricated by heat treatment with peroxo titanic acid at lower temperature (for instance 100°C). The TiO2 photocatalyst was applied to the removal of acetaldehyde in the air with results better than those obtained with commercial P-25 TiO2.
The Food Sanitation Law of Japan provides that the amount of lead eluted from the paint film on baby toys must be less than 90 μg/g. However, the amount of lead eluted from paint films on products to which the Food Sanitation Law is inapplicable is not controlled even if the product is used by babies. We therefore investigated the amount of lead eluted from the paint films on household products which babies may use with reference to the Food Sanitation Law. In addition, we confirmed the validity of capillary electrophoresis for measurement of the lead concentration of test solutions. Of 105 products (107 paint films) such as stationery and hairpins, only one hairpin had a paint film that eluted a small amount of lead. The hairpin package carried a warning of the lead content. Nevertheless, household product which babies may use should ideally not contain lead.
Dust and water-soluble ion concentrations in Osaka City were measured by high-volume air sampler and the factors causing high concentrations of dust and water-soluble ions investigated. An examination of the annual change in dust concentration showed a sudden decrease in the 1980s and 1990s and a gentler decrease in the 2000s. Concentrations of chloride and nitrate have remained at the same level while concentrations of sulfate and ammonium ion have shown a slight increasing trend in the last ten years. Regarding the correlation between dust and water-soluble ion concentrations, a strong correlation was observed between dust concentration and nitrate concentration. Regarding the correlation between dust and water-soluble ion concentrations and meteorological factors, a strong correlation of the temperature differences between Ikoma and Osaka to dust concentration and nitrate and ammonium ion concentrations was observed. Continental sand particle data showed a correlation of low relative humidity to high concentration of chloride, nitrate, and sulfate, and to low concentration of ammonium ions, while typhoon data showed a correlation of high wind velocity to high chloride concentration.
We evaluated a simultaneous analytical method for organophosphorous pesticides in foods using dual-column gas chromatography (GC) with a mass spectrometer (MS) and pulsed flame photometric detector (PFPD, P mode). The pesticides were extracted with ethyl acetate in the presence of anhydrous Na2SO4 using a homogenizer. The extract was concentrated and reconstituted in acetonitrile, followed by clean-up with a tandem C18 column and double-layered SPE cartridge column (graphite carbon black/aminopropyl). The test solution, divided into two vials, was measured simultaneously with two automatic liquid samplers. Mass spectra and selective detection of PFPD were obtained from the results of a single measurement. By comparing the data from various types of detectors, it is possible to obtain more qualitative information. This method was useful for the analysis of organophosphorous pesticides in foods.
Instances of fungal contamination of food that occurred in Osaka during 2000-2008 were studied. Penicillium was the predominant fungus, followed by Cladosporium and Aspergillus restrictus. The food most frequently contaminated by fungi was cake (including Japanese cake) followed by beverages, such as juices and drinks that had been kept in storage. Xerophilic fungi (A. restrictus, Eurotium, Wallemia) were predominant in cakes while saprophytic fungi of many kinds (e.g. Cladosporium, Aureobasidium) were predominant in beverages. The number of instances of fungal contamination was larger in the warmer months (July-October) than in other months of the year, although no seasonal change in the predominant genus of mold was found. Misunderstandings regarding the fungal contamination of food were present in more than 25% of all cases. Regarding the causes of fungal contamination of food, the importance of post-production systems, transportation and storage in reducing fungal contamination of food is emphasized.