Having developed a diffusion passive sampler for measurement of indoor and outdoor nitrogen oxide (NO), nitrogen dioxide (NO2), sulfur dioxide (SO2) and ammonia (NH3), we were able to investigate various types of air pollution. This sampler has many advantages such as long-term sampling ability, as its longer shape allows greater diffusion. Fitting an impermeable PTFE filter to the sampler protects against typhoon-like phenomena such as strong winds and heavy rain. The sampler is recyclable due to its simple design, which also allows cost reduction. We used the sampler to measure the concentration of NO2 and SO2 for one month in big cities in China and South Korea where there is a high concentration of these gases. Also, using the sampler, we conducted tests on emissions from cars, ovens and kerosene heaters. In order to measure the concentration of NO2 both indoors and outdoors, we installed the sampler in rooms and also attached it to people (housewives, children) for three days. The sampler was additionally used to monitor air pollutants such as NO, NO2, SO2, and NH3 in an urban museum where air pollutants are generally at low levels. Finally, we tested the sampler to detect volatile organic compounds in homes and found it very useful for analysis with thermal-desorption GC/MS apparatus. We concluded that our sampler is effective for investigation of various kinds of pollutant gas in air.
Giardia intestinalis is a protozoan parasite found in the intestinal tract of humans and animals. Recent molecular studies show considerable genetic diversity among isolates from humans and animals, suggesting that this species is not a single species but is composed of multiple genotypes that have zoonotic potential or are host-adapted. Cross-infection studies using the isolates from different hosts and molecular epidemiological studies in endemic areas strongly support the zoonotic transmission of G. intestinalis. Molecular analysis of the isolates is therefore essential in order to reveal the sources of Giardia infection and thus develop appropriate countermeasures. In Japan, the molecular epidemiology of Giardia infection is as yet unclear as only a few isolates from humans and animals have been genotyped. This report finds that further studies are required for an understanding of the zoonotic significance and molecular epidemiology of Giardia infection in Japan.
Four kinds of fungi were cultured on various media, including different surfactants, and their growth was compared. Cladosporium cladosporioides and Aureobasidium sp., which are common fungi in indoor environments, were inhibited by detergents, especially synthetic detergent. On the other hand, Scolecobasidium sp. and Exophiala alcalophila, the dominant varieties inside washing machines, were not inhibited. Moreover, growth of the latter two fungi was promoted even on media containing 0.25% of detergent. Scolecobasidium sp. and E. alcalophila are thought to utilize detergent as a nutrient, and to be adapted to the environmental conditions inside washing machines.