Bulletin of National Institute of Health Sciences最新文献

Arsenic is a very harmful environmental pollutant and arsenic contamination of groundwater has been reported in Bangladesh, West Bengal, India and Nepal. In order to examine the risk assessment of arsenic, we made the plan to deliver the safe water for purpose of drinking and cooking for one year to 16 arsenic-affected families in Chunakali village, Chapai Nawabganj district, Bangladesh. We supplied the safe water after treatment of Gravel Sand Filter facility. The arsenic in drinking water didn't exceed almost 50 ppb for one year. Before delivering the safe water both on June 2005 and on February 2006, we visited Chunakali village with Professor Rahman, Associated Professor Belgum and Zaman and diagnosed the arsenic symptom of the arsenic-affected families and collected their urines and hairs. Also we visited that village on August 2006 of a half year after delivering the safe water and on March 2008 of one year after delivering the safe water. Due to the supply of safe water for one year for purpose of drinking and cooking, the arsenic symptoms were recovering and the amounts of arsenic in hairs were decreasing. If Bangladesh government has the good water management in rural areas of arsenic-polluted underground and adopted the appropriate water supply system, the arsenic symptom caused by arsenic should be recovered.

In May 2006, the positive list system for residues of pesticide and veterinary medicines in food was introduced in Japan. Under this system, the number of regulated pesticides remarkably increased. The information of food items and foods/origins combinations in which pesticides were frequently detected over the detection limits and/or exceeding MRL in the foreign pesticides residue monitoring are useful to achieve the Japanese pesticides residue monitoring programme more efficiently and effectively. We investigated pesticides residue monitoring data published by food safety authorities of North America, Europe and Oceania countries in their web sites. We focused food items and foods/origins combinations which Japan imported in large quantity. Most of pesticides residues detected in twelve food items were mainly fungicides and insecticides, and some residues level of their samples were exceeding the MRLs (maximum residue limits) established in Japan. Most of pesticides residues detected in European countries were also fungicides (e.g. maneb-group and procymidone) and insecticides (e.g. pirimiphos-methyl and malathion), but herbicides were less detected. We provided the collection of Web links to information sites of MRLs and the pesticides residue monitoring reports published by food safety authorities of other countries.

Genotoxicity tests play an important role for the safety evaluation of chemicals. It is well known that there are in vitro and in vivo assay systems for evaluation of chemical genotoxicity on different endpoints. Bacterial gene mutation test and chromosomal aberrations test using mammalian cultured cells are representative examples. It is apparent that there are limitations of in vitro assay systems for chemical safety evaluation and risk assessment for human health and in vivo assay systems are becoming more important in the view point of weight of evidence. There are several in vivo assay systems have been developed and used for different endpoints. Among these, the rodent micronucleus test using hematopoietic cells has been most widely and frequently used to detect induction of chromosomal aberration. It is evident that there are chemicals that gave positive result in the in vitro chromosome aberration test but negative in the rodent micronucleus test. In such case, as a rule, the in vivo negativity is dominant to in vitro positivity. It is important and necessary to reduce animals without any loss of accuracy. In the micronucleus test, the development of the method using peripheral blood instead of bone marrow cells succeeded to reduce total number of animals for chromosomal aberration evaluation in vivo. Tiny amount of blood sampling can be done without killing animals, which is one of the most important advantages of the method, also permits to combine other assays for different endpoints that require different optimal sampling times. Based on this development, in vivo multiple endpoint assay system will be realized and lead more reduction of animals for evaluation of chemical genotoxicity. In this manuscript, We describe the history of development and applications of the peripheral blood micronucleus assay.

Organotin compounds are chemicals widely used in agriculture and industry. Widespread use of organotins has caused increasing amounts to be released into the environment. Organotins show many aspects of toxicity, such as immunotoxicity, neurotoxicity, and reproductive/developmental toxicity. However, the reproductive and developmental toxicity of organotins is not well understood. The findings of the studies on reproductive and developmental effects of organotin compounds in mammals were summarized in this review.

Simultaneous determination for 9 ultraviolet absorbers those set a limit to the amount in cosmetics was performed. Ultraviolet absorbers were extracted from cosmetics with tetrahydrofuran (THF) by ultrasonication. After centrifugation, the supernatant was collected, and the sample solution was injected into the HPLC. Separation was archived using an ODS column with the mixture of THF and water as the mobile phase. Detection wavelength was set at 310 nm. The linearity was obtained between the peak areas and the concentrations of each ultraviolet absorber in the range of 5 - 100 microg/ml. In 70 commercial cosmetic products, such as sunscreen, face powder, foundation, massage cream, moisture lotion, lip balm and essence, 2-ethylhexyl-p-methoxycinnamate (EMC), 2-hydroxy-4-methoxybenzophenone (HMB), 4-tert-butyl-4'-methoxydibenzoylmethane (BMB) and 2-ethylhexyl salicylate (ES) were detected.

Non-corrective and decorative contact lenses can be purchased as sundries without the guidance of medical doctor. Recently, many cases of eye injury by utilizing these lenses have been reported. To estimate their cytotoxic potential to cause eye injury, cytotoxicity tests of the commercially available non-corrective and decorative contact lenses were performed utilizing the V79 cell colony assay. By the colony assays of the lenses and their extracts, it was suggested that two tested lenses out of the ten are cytotoxic. Although preservatives for these lenses in the products showed cytotoxicity, the cytotoxicity of the two lenses is suggested to be ascribed to un-identified materials, which can be extracted to a cell culture medium from them. The results of this study indicate that cytotoxicity of the non-corrective and decorative contact lenses would be better to be evaluated for estimating their biological safety.

Identification and removal/replacement of sources of indoor air pollutants, such as volatile organic compounds (VOCs) and aldehydes, are most effective measures to reduce indoor chemical exposures. For instance, formaldehyde emissions from building materials have been successfully decreased by the restrictions on interior finishing materials under the amended Building Standard Low in Japan. This study was performed to estimate quantitatively influence of household products on indoor air quality. VOC emissions were investigated for 51 products including interior materials, bedclothes, stationeries, toys and printed matters by the small chamber test method (JIS A 1901) under the standard conditions of 28 degrees C, 50% relative humidity and 0.5 times/h ventilation. Total VOC (TVOC) emissions from the tablecloth and gloves, both of which were made of polyvinyl chloride, showed the highest emission rates; over 2000 microg/(m2 x h) after 1 day, and then rapidly decreased to less than 500 microg/(m2 x h) in a week. Among stationeries/toys for schoolchildren and infants, jigsaw puzzle and play mat exhibited higher TVOC emission rates (38 and 24 microg/(m2 x h) after 1 day, respectively). As for VOCs emitted from printed matters, high boiling-point compounds (higher than that of n-tridecane) were typically identified along with toluene, xylenes and ethylbenzene. These results revealed that VOC emissions from household products may influence significantly indoor air quality.

Mercury is one kind of prohibited ingredients in cosmetics by the Japanese Pharmaceutical Affairs Act. We established the analytical method for mercury in cosmetics by ICP-MS. Analytical procedures were as followed: Ten microl of 1 g/l mercury solution and 1 g of whitening cream were put into a 50 ml plastic tube. After adding 20 ml of 12% nitric acid into the 50 ml plastic tube, the mixture was sonicated for 10 min. After sonicating, the mixture was centrifuged at 3000 rpm for 10 min and then the supernatant was filtrated through a milli-pore membrane with the pore size of 0.45 microm and 0.1 microm. After filtration, the mixture was made up to 25 ml with 7% nitric acid and used as the test solution. The test solution of 100 microl was analyzed by ICP-MS (HP-4500, monitoring mass 202). The calibration curve from 1 to 1000 microg/l showed a linear line between the concentrations of mercury and the peak areas. Detection limit of mercury was 0.1 microg/l. There was no effect of the ingredients in the whitening cream on mercury determination.

Indoor air quality is a growing health concern because of the increased incidence of the building-related illness, such as sick-building syndrome and multiple chemical sensitivity/idiopathic environmental intolerance. In order to effectively reduce the unnecessary chemical exposure in the indoor environment, it would be important to quantitatively compare the emissions from many types of sources. Besides the chemical emissions from the building materials, daily use of household products may contribute at significant levels to the indoor volatile organic compounds (VOCs). In this study, we investigated the emission rate of VOCs and carbonyl compounds for 30 air fresheners and deodorizers by the standard small chamber test method (JIS A 1901). The total VOC (TVOC) emission rates of these household products ranged from the undetectable level (< 20 microg/unit/h) to 6,900 microg/unit/h. The mean TVOC emission rate of the air fresheners for indoor use (16 products) was 1,400 microg/unit/ h and that of the deodorizers for indoor use (6 products) was 58 microg/unit/h, indicating that the fragrances in the products account for the major part of the TVOC emissions. Based on the emission rates, the impacts on the indoor TVOC were estimated by the simple model with a volume of 17.4 m3 and a ventilation frequency of 0.5 times/h. The mean of the TVOC increment for the indoor air fresheners was 170 microg/m3, accounting for 40% of the current provisional target value, 400 microg/m3. These results suggest that daily use of household products can significantly influence the indoor air quality.

Usage of pesticides in food items in export countries was studied, focusing items which Japan imports in large quantity. Japan has imported field crops such as wheat, corn and soy bean, and also grapefruit in large quantity on a weight base, mainly from United States, Australia and Canada. While, Japan has imported various kinds of vegetables in which China had the largest share. We collected usage data of pesticides for 44 food items of 17 countries of 2004. Pesticides which were used frequently (usage rank within top ten in each item/country) were dichlorvos, carbofuran, chlorpyrifos, dimethoate (insecticides), mancozeb, carbendazim, thiophanate-methyl, chlorthalonil (fungicides), glyphosate, 2,4-D, paraquat, acetochlor (herbicides). Carbendazim, thiophanate-methyl, acetochlor and dichlorvos were mainly used in China. Dithiocarbamates are used frequently in various food items in various countries, and also frequently detected in monitoring in foreign countries. Some pesticides such as bisultap, monosultap, etaboxam and triazmate were used only in certain countries, and available information on toxicity or analytical method was very limited. Some of pesticides described above have not been analyzed in the pesticide residue monitoring in Japan before 2005,however, many of them are subjects of analysis for import food after 2006 with the enforcement of positivelist system for residues of pesticide and veterinary medicines in food in Japan.