Formaldehyde Exposure in a Gross Anatomy Laboratory. Personal Exposure Level Is Higher Than Indoor Concentration (5 pp)

Goal, Scope and Background Cadavers for gross anatomy laboratories are usually prepared by using embalming fluid which contains formaldehyde (FA) as a principal component. During the process of dissection, FA vapors are emitted from the cadavers, resulting in the exposure of medical students and their instructors to elevated levels of FA in the laboratory. The American Conference of Governmental Industrial Hygienists (ACGIH) has set a ceiling limit for FA at 0.3 ppm. In Japan, the Ministry of Health, Labour and Welfare has set an air quality guideline defining two limit values for environmental exposure to FA: 0.08 ppm as an average for general workplaces and 0.25 ppm for specific workplaces such as an FA factory. Although there are many reports on indoor FA concentrations in gross anatomy laboratories, only a few reports have described personal FA exposure levels. The purpose of the present study was to clarify personal exposure levels as well as indoor FA concentrations in our laboratory in order to investigate the relationship between them. Methods The gross anatomy laboratory was evaluated in the 4th, 10th and 18th sessions of 20 laboratory sessions in total over a period of 10 weeks. Air samples were collected using a diffusive sampling device for organic carbonyl compounds. Area samples were taken in the center and four corners of the laboratory during the entire time of each session (4-6 hours). Personal samples were collected from instructors and students using a sampling device pinned on each person's lapel, and they were 1.1 to 6 hours in duration. Analysis was carried out using high performance liquid chromatography. Results and Discussion Room averages of FA concentrations were 0.45, 0.38 and 0.68 ppm for the 4th, 10th and 18th sessions, respectively, ranging from 0.23 to 1.03 ppm. These levels were comparable to or relatively lower than the levels reported previously, but were still higher than the guideline limit for specific workplaces in Japan and the ACGIH ceiling limit. The indoor FA concentrations varied depending on the contents of laboratory sessions and seemed to increase when body cavity or deep structures were being dissected. In all sessions but the 4th, FA levels at the center of the room were higher than those in the corners. This might be related to the arrangement of air supply diffusers and return grills. However, it cannot be ruled out that FA levels in the corners were lowered by leakage of FA through the doors and windows. Average personal exposure levels were 0.80, 0.45 and 0.51 ppm for instructors and 1.02, 1.08 and 0.89 ppm for students for the 4th, 10th and 18th session, respectively. The exposure levels of students were significantly higher than the mean indoor FA concentrations in the 4th and 10th sessions, and the same tendency was also observed in the 18th session. The personal exposure level of instructors was also significantly higher than the indoor FA level in the 4th session, while they were almost the same in the 10th and 18th sessions. Differences in behavior during the sessions might reflect the differential personal exposure levels between students and instructors. Conclusion The present study revealed that, if a person is close to the cadavers during the gross anatomy laboratory, his/her personal exposure level is possibly 2 to 3-fold higher than the mean indoor FA concentration. This should be considered in the risk assessment of FA in gross anatomy laboratories. Recommendation and Outlook If the risk of FA in gross anatomy laboratories is assessed based on the indoor FA levels, the possibility that personal exposure levels are 2 to 3-fold higher than the mean indoor FA level should be taken into account. Otherwise, the risk should be assessed based on the personal exposure levels. However, it is hard to measure everyone's exposure level. Therefore, further studies are necessary to develop a method of personal exposure assessment from the indoor FA concentration.     

日本公司的环境报告

日本是亚洲太平洋地区进行法人报告的首创者.本文回顾了过去的十年中日本环境报告举措的发展.也描述了对日本公司进行的环境报告的调查反应.在日本正在开始注重确保环境报告可靠性的方法.环境上先进公司的环境报告正在朝可持续发展性报告的方向转移.     

Adaptation of solitary corals and their zooxanthellae to low light and UV radiation

Adaptation of solitary corals, Fungia repanda and F. echinata, and their zooxanthellae to low light and ultraviolet light B (UV-B) was studied with respect to changes in their protein contents, photosynthetic pigment contents and the photosynthesis-irradiance (P-I) curves. The corals were collected from 1 to 50 m depths in the Republic of Belau (Paulau) in 1990 and 1991. The chlorophyll a content in a unit surface area of the coral did not change significantly with the depth of the habitat, whereas cellular chlorophyll a in the algae increased with the depth. Zooxanthellae density and protein content in a unit surface area of Fungia spp. decreased with the depth. Photosynthetic parameters normalized by a unit surface area of the Fungia spp., maximum gross photosynthetic rate (P _gmax area^-1) and dark respiration rate (R area^-1), were negatively correlated with the depth, while initial slope of the P-I curve () did not show significant correlation with the depth. Compensation light intensity (Ic) decreased with the depth. In isolated zooxanthellae, P _max chl a ^-1, and R chl a ^-1 decreased with the depth, while _{chl a} was constant. P _gmax cell^-1 and R cell^-1 did not change significantly but _cell increased with the depth. Ic decreased with the depth as in the intact corals. Reduction of protein content in a unit area of the coral from deeper habitat implies decrease of host animal tissues. Reduction of Ic can be explained by decrease of R area^-1, which may be due to the diminution of animal tissues. The photoadaptational response to low light intensity of intact Fungia spp. was found to be a combination of the photoadaptation of symbiotic algae and the decrease of host animal tissue. In order to study their adaptation to ultraviolet (UV) radiation, P-I curves of Fungia spp. and isolated zooxanthellae were analyzed before and after UV-B irradiation. 1 h UV-B irradiation showed no effect on the photosynthetic rate of the shallow water (1 m) corals, while it inhibited the photosynthesis of the deep water (30 m) corals and zooxanthellae isolated from both shallow and deep water corals. These results indicate that the host, Fungia spp., in shallow water have protective mechanism for intense UV-B in their habitat. These photoadaptational mechanisms seem to allow the Fungia spp. to have wide vertical distribution where light intensity spans more than two orders of magnitude.     

Noncatalytic liquefaction of tar with low-temperature hydrothermal treatment

Water at hydrothermal and supercritical conditions is considered a promising solvent for the degradation of hazardous waste into harmless compounds. Tar liquefaction experiments were conducted using a batch-type reactor at temperatures between 623 K and 673 K and at pressures between 25 and 40 MPa. A reaction mechanism for tar liquefaction is proposed. Moreover, on the basis of the experimental results, this method could become an efficient method for tar liquefaction, producing high yields of valuable chemical intermediates.     

Composition of green turtle feeding aggregations along the Japanese archipelago: implications for changes in composition with current flow

In order to develop effective conservation strategies for endangered migratory species, the link between feeding and breeding grounds needs to be clarified. In this study, the genetic compositions of consecutive Japanese feeding aggregations of green turtles (Chelonia mydas) along the Kuroshio Current were examined by mixed-stock analyses of mitochondrial DNA control-region sequences. The results indicated that the southern feeding aggregation around Yaeyama (24.3°N, 124.0°E) was sourced from various Pacific rookeries in the Yaeyama, Ogasawara, Western Pacific, and Indian Oceans and Southeast Asia. Among northern feeding aggregations, the Ginoza (26.5°N, 128.0°E) aggregation was also sourced from the Western Pacific Ocean, but the Nomaike (31.4°N, 130.1°E), Muroto (33.2°N, 134.2°E), and Kanto (35.6°N, 140.5°E) aggregations were contributed mostly by the closer Ogasawara rookeries. The reduced contribution from tropical Pacific rookeries to northern feeding aggregations and the significant correlation between genetic differentiation and geographical distance matrices of feeding aggregations indicated that most hatchlings from these regions transported by the Kuroshio Current settle in upstream feeding grounds along the Japanese archipelago, implying that current flow influences the composition of feeding aggregations. Differences in the composition of relatively close neritic feeding aggregations have important conservation implications, for which both regional and multinational conservation strategies are needed.     

Comparison of energy recovery system from municipal solid waste in terms of energy balance and life cycle CO2 emission

Journal of Material Cycles and Waste Management - We evaluated four systems for recovering energy from municipal solid waste in terms of life cycle energy and CO2 emissions. Two of these were a...