While there is an awareness of the need to quantify inhalation exposure from showers, the potential for dermal exposure to organic contaminants in showers has not been appreciated or explored. To establish routes of environmental exposure from showers, comparisons of the concentration of chloroform in exhaled breath after a normal shower with municipal tap water were made with those after an inhalation-only exposure. The postexposure chloroform breath concentrations ranged from 6.0-21 micrograms/m3 for normal showers and 2.4 to 10 micrograms/m3 for inhalation-only exposure, while the pre-exposure concentrations were all less than the minimum detection limit of 0.86 micrograms/m3. According to an F-test, the difference between the normal shower and the inhalation-only exposures was considered significant at a probability of p = 0.0001. Based on the difference, the mean internal dose due to dermal exposure was found to be approximately equal to that due to the inhalation exposure. The effect of the showering activities on the concentration of chloroform shower air was examined by comparing air concentrations during a normal shower with the air concentrations obtained when the shower was unoccupied. The F-test showed that there is no significant difference between the two sets of data.

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Recently, showers have been suspected to be an important source of indoor exposure to volatile organic compounds (VOC). The chloroform dose to an individual from showering was determined based on exhaled breath analysis. The postexposure chloroform breath concentration ranged from 6.0-21 micrograms/m3, while all corresponding background breath concentrations were less than 0.86 micrograms/m3. The internal dose from showering (inhalation plus dermal) was comparable to estimates of the dose from daily water ingestion. The risk associated with a single, 10-min shower was estimated to be 1.22 x 10(-4), while the estimated risk from daily ingestion of tap water ranged from 0.130 x 10(-4) to 1.80 x 10(-4) for 0.15 and 2.0 L, respectively. Since the estimates of chloroform risk from domestic water use for the three exposure routes--ingestion, inhalation, and dermal--are similar, all routes must be used to calculate the total risk when making policy decisions regarding the quality of the municipal water supply.

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Heterogeneous semiconductor based photocatalytic hydrogen (H2) production by water splitting is one of the widely recognized promising sustainable technologies to deliver clean energy for future energy demands. The present review article mainly focus on the overview of principle of water splitting, different semiconductor nanomaterials used for photocatalytic water splitting in the presence of UV and solar light irradiation, role of sacrificial reagents, simultaneous degradation of pollutants and H2 production reaction, strategy for development of efficient photocatalyst for H2 production. Further the flaws associated with present photocatalytic system like recombination rate of electron–hole pairs, low visible-light response, use of hazardous irradiation sources and surface area of photocatalyst etc. has also been discussed. Recently the use of energy efficient light emitting diodes (LEDs) as an irradiation source for H2 production is highly attracted due to its unique characteristics. Recent literature on LED source based photocatalytic system for H2 production has also been summarized and highlighted. At last, the future prospects and challenges towards the designing of better photocatalytic system for H2 production have also been discussed. From the literature survey, it is concluded that construction of efficient photocatalytic system for simultaneous degradation of pollutants and H2 production under energy efficient irradiation source offer clean and simple system for solving the futuristic environmental concerns and energy crisis.

Real monitoring data are required for the validation of models or methods used to estimate industrial emission inventories of air pollutants. As such, the current study investigated the industrial emissions of four major and three other hazardous air pollutants in four subareas of the Yeongnam area in Korea over five years (2005 through 2009), using direct stack monitoring concentrations, which were obtained from tel-monitoring systems. Yearly variations in the industrial emissions of the target pollutants depended upon the subareas and chemical types. For example, the total suspended particulate (TSP) emissions in Geongnam increased for two consecutive years (2007 and 2008) and then, decreased in 2009, whereas the industrial CO emissions in Ulsan sharply increased since 2007. For TSP, primary metal manufacturing (PMM) and Power, electricity and gas supplying companies (PEGSC) were two major industrial emission sources. PEGSC exhibited the highest source for both SO 2 and NO x emissions, followed by PMM and petroleum and petrochemical companies in descending order. For CO emissions, PPM exhibited the highest source, followed by municipal waste treatment and intermediate waste treatment facilities in descending order. Both NH 3 and HF were emitted primarily from two subareas (Ulsan and Geongbuk), which have fertilizer production companies. Both Geongnam and Geongbuk exhibited the highest and the second highest HCl emissions, presumably due to emissions during the acid treatment processes of various metals. Most of the industry categories, which are associated with fuel combustions or waste incineration, exhibited the highest and the second highest emission proportions for NO x and SO 2 , respectively. Maximum emissions were observed in the winter or summer season, while minimum emissions were observed in the spring or fall season, presumably due to increased energy utilizations for residential as well as industrial heating and cooling.

The light absorbance of photocatalysts and reaction kinetics of environmental pollutants at the liquid-solid and gas-solid interfaces differ from each other. Nevertheless, many previous photocatalytic studies have applied the science to aqueopus applications without due consideration of the environment. As such, this work reports the surface and morphological characteristics and photocatalytic activities of carbon-embedded (C-TiO 2 ) photocatalysts for control of gas-phase methyl tertiary-butyl ether (MTBE) under a range of different operational conditions. The C-TiO 2 photocatalysts were prepared by oxidizing titanium carbide powders at 350 o C. The characteristics of the C-TiO 2 photocatalysts, along with pure TiC and the reference pure TiO 2 , were then determined by X-ray diffraction, scanning emission microscope, diffuse reflectance ultraviolet-visible-near infrared (UV-VIS-NIR), and Fourier transform infrared spectroscopy. The C-TiO 2 powders showed a clear shift in the absorbance spectrum towards the visible region, which indicated that the C-TiO 2 photocatalyst could be activated effectively by visible-light irradiation. The MTBE decomposition efficiency depended on operational parameters, including the air flow rate (AFR), input concentration (IC), and relative humidity (RH). As the AFRs decreased from 1.5 to 0.1 L/min, the average efficiencies for MTBE increased from 11% to 77%. The average decomposition efficiencies for the ICs of 0.1, 0.5, 1.0, and 2.0 ppm were 77%, 77%, 54%, and 38%, respectively. In addition, the decomposition efficiencies for RHs of 20%, 45%, 70%, and 95% were 92%, 76%, 50%, and 32%, respectively. These findings indicate that the prepared photocatalysts could be effectively applied to control airborne MTBE if their operational conditions were optimized.

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