In Bangladesh, use of beauty cream is very much popular and a common daily task for the people. The current study is focusing on the assessment of some toxic heavy metals such as lead, cadmium, chromium, and mercury contamination in some beauty creams commonly used by Bangladeshi people. The results indicate that the concentrations of lead, cadmium, and chromium exceed the maximum allowable concentrations, whereas mercury is found below the acceptable limit set by WHO/EU. However, according to Health Canada, the concentrations of cadmium and chromium for all the selected samples (except cadmium in sample coded A) was within the permissible limit. Health risks associated with these metal intakes via dermal exposure route are evaluated in terms of chronic daily intake (CDI) and hazard quotient (HQ). The carcinogenic risk (CR) estimated for chromium indicates that it is within the acceptable range. The cancer and non-cancer risk results indicate that although the chances of cancer risk and non-cancer risk resulting from the use of these cosmetic products were unlikely, buildup of these toxic heavy metals overtime on continuous usage could be detrimental for Bangladeshi people.
Abstract:In this study safer facility siting of an ammonia-urea complex is demonstrated by risk mapping. This risk map is useful for identifying safer zones within the plant at the design stage as well as before setting temporary shelters, i.e. shelters for contractors and maintenance workers etc. in an existing plant. To prepare the risk map a number of critical process units of an ammonia-urea complex are selected as the sources of toxic release and blast overpressure. Locations of control room and three operators' shelters are considered with respect to five critical units. Consequences of toxic release and blast overpressure are modeled for various worst case scenarios developed in the critical units. Both structural damage and human mortality/injury are converted into risk scores. Risk mapping of the battery limit area are done and locations with minimum risk scores within plant area are identified for the probable siting of the control room and operators' shelters. The findings are compared with the layout of an existing ammonia-urea complex. It is also shown that a simple risk mapping of the plant area is helpful in avoiding facility siting in high risk zone at the same time finding safer locations for different facilities.
In recent years algae has been receiving a lot of interest as an alternate source of biofuel. Fast growth and rich lipid content make algae a great candidate for producing eco-friendly and non-toxic biodiesel. The strain Chlorella vulgaris, has shown great potential as a source of oil. To optimize the mass culture of microalgae Chlorella vulgaris, it is necessary to develop growth kinetic model of Chlorella vulgaris. This work presents a comparative study on growth kinetics of Chlorella vulgaris in batch cultures in four different media, namely- CH, modified CH, Bold’s Basal (BB), and modified Bold’s Basal (BB). Spectroscopic analysis was supported by visual change of color in the algal biomass solution and the microscopic imaging, and was validated with dry cell mass measurement in this study. The data were analyzed to produce growth curves to find exponential phase for each medium. Exponential phases are the best period to harvest the culture. Hence the duration of exponential phase and the final biomass concentration at the end of exponential phase are two important parameters to determine the most suitable medium for mass culture. In this study the overall specific growth, doubling time and biomass productivity of Chlorella vulgaris for CH, modified CH, BB and modified BB media were measured. This study will help to find a suitable media to culture Chlorella vulgaris, a high lipid content algae in the local environment. The information can be used to design a system for mass culture of the strain for biodiesel production.
Chemical Engineering Research Bulletin 21(2020) 133-138
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