With the development of nanotechnology, silver nanoparticles (Ag-NPs) have become one of the most in-demand nanoparticles owing to their exponential number of uses in various sectors. The increased use of Ag-NPs-enhanced products may result in an increased level of toxicity affecting both the environment and living organisms. Several studies have used different model cell lines to exhibit the cytotoxicity of Ag-NPs, and their underlying molecular mechanisms. This review aimed to elucidate different properties of Ag-NPs that are responsible for the induction of cellular toxicity along with the critical mechanism of action and subsequent defense mechanisms observed in vitro. Our results show that the properties of Ag-NPs largely vary based on the diversified synthesis processes. The physiochemical properties of Ag-NPs (e.g., size, shape, concentration, agglomeration, or aggregation interaction with a biological system) can cause impairment of mitochondrial function prior to their penetration and accumulation in the mitochondrial membrane. Thus, Ag-NPs exhibit properties that play a central role in their use as biocides along with their applicability in environmental cleaning. We herein report a current review of the synthesis, applicability, and toxicity of Ag-NPs in relation to their detailed characteristics.

Concentrations of five heavy metals (Pb, Cd, Cr, As and Hg) in eight highly consumed cultured fish species (Labeo rohita, Clarias gariepinus, Hypophthalmichthys molitrix, Cyprinus capio, Puntius sarana, Oreochromis mossambicus, Pangasius pangasius and Anabas testudineus) collected from four wholesale markets of Dhaka city, Bangladesh (Karwan Bazar, Mohammadpur Town Hall, Newmarket and Mirpur-1) were measured using atomic absorption spectrometry (AAS) in order to evaluate the potential human health risks from the consumption of fish. The estimated daily intake (EDI) of all the studied heavy metals calculated on the basis of mean fish consumption of 49.5 g person-1 d-1 by Bangladeshi households indicated that no risk to people's health with respect to the EDI of investigated heavy metals through the consumption of the fish samples. From the human health point of view, the estimation of non-carcinogenic risk indicated that intake of individual heavy metal through the consumption of fish was safe for human health, whereas, consumption of combined heavy metals suggested potential health risk to highly exposed consumers. However, the estimation of carcinogenic risk of arsenic due to the consumption of fish indicated that consumers remain at risk of cancer.

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.