Ecotoxicity studies Clause Samples

Ecotoxicity studies. A number of comprehensive reviews are available that provide in depth discussions of the advantages and disadvantages of a range of analytical techniques available for the characterisation and analysis of engineered nanomaterials (MNM) (▇▇▇▇▇▇▇▇▇, Haus et al. 2007, ▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇ et al. 2009, ▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇ et al. 2011, ▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇ et al. 2011). Environmental fate and effects research of MNM has highlighted the need for comprehensive characterisation of nanomaterials in order to draw conclusive results from the data. In addition to characterisation of the pure MNM, assessment of their behaviour in relevant ecotoxicity exposure media (biological tissues, natural surface waters, soils and sediments) is necessary. MNM properties including particle size and size distribution, surface charge and shape properties, solubility and agglomeration and aggregation states in environmental and experimental media are known to change substantially relative to mono-dispersed controlled media suspensions (▇▇▇▇▇▇▇ 2008, ▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇ et al. 2009, ▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇ et al. 2011). The complexity of test media clearly introduces additional challenges for the extraction and detection of MNM in such matrices (▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇ et al. 2011). Furthermore, the difficulties associated with distinguishing between naturally occurring and anthropogenically generated nanomaterials adds greatly to these analytical challenges (▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇ et al. 2011). Previously, critical MNM characteristics that should be determined for toxicological assessments include particle size/size distribution, surface chemistry, surface area and the particle chemical composition and concentration (▇▇▇▇▇▇▇ 2008, ▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇▇▇▇ et al. 2009, ▇▇▇▇▇▇▇▇, ▇▇▇▇▇▇ et al. 2011). A large number of MNM have been investigated in environmental fate and effects studies. Reviews are available that discuss the environmental behaviour and ecotoxicity of MNM towards aquatic and terrestrial organisms such as algae, crustaceans, ciliates, fish, bacteria, fungi, plants, nematodes and earthworms (▇▇▇▇, ▇▇▇▇▇▇▇▇ et al. 2008, ▇▇▇▇▇▇▇, ▇▇▇▇ et al. 2008, ▇▇▇▇▇ and ▇▇▇▇▇▇▇▇▇▇▇ 2010, ▇▇▇▇▇, ▇▇▇▇▇▇▇▇ et al. 2012, Miralles, Church et al. 2012). A wide range of lethal and sub lethal endpoints have been investigated (▇▇▇▇, ▇▇▇▇▇▇▇▇ et al. 2008), but reported ecotoxicity data is often inconsistent due to the use of different exposure conditions and limited understanding of MNM physical and chemical properties. The majority...