Environmental pollution of heavy metals is increasingly becoming a problem and has become of great concern due to the adverse effects it is causing around the world. These inorganic pollutants are being discarded in our waters, soils and into the atmosphere due to the rapidly growing agriculture and metal industries, improper waste disposal, fertilizers and pesticides. This review shows how pollutants enter the environment together with their fate. Some metals affect biological functions and growth, while other metals accumulate in one or more different organs causing many serious diseases such as cancer. The pharmacokinetics and toxicological processes in humans for each metal is described. In summary, the review shows the physiological and biochemical effects of each heavy metal bioaccumulation in humans and the level of gravity and disquieting factor of the disease.
1 September 2019 in Science of The Total Environment
Current trends in the biodegradable scaffold industry call for powder metallurgy methods in which compression cannot be applied due to the nature of the scaffold template itself and the need to retain the shape of an underlying template throughout the fabrication process. Iron alloys have been shown to be good candidates for biomedical applications where load support is required. Fe-Mn alloys were researched extensively for this purpose. Current research shows that all metallurgical characterisation and corrosion test on Fe-Mn and Fe-Mn-Ag non pre-alloyed powder alloys are performed on alloys which are initially pressed into greens and subsequently sintered. In order to combine the cutting-edge field of biodegradable metallic alloys with scaffold production, metallurgical characterisation of pressed and non-pressed Fe, Fe-Mn and Fe-Mn-Ag sintered elemental powder compacts was carried out in this study. This was performed along with determination of the corrosion rate of the same alloys in in vitro mimicking solutions. These solutions were synthesised to mimic the osteo environment in which the final scaffolds are to be used. Both pressed and non-pressed alloys formed an austenite phase under the right sintering conditions. The corrosion rate of the non-pressed alloy was greater than that of its pressed counterpart. In a potentiodynamic testing scenario, addition of silver to the alloy formed a separate silver phase which galvanically increased the corrosion rate of the pressed alloy. This result wasn't replicated in the non-pressed alloys in which the corrosion rate was seen to remain similar to the non-silver-bearing alloy counterparts.
DBP and DEHP are two of the most common plasticisers used in modern industries, which have aroused a major concern over their ubiquitous occurrence and hazardous environmental effects. This study presents the first data of phthalates occurrence and distribution in Maltese shoreline sand. DBP and DEHP occurrence was investigated in three busy and secluded beaches, respectively. Analytical determination involved quantifying DBP and DEHP from 75 samples using UPLC–MS/MS through triple repeatability. The concentrations ranged between 0.0095 and 0.07034 µg/g and <LOQ and 0.0977 µg/g for DBP and DEHP, respectively. Statistical analysis of the comparison of phthalates in different beaches demonstrated that the occurrence of DBP and DEHP in Maltese shoreline sand varies. The differences in the occurrence of phthalates were attributed to the beach topography and anthropogenic pressures. Analysis of the effects of anthropogenic activities on the occurrence of phthalates showed a positive association. Distribution analysis showed that DBP and DEHP exhibit an uneven distribution along the shoreline. Conversely, different distributions were observed at distances away from the sea. The uneven distributions observed were associated with anthropogenic activities, different chemodynamic properties and wave action. Cluster analysis was performed to prove the interactions between the phthalates concentrations and the characteristics of the beaches.