An overview of the environmental pollution and health effects associated with waste landfilling and open dumping

Environmental Science and Pollution Research - Landfilling is one of the most common waste management methods employed in all countries alike, irrespective of their developmental status. The most...     

Assessment of toxic metals in waste personal computers

Considering the enormous production of waste personal computers nowadays, it is obvious that the study of their composition is necessary in order to regulate their management and prevent any environmental contamination caused by their inappropriate disposal. This study aimed at determining the toxic metals content of motherboards (printed circuit boards), monitor glass and monitor plastic housing of two Cathode Ray Tube (CRT) monitors, three Liquid Crystal Display (LCD) monitors, one LCD touch screen monitor and six motherboards, all of which were discarded. In addition, concentrations of chromium (Cr), cadmium (Cd), lead (Pb) and mercury (Hg) were compared with the respective limits set by the RoHS 2002/95/EC Directive, that was recently renewed by the 2012/19/EU recast, in order to verify manufacturers’ compliance with the regulation. The research included disassembly, pulverization, digestion and chemical analyses of all the aforementioned devices. The toxic metals content of all samples was determined using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). The results demonstrated that concentrations of Pb in motherboards and funnel glass of devices with release dates before 2006, that is when the RoHS Directive came into force, exceeded the permissible limit. In general, except from Pb, higher metal concentrations were detected in motherboards in comparison with plastic housing and glass samples. Finally, the results of this work were encouraging, since concentrations of metals referred in the RoHS Directive were found in lower levels than the legislative limits.     

Use of Sediment Quality Guidelines and pollution indicators for the assessment of heavy metal and PAH contamination in Greek surficial sea and lake sediments

Eight different surface sediment samples (K1–K8) were collected from two separate areas of Lake Koumoundourou and two samples (E1 and E2) from one area of Elefsis Bay, Athens, Greece. The level of pollution attributed to heavy metals was evaluated using several pollution indicators. Degree of Contamination, Modified Contamination Degree and Geoaccumulation Indexes were applied in order to determine and assess the anthropogenic contribution of the selected six elements (Cr, Ni, Cu, Zn, As and Pb). Moreover, the adverse effects of the sediments to aquatic organisms, from both heavy metals and polycyclic aromatic hydrocarbons (PAHs), were determined by using Sediment Quality Guidelines. The results indicated that Lake Koumoundourou is contaminated with heavy metals in a moderate degree and almost 50 % of the sediments are associated with frequent observation of adverse effects, when it comes to Ni and occasional observation of adverse effects, when it comes to Cu, Zn and Pb. As far as PAHs are concerned, around 60 % of the samples can be occasionally associated to toxic biological effects according to the effect-range classification for phenanthrene, benzo(a)anthracene, chrysene and pyrene. Finally, samples taken from the north side of the lake are more contaminated with PAHs than the ones taken from the east side probably due to the existence of the water barrier which acts as a reservoir of PAHs.     

Qualitative and quantitative determination of heavy metals in waste cellular phones

Twenty four waste cellular phones, manufactured between 2002 and 2011, were selected in order to determine the total heavy metal content in each of their parts (printed circuit boards (PCBs), plastic housing (PH) and liquid crystal display monitors (LCDs)) and compare the results with the permissible limits set by the 2003 Directive on Restriction of Hazardous Substances (RoHS). All the selected samples were pulverized and digested with strong acids. Inductively coupled plasma-mass spectrometry was used to measure the heavy metal content in each sample. The results revealed that concentration levels of the examined heavy metals were higher in PCBs, followed by PH and LCD in that particular order (PCB > PH > LCD). With the exception of Pb and Cr present in PCBs of mobile phones released before the year 2006, all the other metal concentrations were according to the Directive. Concentration levels of Cd, Hg were lower than the permissible limits set by the EU, either before or after the validity of the 2003 RoHS Directive. Considering their significant heavy metal content, coupled with their large quantities produced worldwide in an annual rate, waste cellular phones need to be treated under an environmentally sound management scheme, prioritizing recycling and at the same time eliminating the possibility of any harm.