Heavy Metals Levels in Plastics Housing of Televisions: Is there a changing trend across three decades (1980-2000)?

This study investigated the concentration of some heavy metals in plastic housing of televisions produced over three decade (1980-2000) with the aim of providing information and comparing the trend in the concentration of these metals. The heavy metal concentrations were determined by atomic absorption spectroscopy after acid digestion using a 1:1 mixture of sulphuric and nitric acid.  
The mean concentration of the heavy metals (mg/kg) in the television sets for 1980s, 1990s and 2000s, respectively, were as follows: 12.75 (Nd); 1.32 (Pb); 1.84, 1.47 & 2.79 (Ni); 1.53, 16.19 & 40.42 (Ag); 82.24, 159.69 & 113.29 (Zn); 7.12, 4.23 & 5.26 (Cr); 3.26, 2.76 & 2.39 (Cu); 4.84, 24.05 & 26.67 (V); 9.30, 8.40 & 12.63 (Co); 2.59, 4.05 & 4.28 (Cd). Although the mean concentrations for Zn, Cu and Ag in the television samples were relatively high, compared to the total threshold limit concentration (TTLC), they were below the threshold limit. These results suggest that there may not be any immediate environmental hazard posed from the TV plastic housings. The correlations analysis showed that most of the metals declined in TV housings over the subsequent decades.