Microbial pollution and heavy metals in the work environment of the college of engineering and technology sciences-Sebha University-Libya : computer keyboard as a case study

الملخص EN

The paper aims to investigate the concentrations of Pb, Cd, Cr and Ag element of as well as microbial contamination in computer keyboard within the work environment at the Faculty of Engineering and Technology Sciences (FETS) at Sebha University, Libya.

The results showed that the mean elemental concentrations (mg/g) in the samples were Pb (14.2±12.9), Ag (7.49±1.44), Cr (6.09±2.88) and Cd (4.43±1.48).

The most commonly found heavy metals were Pb (44.1%), followed by (Ag 23.3), (Cr 18.9), and (Cd 13.8) %.

The concentrations were higher than the limits allowed by EPA 2009.

The concentration of Cd also exceeded the European standards for paint in plastic toys.

The concentration of Cr element exceeded the limits allowed in all samples except the IBM brand keyboard.

Pb concentration has not exceeded the limit except for the GLK-2010 gaming (16.5 mg/g), IBM (15.5 mg/g), and Discovery (46.4 mg/g) keyboards.

Microbiologically, 16 (65%) positive Gram: Staphylococcus lactobacillus, mycobacterium, Bacillus, Actinomyces, Micrococcus, Clostridium, Erysprlothrix, Eubacterium and (35%) Gram-negative included Pseudomonas, Aeromonas, Brucella, Aeromonas, Bordetella, Acinetobacter, Bacteroides were isolated.

The most polluted sites were administrative offices followed by laboratories and secretarial offices.

While the highest numbers of bacteria were isolated from laboratories due to the large daily use.