Since the production of printed circuit boards (PCBs) generates wastewater contaminated with heavy
metals and organic matter, PCB factories represent potential pollution sites. The wastewater toxicologically
tested in this study contained several metals and the most abundant were copper and iron. At two
exposure times tested (4 and 24 h) PCB wastewater (PCBW) proved to be cytotoxic (decreased cell
viability) and genotoxic (increased comet assay tail intensity and tail moment) to human blood peripheral
lymphocytes in vitro, and the oxidative stress parameter (malondialdehyde concentration) was
also found to be higher. After application of combined treatment by waste base, ozone and waste sludge
methods, concentrations of metals in purified PCBW were below the upper permitted levels and all
tested toxicological parameters did not differ compared to the negative control. Taken together, similar
methods could be implemented in PCB factories before discharging potentially toxic wastewater into the
environment because purified PCBW does not represent a threat from the aspect of cytotoxicity and
genotoxicity.