In the early 1980s, a new clinical study began in Canniesburn Hospital's Burns and Plastic Surgery Unit, in Glasgow, Scotland, into the effects of Q-switched ruby laser energy on blue/black tattoos. Further studies into other tattoo colors were then carried out with various degrees of success. Research at the University of Strathclyde, Glasgow also showed that there was no detectable mutagenicity in tissues following irradiation with the Q-switched ruby laser. This essentially shows that the treatment is safe, from a biological viewpoint, with no detectable risk of the development of cancerous cells.