The following passage is from a BBC news article.

'Prescription pill abuse is taking off in Sudan's conservative society, partly because it lacks the social stigma and pungent, giveaway odour of alcohol and cannabis.'

I get the overall meaning of it. However, I do not understand the grammar structure of the last part 'giveaway odour of alcohol and cannabis' . Shouldn't there be a 'and' before 'giveaway odour of alcohol......' ? Or is the last comma being used as gapping comma? Thanks!