I am a big fan of dirty jobs, not usually the worst for income, but often dangerous. Worst job is so arbitrary, I would decide based more on the willingness/ demand for people willing to do them, rather than income. On this basis most of those listed are by no means the worst.
Some of our attitudes to work really need to change. In the US, people like Mike Rowe are pushing to change our attitude to work, and to make sure the worst jobs get done. You can actually learn quite a bit from doing tough jobs, the challenge is it's own reward usually.
This last Friday at work I refused to do a job, due to it's danger. It was cleaning heavy, sharp blades from a machine. At least 3 coworkers have had pretty severe cuts manipulating them, but management has decided that the job needs to be done. In the end someone will do it, and if they set in place a safer procedure, I will be happy to be that someone. In the mean time all I can do as part of this team is to be prepared for the next injury from these blades, warn others doing the job of the risk, and keep pushing management to change procedures. The job can be done relatively safely if done in the right way (not risk free, but within the risk level of the other work we do).
A worst job for me is when I see inexperienced, reckless, and untrained people getting injured, someone screaming to be released from a machine is not nice at all.