I remember reading about the life expectancy of people who have worked construction all their working lives. The life expectancy in this same was (IIRC) 59. The life expectancy of the guy who owns the construction company was over 80.
So who exactly is taking a risk here?
To your point, you can look at an awful lot of incredibly dirty and dangerous jobs in undesirable locations and they pay surprisingly bad. As an example, underwater welding on North Sea oil rigs pays $100-160k. That is an incredibly dangerous job that wrecks your health. Even if there isn't a risk of acute injury or death, often it wrecks your body. And this fact also gets lost every time the idea is resurrected of raising the retirement age. How exactly is a construction worker or an airport baggage handler meant to work until 68 instead of 65 exactly?
On top of all that, the people who are getting paid very little in a possibly dangerous job can often cost a fortune if they screw up. International shipping tends to use fairly low paid sailors from countries like The Phillipines. The cost of a screw up can be hundreds of thousands of dollars a day when they might be earning as little as $30.