One of the main problems that leads to stress (which is one major type of emotional challenge) is financial trouble. Financial trouble is likely to occur if one works in a low wage job.
Financial troubles, not surprisingly, lead to stress. If you do not have enough money, you might be constantly in danger of losing your home or your car. You will, very likely, be unable to buy the things that you want or (like nice clothes) that your children feel that they need in order to be accepted. In a place like the United States where so much emphasis is placed on material things, you may very well feel like a failure. This, too, brings stress.
Workers in low wage jobs can have emotional problems due to their finances because they will be chronically short on money and will constantly have to be worrying about what might happen to them because of this lack of money.