I am very concerned about this...?

My husband is going through a tough time at work. He works for the city government and at his job are all these women who just pick on him and put him down. He has even been subject to disparaging comments made about his gender to him. ("You men have no common sense.") Plus his supervisor has made it her personal mission to find a reason to get him fired or make him quit. She writes him up every day and tells him he is not a good employee. But, I know his work ethic and he is the best employee you could ask for. He sometimes stays late- without asking for overtime- just to get his work done. How is that a bad employee. These sociopaths have driven my poor husband to the brink where he wants to use physical violence sometimes. Barely controlled anger. And it is spilling over to our home life. He comes home grumpy and we bicker. And, I'm also suspicious that it might be racial because the other employees are predominantly white and my husband is black. But it is almost definately ist. They are all female except him.