Here are some useful links if you are looking for more legal information.

Mobbing/Harassment. Awareness is slowly growing in international organizations about the darker side of work and the devastating effects that mobbing and bullying can have on the self, health, organizations and society. Visit this website for information about mobbing in the workplace.
http://www.mobbing-usa.com/

FICSA “the Federation of International Civil Servants' Associations" was created in 1952 to protect the rights of the staff of the United Nations and its specialized agencies, funds and programmes, and to represent their interests in inter-agency bodies that make decisions and recommendations on conditions of service. Their website has very informative information, especially about harassment/mobbing policies.
http://www.ficsa.org/

Charter of the United Nations.
http://www.un.org/aboutun/charter/