normal structures like law enforcement fall apart and traffickers get possibility to roam and exploit people because there are no structures preventing them from doing so. Natural disasters: children get separated from their parents making them vulnerable, and traffickers will try to round up those kids for forced labor or sex industry. Extreme poverty- lack of resources and unemployment makes people vulnerable, traffickers can prey upon people's dreams for a better life by offering them work abroad. Lack of education- don't have information about human trafficking and accessing risky situations, don't know how to migrate safely or what they can demand in terms of pay. Root causes are related to lack of enjoyment of human rights because these push factors are vulnerabilities people have that make them more likely to be trafficked usually because they are discriminated against (denied rights) or they don't have their full human rights in the first place. --> making them vulnerable to exploitation.
Hope this helps mate =D