Defs Bio-Med or Civil Engineering. Lot of nations especially in Asia and Africa lack sufficient health and construction standards.
For instance when there is an earthquake somewhere like recently few years back in Nepal, the housing and infrastructure was not capable of withstanding an Earthquake and this consequently led to many thousands of casualties when this could have been prevented! Especially in emergency type situation like natural disasters, Civil Engineers need to come up with urgent and sufficient solutions in order to temporarily house people who have lost their homes and families and to also provide temporary hospitals.
Moreover Bio-Med is an interesting one, its vital industry for the future wellbeing of mankind wherever they may be. Unfortunately in many countries there is a technological gap, especially if you witness the substandard conditions in many Hospital and Medical Clinics in those countries. They are years behind and would be benefited if they had more Bio-Med Engineers to advance their health care treatments and end the gap in life expectancy with wealthier nations.