Public health is a discipline focused on promoting the health of communities as well as local, regional, national and international populations. This may include public education and mandatory or voluntary health programs that promote general health and safety research (such as food &water safety and the impact of environmental hazards), preventing widespread outbreaks of disease or other serious health problems within a population (such as through vaccination and the detection and control of infectious diseases), as well as the examining, preparing for, and responding to health threats posed by natural and human-made disasters. As part of its community-based engagement, public health also examines and seeks to limit disparities in healthcare access and outcomes. Bioethical issues specific to public health include among other things the role of public health agencies in limiting personal autonomy, maintaining individual privacy in the collection of public health data, and safety and efficacy of public health programs (including vaccination protocols), and the healthcare response to pandemics.