Public health can be thought of as a series of complex systems. Many things that individual living in high income countries take for granted like the control of infectious disease, clean, potable water, low infant mortality rates require a high functioning systems comprised of numerous actors, locations and interactions to work. Many people only notice public health when that system fails. With widespread globalization occurring, public health issues have become transnational. Infectious diseases like SARS, H1N1 or the common cold can be transmitted within hours across national borders via airplane. Pollution and environmental degradation can be outsourced from high income countries to lower income countries via trade imbalances in.
