the discipline I prefer the most is epidemiology, which is  the  study  of  frequency,  distribution,  and determinants of diseases and other related states or events  in  specified  populations.

the application of this study especially field epidemiology in tracking of disease outbreaks including surveillance helps in curbing outbreaks and halting their spread.

environment and discipline of  public health

Environmental Health is a field of science that studies how the environment influences human health and disease. "Environment" in this context means identifying and addressing how the environment impacts human health.

Environmental health (EH) is a branch of public health protection that is concerned with all aspects of the natural and built environment that may affect human health. Other terms that refer to the discipline of environmental health include environmental public health and environmental health and protection.

EH is a very diverse field where professionals perform a variety of tasks such as research, investigations, outreach and education, environmental cleanups and more