Change in the environment is inevitable and rapid. The cause of the change could be a natural phenomena or life processes. Human activity such as development of agriculture and technology which give rise to widespread industrialization has led to potentially changing environment as a result of pollution culminating in the release of harmful substances such as Agricultural waste, industrial waste, metal scraps, sewage, microbial concentration, oil spills etc. into the soil, water or air. Human environmental intervention as in the construction of dams and diversion of rivers is another cause of change in the environment. Other causes are ozone depletion, Acid rain and acid mine drainage etc. The impact of the changing environment on human health identified in this paper seek to explore the causes of environmental change, effect of human activities on causes of environmental change and effect of changing environment on human health. The findings identified some effects of human activities as outbreaks of infectious diseases leading to human incapacitation and death in severe cases, damage genetic material leading to heritable genetic disorders, malnourishment as a result of wiping out of plants and animal life. Others are skin cancer, reduction of life expectancy etc. some recommendation were made which are Environmental conservation measures, Governments and Non-governmental organizations educating the citizenry.