Health according to the world health organization, is the ability of an individual to reach his or her potential and to respond positively to changes in the environment. Jeanne louise calment french woman died at 122. More than half a billion people in 32 countries (most in sub-saharan africa) have a life expectancy less than 50 years. Human-environmental factors: divisons like social class, occupation and nationality. Environmental racism is the tendancy to heap environmental dangers on the disadvantaged. (north example of dumping and inuit mothers having 10 times more contaminated breastmilk) Lifestyle factors: smoking, alcohol&drugs, poor diet, no exercise, social isolation are among the factors associated with poor health and premature death. Unmarried people have a greater chance of dying prematurely than do married people because of social isolation. Factors related to the public health and health care systems: nations health depends partly on public health system and private efforts to improve peoples well being and treat their illnesses.