lifestyle denotes the way people live i.e. whether they are able to fulfill all the basic needs and additional needs. If your lifestyle is good then automatically you get proper nutrition (all basic needs) which directly provides healthy life
and can be free from diseases and has great role in population. Thus increasing and decreasing of population depends on health and simultaneously lifestyle of people. Environment is the place where we live so if it is damaged or harmed it directly affect our health and population
Lead sometimes may leak into the water due to contamination form either waste that was dumped into the water or there are minerals in the water that may have formed.