Lifespan does vary considerably by country of residence.
First, people in richer countries (members of the OECD) live longer than people in poor countries, and within any given country the rich are longer lived than the poor due to factors like nutrition and access to medical care.
Among rich countries, people living in those with strong public health care systems, like Britain, Canada and Europe live longer than people in the United States, which does not have universal health care.
Other factors such as war, famine, epidemic diseases, standard of pre-natal and maternal health care, and access to clean water also affect national average lifespan.
There is a connection between average life span and where someone lives (their country). With the reasons stated by the above person being huge factors, another is also environmental and dietary factors.
Those who live in countries with more pollution and radiation will tend to have shorter life spans than those who live in countries where there is clean air and water.
Diet and lifestyle are also very large factors. There is typically a longer lifespan in countries where better food (healthier) is a large part of their diet such as fresh vegetables and fruits, and less meat and dairy is consumed. The amount of exercise also depends. Those in countries with people who are more active, like walking more and sitting less, tend to have a higher average life span.
Other factors include things such as amount of time people spend outside in the sun versus melanin levels and other various factors.
I meant is there a conection with countrys and how long we live