Treatment at these plants is quick, taking only about seven hours to remove most of the pollutants from the wastewater. In the natural environment this process could take many weeks and nature alone cannot handle the volume of wastewater that New York City produces.
By Dr Ananya Mandal, MD. Life expectancy refers to the number of years a person is expected to live based on the statistical average. Life expectancy varies by geographical area and by era. In the Bronze age, for example, life expectancy was 26 years, while in 2010, it was 67 years.In mathematical terms, life expectancy refers to the expected number of years remaining for an individual at any given age.ife expectancy varies by geographical area and by era. In the Bronze age, for example, life expectancy was 26 years, while in 2010, it was 67 years. In mathematical terms, life expectancy refers to the expected number of years remaining for an individual at any given age.
List of countries by life expectancy - Methodology. 1  Life expectancy equals the average number of years a person born in a given country is expected to live if mortality rates at each age were to remain steady in the future. The life expectancy is shown separately for males and females, as well as a combined figure.