The masai people of east africa live in communities that make economic choices based mainly on the habits and customs of their ancestors. one example of masai's traditional economy would be --

The Maasai are thought of as the typical cattle herders of Africa, yet they have not always been herders, nor are they all today. Because of population growth, development strategies, and the resulting shortage of land, cattle raising is in decline. However, cattle still represent "the breath of life" for many Maasai. When given the chance, they choose herding above all other livelihoods. For many Westerners, the Maasai are Hollywood's "noble savage"—fierce, proud, handsome, graceful of bearing, and elegantly tall. Hair smeared red with ochre (a pigment), they either carry spears or stand on one foot tending cattle. These depictions oversimplify Maasai life during the twentieth century. Today, Maasai cattle herders may also be growing maize (corn) or wheat, rearing Guinea fowl, raising ostriches, or may be hired by ecologists to take pictures of the countryside.

Air pollution: “combustion results in gases such as nitrogen oxides, nitrogen dioxide and particulates. the main causes of air pollution include transport, domestic combustion and industrial processes. pollutants from these sources can cause problems in the immediate vicinity and a distance away.”

Here is a picture  of the net. its 4 squares in a row diagonal and on the third draw one square aove and under