In the heavily populated South Coast air basin of the Los Angeles area, it is estimated that over 71 percent of African-Americans reside in areas with the most polluted air, while only 34 percent of whites live in highly polluted areas. Environmental racism is made possible by extreme segregation. Eight out of every 10 African-Americans live in neighborhoods where they are in the majority. While residential segregation decreases for most racial and ethnic groups with additional education, income and occupational status, it does not hold true for African-Americans. African-Americans, no matter what their educational or occupational achievement or income level, are exposed to higher crime rates, less effective educational systems, high mortality risks, more dilapidated surroundings and greater environmental threats because of their race.