The problem of poverty became more acute in many U.S. neighbourhoods in the Midwest and South over the last decade, threatening schools, safety and public health, while raising costs for local governments, according to a study released on Thursday.

The Brookings Institution, an independent research group, found the populations of extreme poverty neighbourhoods grew by one-third over the last 10 years.

At least 40 percent of the individuals in extreme poverty areas live below the federal poverty line, defined as an annual income of $22,314 (14,025 pounds) for a family of four.

Altogether, the Midwest led other regions for growth in pockets of extreme poverty.

Rather than spread evenly, the poor tend to cluster and concentrate in certain neighbourhoods or groups of neighbourhoods within a community, Brookings said. Very poor neighbourhoods face a whole host of challenges that come from concentrated disadvantage -- from higher crime rates and poorer health outcomes to lower educational opportunities and weaker job networks.

Brookings also found towns in the South, including Baton Rouge, Louisiana, had some of the largest increases in concentrated poverty rates since 2000.

The recession-induced rise in poverty in the late 2000s likely further increased the concentration of poor individuals into neighbourhoods of extreme poverty, Brookings said in its report, which relied on 2000 U.S. Census data and the American Community Surveys the Census conducted from 2005 to 2009.

DEEP IN THE HEART OF TEXAS

McAllen, Texas, has the highest concentration of poverty in the country, according to Brookings. Another Texas city, El Paso, follows and then comes Memphis, Tennessee.

More than a third of McAllen's residents can be considered poor. In the tracts deemed to be extreme poverty, nearly half of the people are poor.

El Paso also had the second-largest growth in concentration of poverty, after Toledo, Ohio, according to Brookings.

You can think of this in two ways: One is how deeply poor someone is and the other is how persistently poor the community is, said Steve Suits, vice president of the Southern Education Foundation, noting that since the end of the Civil War, poverty has become increasingly concentrated in the South.

In studying the effects of extreme poverty on education, the foundation found that in 2009, nearly 6.5 million children lived in households with incomes below 50 percent of the poverty threshold. The South accounted for nearly half of the nation's increase in extreme poverty, it found.

In 2009, people in extreme poverty was the fastest- growing income group in America, Suits said. Most households in this economy are in jeopardy of falling into poverty or extreme poverty.

The U.S. Census recently reported the ranks of the poor rose in almost all states and cities in 2010.

About 40 percent of the poor live outside major cities, Brookings said, showing poverty is rolling into the suburbs.

While large metro areas experienced the largest absolute increases in extreme poverty neighbourhoods and concentrated poverty, small metropolitan areas were home to the fastest growth in extreme poverty tracts and the number of residents living in them, Brookings found.

CHANGING FACE OF POVERTY

In the same way, the face of poverty shifted slightly.

Although African Americans remained the single-largest group in the extreme poverty neighbourhoods, Brookings said that the rest of the population in these areas was more likely to be white and less likely to be Latino than in 2000, Brookings said.

Having people with no abilities to survive except their own day-to-day ingenuity means there's going to be more crime, more unrest, more mischief, and more sorrow and grief, Suits said. That's not the kind of community anyone would want to live in.

State and local government revenue fell 22.1 percent in 2009 from 2008, while spending rose nearly 5 percent, the Census said on Monday. Education and public welfare made up 43.2 percent of that spending.

The hard thing is that cities are really strapped for cash right now, said Heidi Goldberg, program director for early childhood and family economic success at the National League of Cities.

City budgets are tight -- right as families are struggling.

(Reporting by Lisa Lambert; Editing by Jan Paschal)