Illinois has some 511,000 undocumented immigrants, mostly of Mexican origin, with more than half living in the greater Chicago area, according to a report released Tuesday by the Illinois Coalition for Immigrant and Refugee Rights.

The document is based on demographic research by Rob Paral and Associates and offers calculations that can be used to understand the general characteristics of the undocumented community, the ICIRR said.

While 36 percent of the undocumented live in Chicago, 54 percent are found in the suburbs of the Windy City.

After Chicago, the cities in the area with the greatest number of undocumented inhabitants are Aurora, Cicero and Waukegan. As for counties, Cook (where Chicago is located) is in first place, followed by Kane, Lake and DuPage.

The study divides the origin of the undocumented population into 77 percent Mexicans, followed by 9 percent Asians and 5 percent Poles and other Eastern Europeans.

The study found that 60 percent of the undocumented in Illinois are between 25 and 44, with a slight majority of males.

The vast majority - 87 percent - live in families of mixed migratory status that include U.S. citizens.

A significant finding is that 6 percent of Illinois homes have at least one undocumented immigrant, while in Chicago the proportion climbs to 12 percent.

Those numbers should be a powerful argument against policies that separate immigrants from their families at a rate of over 1,000 deportations a day, the authors said.

"(T)he fact that 78,000 undocumented immigrants in Illinois are married to a U.S. citizen or lawfully present immigrant spouse further suggests that any immigration reform legislation should fix the unlawful presence bars and other obstacles that currently block the undocumented spouses from gaining lawful status through sponsorship of the lawfully present spouses," the study says.

"Such fixes would remove the threat of deportation and separation for these couples, and offer a simpler and quicker alternative to legalization, which, if the Senate bill offers any indication, would involve a long and rigorous process," the ICIRR report says.

"To have a fair opportunity to gain lawful status through a legalization program, our state's undocumented immigrants will need to have available to them English language and vocational training programs that would enable them to enhance their education and job skills," the study insists. EFE