Mexican immigrants are more likely to be uninsured and at risk of adverse effects to their health than any other immigrant group in the United States, according to an October study.

Migration and Health: Mexican Immigrants in the U.S., a collaborative study by UC Berkeley and UCLA along with the Mexican government, looks into how Mexican immigrants’ status affects their access to health care. Although only 4 percent of the U.S. population, Mexican immigrants comprise 13 percent of all uninsured people in the United States.

Xochitl Castaneda, one of the authors of the study and director of Health Initiative of the Americas, said lack of treatment due to lack of health insurance leaves Mexican immigrants more susceptible to both infectious and chronic diseases that only worsen the longer they go untreated.

Among the findings, researchers found that undocumented immigrants in California were the group least likely to visit the emergency room or go to the doctor in 2009. Mexican-born immigrants were also the ethnic group that experienced the most work-related deaths in 2012 at 39 percent.

“It’s an important issue to address when you think about the changing American landscape,” Castaneda said. “By 2050, Mexicans will make up a third of this country. You can’t have that large of the population be second-class citizens.”

With the changing immigrant demographics in the  United States and changing health care policy through the Affordable Care Act, the lack of health care for immigrants has become a national rather than a regional issue, said Steven P. Wallace, one of the authors of the report and the associate director of the Center for Health Policy Research at UCLA.

Despite the hardships faced by many Mexican immigrants, the Affordable Care Act and MediCal in California may provide some relief for those who are uninsured.

MediCal, federal insurance for people whose earnings are below the poverty line, will begin to cover adults without children Jan. 1. The Affordable Care Act also provides private insurance subsidies for those who earn up to four times the poverty line, which many expect will have a big impact on the uninsured community.

“Given the high number of poverty in the Mexican immigrant population, which is currently nearly 50 percent, many would be able to qualify for some sort of insurance,” Wallace said.

These new policies, however, do not help all those who are uninsured, leaving about 11 million undocumented immigrants without viable health care options.

“People often ignore that the vast majority of immigrants from Mexico and Central America come to work,” Wallace said. “Their children become U.S. citizens, and if we do not take the time to provide health and basic needs for this population, we are not only shortchanging people contributing to this society but future generations as well.”