Today marks nine months since the BP Deepwater Horizon offshore oil rig exploded, killing 11 workers and sending millions of gallons of crude oil pouring into the Gulf of Mexico.

Though the gushing well was capped last July, oil continues to wash ashore along the Gulf Coast. BP's oil is also washing up in people's bodies, raising concerns about long-term health effects.

This month the Louisiana Environmental Action Network released the results of tests performed on blood samples collected from Gulf residents. Whole blood samples were collected from 12 people between the ages of 10 and 66 in September, November and December and analyzed by a professional lab in Georgia, with the findings interpreted by environmental chemist and LEAN technical adviser Wilma Subra.

The individuals tested were two boys ages 10 and 11, four men and six women. They included cleanup workers on Orange Beach, Ala., crabbers from the Biloxi, Miss. area  and people living on Perdido Key, Ala.

Four of the people tested -- including three adults and the 10-year-old -- showed unusually high levels of benzene, a particularly toxic component of crude oil. Subra compared the levels found in the test subjects to the levels found in subjects in the National Health and Nutrition Examination Survey (NHANES), a research program conducted by the National Center for Health Statistics.

Specifically, Subra compared the benzene levels in the Gulf residents to the NHANES 95th percentile value -- that is, the score below which 95 percent of the NHANES subjected tested. In other words, she compared the benzene levels found in Gulf residents to some of the highest levels found in the general population.

That comparison shows cause for concern, as the benzene levels in the blood of four Gulf residents ranged between 11.9 and 35.8 times higher than the NHANES 95th percentile value of 0.26 parts per billion. Benzene is known to cause a host of health problems including anemia, irregular menstrual periods, ovarian shrinkage and leukemia.

The Gulf residents with the highest levels of benzene in their blood included a family of crabbers -- a 46-year-old man and woman and a 10-year-old boy -- and a 51-year-old woman crabber, all from the Biloxi area.

Ethylbenzene was detected in all 12 blood samples from Gulf residents over the NHANES 95th percentile value of 0.11 ppb, with some individuals testing over three times that concentration. Ethylbenzene is known to cause dizziness, damage to the inner ear and hearing, and kidney damage, and it's also thought to cause cancer.

Eleven of the 12 individuals tested had relatively high concentrations of xylenes, with some of them testing up to 3.8 times higher than the NHANES 95th percentile value of 0.34 ppb. Xylene exposure can lead to headaches, dizziness, confusion, skin irritation, respiratory problems, memory difficulties and changes to the liver and kidneys. The blood test results also found high levels of other toxic petrochemicals including 2-methylpentane, 3-methylpentane and isooctane.

The two boys showed some of the highest blood concentrations of the chemicals, and the 10-year-old boy from the Biloxi area suffered severe respiratory problems as a result. His mother, the crabber, also had some of the highest concentrations of the chemicals in her blood.

Earlier this month, residents from across the Gulf called on members of the President's oil spill commission -- which recently released its final report on the disaster -- to address the region's growing health crisis. One of them was Cherri Foytlin, co-founder of the grassroots group Gulf Change, who recently learned her own blood has alarming levels of ethylbenzene.

"Today I'm talking to you about my life," she told the commission. "My ethylbenzene levels are 2.5 times the [NHANES] 95th percentile, and there's a very good chance now that I won't get to see my grandbabies."

Foytlin reported seeing children from the region with lesions all over their bodies. "We are very, very ill," she said. Meanwhile, doctors in the region are treating patients with high levels of toxic petrochemicals in their bodies -- even in people who do not live right on the coast and were not involved in the cleanup.

Commission member Frances Beinecke, chair of the Natural Resources Defense Council, pledged to take the health concerns back to the White House. But nine months since the disaster began unfolding, Gulf residents are still waiting for the government to address the ongoing environmental health crisis.