Chemicals used to make non-stick coatings on cookware and to waterproof fabrics may raise levels of cholesterol in children, U.S. researchers said on Monday.

Children in a study with the highest levels of these compounds in their blood had measurably higher levels of total cholesterol and low-density lipoprotein, or LDL - the so-called "bad" cholesterol - compared with children with lower readings.

The findings do not prove exposure to these chemicals, called perfluoroalkyl acids, caused the higher readings, but they show a link and suggest the need for more study, Stephanie Frisbee of West Virginia University and colleagues wrote in the Archives of Pediatrics & Adolescent Medicine.

The researchers studied perfluorooctanoic acid or PFOA and perfluorooctanesulfonate or PFOS. They make their way into people through drinking water, dust, food packaging, breast milk, cord blood, microwave popcorn, air and occupational exposure, according to the researchers.

Studies in animals suggest perfluoroalkyl acid can affect the liver, which could result in changes in cholesterol levels.

Frisbee and colleagues examined cholesterol levels in blood samples taken from more than 12,000 children in the mid-Ohio River Valley who had PFOA in their drinking water.

Children and teens in the study had more PFOA in their bodies than the national average, and a PFOS concentration about the same as the national average.

Children and teens with the highest PFOA concentration had total cholesterol levels that were 4.6 points higher and LDL levels that were 3.8 points higher than those with the lowest PFOA levels.
The team said the findings suggest an association between the compounds and higher cholesterol, but it would take more studies to prove chemical exposure was the cause.

Bernard Weiss of the University of Rochester in New York, an expert on toxins who was not involved in the research, said perfluoroalkyl acids are a known neurotoxin.

"They interfere with brain development, which leaves its mark on later behavioral functions such as cognitive performance," he said in a statement.

The potential health effects of chemicals, such as the plastics chemical bisphenol A used in baby bottles and other products, is becoming a growing concern among U.S., Canadian and European health officials.

Recent studies have shown subtle effects of low doses of BPA in laboratory animals and U.S. health officials in January launched a broader investigation of environmental health risks to children.