Mercury and other toxins from cosmetics can be absorbed through the skin and enter the bloodstream within 90 seconds. Some cosmetics contain "penetration enhancers" that increase absorption of chemicals through the skin. Mercury and other carcinogens in cosmetics pose health risks, as mercury can accumulate in the body and environment over time and inhibit myelin formation. Pregnant women exposed to mercury have given birth to children with defects, and mercury poisoning has been linked to autism.