Did Brittany Murphy Accidentally Poison Herself? And are the recent toxicology results even valid? By Evann Gastaldo, Newser Staff Posted Nov 21, 2013 10:34 AM CST 11 comments Comments This June 2009 photo provided by Hybrid Productions shows Brittany Murphy while working on the set of "Abandoned" in Los Angeles. (AP Photo/Hybrid Productions) (Newser) – Brittany Murphy's dad thinks she was poisoned—but the evidence he found may point to something else, sources tell Page Six. They say that at the time of Murphy's death, meth and cocaine in the LA area were frequently mixed with rat poison and other toxins—meaning Murphy may have accidentally exposed herself to the chemicals found in her hair, blood, and tissue. But as Vanity Fair points out, there's no evidence illegal drugs played a role in her death. And then there's the fact that those findings may not even be valid: The World Health Organization itself has weighed in to act as the voice of reason, ABC News reports. "Hair is not ... a reliable material for the determination of exposure to many chemicals because it is prone to contamination from the external environment," explains a WHO scientist; a forensic pathologist who spoke to Page Six says the same. Other toxicologists also dismissed the findings; one points out that Murphy did not have lines across her fingernails when she died, which is a key sign of heavy metal poisoning.