Thimerosol or ethylmercury have been used as preservatives in multidose vaccine vials and have been blamed for the increase in autism rates over the past two decades. However, studies have failed to show a causative link between environmental exposures and the development of these symptoms. As symptoms of autism occur early in childhood and, possibly, months to years after any potential exposure may have resulted in neurotoxicity, the likelihood of continued presence of such toxicant is low. Parents, however, may be desperate for answers and seek out alternative sources for information and receive advice to obtain laboratory analysis for minerals and metals as causative agents without insurance reimbursement. Finding an abnormal result has led to ill-advised treatments and death in some patients.