Japan from industrial waste and in the 1970s in Iraq from fungicide contamination of wheat. These incidents led to new research on methylmercury safety and culminated in the publication of an array of confusing recommendations by public health agencies in the 1990s warning against methylmercury exposure in adults and pregnant women, which ensured a continued high public awareness of mercury toxicity. Second, the vaccine schedule for infants expanded in the 1990s to include more vaccines, some of which, including the Hib vaccine, DTaP vaccine and hepatitis B vaccine, could have contained thiomersal. Third, the number of diagnoses of autism grew in the 1990s, leading parents of these children to search for an explanation for the apparent rise in diagnoses, including considering possible environmental factors. The dramatic increase in reported cases of autism during the 1990s and early 2000s is largely attributable to changes in diagnostic practices, referral patterns, availability of services, age at diagnosis, and public awareness, and it is unknown whether autism's true prevalence increased during the period. Nevertheless, some parents believed that there was a growing "autism epidemic" and connected these three factors to conclude that the increase in number of vaccines, and specifically the mercury in thiomersal in those vaccines, was causing a dramatic increase in the incidence of autism. Advocates of a thiomersal-autism link also relied on indirect evidence from the scientific literature, including analogy with neurotoxic effects of other mercury compounds, the reported epidemiologic association between autism and vaccine use, and extrapolation from in vitro experiments and animal studies. Studies conducted by Mark Geier and his son David Geier have been the most frequently cited research by parents advocating a link between thiomersal and autism. This research by Geier has received considerable criticism for methodological problems in his research, including not presenting methods and statistical analyses to others for verification, improperly analyzing data taken from Vaccine Adverse Event Reporting System, as well as either mislabelling or confusing fundamental statistical terms in his papers, leading to results that were "uninterpretable". Publicity of concern Several months after the recommendation to have thiomersal removed from vaccines was published, a speculative article was published in Medical Hypotheses, a non-peer-reviewed journal, by parents who launched the parental advocacy group SafeMinds to promote the theory that thiomersal caused autism. The controversy began to gain legitimacy in the eyes of the public and gained widening support within certain elements in the autism