Urinary mercury concentrations are used in research exploring mercury exposure. Some theorists have proposed that autism is caused by mercury toxicity. We set out to test whether mercury concentrations in the urine of children with autism were significantly increased or decreased compared to controls or siblings.
Blinded cohort analyses were carried out on the urine of 56 children with autism spectrum disorders (ASD) compared to their siblings (n = 42) and a control sample of children without ASD in mainstream (n = 121) and special schools (n = 34).
There were no statistically significant differences in creatinine levels, in uncorrected urinary mercury levels or in levels of mercury corrected for creatinine, whether or not the analysis is controlled for age, gender and amalgam fillings.
This study lends no support for the hypothesis of differences in urinary mercury excretion in children with autism compared to other groups. Some of the results, however, do suggest further research in the area may be warranted to replicate this in a larger group and with clear measurement of potential confounding factors.The Wall Street Journal reports:
Pediatricians fed up with parents who refuse to vaccinate their children out of concern it can cause autism or other problems increasingly are "firing" such families from their practices, raising questions about a doctor's responsibility to these patients.
Medical associations don't recommend such patient bans, but the practice appears to be growing, according to vaccine researchers.
In a study of Connecticut pediatricians published last year, some 30% of 133 doctors said they had asked a family to leave their practice for vaccine refusal, and a recent survey of 909 Midwestern pediatricians found that 21% reported discharging families for the same reason.
By comparison, in 2001 and 2006 about 6% of physicians said they "routinely" stopped working with families due to parents' continued vaccine refusal and 16% "sometimes" dismissed them, according to surveys conducted then by the American Academy of Pediatrics.