On 2017 Dec 06, Stuart RAY commented:

This is a meta-analysis that attempts to correlate mercury exposure with autism spectrum disorders. On page 296 of this report, in the Discussion section, the authors note this first among the limitations of their study: "The major problem with case-control studies is the temporal relationship between exposure and outcome. It is possible, for example, that older children with ASD may exhibit more mouthing behavior than healthy controls, leading to increased levels of mercury (and other pollutants) in their biological tissues." Given this (valid) limitation, the primary conclusion appears to be highly questionable.

On 2017 Dec 06, Stuart RAY commented:

This is a meta-analysis that attempts to correlate mercury exposure with autism spectrum disorders. On page 296 of this report, in the Discussion section, the authors note this first among the limitations of their study: "The major problem with case-control studies is the temporal relationship between exposure and outcome. It is possible, for example, that older children with ASD may exhibit more mouthing behavior than healthy controls, leading to increased levels of mercury (and other pollutants) in their biological tissues." Given this (valid) limitation, the primary conclusion appears to be highly questionable.