Update of the Thallium Public Health Goal

The following OEHHA internal memorandum, dated August 17, 2004, describes our review of the chemical thallium as a drinking water contaminant, and the process we followed to determine the lack of significant new toxicity data on this chemical, for risk assessment of thallium in drinking water. Other contaminants for which PHGs documents were prepared in 1997 and 1999 are similarly under review. If no significant new information is available for these chemicals, similar memoranda will be posted here. If important new data are available, a new PHG document will be prepared, and submitted for review and comment as per our usual process.