Government of British Columbia: Ministry of Environment: Ambient Water Quality Guidelines for Silver
Ambient Water Quality Criteria for Silver
Overview Report
Prepared pursuant to Section 2(e) of the
Environment Management Act, 1981
Original signed by Don Fast
Executive Director
Environmental Protection Department
February 19, 1996
TABLE OF CONTENTS
Summary
Tables
- Table 1: Recommended Criteria for the Protection of Marine and Freshwater Life
Introduction
Preface
Recommended Guidelines
Application of the Guidelines
Summary
This document is one in a series that establishes ambient water quality criteria for British Columbia. It includes an overview which is followed by the main body of the report. This document sets criteria for silver to protect freshwater and marine aquatic life.
Criteria were not set for human, livestock or wildlife drinking water, recreational waters, irrigation water or industrial water uses, since, either suitable data documenting the effects of silver for these uses were lacking, or the criteria would have been about 1000 times higher than the aquatic life criteria and therefore redundant.
Silver is most toxic to microscopic organisms or larval forms of aquatic animals. There is no evidence that silver is naturally transformed to a hazardous biologically-available form (such as mercury into methyl mercury). Ionic silver is more toxic to aquatic organisms than silver compounds. Thiosulphate-complexed silver breaks down to silver sulphide which is less toxic than the silver ion. Silver criteria are summarized in the chapter on Recommended Criteria. A more detailed discussion of the criteria is presented in the main body of the report.