# 1.3.5 Radiological screening and reference values Radiological safety is determined by firstly assessing gross alpha and beta activity. If both do not exceed the screening value of 0.5 Bq/L no further action is required. If either exceed 0.5 Bq/L further testing is required to determine the radium-226 and radium-228 activities. Additional radionuclides may also need to be considered. Safety is defined by not exceeding a reference value of 1.0 mSv/L per year. If the total annual dose is between 0.3 and 1.0 mSv/L further assessment and evaluation may be required. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://guidelines.nhmrc.gov.au/australian-drinking-water-guidelines/intro/chapter-1/1.3-water-quality-characteristics/1.3.5-radiological-screening-and-reference-values.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.