ISO 20044:2022

This document provides guidance for —    the sampling process of the aerosol particles in the air using filter media. This document takes into account the specific behaviour of aerosol particles in ambient air (Annex B). —    Two methods for sampling procedures with subsequent or simultaneous measurement: —    the determination of the activity concentration of radionuclides bound to aerosol particles in the air knowing the activity deposited in the filter; —    the operating use of continuous air monitoring devices used for real time measurement. The activity concentration is expressed in becquerel per cubic metre (Bq∙m-3). This document describes the test method to determine activity concentrations of radionuclides bound to aerosol particles after air sampling passing through a filter media designed to trap aerosol particles. The method can be used for any type of environmental study or monitoring. The test method is used in the context of a quality assurance management system (ISO/IEC 17025[2]). This document does not cover the details of measurement test techniques (gamma spectroscopy, global alpha and beta counting, liquid scintillation, alpha spectrometry) used to determine the activity deposited in the media filter, which are either based on existing standards or internal methods developed by the laboratory in charge of those measurements. Also, this document does not cover the variability of the aerosol particle sizes as given by the composition of the dust contained in ambient air[3][4]. This document does not address to sampling of radionuclides bound to aerosol particles in the effluent air of nuclear facilities [see ISO 2889:2021][5]. The procedures described here facilitate the sampling of aerosol bound radionuclides. It is supposed to conform to the national and international requirements for monitoring programmes safety standards of IAEA[6]. The characteristics of the sampling location (coordinates, type of vegetation, obstacles) need to be documented prior to commencing the monitoring. The guidelines of the World Meteorology Organization (WMO) include the criteria for representative measurements of temperature, wind-speed, wind direction, humidity and precipitation for all the weather stations in the world[7].