ISO 18589-6:2019

Overview

ISO 18589-6:2019 - Measurement of radioactivity in the environment - Soil - Part 6 defines a test method for estimating gross alpha and gross beta activities in soil using gas-flow proportional counting. It is intended primarily for comparative inspections and preliminary site studies to guide sample selection and the need for more specific radionuclide analyses. The scope also covers related materials (sludge, sediment, construction materials, NORM/TENORM-containing products) when appropriate sampling and sample preparation are applied.

Key Topics and Requirements

This part of the ISO 18589 series focuses on practical laboratory and measurement requirements rather than isotope-specific assays. Key technical topics include:

• Principle of gross alpha/gross beta estimation using gas-flow proportional counters.
• Sample preparation and preparation of sources for counting (soil, rock, construction materials, etc.).
• Calibration: establishing counting efficiencies and calibration curves for alpha and beta channels.
• Background determination and routine quality checks to ensure reliable low-level measurement.
• Measurement procedure using gas-flow proportional counting equipment.
• Expression of results, including activity per unit mass and reporting conventions for gross α/β.
• Uncertainty evaluation, decision thresholds, detection limits and confidence limits for reported activities.
• Reporting requirements and recommended content for test reports.
• Informative annex on preparation of reference standards (e.g., plutonium‑239) and bibliographic references.

Note: ISO 18589-6 clarifies that gross α/β results are not equivalent to summing individual radionuclide activities; a conventionally applied common counting efficiency is used for all alpha emissions and similarly for beta emissions.

Applications and Users

ISO 18589-6:2019 is useful for organizations that need rapid, comparative assessments of radioactivity in environmental media:

• Environmental monitoring laboratories and accredited testing facilities (ISO/IEC 17025 context).
• Regulatory bodies and public health authorities conducting site screening.
• Mining and mineral-processing operators dealing with NORM/TENORM (e.g., mineral sands, phosphate fertilizers).
• Construction and materials testing (building materials, ceramics, slag).
• Emergency response teams and consultants performing preliminary radiological site assessments.

Use cases include preliminary screening to prioritize samples for detailed radionuclide analysis, site characterization, and comparative monitoring over time.

Related Standards

• ISO 18589 series: ISO 18589-1 (general processing), -2 (sampling), -3 (gamma emitters), -4 (plutonium), -5 (strontium), -7 (in situ gamma).
• ISO/IEC 17025 (laboratory accreditation and quality management).

Keywords: ISO 18589-6:2019, gross alpha, gross beta, gas-flow proportional counting, soil radioactivity, NORM, TENORM, environmental monitoring, radioactivity measurement.