Radioactivity is present in our daily lives, whether it comes from natural or artificial sources, and so we are constantly exposed to it. Therefore, in order to guarantee the protection of human health, various standards and legislation have been implemented with the aim of controlling and monitoring the total alpha and total beta radiation in drinking water.
The greatest example of this is Ordinance GM/MS 888, Brazilian legislation currently in force that defines limits, methodologies and guidelines that ensure the proper monitoring of radionuclides in water for human consumption.
A Analytical EP has complete scope for full compliance with Ordinance 888including analysis of Total Alpha, Total Beta and specific radionuclidesoffering safety, precision and compliance.
What is radioactivity and why can it be present in water?
Radioactivity was discovered in 1896 by Henri Becquerel and further developed by Marie and Pierre Curie, revealing compounds such as thorium, polonium and radium – all of which emit radiation. Natural or artificial radionuclides can reach water via different routes, such as:
- infiltration of natural radioactive materials from the soil;
- industrial processes;
- medical and military activities;
- atmospheric deposition.
This is why radioactivity analysis becomes indispensable for identifying levels of Total Alpha and Beta and ensuring that the water meets drinking water standards.
Types of radiation: Alpha, Beta and Gamma
To understand the importance of monitoring, it is necessary to understand how radiation works:
Alpha Radiation (α)
- Made up of 2 protons and 2 neutrons.
- Low penetration capacity – it can be blocked by paper – but it is highly ionizing.
Beta radiation (β)
- Negative charge, composed of electrons.
- It penetrates up to 2 cm of living tissue and can cause more intense damage.
Gamma Radiation (γ)
- Very high energy electromagnetic waves.
- High penetration power and greater health risk.
Exposure can occur due to:
- irradiation (without direct contact with the radioactive material)
- internal or external contamination (when there is contact, ingestion or inhalation)
For this reason, drinking water legislation incorporates strict limits to prevent harm to human health.
Sources of radioactive exposure
The population is exposed to radiation every day, with approximately 80% of radiation exposure coming from natural sources and around 20% from what are considered artificial sources.
Sources of natural radiation are soil, water/food, radon and cosmic radiation (from various regions of space). Artificial radiation, on the other hand, comes from uses in branches such as: military (as in the use of nuclear weapons); medical (in the use of diagnostic imaging and treatment of certain diseases with controlled doses of radiation); and domestic (as in the case of smoke detectors).
Although most of it is natural, drinking water contaminated by radionuclides can lead to risks such as:
- DNA damage;
- genetic mutations;
- tumors and leukemias;
- acute radiation syndrome at high doses.
Hence the importance of radioactivity analysis as a preventive and mandatory tool.
Evolution of legislation on radioactivity in water
Did you know that Brazil has been monitoring radioactivity in water since 1977? At the time, the reference limit value for total alpha and total beta radioactivity parameters was 0.1 Bq/L for Total Alpha and 1.0 Bq/L for Total Beta.
These limits remained the same until 2010. If the values were exceeded, the radionuclides (chemical species that emit radiation) had to be identified and quantified and their values compared with the limits set by the National Nuclear Energy Commission (CNEN).
In December 2011, Ordinance No. 2,914 was enacted, changing the reference limit value for drinking water to 0.5 Bq/L for Total Alpha and 1.0 Bq/L for Total Beta. If the limits were exceeded, the concentration of specific radionuclides had to be determined, namely Radium-226 and Radium-228.
In 2021, Ministerial Order GM/MS 888 was published, with new procedures for quantifying Total Alpha and Total Beta in drinking water. There were no changes to the reference limit value, but there were some changes to the procedures for exceeding the limit. Thus, if the Total Beta limit is exceeded, the levels of the radionuclide K-40 (Isotope of the potassium atom with mass 40u) must be quantified and its value deducted from the total value of Total Beta radioactivity.
If the value remains above the limit, another sample must be taken and analyzed, and if the values remain above the limit, CNEN REGULATORY POSITION 3.01/012:2020 must be consulted to take action. From then on, CNEN is responsible for analyzing the radiological potability of the water.
Ordinance 888 is today the basis for any analysis of radioactivity applied to the potability of water in Brazil.
The importance of radioactivity analysis to ensure safe water
The presence of radionuclides in water, even in low concentrations, represents a cumulative risk to human health. For this reason, the analysis of Alpha Total, Beta Total and specific radionuclides is a fundamental part of the quality control of water for human consumption.
In addition, sanitation companies, industries, municipalities and other laboratories must comply with Ordinance GM/MS 888 and only laboratories with a validated technical scope can issue results accepted by regulatory bodies.
Radioactivity analysis with EP Analytical
EP Analítica excels in radioactivity analysis, offering precision, regulatory compliance and the technical capacity to fully comply with Ordinance GM/MS 888.
We work with up-to-date methods (CNEN, ABNT and international standards), highly sensitive equipment and a specialized team prepared for highly complex radiological analyses.
A Analytical EP has:
- Full scope for Total Alpha and Total Beta
- Results with traceability and metrological safety
- Personalized studies on demand
- Technical partnerships with other laboratories that need to outsource radioactivity analysis
We serve industries, utilities, environmental consultancies, regulatory bodies and also laboratories looking to broaden their scope. Whether for environmental projects, potability or specific investigations, EP Analítica is the reliable partner for all needs involving radioactivity analysis.
Article by Catharina Mariusso and Leonardo Paiva
Bibliography
Ministry of Health. Available at: <https://bvsms.saude.gov.br/bvs/saudelegis/gm/2021/prt0888_07_05_2021.html>. Accessed on: 23 Dec. 2024.
Available at: <https://www.if.ufrgs.br/tex/fis01001/radio.pdf>. Accessed on: 23 Dec. 2024.
RADIATION – EFFECTS AND SOURCES. Available at: <https://www.aben.com.br/Arquivos/544/544.pdf>. Accessed on: 23 Dec. 2024.
Available at: <https://www.ufrgs.br/colegiodeaplicacao/wp-content/uploads/2020/06/RADIOATIVIDADE-%E2%80%93-2%C2%AA-PARTE1_removed.pdf>. Accessed on: 20 Dec. 2024a.
RESEARCH AND REFERENCE LEVELS FOR RADIOACTIVITY IN DRINKING WATER. Available at: <https://www.gov.br/cnen/pt-br/acesso-rapido/normas/grupo-3/grupo3-pr301_12.pdf>. Accessed on: 26 Dec. 2024.
Available at: <https://www.gov.br/cnen/pt-br/acesso-rapido/normas/grupo-3/grupo3-nrm301.pdf>. Accessed on: 26 Dec. 2024c.
Available at: <https://www.gov.br/ird/pt-br/central-de-conteudo/publicacoes/RadioatividadeemAguaPotavel.pdf>. Accessed on: 26 Dec. 2024d.
Radiation. Available at: <https://fiocruz.br/biosseguranca/Bis/virtual%20tour/hipertextos/up1/radiacao.html>. Accessed on: 26 Dec. 2024.
BUSHBERG, J. T. Exposure and radioactive contamination. Available at: <https://www.msdmanuals.com/pt/profissional/les%C3%B5es-intoxica%C3%A7%C3%A3o/exposi%C3%A7%C3%A3o-e-contamina%C3%A7%C3%A3o-radioativa/exposi%C3%A7%C3%A3o-e-contamina%C3%A7%C3%A3o-radioativa>. Accessed on: 26 Dec. 2024.
Ministry of Health. Available at: <https://bvsms.saude.gov.br/bvs/saudelegis/gm/2011/prt2914_12_12_2011.html>. Accessed on: 26 Dec. 2024b.
D79367. Available at: <https://www.planalto.gov.br/ccivil_03/decreto/1970-1979/d79367.htm>. Accessed on: 26 Dec. 2024.