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05/24/2024 | Press release | Distributed by Public on 05/24/2024 07:08

UN Scientific Committee endorses groundbreaking reports on second primary cancer after radiotherapy and on public exposure to ionizing radiation

24 May 2024

UN Scientific Committee endorses groundbreaking reports on second primary cancer after radiotherapy and on public exposure to ionizing radiation

VIENNA, 24 May (UN Information Service) - The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has approved a pivotal scientific report on second primary cancer after radiotherapy and a new report on public exposure to ionizing radiation at its 71st session in Vienna.

The session, held at the Vienna International Centre, from 20 to 24 May 2024, brought together around 180 expert scientists from 30 State Members of the Committee and 10 international organizations. This impressive gathering highlights the global commitment to advancing scientific knowledge and public health.

In a notable development, the Committee elected its Bureau for the 71st and 72nd sessions: Sarah Baatout (Belgium) as Chair; Anssi Auvinen (Finland), Aayda Al Shehhi (United Arab Emirates) and Reiko Kanda (Japan) as Vice-Chairs; and Carol Robinson (Norway) as Rapporteur. The Committee expressed its gratitude to the outgoing Chair, Jing Chen (Canada), and Vice-Chairs Lidia Vasconcellos de Sá (Brazil) and Anna Friedl (Germany) for their dedicated service.

Addressing the Committee, Elizabeth Mrema, Assistant Secretary-General of the United Nations and Deputy Executive Director of the United Nations Environment Programme (UNEP), praised UNSCEAR's significant and worldwide respected work. She emphasized the importance of continued strong scientific collaboration for the benefit of both people and the environment.

"These newly approved reports mark a significant progress in our understanding of cancer risks following radiotherapy and the impacts of ionizing radiation on public levels of exposure, reinforcing UNSCEAR's role as a leader in global scientific research," said Sarah Baatout (Chair). She added: "Substantial advancements in epidemiological studies linking ionizing radiation to cancer as well as in understanding the effects of ionizing radiation on the circulatory and nervous systems were also made."

"In our groundbreaking scientific report on second primary cancer, considering that radiotherapy is prescribed to treat approximately 50 per cent of all cancer patients and that approximately 40 per cent of all cured cancer patients received radiotherapy as part of their treatment, our evaluation highlights that the risk of developing a second primary cancer due to radiotherapy is very low," said the Chair, "Therefore, it is crucial for cancer patients not to hesitate in pursuing radiotherapy treatment, given its significant benefits."

"In our examination of public exposure to ionizing radiation, we delved into scientific data on sources and levels of exposure spanning from 2007 to 2022", continued the Chair, "The Committee's analysis confirmed a significant finding: the primary contributor to the worldwide average annual effective dose is from natural sources of ionizing radiation. Specifically, inhalation of radon, thoron, and their decay products emerged as the major contributors."

Charting a path forward: UNSCEAR's vision for 2025-2029

In a forward-thinking move, the Committee approved its Future Programme of Work (2025-2029) and endorsed the new innovative Public Information and Outreach Strategy for the same period.

"Acknowledging the importance of robust data collection, the Committee highlighted the UNSCEAR Global Survey on Public Exposure in 2023, which saw participation of 61 Member States," said the Chair, "In a promising development and as part of the implementation of the data collection and analysis strategy on ionizing radiation, the Committee noted an increased engagement, with 112 UN Member States that have now nominated their national contact persons to assist in future data collection."

"In our discussion, we highlighted the necessity for continued dialogue and cooperation from all Member States, stressing the need for additional data on medical, occupational, and public exposures, especially from Africa, Latin America and Asia," said the Chair, "This collective effort is imperative for enabling a geographically balanced scientific evaluation on worldwide levels and trends of exposure of the public to ionizing radiation."

UNSCEAR and International Commission on Radiological Protection Forge Historic Agreement

In the margins of the 71st session the International Commission on Radiological Protection and UNSCEAR forged a historic agreement and signed their first memorandum of understanding on 22 May 2024. This agreement aims to further strengthen the ongoing collaboration between the two organizations. UNSCEAR Secretary Borislava Batandjieva-Metcalf recognized this as "an important step towards continuing efforts for the development of future international radiation protection framework based on independent and objective radiation science".

UNSCEAR releases translated radiation booklet in Italian

On 23 May the UNSCEAR secretariat also released the Italian translation of the United Nations Environment Programme booklet entitled "Radiation: Effects and Sources". The booklet, which is now available in 16 languages on UNSCEAR's public website and UNEP's Knowledge Repository, presents clear and accessible information on the basic science of radiation, including its effects on humans and the environment and its various sources. It is based on the Committee's major scientific reports and aims to expand public knowledge on exposure levels to ionizing radiation and its potential effects.

The UNSCEAR 72nd session is scheduled to take place from 16 to 20 June 2025 in Vienna, Austria.


The mandate of the United Nations Scientific Committee on the Effects of Atomic Radiation, established in 1955, is to undertake broad reviews of the sources of ionizing radiation and the effects on human health and the environment. Its assessments provide a scientific foundation for United Nations agencies and governments to formulate standards and programmes for protection against ionizing radiation. It does not deal with or assess nuclear safety or emergency planning issues. The secretariat in Vienna, which is functionally linked to the UN Environment Programme, organizes the annual sessions and manages the preparation of documents for the Committee's scrutiny.

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For information contact:

UNSCEAR secretariat
Telephone: (+43-1) 26060 4122
Email: unscear[at]