By Barbara Nwaiwu
The United Nations has warned that nuclear tests do not demonstrate strength but erode trust, trigger arms races and leave devastating humanitarian and environmental consequences for generations. The warning was issued at a hybrid event in Nairobi on Wednesday, to commemorate the 2026 International Day against Nuclear Tests.
The event, themed “Humanitarian and Ecological Consequences of Nuclear Weapons Use and Testing”, was organised by the United Nations Office in Nairobi (UNON), in collaboration with the Embassy of the Republic of Kazakhstan in Kenya.
The International Day against Nuclear Tests is observed annually on August 29 in accordance with United Nations General Assembly Resolution 64/35, adopted on December 2, 2009.
The event also marked the 35th anniversary of the closure of the Semipalatinsk Nuclear Test Site in Kazakhstan, the 81th anniversary of the atomic bombings of Hiroshima and Nagasaki, and the 20th anniversary of the signing of the Treaty on a Nuclear-Weapon-Free Zone in Central Asia.
Speaking at the event, Barlybay Sadykov, Ambassador of the Republic of Kazakhstan to Kenya, recalled Kazakhstan’s decision on August 29, 1991, to close the Semipalatinsk Nuclear Test Site, describing it as a defining moment in the country’s history and an important milestone in the global struggle against nuclear testing.
Sadykov said the atomic bombings of Hiroshima and Nagasaki in 1945 remained among the greatest tragedies in human history and a permanent reminder of the catastrophic consequences of nuclear weapons use.
“The pain and suffering experienced by the people of Japan are deeply understood. For humanity, they are a permanent reminder of the catastrophic consequences of nuclear weapons use,” he said.
He said nuclear testing in Kazakhstan had caused severe humanitarian and environmental consequences, noting that the Semipalatinsk test site covered 18,000 square kilometres and had been profoundly affected by radioactive contamination.
“Approximately 1.5 million people were exposed to high levels of radiation, with consequences that have continued to affect generations. The impact has been felt through increased health problems, congenital birth defects, and the long-term psychological and social consequences of living with the legacy of nuclear testing,” the ambassador said.
Sadykov said the environmental consequences included soil contamination, restrictions on land use and the need for long-term monitoring of radioactive pathways in water.
He added that radioactive particles could continue to be transported by wind and enter the food chain through plants and animals.
“Humanitarian and environmental consequences of nuclear testing remind us of a shared responsibility of states to prevent such tragedies from ever recurring,” Sadykov said.
He called on countries to strengthen international efforts to prevent further nuclear testing and advance nuclear disarmament.
Inger Andersen, Executive Director of the United Nations Environment Programme (UNEP), said the Semipalatinsk Test Site in eastern Kazakhstan had served as the primary nuclear testing ground for the Soviet Union, with more than 450 nuclear tests conducted there between 1949 and 1989.
Andersen said the tests exposed approximately 1.5 million residents to radioactive fallout, while people living near the former site continued to experience high rates of cancer, cardiovascular illnesses and intergenerational health issues decades after testing ended.
She said the consequences of nuclear testing also extended to the environment, warning that nuclear waste from tests could enter the environment and cause severe damage to marine life and ecosystems if storage bunkers ruptured.
Andersen said more than 2,000 nuclear tests had been conducted by eight countries since 1945, highlighting the continuing dangers associated with their aftermath.
She said that as of June, there were 9,745 nuclear warheads in the world, an increase of almost 500 since 2018.
According to Andersen, the use of even a small fraction of the weapons could kill millions of people and produce wider global consequences, including damage to the ozone layer, severe and dangerous global cooling and famine.
“We cannot reverse the harm done. But we can listen to the testimony of those who suffered, including through this powerful and poignant exhibition, and do our utmost to never let it happen again.”
The Ambassador of Japan to Kenya, Hiroshi Matsuura, described Kazakhstan’s permanent closure of the Semipalatinsk test site 35 years ago as an act of extraordinary courage.
He said the bombs used at Hiroshima and Nagasaki were limited in their capacity compared with modern nuclear weapons, yet they still killed hundreds of thousands of people.
“The launching speed was zero; the stealth ability was zero because they were just bombs dropped out from the bomber aircrafts. Still, they managed to kill hundreds of thousands of people. Since that attack, the human kind have learned that we cannot use nuclear weapons at all.”
“You do not need special imagination to understand that the attacks and counterattacks, revenge attacks, using today’s hyper powerful nuclear weapons are a sure and instant way to destroy the whole mankind and the civilization.”
The Executive Director of UN-Habitat, Anacláudia Rossbach, said the cost of nuclear testing and nuclear weapons use extended beyond the explosions themselves to include damage to land, water and ecosystems, as well as disruption, displacement and prolonged recovery.
Rossbach said UN-Habitat remained ready to work with member states and communities to support recovery efforts centred on dignity, safety and sustainable homes.
UNON Director-General, Zainab Hawa Bangura, said the commemorative event served as a reminder of the devastating consequences of nuclear testing and the lessons humanity had learned from past experiences.
