Guwahati: A newly published scientific study has, for the first time, evaluated radioactive elements in tea from around the world — offering a rare insight into the radiological safety of the beverage consumed daily by billions.
Published in the Journal of Food Composition and Analysis (August 2025), the study analyzed 141 tea brands from 18 countries across four continents, covering a wide variety of teas — black, green, white, oolong, rooibos, honeybush, yerba mate, and lapacho. The focus: two naturally occurring radionuclides — Polonium-210 (²¹⁰Po) and Lead-210 (²¹⁰Pb) — known for their radiotoxicity when inhaled or ingested in high quantities.
The research was led by Dr. Dagmara Strumińska-Parulska of the University of Gdańsk in Poland.
“In the environment, radionuclides occur both naturally and artificially, and they are ubiquitous throughout nature. Approximately 75 % of the total effective radiation dose received by individuals from all radiation sources is attributed to natural radioactivity (Carvalho et al., 2009). Therefore, the Council of the European Union has already stated that the protection against natural radiation sources should be fully integrated within the overall requirements,” the authors say.
The authors noted that much of the scientific literature has focused on exploring the potential health benefits of tea constituents, such as polyphenols and catechins, particularly in less processed varieties like white, green, and red tea. However, natural deposition containing radionuclides is transported to tea plantations through air and rain, settling on the leaves and soil. The pollution of the natural environment poses a risk of contaminating plants with toxins such as pesticides, metals, or radioactive substances.
“Evaluating the concentrations of radionuclides in frequently consumed teas is a task of human health care and radiological protection. Understanding their potential impact on human health through consumption is of utmost significance. Taking into account that the safety of tea is of great importance and that the highly radiotoxic ²¹⁰Po and ²¹⁰Pb are present in various species of teas, the research focused on assessing the potential intake of ²¹⁰Po and ²¹⁰Pb and evaluating the effective exposure doses from these radionuclides in analyzed teas and the cancer risk due to lifetime exposure to ²¹⁰Po and ²¹⁰Pb ingested with tea,” the authors state.
What the Study Found
The study revealed that the levels of radioactivity varied significantly based on geography, plant species, and tea type. For instance, the lowest levels of ²¹⁰Po were found in Colombian green tea, with just 1.64 Bq/kg recorded. In stark contrast, the highest levels were observed in Chinese green tea from Zhejiang province, with activity concentrations measured at 59.5 Bq/kg for ²¹⁰Po and 72.2 Bq/kg for ²¹⁰Pb. Rooibos teas from South Africa recorded the lowest overall radioactivity among the samples, potentially due to differences in plant species and regional soil composition.
“In an investigation of 141 different tea brands, we identified the presence of radionuclides — ²¹⁰Po and ²¹⁰Pb. The measured activity concentrations, the subsequently calculated annual radiation doses, and associated cancer risk from consuming tea infusions do not pose a threat from a radiological perspective,” the authors conclude.
They further recommend that future research should explore factors such as tea production processes, geological substrates, and other relevant variables to ensure the continued safety of tea consumption.
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