Method of Polonium Source Preparation Using Tellurium Microprecipitation for Alpha Spectrometry

Tracing the Transport and Residence Times of Atmospheric Microplastics Using Natural Radionuclides

While atmospheric microplastics are known to be transported over long distances, their residence times and transport processes lack clarity. This study utilized natural radionuclides 7Be, 210Pb, and 210Po to explore the transport of atmospheric microplastics in Tianjin, a coastal city in Northern China. Microplastic concentrations ranged from 0.03 to 0.13 particles m-3 over the course of a year. The proportion of microplastic fragments in winter was significantly higher than that in other seasons, with median microplastic sizes in autumn and winter being larger than those in spring and summer. The atmospheric microplastic surface was rough, exhibiting irregular pores and multiple depressions and cracks. Microplastics experienced vertical mixing with the upper atmosphere in April and August and were influenced by rainfall in July. The residence time of atmospheric particles ranged from 9.47 to 22.85 days throughout the year, with an average of 14.41 days. The peak residence time of atmospheric particulates in November may be correlated with increased 210Po levels from coal consumption. Their prolonged atmospheric presence and rough surface allow microplastics to act as carriers for various chemical pollutants, underscoring the complexity and potential risks associated with their presence in the atmosphere.

Recent progresses in analytical method development for 210Pb in environmental and biological samples

As a decay product of uranium series, 210Pb spreads widely in the nature and imposes strong radiological and chemical toxicity. It is vital to establish reliable and efficient radioanalytical methods for 210Pb determination to support environment and food radioactivity monitoring programs. This article critically reviews analytical methods developed for determining 210Pb in environmental and biological samples, especially new development in recent years. Techniques applied throughout different analytical steps including sample pretreatment, separation, purification, and detection are summarized and their pros and cons are discussed to provide a holistic overview for 210Pb environmental and biological assay.

Detection of Polonium-210 in Environmental, Biological and Food Samples: A Review

Ingestion of polonium-210 from environmental media and food can cause serious health hazards (e.g., gastrointestinal symptoms, tumours, etc.) and has been a public health concern worldwide since the 2006 poisoning of Agent Litvinenko 210Po in Russia. With the development of uranium mining and applications of nuclear technology in recent decades, the radioactive hazards posed by 210Po to living organisms and the environment have become increasingly prominent. In order to strengthen the monitoring of environmental 210Po and protect both the environment and human health, a series of explorations on the methods of 210Po determination have been ongoing by researchers across the globe. However, previous reviews have focused on individual sample types and have not provided a comprehensive account of environmental, food, and biological samples that are closely related to human health. In this work, the sources, health hazards, chemical purification, and detection methods of trace 210Po in different sample types are systematically reviewed. In particular, the advantages and disadvantages of various pretreatment methods are compared, and relevant domestic and international standards are integrated, which puts forward a new direction for the subsequent establishment of rapid, simple, and efficient measurement methods.

Rapid separation of Po-210 from Pb-210 based on the usage of a commercial Sr-Specific chromatographic resin

The efficient extraction of small quantities of ²¹⁰Po is necessary for preparing ²¹⁰Po standard reference materials. Herein, a commercially available strontrium-specific chromatographic resin (Sr spec resin) was used to rapidly and selectively extract ²¹⁰Po from a ²¹⁰Pb-²¹⁰Bi-²¹⁰Po mixture, and the distribution ratios of Pb, Bi, and ²¹⁰Po on Sr spec resin were probed using batch experiments. In contrast to ²¹⁰Pb and ²¹⁰Bi, ²¹⁰Po was retained on the Sr spec cartridge in 8 M HCl and was then effectively eluted by 0.1 M HNO₃. The contents of ²¹⁰Pb and ²¹⁰Bi in the thus obtained ²¹⁰Po solution were checked using a high purity germanium gamma-ray detector and the corresponding decay curve, respectively, and were found not to exceed 2%. Moreover, the ²¹⁰Pb and ²¹⁰Bi eluates could be used to regenerate ²¹⁰Po by the same method after a certain time period. Therefore, the extracted ²¹⁰Po solution was suitable for the preparation of the ²¹⁰Po standard area source and ²¹⁰Po standard reference materials.

Novel rapid oxidizing fusion method to determine Polonium-210 in air filters

A rapid method for the determination of polonium-210 in air filters has been developed for use following a radiological event and for routine environmental monitoring. Air filter samples, including cellulose and glass fiber, are fused with a sodium or potassium nitrate/sodium hydroxide flux material. The alkaline matrix minimizes polonium volatility during sample digestion steps, while efficiently dissolving the air filter and inorganic matter implanted on the filter. The addition of nitrate to the flux destroys organic material which can decrease Polonium recovery during precipitation, extraction and source preparation steps. Polonium is concentrated and separated from the sample matrix using an iron hydroxide precipitation and extraction chromatography with DGA Resin. Polonium-210 is subsequently measured by alpha spectrometry following rapid microprecipitation with bismuth phosphate. The new method employs extraction chromatographic purification to remove alpha emitting interferences and sample matrix constituents which can interfere with ²¹⁰Po measurements using alpha spectrometry. The novel blend of sodium hydroxide and alkali metal nitrate digests the air filters quickly and effectively.

Rapid method to determine Polonium-210 in urban matrices

A rapid method for the determination of polonium-210 in urban matrices has been developed that can be used following a radiological event. Samples such as concrete, soil and granite are fused with sodium hydroxide to minimize polonium volatility during sample digestion and to achieve complete sample dissolution. Complete dissolution of samples is important to ensure method ruggedness. Polonium is concentrated and separated from the sample matrix using an iron hydroxide precipitation and extraction chromatography and subsequently measured by alpha spectrometry following microprecipitation with bismuth phosphate. The chromatographic separation removes alpha emitting interferences and matrix constituents which can adversely impact the measurement via alpha spectrometry.