In this study, the activities of ⁴⁰K, ²¹⁰Pb, ²³²Th, ²³⁴U, ²³⁵U, and ²³⁸U in size-segregated particulate matter (PM) were measured in the Singrauli Coalfield, India. Different isotopic compositions were found relative to natural uranium ratios. The radioactivity concentration ratios in different PM sizes [PM_2.5, PM₁₀, and suspended particulate matter (SPM)] suggested that anthropogenic sources affected the uranium isotopic compositions in the area. A different isotopic composition from the natural uranium composition was found. The correlation coefficients between the measured isotopes (⁴⁰K, ²¹⁰Pb, ²³²Th, ²³⁴U, ²³⁵U, and ²³⁸U) and meteorological factors were calculated. PM emissions were affected by the meteorological conditions, which in turn, influenced the U and Th concentrations in PM. The ²³²Th/²³⁸U activity ratio in particulate matter was between 0.20 and 1.54 with an average value of 0.9 ± 0.5, 0.2 to 1.1 (0.8 ± 0.7), and 0.2 to 1.2 with an average value of 0.8 ± 0.8 in PM_2.5, PM₁₀, and SPM, respectively. These range were quite different from the average crustal ratio of 3.5, indicating that the ²³⁸U concentrations were elevated in this region relative to Th. However, compared with Th, the dose contribution of U to the public was negligible. The average effective dose in public owing to inhalation of natural radioactive ⁴⁰K, ²¹⁰Pb, ²³²Th, and ²³⁴U, ²³⁵U, and ²³⁸U in the atmosphere was between 0.03 and 327 nSv year⁻¹. These doses associated with the inhalation of particulate matter were lower than world airborne reference value as reported by UNSCEAR (2000a).

在这项研究中，在印度的辛格劳利煤田中测量了⁴⁰ K，²¹⁰ Pb，²³² Th，²³⁴ U，²³⁵ U和²³⁸ U的大小分离颗粒物（PM）的活性。发现相对于天然铀比率不同的同位素组成。不同PM尺寸[PM _2.5，PM ₁₀和悬浮颗粒物（SPM）]的放射性浓度比表明，人为源影响了该地区的铀同位素组成。发现与天然铀组成不同的同位素组成。被测同位素之间的相关系数（⁴⁰ K，^计算了210 Pb，²³² Th，²³⁴ U，²³⁵ U和²³⁸ U）和气象因子。PM排放受气象条件的影响，而气象条件又影响PM中的U和Th浓度。在PM _2.5中，颗粒物的²³² Th / ²³⁸ U活度比在0.20至1.54之间，平均值为0.9±0.5、0.2至1.1（0.8±0.7），以及0.2至1.2，平均值为0.8±0.8。PM ₁₀和SPM分别。这些范围与3.5的平均地壳比率有很大差异，表明²³⁸相对于Th，该区域的U浓度升高。但是，与Th相比，U对公众的剂量贡献可忽略不计。在公共欠平均有效剂量天然放射性的吸入⁴⁰ K，²¹⁰的Pb，²³² Th和²³⁴ U，²³⁵ U和²³⁸中的U气氛NSV年0.03和327之间^-1。这些吸入颗粒物的剂量低于联合国航空航天研究中心（2000a）报告的世界航空参考值。