Simultaneous measurements of radon (Rn²²²) and thoron (Rn ²²⁰) in the atmospheric surface layer

Abstract

Simultaneous, direct measurements of the radon and thoron contents in the air near the ground have been made, using apparatus adapted from those of Norinder et al. (1952) andIsrael (1964). Data of the diurnal variations and the vertical distributions of radon and thoron are presented. According to measurements the vertical gradients of radon and thoron are greatest near the ground surface at night. The ratios between the concentrations of thoron and radon vary on an average from 0.1 to about 3.0 in the layer up to the height 3 m above the ground surface. Fourier analyses are made of variations with time of radon and thoron concentrations. For radon a few harmonics represent the diurnal wave. For thoron, however, several harmonics are needed.

Radioisotope: Applications, Effects, and Occupational Protection

“…The half-life of radon is 3.82 days; it decays by emission of alpha particle to form radon decay products or progeny, which are divided into short-lived and long-lived progeny. These are the significant contributor of natural radiation [9]. On the basis of the epidemiological studies, it has been established that the enhanced levels of indoor radon in dwellings can cause health hazards and may lead to serious diseases like lung cancer in human beings [5,10].…”

“…Each year, this isotope delivers doses of about 18 millirem (mrem) to soft tissues of the body and 14 mrem to the bone. 40 K can present both external and internal health hazards [9].…”

Dynamics, deterministic nature and correlations of outdoor 222Rn and 220Rn progeny concentrations measured at Bacău, Romania

“…In the case of 222 Rn-A4 and 220 Rn-A3 the high value of p (0.793, 0.778) indicates that correlations are not statistically significant. The positive correlation coefficients for night aspirations (A1) may be explained by the increase of exhalation rate with the rise in temperature gradient between atmosphere and soil (Malakov et al, 1966;Israelsson et al 1973), corroborated by the reduction of turbulent diffusion intensity owing to the temperature inversions occurring during nighttime. In the case of radon progeny concentrations for the day aspirations (A2, A3), the correlation coefficients have negative values with a level of significance p 0.01, what means that at 99% confidence the respective time series are correlated.…”

La radioactivité naturelle de l’air hors des maisons

“…Ainsi, sous influence maritime très marquée, on constate un tracé mono tone tout au long de la journée. Certains auteurs [7,11,22] signalent, en fonction du temps, des va riations de la concentration de l'air en radon présentant une structure périodique.…”