Contribution of (222)Rn-bearing water to indoor radon and indoor air quality assessment in hot spring hotels of Guangdong, China

This study investigates the contribution of radon (²²²Rn)-bearing water to indoor ²²²Rn in thermal baths. The ²²²Rn concentrations in air were monitored in the bathroom and the bedroom. Particulate matter (PM, both PM₁₀ and PM_2.5) and carbon dioxide (CO₂) were also monitored with portable analyzers. The bathrooms were supplied with hot spring water containing 66-260 kBq m⁻³ of ²²²Rn. The results show that the spray of hot spring water from the bath spouts is the dominant mechanism by which ²²²Rn is released into the air of the bathroom, and then it diffuses into the bedroom. Average ²²²Rn level was 110-410% higher in the bedrooms and 510-1200% higher in the bathrooms compared to the corresponding average levels when there was no use of hot spring water. The indoor ²²²Rn levels were influenced by the ²²²Rn concentrations in the hot spring water and the bathing times. The average ²²²Rn transfer coefficients from water to air were 6.2 × 10⁻⁴-4.1 × 10⁻³. The 24-h average levels of CO₂ and PM₁₀ in the hotel rooms were 89% and 22% higher than the present Indoor Air Quality (IAQ) standard of China. The main particle pollutant in the hotel rooms was PM_2.5. Radon and PM₁₀ levels in some hotel rooms were at much higher concentrations than guideline levels, and thus the potential health risks to tourists and especially to the hotel workers should be of great concern, and measures should be taken to lower inhalation exposure to these air pollutants.     

Mutagenic properties of PM2.5 air pollution in the Padana Plain (Italy) before and in the course of XX Winter Olympic Games of "Torino 2006"

PM2.5 is one of the most important aspects of environmental health. This air pollutant is breathable and it is implicated in several chronic adverse health effects such as the decrease of respiratory functionality and cancer. Several in vitro bioassays are able to predict the mutagenic/carcinogenic activity of the environmental pollutants and mixtures of them. In this study PM2.5 air pollution was daily monitored in three cities located in the Northern part of Italy and the mutagenic properties of the PM2.5 organic extracts were also assessed. Samplings lasted 14 months and cover the period of the Winter Olympic Games of "Torino 2006". In this work, the levels of PM2.5, its mutagenic properties (detected with Salmonella typhimurium assay), the role of the Olympic Games as environmental factor and some meteorological data are discussed. The mean concentration of PM2.5 measured in Torino was 45.4 (+/-30.6) microg/m(3), in Pavia 37.6 (+/-25.6) microg/m(3), in Verona 43.1 (+/-28.5) microg/m(3). Findings of the monthly pool bioassay were in Torino 107 (+/-104) net revertans/m(3), in Pavia 108 (+/-89) net revertans/m(3), in Verona 128 (+/-109) net revertans/m(3). The Olympic Games period data show that PM2.5 pollution and its load of mutagenic potential are different and partially independent phenomena. The Olympic Games had not a great impact on the PM2.5 pollution. The exclusive PM2.5 gravimetric analysis shows a potential human risk if compared with the latest international guide values but it does not describe exhaustively the human health risk associated to the presence of this particular air pollutant. Moreover, the chemical and biological activity qualification of the PM organic extracts as a whole, can instead improve the knowledge.     

Effect of Ecological Factors on the Accumulation of Fluorine by Larches, <Emphasis Type="Italic">Larix gmelinii</Emphasis> (Rupr.) Rupr. and <Emphasis Type="Italic">L. sibirica</Emphasis> Ledeb., in Eastern Siberia

The accumulation of fluorine in the trunk wood and branches of Larix gmelinii growing on soils with a naturally increased fluoride content and of L. sibirica growing in a zone affected by atmospheric emissions from an aluminum plant has been studied. Based on results of in vivo and in vitro experiments, it is concluded that larch trees manifest individual differences in their response to fluorine.     

Dose assessment for marine biota and humans from discharge of (131)I to the marine environment and uptake by algae in Sydney, Australia

Iodine-131 reaches the marine environment through its excretion to the sewer by nuclear medicine patients followed by discharge through coastal and deepwater outfalls. ¹³¹I has been detected in macroalgae, which bio-accumulate iodine, growing near the coastal outfall of Cronulla sewage treatment plant (STP) since 1995. During this study, ¹³¹I levels in liquid effluent and sludge from three Sydney STPs as well as in macroalgae (Ulva sp. and Ecklonia radiata) growing near their shoreline outfalls were measured. Concentration factors of 176 for Ulva sp. and 526 for E. radiata were derived. Radiation dose rates to marine biota from ¹³¹I discharged to coastal waters calculated using the ERICA dose assessment tool were below the ERICA screening level of 10 μGy/hr. Radiation dose rates to humans from immersion in seawater or consumption of Ulva sp. containing ¹³¹I were three and two orders of magnitude below the IAEA screening level of 10 μSv/year, respectively.