Assessment of Alpha Doses Received by Spa Workers Due to the Inhalation of 214 Po and 218 Po Radon Progeny.

ABSTRACT: In Morocco spas are more and more frequented by bathers for massages, body treatments, and aromatherapy and hair services, among others. Alpha-activities due to 222 Rn, 220 Rn and their progeny have been evaluated inside spa room atmospheres by means of a technique based on using two types of solid-state nuclear track detectors. 222 Rn and 220 Rn concentrations ranged between (67 ± 5 and 103 ± 7) Bq m -3 and (5.5 ± 0.4 and 9.8 ± 0.7) Bq m -3 for the studied spa rooms, respectively. The influence of ventilation rate in spa rooms on 222 Rn and 220 Rn concentrations has been studied. Alpha-activities due to the attached and unattached fractions of 214 Po and 218 Po radon progeny have been evaluated in various compartments of the respiratory system of spa working personnel. It has been shown that the majority of 214 Po and 218 Po radon progeny are attached to aerosols inside the considered spa rooms. Alpha-doses to the respiratory tract tissues of spa working personnel due to the energy loss of the emitted alpha-particles were evaluated. It has been shown that alpha-doses to the respiratory system of spa working personnel are influenced by exposure time of workers, mass of respiratory system target tissues, and radon concentration inside the studied spa rooms. The largest value of alpha-dose due to the 214 Po and 218 Po radon progeny from inhalation of air by female workers working 2,080 hours per year in the studied spa rooms was found equal to 5.16 mSv y -1 .

Measurement of radon, thoron and their daughters in the air of marble factories and resulting alpha-radiation doses to the lung of workers.

Concentrations of radon (222Rn) and thoron (220Rn) were measured in the air of different marble factories by using a nuclear track technique. The influence of the marble dust nature and ventilation on radon and thoron concentrations was investigated. It was observed that measured radon and thoron concentration ranged from 310 to 903 Bq m-3 and 6 to 48 Bq m-3, respectively. In addition, alpha-activities due to the unattached and attached fractions of 218Po and 214Po radon short-lived progeny were evaluated in the marble factories studied. Committed equivalent doses due to the attached and unattached fractions of 218Po and 214Po nuclei were evaluated in the lung tissues of marble factory workers. The dependence of the resulting committed equivalent dose on the concentration of the attached and unattached fractions of the 218Po and 214Po radionuclides and mass of the tissue was investigated. The resulting annual committed effective doses to the lung of marble factory workers due to the attached and unattached fractions of the 218Po and 214Po radionuclides were calculated. The obtained results show that about 80% of the global committed effective doses received by workers in the studied marble factories are due to the attached fraction of the 218Po and 214Po radon short-lived daughters from the inhalation of polluted air. Male workers spending 8 h per day (2080 h per year) in a marble factory receive a maximum dose of 34.46 mSv y-1 which is higher than the (3-10 mSv y-1) dose limit interval given by the ICRP. Good agreement was found between data obtained for the average effective dose gotten by using this method and the UNSCEAR and ICRP conversion dose coefficients.

222Rn, 220Rn and Their Progenies Measured in the Air of Different Dwellings and Workplaces and Resulting Alpha Radiation Doses to the Eyes of Individuals.

In order to assess radiation doses to the eyes of individuals, concentrations of Rn, Rn and their decay products were measured in different dwelling rooms, café rooms and vehicle repair shops by using two different types of solid state nuclear track detectors (SSNTDs). The influence of building materials, pollution and ventilation rate on radon and thoron alpha-activities inside the studied locations has been investigated. A new dosimetric model was developed for evaluating radiation doses to the eyes of individuals due to alpha particles emitted by the radon and thoron series in the air of the studied dwelling rooms, café rooms, and vehicle repair shops. The influence of the radon and thoron activities in the air of the studied locations, as well as exposure time on committed equivalent dose to the eyes of individuals, was investigated. A maximum value of the committed equivalent dose to the eyes of individuals due to alpha particles emitted by the radon and thoron series was found equal to 0.1 mSv y cm. Committed equivalent dose to the eyes of individuals due to the diffusion of the Rn and Rn gases present in ambient air of the studied locations has been evaluated.

Measurement of 238U and 232Th in Petrol, Gas-oil and Lubricant Samples by Using Nuclear Track Detectors and Resulting Radiation Doses to the Skin of Mechanic Workers.

Workers in repair shops of vehicles (cars, buses, truck, etc.) clean carburetors, check fuel distribution, and perform oil changes and greasing. To explore the exposure pathway of (238)U and (232)Th and its decay products to the skin of mechanic workers, these radionuclides were measured inside petrol, gas-oil, and lubricant material samples by means of CR-39 and LR-115 type II solid state nuclear track detectors (SSNTDs), and corresponding annual committed equivalent doses to skin were determined. The maximum total equivalent effective dose to skin due to the (238)U and (232)Th series from the application of different petrol, gas-oil, and lubricant samples by mechanic workers was found equal to 1.2 mSv y(-1) cm(-2).

Radon and Thoron Measured in Petrol and Gas-oil Exhaust Fumes by Using CR-39 and LR-115 II Nuclear Track Detectors: Radiation Doses to the Respiratory Tract of Mechanic Workers.

Mechanic workers are exposed to exhaust fumes when controlling vehicle engines in motion inside repair shops. To assess radiation doses due to radon short-lived progeny from the inhalation of exhaust fumes by mechanic workers, concentrations of these radionuclides were measured in petrol (gasoline) and gas-oil exhaust fumes by evaluating mean critical angles of etching of the CR-39 and LR-115 type II SSNTDs for alpha particles emitted by the radon and thoron decay series. Committed effective doses due to ²¹8Po and ²¹4Po short-lived radon decay products from the inhalation of petrol and gas-oil exhaust fumes by workers were evaluated. A maximum value of 1.35 mSv y⁻¹ due to radon short-lived decay products from the inhalation of gas-oil exhaust fumes by mechanic workers was found, which is lower than the (3-10 mSv y⁻¹) dose limit interval for workers.

Radiation doses to individuals due to ²³8U, ²³²Th and ²²²Rn from the immersion in thermal waters and to radon progeny from the inhalation of air inside thermal stations.

In Morocco, thermal waters have been used for decades for the treatment of various diseases. To explore the exposure pathway of (238)U, (232)Th and (222)Rn to the skin of bathers from the immersion in thermal waters, these radionuclides were measured inside waters collected from different Moroccan thermal springs, by means of CR-39 and LR-115 type II solid-state nuclear track detectors (SSNTDs), and corresponding annual committed effective doses to skin were determined. Accordingly, to assess radiation dose due to radon short-lived decay products from the inhalation of air by individuals, concentrations of these radionuclides were measured in indoor air of two thermal stations by evaluating mean critical angles of etching of the CR-39 and LR-115 II SSNTDs. Committed effective doses due to the short-lived radon decay products (218)Po and (214)Po by bathers and working personnel inside the thermal stations studied were determined.

Concentrations of 222Rn, 220Rn and their decay products measured in outdoor air in various rural zones (Morocco) by using solid-state nuclear track detectors and resulting radiation dose to the rural populations.

Alpha and beta activities per unit volume of air due to radon ((222)Rn), thoron ((220)Rn) and their progenies were measured in the outdoor air at different locations in Morocco by using both CR-39 and LR-115 type II solid-state nuclear track detectors (SSNTDs). In addition, the radon concentration was continuously measured in one location by using the methods with SSNTDs and AlphaGuard counter. The influence of the geological and meteorological conditions as well as phosphate and building material dust on the radon concentration in the outdoor air of the areas studied was investigated. The committed equivalent doses due to (218)Po and (214)Po radon short-lived progeny were evaluated in different tissues of the respiratory tract of the members of the public from the inhalation of outdoor air. The annual effective dose due to radon short-lived progeny from the inhalation of outdoor air by the members of the rural population was estimated.

Radon, thoron and their decay products in natural caves with nuclear track detectors.

Alpha and beta activities per unit volume of air due to radon (222Rn), thoron (220Rn) and their progenies were measured in the air of natural caves by using CR-39 and LR-115 type II solid-state nuclear track detectors. Equilibrium factors between radon and its daughters and between thoron and its progeny were evaluated in the atmospheres studied.