Estimation of human radiation dose caused by indoor radon pollution

1. Foreword

Scorpion corpus is one of the main factors in inducing lung cancer. In recent years, energy-saving measures have been adopted, which has increased the airtightness of the living room, resulting in an increase in indoor radon concentration (about an order of magnitude higher), and the time spent indoors is about 80%. This makes people pay special attention to the health effects of indoor sputum and its daughters. On December 18, 2002, China promulgated the "Indoor Air Quality Standards" ^[3] , which was implemented on March 1, 2003. Therefore, we conducted an indoor radon level survey and analysis of human health hazards.

2 measurement results

    The enthalpy precipitation rate was measured while measuring the concentration of cockroaches and daughters inside and outside the room. The enthalpy precipitation rate of indoor floors and walls was taken as the measured mean value at different locations, as shown in Table 1.

Table 1 Measurement results of indoor and outdoor radon concentration, radon proliferative potential, and radon exhalation rate

Note: Each type is the average of 10 rooms with equivalent conditions; 1-3 are basements, 3-6 are bungalows; others are buildings.

Each water sample was taken 3L, and the enthalpy dissolved in water was transferred to the scintillation chamber which was vacuumed by the adsorption of activated carbon, and waited for 3 hours and then measured with an FD-125 helium gas analyzer. The results are shown in Table 2.

Table 2 measured radon concentration in water

Calculate the consumption ratio of water for different uses according to the per capita water consumption of 9.706×10 ^-2 m ³ / (person ̇d), see Table 3.

Table 3 Estimates of consumption of water for different uses in small districts

    The content of strontium in the gas was measured by flashing instantaneous sampling method, FD-125 helium gas analyzer, and the results are shown in Table 4. The value of radon concentration in the gas measured in Table 4 may be related to the radium content in the raw material (coal) that produces the gas, in addition to the use.

Table 4 Concentration of radon in gas used by residential residents

3 æ°¡ dose equivalent estimation

Factor of 0.8 is selected to stay indoors, outdoors 0.2, according to the average person's respiratory rate is calculated for all of the respiratory volume; _indoor V = 5475m ^3; _outdoor V = 1825m ^3, the inhabitants of radon suffered in an effective dose irradiated The equivalent is calculated as follows:

H=26.42Bq/m ³ ×0.4×0.061mSv/(Bqm ^-3 )+8.64Bq/m ³ ×0.6×0.031mSv/(Bqm ^-3 )

=0.806(mSv)

That is, the total dose equivalent of the radiation received by the resident individual during the year is: H=0.806 (mSv)