Age-Dependent Health Risk Assessment for Radon Concentrations from Drinking Water Available in the Iraqi Markets

Abstract

Radon is occurring naturally, odourless, colourless, radioactive, tasteless, and a noble gas. It is the second most important cause of lung cancer after smoking in many countries. The rate of lung cancers attributable to radon is estimated to range from 3 to 14%. The dose exposure relation is linear, i.e. the risk of lung cancer increases proportionally with increasing radon exposure. So, it is necessary to measure radon concentrations in the drinking water that is of direct contact with human life and health. The study included measurement of radon ( 222 Rn) concentrations in some selected samples of drinking water (bottled water) are available in the Iraqi market. 222 Rn concentrations have been measured the usage of alpha spectroscopy (RAD-7). The RAD-7 measuring process is based on detecting alpha particles produced from the disintegration of radon and its products using a solid-state alpha detector (usually silicon), and then converting alpha radiation directly to an electrical signal. The annual effective dose and lifetime cancer risk in six age groups (3 months, 1 year, 5 years, 10 years, 15 years and adult) associated with the exposure due to an annual intake of 222 Rn were calculated. Results show that the average value of radon concentrations in drinking water samples was ranged from 28.4±2.7 mBq/L to 283±0.34 mBq/L. Also, it is found the average value of annual effective dose in unit µSv/y for six age groups were 0.48±0.08, 0.62±0.11, 0.18±0.03, 0.22±0.04, 0.37±0.06, and 0.27±0.05,respectively. The average value of lifetime cancer risk in same age groups were (17.99±3.26, 31.13±5.65, 46±8.37, 107.33±19.41, 276.5±50, and 926.33±168)×10 -9 respectively. The results of 222 Rn concentrations in present study were found lower than the data of the recommended reference WHO 2008 (500 mBq/L or Bq/m3). Also, the results showed that the annual effective dose from drinking water exhaustion in six age groups were found lower than the permitted limit of (1mSv) suggested by UNSCEAR 2000. As well as, values of lifetime cancer risk were within the accepted level (10 -3 ). Therefore, there are no indications of significant threat from radon concentrations in bottled water brands, and it is safe as far as a health risk is concerned.

Age-dependent Radiological Risk Assessment of Radon (222Rn) in Samples of Commercial Bottled Water from Benin City, Nigeria

“…The electronic detector employs the alpha spectrometry method with a bubbling kit. Alpha spectrometry method using RAD7 has widely been used by [5,7,8,2,12]. It can precisely assess the radon levels in a water sample in 20 minutes.…”

“…Having obtained the values for the radon concentrations in the bottled water, a calculation of the yearly effective dosage of radon from ingestion ( 𝜇𝑆𝑣/𝑦 ) based on equation ( 1) was made [15,16,6,8,17]…”

“…where 𝐴𝐸𝐷 𝐼𝑛ℎ is the effective dose for inhalation, C 𝑅𝑛𝑊 is the radon concentration in water, 𝑅 𝑎.𝑊 is the ratio of radon in air to radon in tap water (1 × 10 −4 ), F is the equilibrium factor between radon and its decay products (0.4), O is the average indoor occupancy time per person (7000 h/y) and 𝐷 𝐶𝐹 is the Dose Conversion Factor for radon exposure. Infants, children, and adults consume approximately 260, 350, and 730 litres of water per year, respectively [18,19] and the ingested dose conversion factor per age group are 2.3 × 10 −8 , 5.9 × 10 −9 , and 3.5 × 10 −9 (Sv/Bq) respectively [15,6,8,17].…”

“…The lifetime cancer risk associated with radon concentrations in drinking water was calculated using equation ( 4) [8,20].…”

“…[2] determined the radon concentrations present in seventeen brands of sachet and bottled water packaged in Ile-Ife, South West Nigeria. [8] assessed the radon concentrations from samples of bottled water available in the Iraqi markets. A study conducted by [9] measured the levels of activity in radon-222 in water samples collected from different sachet water companies in Dutsin-Ma local government area of Katsina State, Nigeria.…”