Radionuclides of U, Th and K in Beach Sand of Southern Regions
Total Page：16
File Type：pdf, Size：1020Kb
Indian Journal of Pure & Applied Physics Vol. 55, March 2017, pp. 218-230 Radionuclides of 238 U, 232 Th and 40 K in beach sand of southern regions in Tamilnadu State, India (Post-Tsunami) J Punniyakotti a,b & V Ponnusamy b* aDepartment of Physics, Meenakshi Sundararajan Engineering College, Chennai 600 024, India bDepartment of Physics, Anna University (MIT campus), Chennai 600 044, India Received 1 March 2016; revised 20 August 2016; accepted 29 December 2016 The natural radioactivity content of 238 U, 232 Th and 40 K in beach sand of southern regions of Tamilnadu, India have been analyzed using gamma-ray spectroscopy. From the spectral analysis, the average radioactivity content of 238 U, 232 Th and 40 K in beach sand samples are 8.77 ±3.77, 76.48 ± 4.74 and 202.87 ± 26.72 Bq.kg -1, respectively. Univariate statistics has been applied successfully to assess the distribution of radionuclides and it shows that the decay series radionuclides such as 238 U and 232 Th are non-existence of normal distribution in the sands; however non-decay series radionuclide of 40 K is distributed uniformly. Radiological parameters such as absorbed dose rate, annual effective dose equivalent, annual gonadal dose equivalent, radium equivalent, hazard index, gamma index, activity utilization index, alpha index and excess lifetime cancer risk have been calculated to know the complete radiological status of the coastal sands. The results of the present study indicate that the natural radioactivity content in the beach sands do not pose any radiation effect to the members of public in the southern region of Tamilnadu coast. Keywords: Radionuclides, Radiological parameters, Tamilnadu, Post-Tsunami 1 Introduction The distribution of natural radioactivity content of Environs and Human being have been exposed by 238 U, 232 Th and 40 K in beach sand samples in different ionizing radiations continuously due to the presence Indian coastal segments have been studied by of naturally occurring primordial radionuclides many investigators such as Tripathi et al. 4 (Andhra (238 U and 232 Th and their daughter products and 40 K) coast), Ramasamy et al. 5 (Kerala coast), Narayana et in various geological formation like rocks, soil, beach al. 6 and Radhakrishna et al. 7 (Karnataka coast), sand, even in our building materials and homes 1,2 . Gusain et al. 8 (Odisha coast), Sengupta et al. 9, Human exposure to ionizing radiation is one of the Mohanty et al. 10 (Orissa coast), Kannan et al. 11 most-discussed scientific subjects that attract public (Kalpakkam coast) and Lakshmi et al. 12 (entire stretch attention. Hence, humans should be aware of their of Tamilnadu coast). natural environment with regard to the radiation Especially in Tamilnadu coastal region, the natural effects due to the naturally occurring and induced radioactivity content of 238 U, 232 Th and 40 K have been radioactive elements. The long term exposure to reported by few investigators as follows. Kannan uranium and its daughters through inhalation has et al. 11 had determined the activity content of 238 U, 232 40 several health effects such as chronic lung diseases, Th and K in the beach sand of Kalpakkam, acute leucopoenia, anemia and necrosis of the mouth. Tamilnadu and their average values are 124, 1613 -1 11 Thorium exposure may cause lung, pancreas, hepatic, and 358 Bq.kg , respectively . Subsequently, 12 bone, kidney cancers and leukemia 3. Lakshmi et al. had studied the entire east coast The natural radioactivity present in beach sand of Tamilnadu (length of the coast about 1000 km) 238 232 40 is a key source of external exposure that contributes to for the determination of U, Th and K in beach an increase in the environmental dose. Therefore, sand samples and reported the average activity 238 232 40 the content and distributions of naturally occurring content of U, Th and K are 40, 386 and 225 -1 12 radionuclides, and its associated dose rates in the Bq.kg , respectively . While the above two studies beach sand samples present in the coastal were carried out prior to the occurrence of Tsunami in environments should necessarily be monitored. December 2004 and hence the radioactivity profile —————— data obtained in these two studies would serve as base *Corresponding author (E-mail: [email protected]) line reference for pre-Tsunami. PUNNIYAKOTTI & PONNUSAMY: RADIONUCLIDES IN BEACH SAND OF TAMILNADU (POST-TSUNAMI) 219 After (Post-Tsunami), Ramasamy et al. 13 had collected 2 Materials and Method beach sand samples from Chennai to Port novo 2.1 Description of study area (Cuddalore) of the Tamilnadu coast and reported that The State of Tamilnadu is gifted with a beautiful the average activity content of 238 U= 8 Bq.kg -1, and resource-rich coastline and second longest coastal 232 Th=25 Bq.kg -1 and 40 K=275 Bq.kg -1. Kumar et al. 14 region in India after Gujarat 15 . Tamilnadu has a had collected beach sand samples from Pondicherry to coastal stretch of about 1000 km encompassed in 13 Velankanni and reported that the average activity coastal districts. The present study area covers a total content of 238 U= 18.4 Bq.kg -1, 232 Th =56.5 Bq.kg -1 and length of about 500 km (six coastal districts such as 40 K=285 Bq.kg -1. The above said studies covered Thanjavur, Pudukottai, Ramanathapuram, Tuticorin, about 490 km stretch of east coast of Tamilnadu. In Tirunelveli and Kanyakumari), from which 50 sites present study, rest of the Tamilnadu coastal length were selected and numbered as S1 to S50 (Table 1). about 500 km stretch was chosen and thus, the These 50 sites longitude and latitude with their name observed results (Present study) and reported results of the sites are shown in Table 1. The sampling sites (Ramasamy et al. 13 and Kumar et al. 14 ) will cover the were recorded in terms of degree-minute-second entire east coast of Tamilnadu which can be served as (Latitudinal and Longitudinal positions) using a hand- a baseline data to assess the radioactivity profile for held Global Positioning System (GPS) unit (Model: post-Tsunami. GARMIN GPS map76). Each site is separated by The objectives of this study are: (i) to determine about 10 km distance. The study area has broadly the activity content of 238 U, 232 Th and 40 K in beach been classified into northern part (Site numbers S1 to sands of southern region of Tamilnadu, India (ii) S25) and southern part of study area (Site numbers assess the spatial distribution of radionuclides in the S26 to S50). study area using univariate statistical analysis and (iii) Importance of the coastal region of the present study calculate the important radiological parameters to area is as follows. Aquaculture farms are main activity assess the complete radiological status of the coastal in the coastal districts of Thanjavur and Pudukottai. In sands of southern region of Tamilnadu, India. Thanjavur and Pudukottai coastal districts, trace of Table 1 – Name of the sites along with their longitude(E) and latitude(N) coordinates SiteNo Name of the site Longitude (E) Latitude (N) SiteNo Name of the site Longitude (E) Latitude (N) S1 Adhiramapatinam 79° 22’ 58.32’’ 10° 18’ 55.20’’ S26 Vaipar 78° 17’ 12.24’’ 09° 00’ 58.38’’ S2 Manora 79° 18’ 13.44’’ 10° 15’ 56.22’’ S27 Sippikulam 78° 15’ 09.00’’ 08° 59’ 39.36’’ S3 Adaikadevan 79° 15’ 35.88’’ 10° 11’ 38.04’’ S28 Pattana Maruthur 78° 11’ 09.78’’ 08° 55’ 21.96’’ S4 Manalmelkudi 79° 15’ 59.82’’ 10° 02’ 17.22’’ S29 Vallaipatti 78° 10’ 00.06’’ 08° 51’ 25.20’’ S5 Kottaipattinam 79° 11’ 56.88’’ 09° 58’ 19.26’’ S30 Muthunagar 78° 09’ 46.26’’ 08° 48’ 25.68’’ S6 Gopalapatinam 79° 09’ 09.24’’ 09° 55’ 29.82’’ S31 Pazhayakayal 78° 06’ 16.80’’ 08° 40’ 14.70’’ S7 Pasipattinam 79° 05’ 21.66’’ 09° 49’ 32.04’’ S32 Kayalpatinam 78° 07’ 59.04’’ 08° 33’ 39.84’’ S8 Thondi 79° 01’ 14.70’’ 09° 44’ 29.10’’ S33 Veeramapatinam 78° 07’ 22.86’’ 08° 30’ 58.20’’ S9 Devipatinam 78° 54’ 00.72’’ 09° 28’ 12.24’’ S34 Tiruchendur 78° 07’ 36.30’’ 08° 29’ 28.74’’ S10 Athiyuthu 78° 56’ 15.78’’ 09° 24’ 31.86’’ S35 Alanthazhai 78° 06’ 09.24’’ 08° 27’ 59.04’’ S11 Athankarai 78° 59’ 45.60’’ 09° 20’ 47.70’’ S36 Kallamoli 78° 04’ 43.32’’ 08° 25’ 17.40’’ S12 Rameswaram 79° 19’ 16.86’’ 09° 17’ 23.76’’ S37 Kulasekharapatnam 78° 03’ 33.66’’ 08° 23’ 48.00’’ S13 Rameswaram Dock 79° 10’ 41.04’’ 09° 16’ 51.96’’ S38 Manapad 78° 03’ 41.94’’ 08° 22’ 29.46’’ S14 Chathiram 79° 22’ 50.40’’ 09° 11’ 58.44’’ S39 Periyathazhai 77° 58’ 29.94’’ 08° 20’ 05.82’’ S15 Dhanuskodi 79° 21’ 18.30’’ 09° 12’ 57.30’’ S40 Kooduthazhai 77° 55’ 37.08’’ 08° 17’ 51.60’’ S16 Vadalai 79° 06’ 32.46’’ 09° 15’ 54.42’’ S41 Uvari 77° 53’ 34.92’’ 08° 16’ 40.62’’ S17 Periyapatinam 78° 55’ 18.90’’ 09° 15’ 48.84’’ S42 Kuthenkuly 77° 46’ 57.72’’ 08° 13’ 02.70’’ S18 Sethukkarai 78° 50’ 36.54’’ 09° 14’ 54.00’’ S43 Idinthakarai 77° 44’ 34.62’’ 08° 10’ 34.08’’ S19 Keelakarai 78° 47’ 01.68’’ 09° 13’ 34.38’’ S44 Perumanal 77° 38’ 43.44’ 08° 09’ 30.66’’ S20 Earvadi 78° 43’ 09.84’’ 09° 11’ 39.42’’ S45 Chettikulam 77° 37’ 16.02’ 08° 09’ 09.30’’ S21 Valinokkam 78° 37’ 47.22’’ 09° 09’ 15.12’’ S46 Kootapuli 77° 36’ 12.00’ 08° 08’48.24’’ S22 Keezhamundal 78° 35’ 09.48’’ 09° 08’ 15.90’’ S47 Vattakotai Beach 77° 33’ 58.86’ 08° 07’ 35.82’’ S23 Oppilan 78° 30’ 16.56’’ 09° 07’ 59.58’’ S48 Lakshmipuram 77° 33’ 25.56’ 08° 06’ 35.82’’ S24 Mookaiyur 78° 28’ 44.82’’ 09° 07’ 40.08’’ S49 Chinnamuttom 77° 33’ 34.08’ 08° 05’ 44.64’’ S25 Vembar 78° 21’ 53.76’’ 09° 04’ 34.92’’ S50 Vavaturai Beach 77° 33’ 09.48’ 08° 05’ 01.20’’ 220 INDIAN J PURE & APPL PHYS, VOL 55, MARCH 2017 mangroves are affected by chemical wastes from the EG&G ORTEC, USA) is used for gamma spectral aquaculture farms.