Environ Monit Assess (2015) 187:356 DOI 10.1007/s10661-015-4501-y
Natural radionuclides in soil near a coal-fired power plant in the high background radiation area, South China Guoqing Liu & Qi Luo & Mingxia Ding & Jiangping Feng
Received: 10 October 2014 / Accepted: 1 April 2015 # Springer International Publishing Switzerland 2015
Abstract In this study, soil samples around Mawan coal-fired power plant (CFPP) in Shenzhen, a high background radiation area in South China, were analyzed for natural radionuclides. The activity concentration of 226Ra, 232Th, and 40K in soils around Mawan CFPP ranged from approximately 72 to 358 Bq kg−1 (averaged 204 Bq kg−1), 118 to 432 Bq kg−1 (averaged 265 Bq kg−1), and 101 to 2168 Bq kg−1 (averaged 1269 Bq kg−1), respectively, being found to be significantly higher than the world range values. The levels of these radionuclides in soil largely decreased with increasing distance from the CFPP, indicating a technologically enhanced natural radiation near the CFPP. The Raeq values for the soil samples around Mawan CFPP ranged from 346 to 878 Bq kg−1, most of which exceeded the allowed maximum Ra eq value of 370 Bq kg−1. The operating of CFPP has increased the total radioactive dose received for the nearby population.
Keywords CFPP . Soil . Natural radionuclide . High background radiation area . Shenzhen G. Liu (*) : Q. Luo : M. Ding Institute of Applied Nuclear Technology, Shenzhen University, Nanhai Ave 3688, Shenzhen, Guangdong 518060, People’s Republic of China e-mail: [email protected] J. Feng Shenzhen Environmental Protection Monitoring Station, Shenzhen, Guangdong 518049, People’s Republic of China
Introduction Coal, the most abundant natural resource and fossil fuel, plays an important role in electricity generation; it is estimated that approximately 25 % of the world’s energy consumption was derived from the combustion of coal (Bhuiyan et al. 2010). Much of the environmental concerns regarding coal-fired power plant (CFPP) focus on emissions of pollutants such as SO2, CO2, and NOx, organic compounds like polycyclic aromatic hydrocarbons (PAHs), trace metals, particles, and ash disposal (Papaefthymiou 2008; Liu et al. 2008). Coal, like most materials found in nature, contains the natural radionuclides 226Ra, 232Th, and 40K. In the process of coal combustion, these radionuclides can be released as fly ash from the CFPP with an enrichment factor of 5–10 times (Flues et al. 2006), which can cause additional radiation exposures to the public living and working in the immediate vicinity of the CFPP (Mondal et al. 2006). Since Eisenbud and Petro (1964) first pointed out that the radiation dose from the use of fossil fuel for power generation could be a significant addition to the natural radiation dose, the impact of environmental radioactivity from CFPP has been a continuous subject of concern (Bem et al. 2002). Studies on the radioactivity levels in coal and ash and the radioactive influence of CFPP on ambient environment has been well documented in recent years, especially in countries as Brazil, Spain, Greece, Turkey, and China (Flues et al. 2002; Cevik et al. 2007, 2008; Papastefanou 2010; Lu et al. 2012a, b). Soil serves as the primary reservoir for radionuclides in the terrestrial environment. A number of studies concerning soil
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contamination around CFPPs have revealed nonsignificant radioactive impact (Lu et al. 2014; Charro et al. 2013a, b; Papaefthymiou et al. 2013), whereas several studies have reported a possible influence (Bem et al. 2002; Flues et al. 2002; Papp et al. 2002; Dai et al. 2007). In Figueira Brazil (Flues et al. 2002) and Aska Hungary (Papp et al. 2002), significant radioactive contamination were found in soil around CFPPs, largely due to the unusually high concentration of 238U (and 226Ra) in the burnt coal. Recently, elevated concentration of 226Ra, 232 Th, and 40K was also found in soil around a thermal power plant fueled predominantly by bituminous coal in Malaysia (Amin et al. 2013). Nowadays, coal burning still plays a major role in electric generation throughout the world; the impact of environmental radioactivity from CFPP still need further study. China is the largest coal producer and consumer in the world. It has been estimated that more than 75 % of the energy production in China is based on coal (Lu et al. 2013) and more than 400 million people in China rely on coal for their domestic energy needs, such as heating and daily cooking. In the past few years, several studies have been undertaken concerning the impact of coal-fired power plants on the radioactivity levels in their vicinity (Dai et al. 2007; Lu et al. 2012a, b, 2013). However, few studies have been performed in South China. Guangdong province in South China is known as a high background radiation area; the level of 238 U and 232Th are high in soils of Guangzhou, Yangjiang, Zhuhai, and Shenzhen city (Wang 2002; Shi et al. 2010). Natural radionuclides in soil represent the significant component of background exposure of the general population, and exposure to external radiation from contaminated soil is a central focus of health risk assessment. The main objective of this study is to determine the activity concentration of 226Ra, 232Th, and 40 K in soil around a CFPP in Shenzhen, to understand the natural radioactivity background levels, and to estimate the radioactive influence of CFPP on the ambient environment, as well as the total radioactive dose received for the nearby population.
Material and method Study area Situated in the south of the Pearl River Delta in China’s Guangdong Province, Shenzhen is a Special Economic
Environ Monit Assess (2015) 187:356
Zone (SEZ) and one of the most important industrial centers in China, with an area of 2021 km2 and a population approaching ten million. The surface deposits that formed since the Late Quaternary mainly consist of arene, medium-sized arentilla, or silty sand and silty clay (Wang et al. 2012). The intrusive rocks include the Middle and Late Jurassic and Cretaceous biotitic-granite and granodiorite. Since the establishment of the SEZ in 1980, Shenzhen has made rapid economic progress; its gross domestic product (GDP) surpassed $237 billion in 2013, with an average annual GDP growth rate of 26.9 % in the past 30 years. Shenzhen has a subtropical monsoon climate; winters are short, mild, and relatively dry, while summers are long, hot, and very wet. Located at Shenzhen’s western port area, Mawan CFPP serves as an important power supply of Shenzhen city; it consists of 6×300 MW coal-fired units, has three stacks (180 m height), and has been operating for more than 20 years since 1993. The daily consumption of coal in Mawan CFPP is about 14000 t, the coal used in the plant is mainly from North China, and some are imported from abroad. Sample collection and preparation Soil samples were collected around Mawan CFPP from 43 sites at the distance of
Natural radionuclides in soil near a coal-fired power plant in the high background radiation area, South China Guoqing Liu & Qi Luo & Mingxia Ding & Jiangping Feng
Received: 10 October 2014 / Accepted: 1 April 2015 # Springer International Publishing Switzerland 2015
Abstract In this study, soil samples around Mawan coal-fired power plant (CFPP) in Shenzhen, a high background radiation area in South China, were analyzed for natural radionuclides. The activity concentration of 226Ra, 232Th, and 40K in soils around Mawan CFPP ranged from approximately 72 to 358 Bq kg−1 (averaged 204 Bq kg−1), 118 to 432 Bq kg−1 (averaged 265 Bq kg−1), and 101 to 2168 Bq kg−1 (averaged 1269 Bq kg−1), respectively, being found to be significantly higher than the world range values. The levels of these radionuclides in soil largely decreased with increasing distance from the CFPP, indicating a technologically enhanced natural radiation near the CFPP. The Raeq values for the soil samples around Mawan CFPP ranged from 346 to 878 Bq kg−1, most of which exceeded the allowed maximum Ra eq value of 370 Bq kg−1. The operating of CFPP has increased the total radioactive dose received for the nearby population.
Keywords CFPP . Soil . Natural radionuclide . High background radiation area . Shenzhen G. Liu (*) : Q. Luo : M. Ding Institute of Applied Nuclear Technology, Shenzhen University, Nanhai Ave 3688, Shenzhen, Guangdong 518060, People’s Republic of China e-mail: [email protected] J. Feng Shenzhen Environmental Protection Monitoring Station, Shenzhen, Guangdong 518049, People’s Republic of China
Introduction Coal, the most abundant natural resource and fossil fuel, plays an important role in electricity generation; it is estimated that approximately 25 % of the world’s energy consumption was derived from the combustion of coal (Bhuiyan et al. 2010). Much of the environmental concerns regarding coal-fired power plant (CFPP) focus on emissions of pollutants such as SO2, CO2, and NOx, organic compounds like polycyclic aromatic hydrocarbons (PAHs), trace metals, particles, and ash disposal (Papaefthymiou 2008; Liu et al. 2008). Coal, like most materials found in nature, contains the natural radionuclides 226Ra, 232Th, and 40K. In the process of coal combustion, these radionuclides can be released as fly ash from the CFPP with an enrichment factor of 5–10 times (Flues et al. 2006), which can cause additional radiation exposures to the public living and working in the immediate vicinity of the CFPP (Mondal et al. 2006). Since Eisenbud and Petro (1964) first pointed out that the radiation dose from the use of fossil fuel for power generation could be a significant addition to the natural radiation dose, the impact of environmental radioactivity from CFPP has been a continuous subject of concern (Bem et al. 2002). Studies on the radioactivity levels in coal and ash and the radioactive influence of CFPP on ambient environment has been well documented in recent years, especially in countries as Brazil, Spain, Greece, Turkey, and China (Flues et al. 2002; Cevik et al. 2007, 2008; Papastefanou 2010; Lu et al. 2012a, b). Soil serves as the primary reservoir for radionuclides in the terrestrial environment. A number of studies concerning soil
356
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contamination around CFPPs have revealed nonsignificant radioactive impact (Lu et al. 2014; Charro et al. 2013a, b; Papaefthymiou et al. 2013), whereas several studies have reported a possible influence (Bem et al. 2002; Flues et al. 2002; Papp et al. 2002; Dai et al. 2007). In Figueira Brazil (Flues et al. 2002) and Aska Hungary (Papp et al. 2002), significant radioactive contamination were found in soil around CFPPs, largely due to the unusually high concentration of 238U (and 226Ra) in the burnt coal. Recently, elevated concentration of 226Ra, 232 Th, and 40K was also found in soil around a thermal power plant fueled predominantly by bituminous coal in Malaysia (Amin et al. 2013). Nowadays, coal burning still plays a major role in electric generation throughout the world; the impact of environmental radioactivity from CFPP still need further study. China is the largest coal producer and consumer in the world. It has been estimated that more than 75 % of the energy production in China is based on coal (Lu et al. 2013) and more than 400 million people in China rely on coal for their domestic energy needs, such as heating and daily cooking. In the past few years, several studies have been undertaken concerning the impact of coal-fired power plants on the radioactivity levels in their vicinity (Dai et al. 2007; Lu et al. 2012a, b, 2013). However, few studies have been performed in South China. Guangdong province in South China is known as a high background radiation area; the level of 238 U and 232Th are high in soils of Guangzhou, Yangjiang, Zhuhai, and Shenzhen city (Wang 2002; Shi et al. 2010). Natural radionuclides in soil represent the significant component of background exposure of the general population, and exposure to external radiation from contaminated soil is a central focus of health risk assessment. The main objective of this study is to determine the activity concentration of 226Ra, 232Th, and 40 K in soil around a CFPP in Shenzhen, to understand the natural radioactivity background levels, and to estimate the radioactive influence of CFPP on the ambient environment, as well as the total radioactive dose received for the nearby population.
Material and method Study area Situated in the south of the Pearl River Delta in China’s Guangdong Province, Shenzhen is a Special Economic
Environ Monit Assess (2015) 187:356
Zone (SEZ) and one of the most important industrial centers in China, with an area of 2021 km2 and a population approaching ten million. The surface deposits that formed since the Late Quaternary mainly consist of arene, medium-sized arentilla, or silty sand and silty clay (Wang et al. 2012). The intrusive rocks include the Middle and Late Jurassic and Cretaceous biotitic-granite and granodiorite. Since the establishment of the SEZ in 1980, Shenzhen has made rapid economic progress; its gross domestic product (GDP) surpassed $237 billion in 2013, with an average annual GDP growth rate of 26.9 % in the past 30 years. Shenzhen has a subtropical monsoon climate; winters are short, mild, and relatively dry, while summers are long, hot, and very wet. Located at Shenzhen’s western port area, Mawan CFPP serves as an important power supply of Shenzhen city; it consists of 6×300 MW coal-fired units, has three stacks (180 m height), and has been operating for more than 20 years since 1993. The daily consumption of coal in Mawan CFPP is about 14000 t, the coal used in the plant is mainly from North China, and some are imported from abroad. Sample collection and preparation Soil samples were collected around Mawan CFPP from 43 sites at the distance of
