Impact of meteorological parameters on soil radon at Kolkata, India: investigation using machine learning techniques.

The daily soil radon activity has been measured continuously over a year with BARASOL BMC2 probe at a measuring site of Jadavpur University Campus in Kolkata, India. The dependency of soil radon activity with different atmospheric parameters such as soil temperature, soil pressure, humidity, air temperature, and rainfall has been also analyzed. The whole study period is divided in four seasons as proposed by the Indian Meteorological Department (IMD). Minimum soil radon level has been observed during the winter season (December-February). On the other hand, higher soil radon level has been observed both for summer and monsoon. Except soil pressure, all other variables have shown positive correlation with soil radon activity. Among five variables, soil temperature has been the most significant variable in terms of correlation with soil radon level whereas maximum humidity has been the least significant correlated variable. It has been observed that considerable reduction of soil radon level occurred after four heavy rainfall events during the study period. The combined effect of these multi-parameters on soil radon gas has been evaluated using machine learning methods like principal component regression (PCR), support vector regression (SVR), random forest regression (RF), and gradient boosting machine (GBM). In terms of performances, RF and GBM have performed much better than SVR and PCR. More robust and consistent results have been obtained for GBM during both training and testing periods.

Elevated radon level in drinking water of Ajodhya Hill Area of West Bengal, India: probable health impact on lung and stomach.

A screening survey has been carried out to measure the radon concentration in drinking water at various locations of Ajodhya hill and surrounding areas in Purulia district of West Bengal, India, using AlphaGUARD radon monitor. The obtained 222Rn concentration in ground water varies from 5.71 ± 0.29 to 579.47 ± 23.18 Bq/l with an average of 110.00 ± 6.61 Bq/l. Comparison between our results with the internationally recommended reference levels reveals that drinking of water from the majority of these tube-wells can pose significant health risks to the local people. Correlation study indicates that tube-well depth has significant influence on the radon level in water samples. Using 60 l/yr and 1642.50 l/yr water consumption estimated annual effective radon doses for most of the samples (almost 70% and 96%, respectively) are high compared to the World Health Organization (WHO) and the European Union (EU) Commission prescribed reference dose limit of 100 µSv/yr. Also, the evaluated Excess Lifetime Cancer Risk (ELCR) values associated with the tube-wells are showing serious threat to the health of the locals.The primary goal of this work is to develop a radon profile map of this area and to find out the possible reasons behind the elevated radon level in ground water. This type of work may play a very crucial role to aware the locals in perspective of human exposure to radon. The local health officials and the water quality regulators of India are requested to take necessary steps for protecting the local people from water radon hazard.

A systematic review on groundwater radon distribution with human health consequences and probable mitigation strategy.

Groundwater radon contamination is a serious global concern for its eco-toxicological effects. The major health hazard occurs due to toxic indoor air inhalation and consumption of contaminated drinking water supplied from different distribution systems, especially groundwater. There are fragmented reports on the measurement of radon contamination and their health consequences with physical radon removal strategies as well as characterization of inhabitant microbial communities. As it concerned with human health, collective information is much essential on their groundwater distribution, their physicochemical properties and possible mitigation strategies, not done so far. In such prospect, this review summarizes the physicochemical properties of radon, their sources, global as well as Indian groundwater radon contamination scenario, health effects and inhabitant microbes along with their survival strategies. It also summarizes the physical radon removal techniques and especially emphasizes the microbes based bioremediation process as well as a combination of both as a future effective radon remediation process.

Water radon risk in Susunia hill area: an assessment in terms of radiation dose.

Radiological impact of radon in air is a global issue whereas radon in water has local consequences. Considering its importance, we have conducted a study on radon activity measurements in 316 tube-well water samples collected from Susunia hill area in Bankura district of West Bengal, India during the period of 25th December 2018-2nd February 2020. Radon contents are measured using AlphaGUARD radon monitor. The obtained radon activities in drinking water samples lie between 1.78 ± 0.07 and 3213.50 ± 77.32 Bq/l with an average of 128.30 ± 14.09 Bq/l. This study reveals that 93% of the samples have radon levels in excess of the USEPA proposed maximum contamination level (MCL) of 11.1 Bq/l while radon levels of 40% samples have exceeded the WHO and EU Council Directive recommended reference level of 100 Bq/l. The total annual effective dose of the samples have been estimated by considering the per day water intake of 3 l. The calculated total annual effective dose widely fluctuates between 10.39 and 18649.55 µSv/year with an average value of 744.59 µSv/year. 269 water samples have exceeded the WHO and EU Council Directive recommended reference level of 100 µSv/year. However, if we consider the UNSCEAR prescribed annual water intake of 60 l, the average dose becomes 279.82 µSv/year. The situation demands attention of the local authorities. Local people are advised to take some easy preventive measures for their radiological protection against such contamination.

Monitoring of soil radon by SSNTD in Eastern India in search of possible earthquake precursor.

The present paper deals with monitoring soil radon-222 concentration at two different locations, designated Site A and Site B, 200 m apart at Jadavpur University campus, Kolkata, India, with a view to find possible precursors for the earthquakes that occurred within a few hundred kilometers from the monitoring site. The solid state nuclear track detector CR-39 has been used for detection of radon gas coming out from soil. Radon-222 time series at both locations during the period August 2012-December 2013 have been analysed. Distinct anomalies in the soil radon time series have been observed for seven earthquakes of magnitude greater than 4.0 M that occurred during this time. Of these, radon anomalies for two earthquakes have been observed at both locations A and B. Absence of anomalies for some other earthquakes has been discussed, and the observations have been compared with some earthquake precursor models.

RADIOLOGICAL IMPACT OF SOME COMMON FOODS OF SOUTHERN PART OF WEST BENGAL, INDIA.

An appreciable portion of human exposure to natural radioactivity comes from food and drinking water. Gross alpha radioactivity has been measured in thirty one food items consumed almost every day by the people of southern part of West Bengal, India, by using the solid state nuclear track detector LR-115. The annual effective doses due to intake of alpha-emitting radionuclides through these food items have also been estimated, and the total average annual dose received by an adultthrough ingestion of these foodstuffs calculated, considering the food habit of the people of the region. The total average annual dose is below the 1 mSv y-1 limit proposed by WHO, and over half of this annual dose comes from consumption of cereals.

Assessment of alpha radioactivity and dose estimation in widely used medicinal plants environmental monitoring of afforestation.

This paper reports the presence of alpha radioactivity in a few medicinal plants, which form the main components of some hebal drugs. Assessment of effective dose has also. been done. The total alpha radio activity in medicinal plants has been found within 47 - 245 Bq/Kg and the effective dose found in the range 2.8 - 4.7 µSv. This data is required for environmental monitoring.

Assessment of real time traffic noise attenuation by tree belts within Kolkata city (India).

The study of the existing scenario of the effect of trees and shrubs as urban screen plantings for abating the level of real time traffic-induced noise pollution in Kolkata city deserves extreme importance. However, no such data are available till date in this area. This paper reports the result of a preliminary study to assess the attenuation of real time traffic noise by tree belts at three different important locations of the city. This measurement provides some new and interesting data which will be useful for further study and subsequent plan.

Measurement of alpha radioactivity and dose assessment in common food crops with SSNTD.

Radioactivity is present everywhere in the environment including soil, from where it transfers to vegetation and plants. These vegetations when taken as food result in transfer of the radioactivity to human beings which may cause health hazards. Thus information about the presence of radioactivity in vegetation, plants and soil is highly desirable. In this context, measurements of alpha radioactivity present in soil as well as in some of the staple food crops which form the main components of the composite Indian diet are presented in this study. Assessment of effective dose rate has also been done. The total alpha activity in soil has been found within 100-700 Bq kg(-1) and in food within 10-200 Bq kg(-1). The annual effective dose rate in food crops has been estimated in the range of 0.8-300 ì S v.

Assessment of alpha radioactivity in lipstick, nailpolish, toothpaste and vermilion using CR-39 detector.

Human beings are always exposed to radiation from chemical cosmetics. In order to collect information regarding the radioactivity of chemical cosmetics used in our daily life, we studied the alpha radioactivity in different cosmetics samples, such as lipsticks, nail-polish, toothpaste and vermilion. The significant accumulation ofradionuclide in and on the tissues, directly or indirectly exposed due to the lipsticks, toothpaste, vermilion, may cause health hazards. Different samples of these cosmetic materials (Indian and foreign brands) were collected from the local markets of Kolkata, India. CR-39--a useful solid state nuclear track detector (SSNTD) was used to detect alpha radioactivity of these samples. Such exhaustive measurement of radioactivity in lipsticks, nail-polish, toothpaste and vermilion has not been reported so far.

Measurement of natural radioactivity in chemical fertilizer and agricultural soil: evidence of high alpha activity.

People are exposed to ionizing radiation from the radionuclides that are present in different types of natural sources, of which phosphate fertilizer is one of the most important sources. Radionuclides in phosphate fertilizer belonging to 232Th and 238U series as well as radioisotope of potassium (40K) are the major contributors of outdoor terrestrial natural radiation. The study of alpha activity in fertilizers, which is the first ever in West Bengal, has been performed in order to determine the effect of the use of phosphate fertilizers on human health. The data have been compared with the alpha activity of different types of chemical fertilizers. The measurement of alpha activity in surface soil samples collected from the cultivated land was also performed. The sampling sites were randomly selected in the cultivated land in the Midnapore district, which is the largest district in West Bengal. The phosphate fertilizer is widely used for large agricultural production, mainly potatoes. The alpha activities have been measured using solid-state nuclear track detectors (SSNTD), a very sensitive detector for alpha particles. The results show that alpha activity of those fertilizer and soil samples varies from 141 Bq/kg to 2,589 Bq/kg and from 109 Bq/kg to 660 Bq/kg, respectively. These results were used to estimate environmental radiation exposure on human health contributed by the direct application of fertilizers.

Assessment of alpha activity of building materials commonly used in West Bengal, India.

This paper, reports for the first time, an extensive study of alpha activity of all widely used building materials (plaster of Paris, stone chips, marble, white cement, mosaic stone, limestone, sand, granite, cement brick, asbestos, red brick, cement tile, ceramic tile and ceramics) in West Bengal, India. The alpha activities have been measured using Solid State Nuclear Track Detector (SSNTD), a very sensitive detector for alpha particles. The samples were collected from local markets of Kolkata. The measured average alpha activities ranged from 22.7+/-2.5 to 590.6+/-16.8Bqkg(-1). The alpha activity of ceramic tiles was highest and provides additional data to estimate the effect of environmental radiation exposure on human health.