A. G. Hegde

Soil to leaf transfer factor for the radionuclides 226Ra, 40K, 137Cs and 90Sr at Kaiga region, India

Transfer factors are the most important parameters required for mathematical modeling used for environmental impact assessment of radioactive contamination in the environment. In this paper soil to leaf transfer factor for the radionuclides ⁴⁰K, ²²⁶Ra, ¹³⁷Cs and ⁹⁰Sr is estimated for Kaiga region in Karnataka state, India. Among the plants in which study is carried out, ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr activity in leaves of herbaceous plants is higher than that of tree leaves. Soil to leaf transfer factor for ²²⁶Ra, ⁴⁰K, ¹³⁷Cs and ⁹⁰Sr was found to be in the range of 0.03-0.65, 0.32-8.04, 0.05-3.03 and 0.42-2.67 respectively.

Application of Cherenkov radiation counting for determination of 90Sr in environmental samples.

Abstract Cherenkov radiation produced by the hard β -emitter 90Y was measured by using a commercial liquid scintillation analyser (LSA) for determination of 90Sr in environmental samples. The conventionally used chemical procedures for separation of 90Sr were simplified and a non-destructive Cherenkov assay method (NDCA) was developed. The analytical procedures and measurement techniques were tested by participating in the quality assurance programme conducted by the International Reference Centre (IRC, France) for the determination of 90Sr in diet and IAEA soil samples. The paper presents the methodologies developed for determination of 90Sr in several matrices such as fresh water, soil, grass, seaweed, diet and air filter samples. The results were compared with those by the conventional nitrate method, showing an excellent agreement.

Evaluation and assessment of 25 years of environmental radioactivity monitoring data at Tarapur (India) nuclear site

The evaluation and assessment of monitoring data generated over a period of 1983-2007 (25 years) of a nuclear facility is presented. Time trends of particulate radioactivity, correlation between (137)Cs in discharge canal seawater and station discharged activity and correlation of (137)Cs, (60)Co, and (131)I in marine species such as sponge and Nerita (gastropod) and corresponding discharged activity are discussed. The concentration of (137)Cs and (131)I in seawater versus biota are discussed. A good correlation between (137)Cs in seawater and (137)Cs in liquid waste discharged was observed (R(2) = 0.8, p < 0.001). Similarly, correlation was good for Nerita and discharged concentration of (137)Cs, (131)I and (60)Co (R(2) = 0.55-0.73 and p < 0.001). The measurements over the years indicated that there is no accumulation of radionuclides in either the terrestrial or aquatic environments. The mean (137)Cs decreased from the pre-operational levels: 7.0-3.6 Bq kg(-1) in soil, 0.91-0.016 Bq L(-1) in milk and 0.28-0.036 Bq kg(-1) in vegetation. Similarly, the mean (90)Sr in these matrixes decreased from 3.9 to 0.26 Bq kg(-1); 0.37-0.011 Bq L(-1) and 0.34-0.022 Bq kg(-1) respectively. Cesium-137 of about 700 microBq m(-3) was measured in the air filter disks during 1986 and there was a decrease of three orders of magnitude in concentration over the 25 years. The evaluation of environmental data indicated that the radionuclide concentrations and potential impacts, in terms of effective dose to the members of public, have significantly reduced since 1969.

Assessment of radiological significance of naturally occurring radionuclides in soil and rock matrices around Kakrapar environment

The activity and gamma-absorbed dose rate due to the naturally occurring radionuclides in the terrestrial environment such as (238)U, (232)Th and (40)K were determined in soil and rock samples collected around Kakrapar Atomic Power Plant site, using gamma-ray spectrometry. The mean concentration levels measured in Kakrapar soil from naturally occurring radioisotopes such as (238)U, (232)Th and (40)K are lower than the corresponding global average values obtained in worldwide soil. The external hazard index (H(ex)) and absorbed gamma dose rate in air outdoors is observed to be 0.04-0.18 and 3.1-14.1 nGy h(-1), respectively.

Measurement of High Energy Gross Beta and 40K by Cerenkov Counting in Liquid Scintillation Analyser

The Environmental Survey Laboratory is responsible for the monitoring of radioactivity due to natural and artificially produced radionuclides in a variety of samples available around the nuclear facilities at Tarapur. Standard methods of radiochemical separation and counting are followed to determine β-emitters in various matrices. To make the measurement simple and detect lower levels of contamination in some of the matrices, a method was developed to measure the high energy gross β-activity primarily due to 90Y in borehole water and urine samples of occupational workers by Cerenkov counting in a liquid scintillation analyser. Cerenkov counting results of borehole samples were compared with the total gross β-activity measured by a low background beta-counter. The combined measurements were used to evaluate 90Sr and 137Cs levels without chemical separation or gamma-spectrometry. Cerenkov counting technique was also utilised to evaluate 40K in drinking water and intercomparison water samples. The paper presents the methodology and results of a few measurements using the technique.

Olanzapine-Associated Leukopenia and Thrombocytopenia Managed With Lithium in a Patient Who Developed Leukopenia With Clozapine in the Past: A Case Report

To the Editor: There are very few case reports of thrombocytopenia associated with olanzapine.1–7 We present a case of a man who developed leukopenia with clozapine and later had recurrence of leukopenia with olanzapine. Additionally, the leukopenia that developed during olanzapine treatment was accompanied by thrombocytopenia. Case report. Mr A, a 23-year-old man, presented with an illness of 3 years’ duration suggestive of paranoid schizophrenia (DSM-IV) along with sustained neck dystonia due to paliperidone use. He had partial response to an adequate trial of quetiapine and a course of electroconvulsive therapy (ECT); as a result, clozapine was considered. Prior to consideration of clozapine, hemogram revealed no abnormality. Clozapine was started at 12.5 mg/d and was increased by 12.5 mg/d at each increment after 3 or 4 days depending on tolerability. When the dosage of clozapine was increased to 87.5 mg/d, hemogram revealed, for the first time, evidence of leukopenia without thrombocytopenia. As a result, clozapine was stopped, and illness was managed only with lorazepam. After clozapine was stopped, hemogram normalized. Over the next 3 weeks, repeated hemogram revealed no abnormality. In view of the patient’s past history of extrapyramidal side effects (neck dystonia) and of his partial response to quetiapine, olanzapine was chosen. Prior to his starting olanzapine, his total leukocyte count was 6,900/dL and platelet count was 200,000/dL. Two weeks after start of olanzapine at a dosage of 7.5 mg/d, hemogram revealed, for the first time, leukopenia (total leukocyte count, 2,700/dL), which was accompanied by thrombocytopenia (platelet count, 20,000/dL). There was no evidence of fever, skin rash, or any infective focus or history of intake of any other medications other than lorazepam preceding either incidence, ie, when he developed leukopenia with clozapine and when he developed leukopenia and thrombocytopenia with olanzapine. Olanzapine was stopped. The possibility of drug-induced leukopenia and thrombocytopenia was considered. Following this, he was started on treatment with lithium, which was gradually increased to 600 mg/d to manage his agitation and low blood counts. Within a few days, his total leukocyte count recovered to 4,600/dL and his platelet count was 140,000/dL. In the next 2 weeks, his total leukocyte count and platelet count increased to 7,000/dL and 220,000/dL, respectively. After the risk of recurrence of hematologic abnormalities was explained and the pros and cons were weighed, an informed decision was made to restart olanzapine along with continuation of lithium (600 mg/d). Gradually, olanzapine was increased to 7.5 mg/d. With this combination, he achieved remission without recurrence of hematologic abnormalities. Thrombocytopenia is defined as platelet count less than 150,000/dL. In our literature search, we could find only 7 case reports of olanzapine-associated thrombocytopenia (see Table 1).1–7 In 2 of the 7 case reports, thrombocytopenia was seen in the background of idiopathic thrombocytopenic purpura, and in 1 case report, thrombocytopenia was seen in the presence of folate deficiency. In all cases, thrombocytopenia improved after removal of the offending agent. Additionally, prednisolone in 1 case report and folic acid supplementation in another were used to manage thrombocytopenia. Besides these case reports, Tu and Yang8 reported an interesting case of olanzapine-induced ethylenediaminetetraacetic acid–dependent pseudothrombocytopenia.8 Table 1. Case Reports of Olanzapine-Induced Thrombocytopenia Previous reports have shown that subjects who develop blood dyscrasias with clozapine can have recurrence of blood dyscrasias9 or can have prolonged deranged blood counts10–12 when started on olanzapine treatment. Structural similarities in clozapine and olanzapine have been hypothesized as a possible reason of development of hematologic abnormalities in subjects initially treated with clozapine and subsequently treated with olanzapine.13 Fortunately, in our case, rechallenge with olanzapine while the patient was on lithium treatment did not result in recurrence of thrombocytopenia. Our case reflects that, in rare cases, especially in those who develop leukopenia with clozapine treatment, olanzapine can lead to leukopenia and thrombocytopenia; hence, close hematologic monitoring should be considered in such cases.

Arachnoid cyst masquerades as late onset obsessive–compulsive disorder

Literature evidence suggests that onset of obsessive-compulsive disorder (OCD) at a later age is usually associated with brain lesions. However, none of previous reports suggest an association between arachnoid cyst and OCD. In this report, we present a case of OCD, starting at the age of 40 years, in which the obsessive symptoms were characteristically associated with fluctuating insight. Investigation revealed an arachnoid cyst, in the area of left fronto-parietal region, with broad base towards the falx.

Transfer coefficient of 137Cs from feed to cow milk in tropical region Kaiga, India.

In the transport model for the prediction of the concentration of (137)Cs in milk, the transfer coefficient from feed to milk, F(m), is an important parameter. Site-specific transfer coefficient from feed to cows milk, for (137)Cs in the Kaiga environment, a nuclear power station site in India, determined over a period of 10 y is presented in this paper. The value is determined from (137)Cs concentration in milk and grass samples of the Kaiga region and the result ranged from 6.43E-03 to 1.09E-02 d l(-1) with a geometric mean value of 8.0E-03 d l(-1). The result is compared with that for (40)K, determined concurrently at the same region and ranged from 3.06E-03 to 3.48E-03 d l(-1) with a geometric mean value of 3.26E-03 d l(-1). This parameter is quite useful in decision-making for implementing countermeasures during a large area contamination with (137)Cs in tropical areas like Kaiga.

Evaluation of 25 y of environmental monitoring data around Madras Atomic Power Station (MAPS), Kalpakkam, India.

The Environmental Survey Laboratory at Kalpakkam, India carries out elaborate monitoring programme involving atmospheric, terrestrial and aquatic samples for radioactivity to evaluate the impact of operating two pressurised heavy water reactors. This paper presents the evaluation of 25 y (1983-2008) data. Statistical analysis of the environmental data for different radionuclides showed that the data best fits log-normal distribution. The data analysed showed that fission products such as (137)Cs, (90)Sr and (131)I were due to global fallout only. A ratio of 0.2 was obtained for (90)Sr to (137)Cs in air filter samples, only during Chernobyl accident period. The transfer factor of (137)Cs and (90)Sr for rice was computed to be 0.23 and 0.03 and vegetables 0.25 and 0.10, respectively. Activation products (3)H and (41)Ar are the only radionuclides that are related to MAPS operation. A strong correlation (r = 0.9) was observed between (3)H activity in air and (3)H discharged to the atmosphere. A similar correlation (r = 0.8) was observed in (3)H concentration in seawater and (3)H discharged in the liquid waste. The annual internal dose due to (3)H and annual external dose due to (41)Ar evaluated in the last 25 y show that the members of the public received less than 2 % of the dose limit (1 mSv y(-1)) set by ICRP 72.

Mirtazapine-associated hyponatremia presenting as delirium.

Though there is ample evidence for the association between selective serotonin reuptake inhibitors and hyponatremia, evidence for the relationship between mirtazapine and hyponatremia is scarce. We present a case of mirtazapine-induced hyponatremia in an adult patient, which was dose related.