The chernobyl accident 20 years on: an assessment of the health consequences and the international response

Theorizing on neo public assistance: How do race and class impact resource uptake and behavior following disaster?

The consequences of environmental disasters and other ecologic and communal crises are frequently worst in racially/ethnically minoritized and low-income populations relative to other groups. This disproportionality may create or deepen patterns of governmental distrust and stoke health promotion disengagement in these groups. To date, there has been limited contextualization of how historically disenfranchised populations utilize government-administered or facilitated resources following such disasters. Focusing on the water crisis in Flint, Michigan, we examine and theorize on the usage of neo public assistance, free risk reduction resources that are provided to disaster survivors as a liminal means of redressing ills created and/or insufficiently mitigated by the state. We surveyed 331 Flint residents, evaluating their usage of four neo public assistance resources following the FWC, finding low to moderate uptake: 131 residents (39.6%) indicated that they obtained blood lead level (BLL) screenings, 216 (65.3%) had their tap water tested for lead (Pb) and other contaminants, 137 (41.4%) had their home water infrastructure replaced, and 293 (88.5%) had acquired bottled water at community distribution sites. Unemployment, receiving public benefits, and lacking reliable transportation and stable housing were associated with lower uptake of some resources. Compared to White and "Other" race individuals, Black residents were generally more likely to acquire/utilize these resources, suggesting heightened concerns and health promotion proclivities even in the face of observed macro and individual-level challenges. Potential reasons and implications are discussed.

The truth will out: a reflection on the life and times of Alice Stewart

CONCLUSIONS

Dr Alice Stewart's research was pioneering, fundamental and challenging, and is now widely accepted.

Quantitative modeling of radioactive cesium concentrations in large omnivorous mammals after the Fukushima nuclear power plant accident

Large quantities of radionuclides released by the Fukushima nuclear power plant accident entered terrestrial and marine ecosystems. The resulting radioactive contamination of large omnivorous wild mammals such as wild boar (Sus scrofa) and Asian black bear (Ursus thibetanus) varied greatly depending on location, season, and time after the accident. Quantitative modeling of how such factors influence radionuclide burdens in these species is important for enhancing current knowledge of chronic radionuclide exposure consequences in mammalian populations, and for assessing potential human risks from consumption of contaminated animal meat. Here we modeled the time course of radioactive cesium (¹³⁴Cs + ¹³⁷Cs) concentrations in boar and black bears from Fukushima Prefecture over ~ 7 years after the accident, using nonlinear robust and quantile regressions and mixed-effects modeling. To estimate predictive performance, models fitted to the full data set were compared with those fitted only to the first 3.5 years of data, and tested on the last 3.5 years of data. Ecological half-lives for radioactive cesium, and magnitudes and phase shifts for sinusoidal seasonal oscillations in cesium burdens, were estimated by each analysis method for each species. These results can improve the understanding and prediction of radionuclide concentrations in large mammals that inhabit radioactively contaminated areas.

Adiponectin and Thyroid Cancer: Insight into the Association between Adiponectin and Obesity

In recent decades, the incidence and diagnosis of thyroid cancer have risen dramatically, and thyroid cancer has now become the most common endocrine cancer in the world. The onset of thyroid cancer is insidious, and its progression is slow and difficult to detect. Therefore, early prevention and treatment have important strategic significance. Moreover, an in-depth exploration of the pathogenesis of thyroid cancer is key to early prevention and treatment. Substantial evidence supports obesity as an independent risk factor for thyroid cancer. Adipose tissue dysfunction in the obese state is accompanied by dysregulation of a variety of adipocytokines. Adiponectin (APN) is one of the most pivotal adipocytokines, and its connection with obesity and obesity-related disease has gradually become a hot topic in research. Recently, the association between APN and thyroid cancer has received increasing attention. The purpose of this review is to systematically review previous studies, give prominence to APN, focus on the relationship between APN, obesity and thyroid cancer, and uncover the underlying pathogenic mechanisms.

Dose and Dose-Rate Effects in a Mouse Model of Internal Exposure from 137Cs. Part 2: Integration of Gamma-H2AX and Gene Expression Biomarkers for Retrospective Radiation Biodosimetry

Inhalation and ingestion of 137Cs and other long-lived radionuclides can occur after large-scale accidental or malicious radioactive contamination incidents, resulting in a complex temporal pattern of radiation dose/dose rate, influenced by radionuclide pharmacokinetics and chemical properties. High-throughput radiation biodosimetry techniques for such internal exposure are needed to assess potential risks of short-term toxicity and delayed effects (e.g., carcinogenesis) for exposed individuals. Previously, we used γ-H2AX to reconstruct injected 137Cs activity in experimentally-exposed mice, and converted activity values into radiation doses based on time since injection and 137Cs-elimination kinetics. In the current study, we sought to assess the feasibility and possible advantages of combining γ-H2AX with transcriptomics to improve 137Cs activity reconstructions. We selected five genes (Atf5, Hist2h2aa2, Olfr358, Psrc1, Hist2h2ac) with strong statistically-significant Spearman's correlations with injected activity and stable expression over time after 137Cs injection. The geometric mean of log-transformed signals of these five genes, combined with γ-H2AX fluorescence, were used as predictors in a nonlinear model for reconstructing injected 137Cs activity. The coefficient of determination (R2) comparing actual and reconstructed activities was 0.91 and root mean squared error (RMSE) was 0.95 MBq. These metrics remained stable when the model was fitted to a randomly-selected half of the data and tested on the other half, repeated 100 times. Model performance was significantly better when compared to our previous analysis using γ-H2AX alone, and when compared to an analysis where genes are used without γ-H2AX, suggesting that integrating γ-H2AX with gene expression provides an important advantage. Our findings show a proof of principle that integration of radiation-responsive biomarkers from different fields is promising for radiation biodosimetry of internal emitters.

Adaptation to ionizing radiation of higher plants: From environmental radioactivity to chernobyl disaster

The purpose of this work is to highlight the effects of ionizing radiation on the genetic material in higher plants by assessing both adaptive processes as well as the evolution of plant species. The effects that the ionizing radiation has on greenery following a nuclear accident, was examined by taking the Chernobyl Nuclear Power Plant disaster as a case study. The genetic and evolutionary effects that ionizing radiation had on plants after the Chernobyl accident were highlighted. The response of biota to Chernobyl irradiation was a complex interaction among radiation dose, dose rate, temporal and spatial variation, varying radiation sensitivities of the different plants' species, and indirect effects from other events. Ionizing radiation causes water radiolysis, generating highly reactive oxygen species (ROS). ROS induce the rapid activation of detoxifying enzymes. DeoxyriboNucleic Acid (DNA) is the object of an attack by both, the hydroxyl ions and the radiation itself, thus triggering a mechanism both direct and indirect. The effects on DNA are harmful to the organism and the long-term development of the species. Dose-dependent aberrations in chromosomes are often observed after irradiation. Although multiple DNA repair mechanisms exist, double-strand breaks (DSBs or DNA-DSBs) are often subject to errors. Plants DSBs repair mechanisms mainly involve homologous and non-homologous dependent systems, the latter especially causing a loss of genetic information. Repeated ionizing radiation (acute or chronic) ensures that plants adapt, demonstrating radioresistance. An adaptive response has been suggested for this phenomenon. As a result, ionizing radiation influences the genetic structure, especially during chronic irradiation, reducing genetic variability. This reduction may be associated with the fact that particular plant species are more subject to chronic stress, confirming the adaptive theory. Therefore, the genomic effects of ionizing radiation demonstrate their likely involvement in the evolution of plant species.

Sex Difference of Radiation Response in Occupational and Accidental Exposure

Ionizing radiation is a well-established cause of deleterious effects on human health. Understanding the risks of radiation exposure is important for the development of protective measures and guidelines. Demographic factors such as age, sex, genetic susceptibility, comorbidities, and various other lifestyle factors influence the radiosensitivity of different subpopulations. Amongst these factors, the influence of sex differences on radiation sensitivity has been given very less attention. In fact, the International Commission on Radiological Protection (ICRP) has based its recommendations on a population average, rather than the data on the radiosensitivity of distinct subpopulations. In this study, we reviewed major human studies on the health risks of radiation exposure and showed that sex-related factors may potentially influence the long-term response to radiation exposure. Available data suggest that long-term radiosensitivity in women is higher than that in men who receive a comparable dose of radiation. The report on the biological effects of ionizing radiation (BEIR VII) published in 2006 by the National Academy of Sciences, United States emphasized that women may be at significantly greater risk of suffering and dying from radiation-induced cancer than men exposed to the same dose of radiation. We show that radiation effects are sex-specific, and long-term radiosensitivity in females is higher than that in males. We also discuss the radiation effects as a function of age. In the future, more systematic studies are needed to elucidate the sex differences in radiation responses across the life continuum - from preconception through childhood, adulthood, and old age - to ensure that boys and girls and men and women are equally protected across ages.

Nuclear disaster as chronic crisis: Accounts of radiation embodiment by survivors of the Chernobyl nuclear disaster from Belarus born before, in and after 1986

This article looks at chronic crisis on an empirical example of radiation embodiment by survivors of a nuclear disaster. Developing further the work of Henrik Vigh, this article argues that chronic crisis is conflictual in nature, where some individuals fully embrace it, while others reject it. A total of 16 in-depth interviews were conducted with survivors of the Chernobyl nuclear disaster from Belarus who were below 18 years in 1986 and born in or after 1986. It is shown that survivors do not consider themselves affected, when they argue against social stigma imposed by others and when development discourse in relation to post-communist health care is used as a background against which nuclear victimhood can be argued. It is also demonstrated that survivors do consider themselves affected, when they embrace disaster temporality and victimhood and argue against narrow scientific definitions of victimhood which downplay a variety of health conditions attributed to the disaster. This article concludes that chronic crisis may not always be transformative, but reproduce the existing inequalities. It contributes to the anthropology of disaster and the anthropology of suffering by bringing together scholarship in feminist theory of disability and critical perspectives on development.

Demographic and onco-epidemiological situation in radioactive contaminated territory of Zhytomyr Oblast

We performed an assessment of demographic parameters of occurrence of malignant tumours and mortality of the population which lives in the radioactive contaminated territory of Zhytomyr Oblast (Yemilchynskyi, Luhynskyi, Narodytskyi, Korostenskyi, Olevskyi, and Ovrutskyi districts) over a 32-year period (1985–2017). The source material for the study of the demographic situation and malignant tumours in the population of the radioactive contaminated administrative districts of Zhytomyr Oblast during 1985–2017 was the statistical data of the Management of Healthcare of Zhytomyr Oblast State Administration, Central Department of Statistics in Zhytomyr Oblasts, reports on occurrences of malignant tumours of the state institution Center of Medical Statistics of the Ministry of Healthcare of Ukraine, data of the Radiological Control Service in Zhytomyr Oblast. It was determined that over 1985–2017 in the radioactive contaminated territory of Zhytomyr Oblast, a natural decline of population was observed, maximum values of which occurred in 2005 (except Narodnytsky district – 2000). The highest levels of occurrence of tumours and mortality caused by them among the adult population were observed 14 years after the Chornobyl nuclear power plant disaster. The peak of the occurrence of malignant tumours among children in the radioactive contaminated territory of Zhytomyr Oblast was observed 9 years after the explosion. A relationship was determined between doses of irradiation of the population and the risk of occurrence of malignant tumours in the radioactive contaminated regions of Zhytomyr Oblast. Taking into account that the method of calculation of passport dose (average annual effective dose of irradiation) was developed 23 years ago, nowadays it can lead to errors. This is related to change in amounts of consumption of different products by the population, which needs to be considered when determining radiological risks. The obtained data indicate that analysis of demographic and onco-epidemiological consequences of the Chornobyl catastrophe remains a relevant issue nowadays and will remain so in the near future.

Long-Term Consequences of the Chernobyl Radioactive Fallout: An Exploration of the Aggregate Data

Policy Points Policymakers should invest more on researching the long-term health effects of low-ionizing radiation exposure, as we are far from reaching a consensus on a topic that is of enormous importance for public health and safety. Public policies such as those limiting the import of contaminated food from areas hit by a radioactive disaster or those regulating the resident population's access to such areas should follow a precautionary approach. Neoplasm diagnosis and medical care should be designed in order to take into account the possible role of long-term, low-dose radiation exposure. Health care policies should provide effective screening and prevention strategies with a specific focus on the regions that were hit most severely by the Chernobyl nuclear fallout. Health care expenditure should be targeted, taking into account the geographical dispersion of the fallout in order to attenuate its possible effect on neoplasm incidence.

CONTEXT

This study investigates the association between the radioactive ¹³⁷ Cesium fallout originated by the 1986 Chernobyl nuclear accident and dispersed over Western Europe, as a result of a combination of radioactive cloud passage days and rainy days over a 10-day period, and long-term health patterns and related costs. Since the half-life of ¹³⁷ Cesium is 30.17 years, part of the radioactivity in the affected regions is still present today, and it is usually still detected in the food chain, although at lower concentration levels.

METHODS

We match longitudinal data on neoplasm incidence over the time span 2000-2013 in a number of European regions not immediately adjacent to Chernobyl with the randomly distributed levels of cesium deposition after the nuclear disaster in order to assess whether we can detect an association with the long-term health effects on the European population through a random effects model.

FINDINGS

Considering 3 levels of fallout deposition-low, medium, and high-hospital discharges after treatment for neoplasms are, respectively, 0.36, 0.44, and 0.98 discharges over 100 inhabitants higher compared to regions with no fallout, with the population average being around 1.7 hospital discharges by neoplasms over 100 inhabitants. We checked the robustness of our findings to a number of tests including a placebo simulation and different model specifications.

CONCLUSIONS

Radioactive fallout is positively associated with a higher incidence of hospital discharges after treatment for neoplasms almost 30 years after its release, with larger effects in regions where the radioactivity was more intense. Our estimates are comparable to the findings of the largest-scale study on the long-term health effects of continuous low levels of radiation exposure among workers in the nuclear industry and suggest that more research is needed on this topic, given its enormous importance for public health and safety.

Thyroid cancer incidence in the vicinity of nuclear sites in Belgium, 2000-2008

BACKGROUND

Public health concern about nuclear activities have existed since the 1980s. Most studies on this subject investigated childhood leukemia. Thyroid cancer may be another health outcome of interest, because some nuclear installations are a potential source of radioactive iodine isotopes in the environment and because thyroid cancer is known to occur after exposure to these isotopes.

METHODS

This study describes an ecological study investigating whether there is excessive thyroid cancer incidence among residents living in the vicinity of nuclear sites. Single-site analyses using indirect standardization (standardized incidence ratios [SIRs]) and Poisson regression modeling (rate ratios [RRs]) were conducted. The proximity area is typically defined as a circular zone with a radius of 20 km centered on the site. However, the choice of the size of this area is somewhat arbitrary. Therefore, a sensitivity analysis was carried out to investigate whether the results vary with radii of increasing proximity.

RESULTS

No increased thyroid cancer incidence was found within the 20 km proximity area around the nuclear power plants of Doel (SIR=0.74 [95% confidence interval (CI)=0.64; 0.84] and RR=0.72 [95% CI=0.63; 0.83]) and Tihange (SIR=0.86 [95% CI=0.70; 1.01] and RR=0.85 [95% CI=0.70; 1.02]). For the sites of Mol-Dessel and Fleurus, where a combination of nuclear research and industrial activities are located, the incidences of thyroid cancer within the 20 km proximity area were higher than expected (Mol-Dessel: SIR=1.19 [95% CI=1.01; 1.36] and RR=1.19 [95% CI=1.02; 1.38]; Fleurus: SIR=1.15 [95% CI=1.02; 1.28] and RR=1.17 [95% CI=1.04; 1.33]). For Chooz, a French nuclear power plant close to the Belgian border, the results were unstable as a result of the small population denominator. For all Belgian nuclear sites, the results were generally insensitive to the choice of the proximity area.

CONCLUSIONS

No evidence for excessive thyroid cancer incidence around the Belgian nuclear power plants was found. On the other hand, an increased incidence of thyroid cancer was observed around the sites with other nuclear activities. Further research is recommended to verify whether the observed increases could be related to the site-specific nuclear activities.

Effects of the chernobyl disaster on thyroid cancer incidence in Turkey after 22 years

Background. Separate studies involving people who survived atomic bombs have shown that the risk for cancer remains high after 40 years, compared with the risk in the general population. An elevated risk may also remain in regions of Turkey near the Chernobyl disaster. Patients and Methods. A multidisciplinary study conducted in 2008, 22 years after the Chernobyl disaster, examined the thyroid cancer incidence in Rize, a province of Turkey located on the shore of the middle Black Sea. Approximately 100,000 people were screened, and a fine-needle aspiration biopsy was performed in 89 patients. Results. Based on postoperative histopathological examinations, thyroid cancer was diagnosed in six of the 100,000 people screened. Conclusion. Given a thyroid cancer frequency of approximately 8 in 100,000 in the Turkish population, according to the Turkish Cancer Research Association, the rate in Rize reflects no increase in the thyroid cancer incidence 22 years after the Chernobyl disaster.

Psychological well-being and risk perceptions of mothers in Kyiv, Ukraine, 19 years after the Chornobyl disaster

BACKGROUND

The Chornobyl nuclear power plant explosion in April 1986 was one of the worst ecological disasters of the 20th century. As with most disasters, its long-term mental health consequences have not been examined.

AIMS

This study describes the psychological well-being and risk perceptions of exposed women 19-20 years later and the risk factors associated with mental health.

METHODS

We assessed Chornobyl-related post-traumatic stress disorder (PTSD), major depressive episode (MDE) and overall distress among three groups of women in Kyiv, Ukraine (N = 797): mothers of small children evacuated to Kyiv in 1986 from the contaminated area near the plant (evacuees); mothers of their children's classmates (neighbourhood controls); and population-based controls from Kyiv. Risk perceptions and epidemiologic correlates were also obtained.

RESULTS

Evacuees reported poorer well-being and more negative risk perceptions than controls. Group differences in psychological well-being remained after adjustment for epidemiologic risk factors but became non-significant when Chornobyl risk perceptions were added to the models.

CONCLUSIONS

The relatively poorer psychological well-being among evacuees is largely explained by their continued concerns about the physical health risks stemming from the accident. We suggest that this is due to the long-term, non-resolvable nature of health fears associated with exposure.

Effective dose estimation and lifetime cancer mortality risk assessment from exposure to Chernobyl 137Cs on the territory of Belgrade City and the region of Vojvodina, Serbia

PURPOSE

The purpose of this paper is to determine the activity concentrations of radionuclide (137)Cs in soil samples on the territory of Belgrade and the province of Vojvodina. Also, the lifetime cancer mortality risk from external exposure during 1 year is assessed, and the effective dose is estimated.

METHODS

Eighty eight soil samples were collected from 30 uncultivated locations in Belgrade, and 30 soil samples were collected from 10 locations in the province of Vojvodina. Activity concentrations were measured using an HPGe detector. Using dose conversion factors taken from "EPA Federal Guidance Report 12," annual effective doses from external sources were estimated. The lifetime cancer mortality risk was assessed using cancer risk coefficients taken from "EPA Federal Guidance Report 13."

RESULTS

Activity concentrations of (137)Cs for the territory of Belgrade are in the range of 2.07-89.1 Bq/kg with a mean value of 23.77 Bq/kg; the estimated annual effective doses are in the range of 0.41-17.5 nSv with a mean value of 4.67 nSv, and assessed lifetime cancer mortality risks, normalized on 100,000 inhabitants, are in the range 0.2-9.5 × 10(-5) with a mean value 2.5 × 10(-5). Activity concentrations of (137)Cs for the province of Vojvodina are in the range of 2.73-18.9 Bq/kg with a mean value of 8.57 Bq/kg; estimated annual effective doses are in the range of 0.54-3.71 nSv with a mean value of 1.68 nSv, and assessed lifetime cancer mortality risks, normalized on 100,000 inhabitants, are in the range of 0.3-2.0 × 10(-5) with a mean value 0.9 × 10(-5).

CONCLUSION

Receiving doses are low from (137)Cs radionuclides occurring in soil, according to the linear no-threshold approach; the risk for cancer development exists but is very small.

Growing up in the shadow of Chornobyl: adolescents' risk perceptions and mental health

PURPOSE

Despite long-term research on risk perceptions of adults after ecological disasters, little is known about the legacy for the generation exposed to toxic elements as infants. This study examined Chornobyl-related risk perceptions and their relationship to mental health in adolescents raised in Kyiv in the aftermath of the accident.

METHODS

Risk perceptions, 12-month DSM-IV major depression (MDD)/generalized anxiety disorder (GAD), and current symptomatology were examined in 265 evacuee adolescents, 261 classmate controls, and 327 population-based controls 19 years after the accident. Competing risk factors, including maternal risk perceptions and MDD/GAD, were taken into account.

RESULTS

Significantly more evacuees (48.7%) than controls (33.4-40.0%) reported at least one negative perception of Chornobyl; 18.1% of evacuees versus 10.0-12.8% of controls reported 2-4. In contrast, 75.7% of evacuee mothers versus 34.8-37.6% of controls endorsed 2-4 negative perceptions. In the unadjusted analyses, adolescents' perceptions were associated with both MDD/GAD and symptomatology. After adjusting for competing risk factors, their perceptions were associated with symptomatology only (p < 0.01). Among the competing risk factors, gender, self-esteem, life events, and peer support were significantly associated with MDD/GAD. These measures, along with quality of parental communication, father belligerence when drunk, and maternal MDD/GAD, were significantly associated with symptoms.

CONCLUSIONS

More evacuee teens reported negative risk perceptions than controls, but these perceptions were only modestly associated with mental health. Instead, the strongest risk factors comported with epidemiologic studies conducted in other parts of the world. Research is needed to determine whether children raised in the aftermath of other ecological disasters demonstrate similar resilience.

Nuclear detonation, thyroid cancer and potassium iodide prophylaxis

The recent nuclear disaster at Japan has raised global concerns about effects of radioactive leakage in the environment, associated hazards, and how they can be prevented. In this article, we have tried to explain about the guidelines laid down by World Health Organization for a potassium iodide prophylaxis following a nuclear disaster, and its mechanism of action in preventing thyroid cancer. Data was collected mainly from the studies carried out during the Chernobyl disaster of Russia in 1986 and the hazardous effects especially on the thyroid gland were studied. It was seen that radioactive iodine leakage from the nuclear plants mainly affected the thyroid gland, and especially children were at a higher risk at developing the cancers. Potassium Iodide prophylaxis can be administered in order to prevent an increase in the incidence of thyroid cancers in the population of an area affected by a nuclear disaster. However, one has to be cautious while giving it, as using it without indication has its own risks.

A 25 year retrospective review of the psychological consequences of the Chernobyl accident

The Chernobyl Forum Report from the 20th anniversary of the Chernobyl nuclear power plant disaster concluded that mental health effects were the most significant public health consequence of the accident. This paper provides an updated review of research on the psychological impact of the accident during the 25 year period since the catastrophe began. First responders and clean-up workers had the greatest exposure to radiation. Recent studies show that their rates of depression and post-traumatic stress disorder remain elevated two decades later. Very young children and those in utero who lived near the plant when it exploded or in severely contaminated areas have been the subject of considerable research, but the findings are inconsistent. Recent studies of prenatally exposed children conducted in Kiev, Norway and Finland point to specific neuropsychological and psychological impairments associated with radiation exposure, whereas other studies found no significant cognitive or mental health effects in exposed children grown up. General population studies report increased rates of poor self-rated health as well as clinical and subclinical depression, anxiety, and post-traumatic stress disorder. Mothers of young children exposed to the disaster remain a high-risk group for these conditions, primarily due to lingering worries about the adverse health effects on their families. Thus, long-term mental health consequences continue to be a concern. The unmet need for mental health care in affected regions remains an important public health challenge 25 years later. Future research is needed that combines physical and mental health outcome measures to complete the clinical picture.

Subjective health legacy of the Chornobyl accident: a comparative study of 19-year olds in Kyiv

Background

Since the Chornobyl accident in 1986, the physical health of exposed children in Ukraine has been monitored, but their perceived health has not been studied. This study examines health perceptions of Ukrainian adolescents exposed to radioactive fallout in utero or as infants, and the epidemiologic and Chornobyl-related influences on self-reported health.

Method

We assessed three groups of 19-year olds in Kyiv: 262 evacuees from contaminated areas near the plant; 261 classmate controls; and 325 population-based controls. The evacuees and classmates were previously assessed at age 11. Structured interviews were conducted with the adolescents and their mothers (N = 766), followed by general physical examinations (N = 722) and blood tests (N = 707). Proportional odds logistic regression and multi-group path analysis were the major statistical tests.

Results

The examination and blood test results were similar across groups except for a significantly elevated rate of thyroid enlargement found by palpation in evacuees (17.8%) compared former classmates (8.7%) and population-based controls (8.0%). In addition, four evacuees and one population control had had a thyroidectomy. Compared to controls, the evacuees rated their health the least positively and reported more medically diagnosed illnesses during the 5 years preceding the interview, particularly thyroid disease, migraine headache, and vascular dystony. The consistent risk factors (p < 0.001) for these subjective health reports were evacuee status, female gender, multiple hospitalizations, and health risk perception regarding Chornobyl. All three groups of mothers rated their children's health more negatively than the adolescents themselves, and maternal ratings were uniquely associated with the adolescents' health reports in the adjusted models. In the longitudinal evacuee and classmate subsamples, path analysis showed that mothers' health ratings when the children were age 11 predicted their later evaluations which in turn were associated with the adolescent self-reports.

Conclusion

The more negative self-evaluations of the evacuees were linked to a number of risk factors, including multiple hospitalizations, health risk perceptions, and epidemiologic risk factors. The increased rate of thyroid cancer and other diagnoses no doubt contributed to the evacuees' less positive subjective health. The strong effect of the mothers' perceptions argues in favor of developing risk communication programs for families rather than for mothers or adolescents as separate target groups.

Epidemiologic research on man-made disasters: strategies and implications of cohort definition for World Trade Center worker and volunteer surveillance program

Studies of long-term health consequences of disasters face unique methodologic challenges. The authors focused on studies of the health of cleanup and recovery workers, who are often poorly enumerated at the outset and difficult to follow over time. Comparison of the experience at the World Trade Center disaster with 4 past incidents of chemical and radiation releases at Seveso, Italy; Bhopal, India; Chernobyl, Ukraine; and Three Mile Island, USA, provided useful contrasts. Each event had methodologic advantages and disadvantages that depended on the nature of the disaster and the availability of records on area residents, and the emergency-response and cleanup protocol. The World Trade Center Worker Monitoring Program has well-defined eligibility criteria but lacks information on the universe of eligible workers to characterize response proportions or the potential for distortion of reported health effects. Nonparticipation may result from lack of interest, lack of awareness of the program, availability of another source of medical care, medical conditions precluding participation, inability to take time off from work, moving out of the area, death, or shift from initially ineligible to eligible status. Some of these considerations suggest selective participation by the sickest individuals, whereas others favor participation by the healthiest. The greatest concern with the validity of inferences regarding elevated health risks relative to external populations is the potential for selective enrollment among those who are affected. If there were a large pool of nonparticipating workers and those who suffered ill health were most motivated to enroll, the rates of disease among participants would be substantially higher than among all those eligible for the program. Future disaster follow-up studies would benefit substantially by having access to accurate estimates of the number of workers and information on the individuals who contributed to the cleanup and recovery effort.

Exposure from the Chernobyl accident had adverse effects on erythrocytes, leukocytes, and, platelets in children in the Narodichesky region, Ukraine: a 6-year follow-up study

BACKGROUND

After the Chernobyl nuclear accident on April 26, 1986, all children in the contaminated territory of the Narodichesky region, Zhitomir Oblast, Ukraine, were obliged to participate in a yearly medical examination. We present the results from these examinations for the years 1993 to 1998. Since the hematopoietic system is an important target, we investigated the association between residential soil density of 137Caesium (137Cs) and hemoglobin concentration, and erythrocyte, platelet, and leukocyte counts in 1,251 children, using 4,989 repeated measurements taken from 1993 to 1998.

METHODS

Soil contamination measurements from 38 settlements were used as exposures. Blood counts were conducted using the same auto-analyzer in all investigations for all years. We used linear mixed models to compensate for the repeated measurements of each child over the six year period. We estimated the adjusted means for all markers, controlling for potential confounders.

RESULTS

Data show a statistically significant reduction in red and white blood cell counts, platelet counts and hemoglobin with increasing residential 137Cs soil contamination. Over the six-year observation period, hematologic markers did improve. In children with the higher exposure who were born before the accident, this improvement was more pronounced for platelet counts, and less for red blood cells and hemoglobin. There was no exposurextime interaction for white blood cell counts and not in 702 children who were born after the accident. The initial exposure gradient persisted in this sub-sample of children.

CONCLUSION

The study is the first longitudinal analysis from a large cohort of children after the Chernobyl accident. The findings suggest persistent adverse hematological effects associated with residential 137Cs exposure.

Determinants of participation in a longitudinal two-stage study of the health consequences of the Chornobyl nuclear power plant accident

Background

The determinants of participation in long-term follow-up studies of disasters have rarely been delineated. Even less is known from studies of events that occurred in eastern Europe. We examined the factors associated with participation in a longitudinal two-stage study conducted in Kyiv following the 1986 Chornobyl nuclear power plant accident.

Methods

Six hundred child-mother dyads (300 evacuees and 300 classmate controls) were initially assessed in 1997 when the children were 11 years old, and followed up in 2005–6 when they were 19 years old. A population control group (304 mothers and 327 children) was added in 2005–6. Each assessment point involved home interviews with the children and mothers (stage 1), followed by medical examinations of the children at a clinic (stage 2). Background characteristics, health status, and Chornobyl risk perceptions were examined.

Results

The participation rates in the follow-up home interviews were 87.8% for the children (88.6% for evacuees; 87.0% for classmates) and 83.7% for their mothers (86.4% for evacuees and 81.0% for classmates). Children's and mothers' participation was predicted by one another's study participation and attendance at the medical examination at time 1. Mother's participation was also predicted by initial concerns about her child's health, greater psychological distress, and Chornobyl risk perceptions. In 1997, 91.2% of the children had a medical examination (91.7% of evacuees and 90.7% of classmates); in 2005–6, 85.2% were examined (83.0% of evacuees, 87.7% of classmates, 85.0% of population controls). At both times, poor health perceptions were associated with receiving a medical examination. In 2005–6, clinic attendance was also associated with the young adults' risk perceptions, depression or generalized anxiety disorder, lower standard of living, and female gender.

Conclusion

Despite our low attrition rates, we identified several determinants of selective participation consistent with previous research. Although evacuee status was not associated with participation, Chornobyl risk perceptions were strong predictors of mothers' follow-up participation and attendance at the medical examinations. Understanding selective participation offers valuable insight for future longitudinal disaster studies that integrate psychiatric and medical epidemiologic research.

The thyroid dose burden in medical imaging A re-examination

Radiation is the best defined causative factor in thyroid cancer. The thyroid is especially susceptible to injury from radiation to which it may be exposed in a variety of circumstances in addition to natural background: radiotherapy, including, historically, therapy of such benign conditions as ring worm and haemangiomata, radiation exposure in nuclear accidents and fallout from nuclear bomb tests, and diagnostic exposures, particularly in the relatively high dose CT examination of head and neck. Both use of CT and the incidence of thyroid cancer appear to be increasing worldwide and it has been suggested that there may be a causative relationship between the two. It has been further posited that the iodine content of the thyroid might play a role in increasing the radiation dose absorption. Indeed, on the same basis, iodine administered in the form of an X-ray contrast-enhancing agent might also be expected to play some role in increasing thyroid radiation absorption resulting in a yet higher dose burden in any give circumstances than is generally assumed. In view of the importance of these ideas we have performed some calculations to estimate the magnitude of the iodine effects. We conclude that they are not great enough to cause concern.

Manipulating public health research: the nuclear and radiation health establishments

Industry, government, and the military have systematically suppressed or manipulated epidemiologic research showing detrimental effects on human health from accidental or occupational exposures to ionizing radiation. This leads to conflicts of interest and compromised integrity among scientists in the radiation health establishment, it stifles dissemination of "unwelcome" findings and endangers public health.