Electromagnetic Radiation Exposure and Childhood Leukemia: Meta-Analysis and Systematic Review.

Objective: Leukemia is the most prevalent cancer among children and adolescents. This study investigated the potential association between exposure to magnetic fields and the risk of pediatric leukemia. Methods: We conducted a comprehensive search of electronic databases, including Scopus, EMBASE, Cochrane, Web of Science, and Medline, up to December 15, 2022, to identify relevant studies examining the link between childhood leukemia and magnetic field exposure. Results: The first meta-analysis revealed a statistically significant inverse association between pediatric leukemia and magnetic field strengths ranging from 0.4 µT to 0.2 µT, suggesting a reduced risk associated with this range. The second meta-analysis focused on wiring configuration codes and observed a potential link between residential magnetic field exposure and childhood leukemia. Pooled relative risk estimates were 1.52 (95% CI = 1.05-2.04, P = .021) and 1.58 (95% CI = 1.15-2.23, P = .006) for exposure to 24-hour magnetic field measurements, suggesting a possible causal relationship. In the third meta-analysis, the odds ratios for the exposure groups of 0.1 to 0.2 µT, 0.2 to 0.3 µT, 0.3 to 0.4 µT, and 0.4 µT above 0.2 µT were 1.09 (95% confidence interval = 0.82 to 1.43 µT), 1.14 (95% confidence interval = 0.68 to 1.92 µT), and 1.45 (95% confidence interval = 0.87 to 2.37 µT), respectively. In contrast to the findings of the three meta-analyses, there was no evidence of a statistically significant connection between exposure to 0.2 µT and the risk of juvenile leukemia. A further result showed no discernible difference between the two groups of children who lived less than 100 meters from the source of magnetic fields and those who lived closer (OR = 1.33; 95% CI = 0.98-1.73 µT). Conclusions: The collective results of three meta-analyses, encompassing magnetic field strengths ranging from 0.1 µT to 2.38 µT, underscore a statistically significant association between the intensity of magnetic fields and the occurrence of childhood leukemia. However, one specific analysis concluded that no apparent relationship exists between exposure to 0.1 µT and an elevated risk of leukemia development in children.

Incidence of Severe Chronic Neutropenia in South Korea and Related Clinical Manifestations: A National Health Insurance Database Study.

Background and objectives: Severe chronic neutropenia (SCN) is a condition in which absolute neutrophil counts remain at a low level (under 500/µL) over months or years. Because of the rare onset of SCN, its epidemiology, prognosis, and clinical manifestations have not yet been fully understood. In particular, large-cohort studies in Asian countries are still insufficient. Therefore, in this study, national health insurance data was used to investigate the epidemiologic features and prognosis of SCN in South Korea. MATERIALS AND METHODS: The data from the Health Insurance Review and Assessment database recorded between 1 January 2011 and 31 December 2015 were explored. SCN was defined based on the ICD-10 code, registry of benefit extension policy, and inclusion criteria of the study. After identifying patients with SCN, annual incidence and their co-morbidities were analyzed. RESULTS: Among the initially identified patients with severe neutropenia (N = 2145), a total of 367 patients had SCN and were enrolled. The annual incidence rate of SCN ranged from 0.12 to 0.17 per 100,000 person-year (PY) during the study period. The highest incidence was observed in pediatric patients aged between 0 to 9 years (N = 156), followed by women in their fifties (N = 43). The total incidence rate was 0.17 in females and 0.12 in males (Relative risk (RR): 1.43, 95%, CI: 1.16-1.76). The most common accompanying condition was mild respiratory infection, but about 3.2% of patients progressed to hematologic malignancy after an average of 2.4 years. CONCLUSIONS: This nationwide population-based epidemiological study showed that incidence of SCN is higher in pediatrics and middle-aged women. As progression to hematologic malignancy was significantly higher in the age of in 45-49 year olds, careful follow-up is necessary in this group. However, since this study lacks the molecular information, these finding need to be interpreted with great caution.

Residential exposure to petrochemical industrial complexes and the risk of leukemia: A systematic review and exposure-response meta-analysis.

Exposure to chemicals produced by petrochemical industrial complexes (PICs), such as benzene, ionizing radiation, and particulate matters, may contribute to the development of leukemia. However, epidemiological studies showed controversial results. This systematic review and meta-analysis aimed to summarize the association between residential exposure to PICs and the risk of leukemia incidence, focusing on exposure-response effects. We searched PubMed, Embase, Web of Science, and Cochrane Library databases for studies published before September 1st, 2019. Observational studies investigating residential exposure to PICs and the risk of leukemia were included. The outcome of interest was the incidence of leukemia comparing to reference groups. Relative risk (RR) was used as the summary effect measure, synthesized by characteristics of populations, distance to PICs, and calendar time in meta-regression. We identified 7 observational studies, including 2322 leukemia cases and substantial reference groups, in this meta-analysis. Residential exposure to PICs within a maximal 8-km distance had a 36% increased risk of leukemia (pooled RR = 1.36, 95% CI = 1.14-1.62) compared to controls, regardless of sex and age. In terms of leukemia subtypes, residential exposure to PICs was associated with the risks of acute myeloid leukemia (AML, pooled RR = 1.61, 95% CI = 1.12-2.31) and chronic lymphocytic leukemia (CLL, pooled RR = 1.85, 95% CI = 1.11-6.42). In meta-regression, the positive association occurred after 10 years of follow-up with a pooled RRs of 1.21 (95% CI = 1.02-1.44) and then slightly increased to 1.77 (95% CI = 1.35-2.33) at 30 years after follow-up. No effect modification was found by sex, age, and geographic locations.

Pain in patients with newly diagnosed or relapsed acute leukemia.

PURPOSE: Acute leukemia (AL) is associated with substantial morbidity and mortality. We assessed the prevalence and correlates of pain in patients with newly diagnosed or relapsed AL. METHODS: Patients with newly diagnosed or relapsed AL admitted to a comprehensive cancer center completed the Memorial Symptom Assessment Scale (MSAS), which assesses prevalence, severity, and distress associated with pain and other symptoms. Factors associated with severe pain were assessed using logistic regression. Two raters completed chart reviews in duplicate for patients with severe pain (MSAS severity ≥ 3/4) to determine the site of pain. RESULTS: Three hundred eighteen patients were recruited from January 2008 to October 2013: 245 (77.0%) had acute myeloid or acute promyelocytic leukemia (AML/APL) and 73 (23.0%) had acute lymphoblastic leukemia (ALL); 289 (90.9%) were newly diagnosed and 29 (9.1%) had relapsed disease. Pain was reported in 156/318 (49.2%), of whom 55/156 (35.3%) reported severe pain (≥ 3/4). Pain was associated with all psychological symptoms (all p < 0.005) and some physical symptoms. Severe pain was associated with younger age (p = 0.02), worse performance status (p = 0.04), ALL diagnosis (p = 0.04), and time from onset of chemotherapy (p = 0.03), with pain peaking at 4 weeks after chemotherapy initiation. The most common sites of severe pain were oropharynx (22; 40%), head (12; 21.8%), and abdomen (11; 20%). Only 3 patients (0.9%) were referred to the symptom control/palliative care team during the month prior to or following assessment. CONCLUSIONS: Pain is frequent, distressing, and predictable in patients undergoing induction chemotherapy for AL. Further research is needed to assess the efficacy of early supportive care in this population.

A proposed explanation for thunderstorm asthma and leukemia risk near high-voltage power lines: a supported hypothesis.

Thunderstorm asthma and increased childhood leukemia risk near high-voltage power lines (HVPL) are occurrences whose mechanism of effect is not fully understood. This paper proposes and discusses a key similarity: both thunderstorms and HVPL generate a high enough electrical field in the environment to ionize nearby air and air-borne particles. I argue that the repeatedly demonstrated acute asthma response to pollen-laden air during thunderstorms is largely due to ionization of air-borne allergens, which adhere more readily and in greater quantity in the lungs than non-ionized particles. If these bind to mucous or phagocytic cells, it would enhance immune response. A rapid temperature drop and high ozone also seem to be drivers of thunderstorm asthma. This causal nexus provides strong support for the parallel situation of prolonged exposure to ionized particles near HVPL and an increased rate of childhood leukemia. Here, it is proposed that upwind carcinogens are ionized when passing HVPL and then residential and business areas. Published evidence for most steps are presented, but have not previously been published as a coherent whole, nor has it been suggested that the inhaled ionized micro-particle explanation for acute asthma may also explain development of childhood leukemia over time. The demonstrated series of events leading to increased deposition and retention of ionized particles in airways provides support for explaining both adverse health outcomes: acute thunderstorm asthma and increased risk of childhood leukemia near HVPL. Further support for this explanation of both outcomes is provided by effects of on-going proximity to highways.

Drinking Water Uranium and Potential Health Effects in the German Federal State of Bavaria.

Mainly due to its nephrotoxic and osteotoxic potential, uranium (U) increasingly finds itself in the spotlight of environmental and health-related research. Germany decided on a binding U guideline value in drinking water of 10 µg/L, valid since 2011. It is yet widely unknown if and how public health was affected by elevated U concentrations before that. In this ecological study we summarized available drinking water U data for the German federal state of Bavaria (703 analyses in total for 553 different municipalities) at county level (for 76 out of 96 Bavarian counties, representing about 83% of Bavaria's and about 13% of Germany's total population) in terms of mean and maximum U concentration. Bavaria is known to regionally exhibit mainly geogenically elevated groundwater U with a maximum value of 40 µg/L in the database used here. Public health data were obtained from federal statistical authorities at county resolution. These included incidence rates of diagnosed diseases suspected to be potentially associated with chronic U uptake, e.g., diseases of the skeleton, the liver or the thyroid as well as tumor and genito-urinary diseases. The datasets were analyzed for interrelations and mutual spatial occurrence using statistical approaches and GIS as well as odds ratios and relative risks calculations. Weak but significant positive associations between maximum U concentrations and aggregated ICD-10 diagnose groups for growths/tumors as well as liver diseases were observed, elevated incidence rates of thyroid diseases seem to occur where mean drinking water U concentrations exceed 2 µg/L. Here, we discuss obtained results and their implications for potential impacts of hydrochemistry on public health in southeast Germany.

Aspectos clínicos y epidemiológicos de las leucemias / Clinical and epidemiological aspects of leukemias

Leukemia is a group of clonal diseases derived from a single cell with a genetic alteration in bone marrow or peripheral lymphoid tissue, and each type is determined by the specificity of the source cell. The objective of this research was to synthesize studies that characterize the clinical and epidemiological profile of patients with leukemia, the types of treatments used, duration and outcomes for the cases. This study is an integrative review of literature through databases Medical Literature Analysis and Retrieval System Online (MEDLINE), SCOPUS, Cumulative Index to Nursing & Allied Health Literature (CINAHL) and Science Direct. There were 4,274 articles rescued in the initial search, 188 were selected to compose the review sample after applying all the criteria for inclusion and exclusion adopted. Full articles were grouped into four categories, according to the variables of research: (a) more frequent subtypes of leukemia; (b) most widely used treatment; (c) duration of treatment; and (d) endpoint of the cases. It is concluded a prevalence of leukemia in pediatric patients, with a predominance of the subtype Acute Lymphoblastic Leukemia (ALL). In general, the male population is more affected by hematological malignancies. As the therapy is used, each leukemia subtype had its peculiarities regarding the treatment, especially the introduction of imatinib for chronic myeloid leukemia (CML) and prophylactic cranial irradiation for cases of ALL. Chronic leukemia showed higher treatment duration. There was a significant improvement in survival of Acute Myeloid Leukemia, Chronic Lymphoid leukemia, CML and ALL, the latter approximately with 90% cure rate in children.

La leucemia es un grupo de enfermedades clonales derivadas de una única célula con una alteración genética en la médula ósea o tejido linfoide periférico, y cada tipo se determina por la especificidad de la célula de origen. El objetivo de esta investigación fue sintetizar los estudios que caracterizan el perfil clínico y epidemiológico de los pacientes con leucemia, los tipos de tratamientos usados, la duración y los resultados para los casos. Este estudio es una revisión integradora de la literatura a través de bases de datos de análisis médicos, literatura y recuperación de sistema en línea (MEDLINE), SCOPUS, Cumulative Index de Enfermería y Salud Aliada Literatura (CINAHL) y Science Direct. Había 4 274 artículos rescatados en la búsqueda inicial, se seleccionaron 188 para componer la muestra de revisión después de aplicar todos los criterios de inclusión y exclusión adoptada. Los artículos completos se agruparon en cuatro categorías, según las variables de investigación: (a) los subtipos más frecuentes de leucemia; (b) el tratamiento más utilizado; (c) la duración del tratamiento; y (d) el punto final de los casos. Se concluye una prevalencia de leucemia en pacientes pediátricos, con predominio del subtipo de leucemia linfoblástica aguda (LLA). En general, la población masculina se ve más afectada por neoplasias hematológicas. Como se utiliza la terapia, cada subtipo de leucemia tenía sus peculiaridades con respecto al tratamiento, especialmente la introducción de imatinib para la leucemia mieloide crónica (CML) y la irradiación craneal profiláctica para los casos de ALL. La leucemia crónica mostró una mayor duración del tratamiento. Hubo una mejora significativa en la supervivencia de la leucemia mieloide aguda, leucemia linfoide crónica, LMC y LLA, aproximadamente, este último con la tasa de curación del 90% en los niños.

Preclinical models in the study of sex differences.

The biology of sex differences deals with the study of the disparities between females and males and the related biological mechanisms. Gender medicine focuses on the impact of gender and sex on human physiology, pathophysiology and clinical features of diseases that are common to women and men. The term gender refers to a complex interrelation and integration of sex-as a biological and functional determinant-and psychological and cultural behaviours (due to ethnical, social or religious background). The attention to the impact of gender differences on the pathophysiology and, therefore, on the clinical management of the most common diseases, such as cardiovascular diseases (CVD), neurodegenerative disorders, immune and autoimmune diseases as well as several tumours, is in fact often neglected. Hence, studies covering different fields of investigation and including sex differences in the pathogenesis, in diagnostic and prognostic criteria as well as in response to therapy appear mandatory. However, prerequisites for this development are preclinical studies, including in vitro and in vivo approaches. They represent the first step in the development of a drug or in the comprehension of the pathogenetic mechanisms of diseases, in turn a necessary step for the development of new or more appropriate therapeutic strategies. However, sex differences are still poorly considered and the great majority of preclinical studies do not take into account the relevance of such disparities. In this review, we describe the state of the art of these studies and provide some paradigmatic examples of key fields of investigation, such as oncology, neurology and CVD, where preclinical models should be improved.

Coffee and tea consumption and risk of leukaemia in an adult population: A reanalysis of the Italian multicentre case-control study.

BACKGROUND: Coffee and tea are the most frequently consumed beverages in the world. Their potential effect on the risk of developing different types of malignancies has been largely investigated, but studies on leukaemia in adults are scarce. METHODS: The present investigation is aimed at evaluating the potential role of regular coffee and tea intake on the risk of adult leukaemia by reanalysing a large population based case-control study carried out in Italy, a country with a high coffee consumption and a low use of green tea. Interviewed subjects, recruited between 1990 and 1993 in 11 Italian areas, included 1771 controls and 651 leukaemia cases. Association between Acute Myeloid Leukaemia (AML), Acute Lymphoid Leukaemia, Chronic Myeloid Leukaemia, Chronic Lymphoid Leukaemia, and use of coffee and tea was evaluated by standard logistic regression. Odds Ratios (OR) were estimated adjusting for the following potential confounders: gender, age, residence area, smoking habit, educational level, previous chemotherapy treatment, alcohol consumption and exposure to electromagnetic fields, radiation, pesticides and aromatic hydrocarbons. RESULTS: No association was observed between regular use of coffee and any type of leukaemia. A small protective effect of tea intake was found among myeloid malignancies, which was more evident among AML (OR=0.68, 95%CI: 0.49-0.94). However, no clear dose-response relation was found. CONCLUSION: The lower risk of leukaemia among regular coffee consumers, reported by a few of previous small studies, was not confirmed. The protective effect of tea on the AML risk is only partly consistent with results from other investigations.

Uranium contaminated drinking water linked to leukaemia-Revisiting a case study from South Africa taking alternative exposure pathways into account.

The paper presents results of a follow-up to an earlier study which established a geospatial link between naturally elevated uranium (U) levels in borehole water and haematological abnormalities in local residents serving as a proxy for leukaemia prevalent in the area. While the original study focussed on drinking water only, this paper also explores alternative exposure pathways including the inhalation of dust and the food chain. U-levels in grass and tissue of sheep generally reflect U-levels in nearby borehole water and exceed background concentrations by 20 to nearly 500 times. U-levels in sheep tissue increase with age of the animal. Wool showed the highest U-concentration followed by other non-consumable tissue such as hooves, teeth and bones. Lower levels occur in edible parts such as meat and inner organs. The U-deposition rate in wool is several orders of magnitudes higher than in bone as a known target organ. Wool is an easy-to-sample non-invasive bioindicator for U-levels in meat. Depending on the original water content, dried samples show up to 5 times higher U-levels than identical fresh material. Contaminated drinking water is the main exposure pathway for farm residents resulting in U-uptake rates exceeding the WHO's tolerable daily intake (TDI) limit by up to 900%. This is somewhat mitigated by the fact that U-speciation is dominated by a neutral calcium-uranyl-carbonate complex of relatively low toxicity. Commercially available household filters are able to significantly reduce U-levels in well water and are thus recommended as a short-term intervention. Based on average consumption rates sheep meat, as local staple food, accounts for 34% of the TDI for U. Indoor levels of radon should be monitored, too, since it is linked to both, U and leukaemia. With elevated U-levels being present in other geological formations across South Africa boreholes in these areas should be surveyed.

Green tea consumption and glutathione S-transferases genetic polymorphisms on the risk of adult leukemia.

PURPOSE: Green tea may have a beneficial role of inhibiting leukemia. Glutathione S-transferases (GSTs) are known to detoxify certain carcinogens. We investigated the roles of green tea consumption and polymorphisms of GSTM1, GSTT1 and GSTP1 on the risk of adult leukemia, and to determine whether the associations varied within GSTs genotypes. METHODS: A multicenter case-control study was conducted in China, 2008-2013. It comprised 442 incident, hematologically confirmed adult leukemia cases and 442 outpatient controls, individually matched to cases by gender, birth quinquennium and study site. Data were collected by face-to-face interview using a validated questionnaire. Genetic polymorphisms were assayed by PCR. RESULTS: An inverse association between green tea consumption and adult leukemia risk was observed. Compared with non-tea drinkers, the adjusted odds ratios (95 % confidence intervals) were 0.50 (0.27-0.93), 0.31 (0.17-0.55) and 0.53 (0.29-0.99) for those who, respectively, consumed green tea >20 years, ≥2 cups daily and dried tea leaves >1000 g annually. In assessing the associations by GSTs genotypes, risk reduction associated with green tea consumption was stronger in individuals with the GSTT1-null genotype (OR 0.24; 95 % CI 0.11-0.53) than GSTT1-normal carriers (OR 0.67; 95 % CI 0.42-1.05; P interaction = 0.02). GSTM1 and GSTP1 did not significantly modify the inverse association of leukemia with green tea. CONCLUSIONS: The results suggest that regular daily green tea consumption may reduce leukemia risk in Chinese adults regardless of GSTM1 and GSTP1 polymorphic status. The association between green tea and adult leukemia risk varied with GSTT1 genotype and highlights further study.

Epidemiology of complementary and alternative medicine therapy use in allogeneic hematopoietic stem cell transplant survivorship patients in Australia.

In addition to prescribed conventional medicines, many allogeneic hematopoietic stem cell transplant (HSCT) survivors also use complementary and alternative medical therapies (CAM), however, the frequency and types of CAMs used by allogeneic HSCT survivors remain unclear. Study participants were adults who had undergone an allogeneic HSCT between 1st January 2000 and 31st December 2012. Participants completed a 402-item questionnaire regarding the use of CAM, medical complications, specialist referrals, medications and therapies, infections, vaccinations, cancer screening, lifestyle, and occupational issues and relationship status following stem cell transplantation. A total of 1475 allogeneic HSCT were performed in the study period. Of the 669 recipients known to be alive at study sampling, 583 were contactable and were sent study packs. Of 432 participants who returned the completed survey (66% of total eligible, 76% of those contacted), 239 (54.1%) HSCT survivors used at least one form of CAM. These included dietary modification (13.6%), vitamin therapy (30%), spiritual or mind-body therapy (17.2%), herbal supplements (13.5%), manipulative and body-based therapies (26%), Chinese medicine (3.5%), reiki (3%), and homeopathy (3%). These results definitively demonstrate that a large proportion of HSCT survivors are using one or more form of CAM therapy. Given the potential benefits demonstrated by small studies of specific CAM therapies in this patient group, as well as clearly documented therapies with no benefit or even toxicity, this result shows there is a large unmet need for additional studies to ascertain efficacy and safety of CAM therapies in this growing population.

Breastfeeding, Other Early Life Exposures and Childhood Leukemia and Lymphoma.

Childhood cancer incidence increases and although rare, it is a leading cause of mortality. Leukemia and lymphoma comprise 40% of all cancers in children but little is known of their etiology. In this study, we examined the associations of breastfeeding and other early life exposures with childhood leukemia and lymphoma. A population-based case-control study carried out in 2011-2013 comprised mothers of 190 incidents (2005-2013) of leukemia/lymphoma cases aged 1-19 yr at diagnosis and 384 population-based controls. Interviews based on a computerized structured questionnaire were conducted with the mothers. Multivariate logistic regression models adjusted for potential confounders assessed the association between breastfeeding patterns and childhood leukemia/lymphoma. Ever breastfeeding category was associated with a 64% decreased risk for childhood leukemia/lymphoma lsqb;odds ratio (OR) = 0.36, 95% confidence interval (CI): 0.22, 0.60lrqb; and similar trends, with a dose-response effect, were observed for any breastfeeding (exclusive and/or partial) category for 6, 12, and 18+ mo. Other infant exposures associated with cancer risk were child iron supplementation (OR = 0.39, 95% CI: 0.26, 0.59), pet ownership (OR = 0.50, 95% CI: 0.33, 0.78), paternal smoking (OR = 1.93, 95% CI: 1.18, 3.15), and having older siblings (OR = 1.18, 95% CI: 1.05, 1.33). Breastfeeding-a controllable and modifiable exposure-is inversely associated with risk for childhood leukemia and lymphoma with a dose-response effect.

Is the Linear No-Threshold Dose-Response Paradigm Still Necessary for the Assessment of Health Effects of Low Dose Radiation?

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.

Lifestyle factors and risk of leukemia and non-Hodgkin's lymphoma: a case-control study.

PURPOSE: Risk factors for leukemia and lymphomas in adults are largely unknown. This study was aimed at evaluating the association between lifestyle factors and the risk of hematological malignancies in an adult population. METHODS: Data were drawn from a population-based case-control study carried out in Italy and included 294 cases (199 lymphoid and 95 myeloid) and 279 controls. Analyses were performed using standard multivariable logistic regression. RESULTS: Hair dye use for at least 15 years was associated with a higher risk of lymphoid malignancies among females (OR 2.3, 95 % CI 1.0-4.9, p = 0.036, test for trend). Furthermore, a protective effect of a moderate to heavy tea consumption on the risk of myeloid malignancies was observed (OR 0.4, 95 % CI 0.2-0.9, p = 0.017). No association was found for the use of alcoholic beverages and tobacco smoking. CONCLUSIONS: Our results confirm the potential carcinogenic effect of prolonged hair dye use observed in previous investigations. The excess risk could be explained by exposure to a higher concentration of toxic compounds in hair products used in the past. The protective effect of regular tea consumption observed in an area with a very high prevalence of black tea consumers deserves further investigation.

Is the Linear No-Threshold Dose-Response Paradigm Still Necessary for the Assessment of Health Effects of Low Dose Radiation?

Inevitable human exposure to ionizing radiation from man-made sources has been increased with the proceeding of human civilization and consequently public concerns focus on the possible risk to human health. Moreover, Fukushima nuclear power plant accidents after the 2011 East-Japan earthquake and tsunami has brought the great fear and anxiety for the exposure of radiation at low levels, even much lower levels similar to natural background. Health effects of low dose radiation less than 100 mSv have been debated whether they are beneficial or detrimental because sample sizes were not large enough to allow epidemiological detection of excess effects and there was lack of consistency among the available experimental data. We have reviewed an extensive literature on the low dose radiation effects in both radiation biology and epidemiology, and highlighted some of the controversies therein. This article could provide a reasonable view of utilizing radiation for human life and responding to the public questions about radiation risk. In addition, it suggests the necessity of integrated studies of radiobiology and epidemiology at the national level in order to collect more systematic and profound information about health effects of low dose radiation.

Non-radiation risk factors for leukemia: A case-control study among chornobyl cleanup workers in Ukraine.

BACKGROUND: Occupational and environmental exposure to chemicals such as benzene has been linked to increased risk of leukemia. Cigarette smoking and alcohol consumption have also been found to affect leukemia risk. Previous analyses in a large cohort of Chornobyl clean-up workers in Ukraine found significant radiation-related increased risk for all leukemia types. We investigated the potential for additional effects of occupational and lifestyle factors on leukemia risk in this radiation-exposed cohort. METHODS: In a case-control study of chronic lymphocytic and other leukemias among Chornobyl cleanup workers, we collected data on a range of non-radiation exposures. We evaluated these and other potential risk factors in analyses adjusting for estimated bone marrow radiation dose. We calculated Odds Ratios and 95% Confidence Intervals in relation to lifestyle factors and occupational hazards. RESULTS: After adjusting for radiation, we found no clear association of leukemia risk with smoking or alcohol but identified a two-fold elevated risk for non-CLL leukemia with occupational exposure to petroleum (OR=2.28; 95% Confidence Interval 1.13, 6.79). Risks were particularly high for myeloid leukemias. No associations with risk factors other than radiation were found for chronic lymphocytic leukemia. CONCLUSIONS: These data - the first from a working population in Ukraine - add to evidence from several previous reports of excess leukemia morbidity in groups exposed environmentally or occupationally to petroleum or its products.

Benzene exposure and risk of lymphohaematopoietic cancers in 25 000 offshore oil industry workers.

BACKGROUND: The aim of this work was to examine the risk of lymphohaematopoietic (LH) cancer according to benzene exposure among offshore workers. METHODS: Cancer registry data were used to identify 112 cancer cases diagnosed during 1999-2011 in a cohort of 24 917 Norwegian men reporting offshore work between 1965 and 1999. Analyses were conducted according to a stratified case-cohort design with a reference subcohort of 1661 workers. Cox regression was used to estimate hazard ratios with 95% confidence intervals, adjusted for other benzene exposure and smoking. RESULTS: Most workers were exposed to benzene for <15 years. The upper range values of average intensity and cumulative exposure were estimated to 0.040 p.p.m. and 0.948 p.p.m.-years, respectively. Risks were consistently elevated among exposed workers for all LH cancers combined and for most subgroups, although case numbers were small and yielded imprecise risk estimates. There was evidence of dose-related risk patterns according to cumulative exposure for acute myeloid leukaemia (AML), multiple myeloma (MM) (P trends 0.052 and 0.024, respectively), and suggestively so for chronic lymphocytic leukaemia (CLL) according to average intensity (P trend 0.094). CONCLUSIONS: Our results support an association between cumulative and intensity metrics of low-level benzene exposure and risk for AML, MM, and suggestively for CLL.

Prenatal recruitment of participants for a birth cohort study including cord blood collection: results of a feasibility study in Bremen, Germany.

BACKGROUND: Prospective birth cohort studies comprising follow up of children from pregnancy or birth over a long period of time, and collecting various biological samples at different times through the life-course offer a promising approach to enhance etiologic knowledge of various diseases. Especially for those where early lifetime exposures and conditions are thought to play an important role. The collection and storage of biological samples is a critical component in epidemiological studies, notably for research regarding prenatal exposures to various environmental factors as well as for DNA extraction. Our feasibility study for a birth cohort within the scope of etiology of childhood leukemia with prospective sampling of mothers and their future newborns aimed to investigate the willingness of pregnant women to participate in a birth cohort study involving collection of blood and umbilical cord blood samples. The overall aim was to develop practice-based research recommendations for a possible German birth cohort study. METHODS: The study was conducted in Bremen, Germany, between January 2012 and March 2013. Pregnant women were eligible for recruitment if (i) their expected date of delivery was during the study recruitment phase (September 2012-February 2013), (ii) they planned to give birth at the cooperating hospital's obstetric unit and (iii) their knowledge of the German language was sufficient to understand study materials, details of participation and to fill out the prenatal self-administered questionnaire. Maternal blood and umbilical cord blood samples to be used for later research activities were collected and stored at a stem cell bank already collaborating with the hospital. 22 primary care gynecologists were invited to enroll pregnant women for the study and cooperation with one hospital was established. Expectant women were recruited during the last trimester of pregnancy, either during one of their prenatal care visits at their primary care gynecologist or later on in hospital by the attending obstetricians or project staff. RESULTS: Of the 22 invited primary care gynecologists requested to enroll pregnant women for the study, 8 gynecologists actually collaborated. A total of 200 eligible women were invited to participate in the study, 48 (24%) of whom agreed. 34 women were enrolled by primary care gynecologists, with one gynecologist enrolling 26 women. Twelve of 14 women recruited via hospitals were enrolled by study staff. A total of 41 women consented to the collection of umbilical cord blood and maternal blood samples, and samples could be stored for 54% of them. Reason for non-participation were the uncertainty whether or not the full study would be conducted and the fact that the participants were not willing to decide for their children whether or not genetic information (cord blood) can be stored for research purposes. CONCLUSION: Enrolling parents in a birth cohort study that includes biosampling is a challenge, but participation can be improved through close collaboration with primary care gynecologists and maternity hospitals. Cord blood collection may impede participation, especially when maternity hospitals offer an alternative option for cord blood donation.

Risk of death for hematological malignancies for residents close to an Italian petrochemical refinery: a population-based case-control study.

PURPOSE: We investigated the risk of death for hematological malignancies (HMs) in the area surrounding an Italian petrochemical refinery, where atmospheric concentrations of benzene (known carcinogen) had not been adequately monitored in the past. METHODS: We performed a population-based case-control study, using conditional logistic regression to estimate odds ratios (ORs) of HM death, with 95 % confidence intervals (CIs), and p trends, in relation to tertiles of time-weighted average residential proximity to the refinery. We identified 177 HM deaths and 349 sex- and age-matched controls from municipal files. Confounding factors were investigated from interviews with consenting relatives for 109 HM deaths and 178 matched controls. RESULTS: For males and females combined, risk of HM death was unrelated to residential proximity. For females, ORs of HM death by increasing tertiles of proximity were 1, 2.74 (95 % CI 1.48-5.09, significant) and 1.49 (95 % CI 0.76-2.92) (p trend 0.184). For the subgroup of persons who plausibly spent most of their time at home (long-term retired, homemakers or unemployed, 53 cases, 79 controls), the ORs of leukemia plus non-Hodgkin lymphoma death (38 cases, 56 controls) by increasing tertiles of proximity were 1, 3.44 (95 % CI 1.04-11.37, significant) and 3.25 (95 % CI 0.82-12.87) (p trend 0.083). CONCLUSIONS: No increased risk of HM death for males and females combined living close to the refinery was found. However, the findings for females and a subgroup plausibly spending most of their time at home suggest a relation between increased risk of HM death and residential proximity to the refinery.