Iodine Exposure Research Articles

Age-dependent association of high urinary iodine concentration with major depression in adults: NHANES 2007–2020

Excessive iodine exposure can have detrimental effects on thyroid function and overall health. This study aimed to investigate the age-dependent association between high urinary iodine concentration (UIC) and major depression symptoms in adults, using data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2020. To perform stratified analysis by age, we utilized a rolling window method with a 15-year window width to examine the trend of the odds ratios (ORs) of UIC on depression symptoms with age. Full-factor and one-factor multinomial logistic regression models were employed to calculate the ORs, and violin plots were utilized to depict the ORs of UIC on major depression. The LASSO regression was applied to select variables for one-factor models. The bootstrap method was utilized to ensure the robustness of the results, and the Games-Howell test was applied to compare the differences in the bootstrapped ORs of different UIC groups. Our results indicate that, after age 46, the ORs of high UIC (≥ 300 μg/L) on major depression are significantly higher than those of normal UIC (100–199 μg/L). The bootstrapped ORs of high UIC on major depression calculated by the full-factor and one-factor multinomial logistic regression models are 1.9 (1.28, 2.82) and 1.42 (1.02, 1.93) among participants aged 46 and older, respectively. Based on these findings, we conclude that major depressive symptoms are significantly associated with high UIC among older individuals aged 46 and above.

The Joint Effects of Bisphenols and Iodine Exposure on Thyroid during Pregnancy.

The aim of this research was to study the combined effects of bisphenols and iodine exposure on the thyroid gland during pregnancy. We included 162 pregnant women from a cohort established in Shanghai. Urinary concentrations of bisphenol A, bisphenol B(BPB), bisphenol C(BPC), bisphenol F, bisphenol S, and bisphenol AF(BPAF) were examined. Bayesian kernel machine regression (BKMR) and quantile g-computation models were used. The geometric means of BPA, BPB, BPC, BPF, BPS, BPAF, and ΣBPs levels in urine were 3.03, 0.24, 2.66, 0.36, 0.26, 0.72, and 7.55 μg/g creatinine, respectively. We observed a positive trend in the cumulative effects of BPs and iodine on serum triiodothyronine (FT3) and free thyroxine (FT4), as well as a U-shaped dose-response relationship between BPs and the probability of occurrence of thyroperoxidase autoantibody positivity in women with low urinary iodine concentration. In addition, a synergistic effect on the probability of occurrence of thyroid autoantibody positivity was observed between BPF and BPB, as well as between BPC and BPAF in this study. There were adverse health effects on the thyroid after co-exposure to BPs and iodine. Even if pregnant women were exposed to lower levels of BPs, women with iodine deficiency remained vulnerable to thyroid autoimmune disease.

Iodine-induced hypothyroidism (IIH) in paediatric patients receiving peritoneal dialysis: Is risk mitigation possible?

Children with kidney failure who receive maintenance peritoneal dialysis (PD) are at increased risk for thyroid dysfunction. A poorly appreciated cause of hypothyroidism related to PD is iodine overload from exposure to iodine-containing cleaning solutions, iodinated contrast agents or povidone-iodine-containing PD caps, particularly in infants and small children. An international survey was conducted to understand current practices regarding iodine exposure in PD patients, the frequency of iodine-induced hypothyroidism (IIH) in patients receiving PD, and to assess awareness of this issue among paediatric nephrologists. Eighty-nine paediatric nephrology centres responded to the survey. Hypothyroidism in PD patients was diagnosed in 64% (n = 57) of responding centres, although only 19 of these centres (33%) suspected or diagnosed IIH. Aetiologies of IIH included exposure to povidone-iodine-containing PD caps (53%), cleaning solutions with iodine (37%) and iodinated contrast (10%). While most centres (58%, n = 52) routinely evaluate thyroid function, only 34% (n = 30) specifically aim to limit iodine exposure. Of centres not routinely evaluating for or utilising methods to prevent iodine exposure and hypothyroidism, 81% reported being unaware of the risk of IIH in PD patients. Hypothyroidism is diagnosed in a substantial percentage of paediatric PD programmes internationally. Increased education on the risk of iodine exposure in children receiving PD may decrease the incidence of IIH as an aetiology of hypothyroidism.

The Role of Thyroid Hormone Synthesis Gene-Related miRNAs Profiling in Structural and Functional Changes of The Thyroid Gland Induced by Excess Iodine.

At recent years, the impairment caused by iodine excess are paid more attention. However, there is still largely unknown about the exact mechanism induced by excessive iodine. MiRNAs have been found to act as biomarkers for a variety of diseases, whereas fewer studies focused on miRNAs related to a cluster of genes regulating thyroid hormone synthesis, such as NIS, Pendrin, TPO, MCT8, TSHR, TSHα, and TSHβ-related miRNAs in structural and functional changes of the thyroid gland induced by subchronic and chronic high iodine exposure. In the present study, one hundred and twenty 4-week-old female Wistar rats were randomly divided into control group (I50µg/L KIO3); HI 1 (I6000µg/L KIO3); HI 2 (I10000µg/L KIO3); and HI 3 (I50000µg/L KIO3), the exposure period was 3months and 6months, respectively. The iodine contents in the urine and blood, thyroid function, and pathological changes were determined. In addition, levels of thyroid hormone synthesis genes and the associated miRNAs profiling were detected. The results showed that subclinical hypothyroidism occurred in the high iodine groups with subchronic high iodine exposure, while 6-month exposure led to hypothyroidism in the I10000µg/L and I50000µg/L groups. Subchronic and chronic high iodine exposure caused mRNA and protein levels of NIS, TPO, and TSHR decreased significantly, and Pendrin expression increased significantly. In addition, MCT8 mRNA and protein levels are only remarkably decreased under the subchronic exposure. PCR results showed that levels of miR-200b-3p, miR-185-5p, miR-24-3p, miR-200a-3p, and miR-25-3p increased significantly exposed to high iodine for 3months, while miR-675-5p, miR-883-5p, and miR-300-3p levels increased significantly under the exposure to high iodine for 6months. In addition, miR-1839-3p level was markedly decreased exposed to high iodine for 3 and 6months. Taken together, the miRNA profiling of genes regulating thyroid hormone synthesis remarkably altered from subclinical hypothyroidism to hypothyroidism induced by excess iodine exposure, and some miRNAs may play an important role in subclinical hypothyroidism or hypothyroidism through regulating NIS, Pendrin, TPO, MCT8, and TSHR providing promising targets to alleviate the impairment on the structure and function of thyroid gland.

Topographic and anatomical features of the nasolacrimal duct obstruction due to radioiodine treatment.

To investigate the topographic and anatomical features of secondary acquired nasolacrimal duct obstruction (SALDO) due to radioiodine therapy. Dacryocystography-computed tomography (DCG-CT) scans of the nasolacrimal ducts in 64 cases with SALDO due to radioiodine therapy and in 69 cases with primary acquired nasolacrimal duct obstruction (PANDO) were studied. The anatomical site of obstruction was located, and morphometric characteristics of the nasolacrimal ducts were calculated: volume, length, and average sectional area. The statistical analysis was performed using the t-criterion, ROC analysis, and the odds ratio (OR). The mean nasolacrimal section area was 10.7 ± 0.8mm2 in patients with PANDO and 13.2 ± 0.9mm2 in patients with SALDO due to radioiodine therapy (p = 0.039); the AUC value in ROC analysis for this parameter was 0.607 (p = 0.037). The development of "proximal" obstruction including lacrimal canaliculi obstruction and obstruction at the site of the lacrimal sac was 4.076 times more likely (CI: 1.967-8.443) in patients with PANDO than in patients with SALDO due to radioactive iodine exposure. By comparing CT scans of the nasolacrimal ducts, we observed that in SALDO obstruction due to radioactive iodine therapy is predominantly "distal," while in PANDO it is more often "proximal." The development of obstruction within SALDO is followed by more pronounced suprastenotic ectasia.

Iodine-Induced Hyperthyroidism and Long-term Risks of Incident Atrial Fibrillation and Flutter.

Although iodine-induced hyperthyroidism is a potential consequence of iodinated radiologic contrast administration, its association with long-term cardiovascular outcomes has not been previously studied. To investigate the relationships between hyperthyroidism observed after iodine contrast administration and incident atrial fibrillation/flutter. Retrospective cohort study of the U.S. Veterans Health Administration (1998-2021) of patients age ≥18 years with a normal baseline serum thyrotropin (TSH) concentration, subsequent TSH <1 year, and receipt of iodine contrast <60 days before the subsequent TSH. Cox proportional hazards regression was employed to ascertain the adjusted hazard ratio (HR) with 95% CI of incident atrial fibrillation/flutter following iodine-induced hyperthyroidism, compared with iodine-induced euthyroidism. Iodine-induced hyperthyroidism was observed in 2500 (5.6%) of 44 607 Veterans (mean ± SD age, 60.9 ± 14.1 years; 88% men) and atrial fibrillation/flutter in 10.4% over a median follow-up of 3.7 years (interquartile range 1.9-7.4). Adjusted for sociodemographic and cardiovascular risk factors, iodine-induced hyperthyroidism was associated with an increased risk of atrial fibrillation/flutter compared with those who remained euthyroid after iodine exposure (adjusted HR 1.19, 95% CI 1.06-1.33). Females were at greater risk for incident atrial fibrillation/flutter than males (females, HR 1.81, 95% CI 1.12-2.92; males, HR 1.15, 95% CI 1.03-1.30; P for interaction = .04). Hyperthyroidism following a high iodine load was associated with an increased risk of incident atrial fibrillation/flutter, particularly among females. The observed sex-based differences should be confirmed in a more sex-diverse study sample, and the cost-benefit analysis of long-term monitoring for cardiac arrhythmias following iodine-induced hyperthyroidism should be evaluated.

Abstract #1406373: A Rare Case of Hyperthyroidism in a Patient with Metastatic Thyroid Cancer Presenting as Flaccid Paralysis

Hyperthyroidism in patients with thyroid cancer is rare although increasingly reported. We describe an unusual case of hyperthyroidism associated with metastatic thyroid cancer presenting as flaccid paralysis. A 53-year-old man with a history of a goiter presented to our hospital with severe low back pain for 1 month and inability to walk. He experienced loss of sensation and motor strength in his legs a few days prior to admission. Of note, he was informed about a neck mass years ago, but elected not to follow-up with any medical providers. MRI and CT imaging revealed a large mediastinal mass with cervical lymphadenopathy and multiple lytic lesions in the spine (T11, L1, L5), right ilium, lung, and liver. Initial labs showed mild hyperthyroidism. Biopsy of a right cervical lymph node revealed metastatic thyroid carcinoma, favoring follicular variant of papillary thyroid carcinoma. His hospital course was further complicated by bowel perforation and atrial fibrillation, requiring amiodarone to control his tachyarrhythmia. Subsequent labs revealed worsening thyrotoxicosis with free T4 of 7.62 ng/dL, free T3 of 14.55 pmol/L, and negative thyroid antibodies. He was a poor surgical candidate and unable to receive radioiodine for diagnosis or treatment due to his recent iodine exposure. Methimazole and PTU were not administered as he was strict NPO due to concerns of worsening his bowel perforation. Instead, he received high-dose dexamethasone for both his spinal cord compression and hyperthyroidism. After extensive goals of care discussion, he was eventually transitioned to hospice care. Hyperthyroidism associated with thyroid cancer is rare, as these cancers are typically hypo-functioning and suppression of thyrotropin helps decrease cancer progression. However, these cases are increasingly described in the literature, with a recent systematic review reporting 28 cases of hyperthyroidism in metastatic thyroid cancer patients. Among patients with thyroid cancers, hyperthyroidism can arise from the primary lesion, metastatic lesions, underlying Graves’ disease, toxic nodules, or even precipitated by a large iodine load. The etiology of hyperthyroidism in our patient is unconfirmed, but given the degree of his thyrotoxicosis, we suspect it was primarily from his metastatic disease and worsened by iodinated contrast and/or amiodarone. Our case highlights the importance of monitoring thyroid hormone levels in patients with thyroid cancers and the consequence of using iodine-containing medications, which can precipitate thyroid hormone dysfunction and delay appropriate treatments such as radioiodine ablation.

Reduction of thyroid radioactive iodine exposure by oral administration of cyclic oligosaccharides

Alpha-cyclodextrin, a six d-glucose cyclic oligosaccharide, has several applications in food and pharmaceuticals, but has also been reported to retain iodine in a stable manner for 16 months. Radioactive iodine, which may cause thyroid cancer and hypofunction, must be properly managed. If the absorption of radioactive iodine is suppressed, it can be expected to lead to a reduction in thyroid exposure. This study clarified the inhibition of radioactive iodine absorption by the oral administration of α-cyclodextrin in a murine model using direct measurement of single photon emission computed tomography. The uptake of radioactive iodine into the thyroid gland in mice administered with radioactive iodine and an α-cyclodextrin solution was approximately 40% lower after 24 h. The finding that oral uptake of α-cyclodextrin has an inhibitory effect on the transfer of radioactive iodine to the thyroid gland has potential for application in many fields such as food, pharmaceuticals, nuclear emergency preparedness, and medicine.

Thyroid cancer in pregnancy: diagnosis, management, and treatment.

The evaluation and management of cancer during pregnancy requires special care to assure the health and safety of both the mother and fetus. The diagnosis and treatment of thyroid cancer in the non-pregnant patient often involves radioactive iodine exposure. However, radioactive iodine is contraindicated in pregnancy and surgical interventions pose risks to both the mother and fetus. Thus, the management of thyroid cancer during pregnancy is a unique clinical challenge. In this review, we discuss the imaging of thyroid nodules during pregnancy, including the role of CT, MRI, and nuclear Imaging, as well as that of Ultrasound and FNA. The staging and prognosis are discussed along with the management, treatment, and surveillance of thyroid cancer in pregnancy. Finally, the risks to the fetus through treatment are examined. Case examples are provided with an emphasis on the appropriate direction of care from a radiologist's perspective.

Iodinated Contrast Administration and Risks of Thyroid Dysfunction: A Retrospective Cohort Analysis of the U.S. Veterans Health Administration System.

Background: Iodine-induced thyroid dysfunction is a potential risk among susceptible individuals. Iodinated contrast media is a common source of an acute iodine load used in the health care setting and is frequently required for diagnostic computed tomography scans, coronary angiograms, and other radiologic studies. However, the epidemiologic risks of iodine-thyroid dysfunction have not been fully established in the United States. Methods: This population-based retrospective cohort study used the U.S. Veterans Health Administration database between 1998 and 2021 and included adults aged ≥18 years with a serum thyrotropin (TSH) measurement. Multivariable logistic regression was used to ascertain the risk of incident thyroid dysfunction (defined by repeated measurements of serum thyroid function) following iodine exposure, adjusting for age, sex, race/ethnicity, baseline serum TSH concentration, and duration between baseline and follow-up TSH concentration. Results: The cohort was composed of N = 4,253,119 veterans (mean ± SD = 63.5 ± 14.3 years; 92.9% men; 65.6% non-Hispanic Whites) with 8,729,155 corresponding pairs of serum TSH measurements, from which there were 499,897 TSH pairs with intervening iodine exposure. Thyroid dysfunction occurred in 4.8% of those pairs who had received iodine contrast and 3.6% of those without iodine exposure. Iodinated exposure was associated with an increased risk of thyroid dysfunction (odds ratio [OR] = 1.39, 95% confidence intervals [CI] = 1.37-1.41, p < 0.001) and consistent for all types of serum thyroid dysfunction (overt or subclinical hypo-/hyperthyroidism). Men were at higher risk for the development of thyroid dysfunction than women (men: OR = 1.42, 95% CI = 1.40-1.44; women: OR = 1.16, 95% CI = 1.11-1.21; p-for-interaction <0.001). Conclusions: In this largest analysis of U.S. adults to date, iodine exposure was associated with only clinically small absolute increased risks of thyroid dysfunction, particularly in men. These findings suggest that screening of thyroid function following iodinated contrast administration should be targeted to high-risk individuals.

Management of iodine contrast induced salivary gland swelling (sialadenitis): experiences from an observational study

Background Iodine contrast-induced sialadenitis (CIS) is an uncommon adverse effect to iodine-containing contrast exposition. There is scarce literature about its clinical course and demography. Objectives (1) To determine the clinical course and management of CIS. (2) To understand if CIS might be as rare as reported. Material and Methods A 2-month prospective observational study was conducted in the emergency room of a tertiary institution. ENT physicians on call received clinical formation about CIS while emergency physicians did not. During the study period, patients admitted at the emergency room matching the clinical and radiological features of CIS, were included. Information about demographics, iodine exposure, diagnostic workup, clinical course, and management was analyzed. Results ENT physicians on call detected 4 cases, however, emergency physicians did not. Patients were aged 68–76 years and presented a bilateral submandibular gland swelling debuting 12 to 72 h after an exposure to iodinated contrast. Characteristic ultrasonographic findings supported the diagnosis and the clinical course was self-limited after 60 to 150 h. Conclusions and significance Physicians’ familiarity with CIS allows its detection and avoids costly and potentially harmful therapeutic/diagnostic efforts. The incidence is probably underestimated; however, further incidence studies are needed.

Protection of Vitamin C on Oxidative Damage Caused by Long-Term Excess Iodine Exposure in Wistar Rats.

Vitamin C was reported to be able to protect against oxidative damage due to its reducibility. 120 Wistar rats were randomly divided into 4 × 2 groups, including normal iodine (NI), high iodine (HI), low vitamin C (HI + LC), and high vitamin C (HI + HC); potassium iodide (KI) and potassium iodate (KIO3) were commonly used as additives for iodized salt, so every group was also divided into KI and KIO3 groups. After 6 months' feed, the activities of antioxidant enzymes and Lipid Peroxide (MDA) content in serum, liver, kidney, brain, thyroid and lens were determined. In serum, for males, long-term excess iodine intake caused oxidative damage; in the liver, male rats in the HI + LC group had the highest MDA content, which showed that low-dose vitamin C might promote oxidative damage; in kidneys, the MDA content in the HI and HI + LC groups of females was higher; in the brain, high-dose vitamin C could increase the activity of superoxide dismutase (SOD), which was decreased by high iodine intake, and it also decreased MDA content; in the thyroid, for KIO3, the activity of SOD in the HI group was lower than NI and HI + LC; in the lens, the MDA content in females was lower than males. Long-term excess iodine exposure caused oxidative damage and showed sex difference, and vitamin C had a protective effect on it, especially for high-dose vitamin C.

Excess iodine exposure acutely increases salivary iodide and antimicrobial hypoiodous acid concentrations in humans

The lactoperoxidase (LPO)-hydrogen peroxide-halides reaction (LPO system) converts iodide and thiocyanate (SCN−) into hypoiodous acid (HOI) and hypothiocyanite (OSCN−), respectively. Since this system has been implicated in defense of the airways and oropharynx from microbial invasion, in this proof-of-concept study we measured the concentrations of these analytes in human saliva from a convenience clinical sample of 40 qualifying subjects before and after acute iodine administration via the iodinated contrast medium used in coronary angiography to test the hypothesis that an iodide load increases salivary iodide and HOI concentrations. Saliva was collected and salivary iodide, SCN−, HOI and OSCN− were measured using standard methodology. The large iodine load delivered by the angiographic dye, several 100-fold in excess of the U.S. Recommended Daily Allowance for iodine (150 µg/day), significantly increased salivary iodide and HOI levels compared with baseline levels, whereas there was no significant change in salivary SCN− and OSCN− levels. Iodine load and changes of salivary iodide and HOI levels were positively correlated, suggesting that higher iodide in the circulation increases iodide output and salivary HOI production. This first of its kind study suggests that a sufficient but safe iodide supplementation less than the Tolerable Upper Limit for iodine set by the U.S. Institute of Medicine (1,100 µg/day) may augment the generation of antimicrobial HOI by the salivary LPO system in concentrations sufficient to at least in theory protect the host against susceptible airborne microbial pathogens, including enveloped viruses such as coronaviruses and influenza viruses.

Iodine contrast exposure and incident COVID-19 infection.

Iodine and particularly its oxidated forms have long been recognized for its effective antiseptic properties. Limited in vitro and in vivo data suggest that iodine exposure may rapidly inactivate, reduce transmission, and reduce infectivity of SARS-CoV-2. We hypothesized that iodine exposure may be associated with decreased incident COVID-19 infection. A retrospective population-level cohort analysis was performed of the U.S. Veterans Health Administration between 1 March 2020 and 31 December 2020, before the widespread availability of vaccines against SARS-CoV-2. Multivariable logistic regression models estimated the adjusted odds ratios (OR) and 95% confidence intervals (CI) of the associations between iodinated contrast exposure and incident COVID-19 infection, adjusting for age, sex, race/ethnicity, place of residence, socioeconomic status, and insurance status. 530,942 COVID-19 tests from 333,841 Veterans (mean ± SD age, 62.7 ± 15.2 years; 90.2% men; 61.9% non-Hispanic Whites) were analyzed, of whom 9% had received iodinated contrast ≤60 days of a COVID-19 test. Iodine exposure was associated with decreased incident COVID-19 test positivity (OR, 0.75 95% CI, 0.71-0.78). In stratified analyses, the associations between iodinated contrast use and decreased COVID-19 infection risk did not differ by age, sex, and race/ethnicity. Iodine exposure may be protective against incident COVID-19 infection. Weighed against the risks of supraphysiologic iodine intake, dietary, and supplemental iodine nutrition not to exceed its Tolerable Upper Limit may confer an antimicrobial benefit against SARS-CoV-2. A safe but antimicrobial level of iodine supplementation may be considered in susceptible individuals, particularly in geographic regions where effective COVID-19 vaccines are not yet readily available.

The relationship between urinary iodine concentration and papillary thyroid cancer: A systematic review and meta-analysis.

The effect of iodine on papillary thyroid cancer (PTC) has been controversial for many years. Since urinary iodine is an effective indicator of iodine intake, some recent epidemiological studies have described the relationship between urinary iodine concentration (UIC) and PTC. We searched PubMed, Embase, Cochrane Library, and Web of Science for case-control studies about UIC and PTC published before September 2022. Results are presented as the overall odds ratio (OR) and 95% confidence intervals (CI). According to the analysis of the included studies, excessive iodine intake (UIC≥300ug/L) was positively associated with the occurrence of PTC patients compared with healthy controls (OR4.05, 95%CI 1.64-10.02, P=0.002). Meanwhile, adequate iodine exposure (100≤UIC&lt;200ug/L) may play a protective role in the occurrence of PTC compared with healthy individuals (OR 0.36, 95%CI 0.14-0.91, P=0.03) while the difference in the prevalence of insufficient iodine intake (UIC&lt;100ug/L) and iodine above requirements (200≤UIC&lt;300ug/L) among the two groups were not significant (deficiency: OR 0.38, 95%CI 0.13-1.16, P=0.09; above requirements: OR 0.92, 95%CI 0.40-2.10, P=0.84). After comparing the UIC levels of PTC patients with those of other thyroid diseases, we found that there was also no significant difference in the incidence of different levels of UIC in the two groups (excessive: OR 1.25, 95%CI 0.87-1.80, P=0.22; above requirements: OR 0.93, 95%CI 0.77-1.14, P=0.49; adequate: OR 0.96, 95%CI 0.78-1.17, P=0.67; deficiency: OR 1.02, 95%CI 0.86-1.22, P=0.80). The result of this meta-analysis also did not support the relationship between UIC and the BRAF mutation and lymph node metastasis (LNM) of PTC patients. Besides, we also found that studies on the relationship between urinary iodine and PTC may be influenced by the way UIC was measured. The 10 case-control included studies involved a total of 6,544 participants. The results of this meta-analysis showed excessive iodine intake, that is, UIC≥300ug/L was associated with the occurrence of PTC but not with BRAF mutation and LNM while adequate iodine intake (100≤UIC&lt;200ug/L) may be one of the protective factors for PTC.

Individual Dose Response and Radiation Origin of Childhood and Adolescent Thyroid Cancer in Fukushima II: Possibility of High I-131 Exposure as in Chernobyl

Background: Thyroid cancer incidence of individual dose groups in Fukushima residents exposed at ≤18 years of age demonstrated a linear response to thyroid dose estimated in the United Nations Scientific Committee on the effects of Atomic Radiation (UNSCEAR) 2020/2021. Increased childhood thyroid cancer in Fukushima was found to come dominantly from radiation exposure from the nuclear accident. The UNSCEAR 2020/2021 concluded that the apparent excess of thyroid cancers would not be expected at thyroid doses estimated by the UNSCEAR. The purpose of this paper is to solve the puzzle of the high childhood thyroid cancer incidence in Fukushima despite the estimated low thyroid dose. Methods: The conversion coefficient k connecting thyroid doses estimated in UNSCEAR 2020/2021 and doses based on direct thyroid dose measurements in Chernobyl: 1 GyUN2021 = k × 1 Gy (gray), was estimated by comparing incidences and dose dependences of thyroid cancers in Fukushima and Chernobyl after nuclear disasters. Results: The ratio of the observed cases /expected cases from cancer registry: of about 60 in Fukushima prefecture, was higher than the ratios observed after the Chernobyl accident. The thyroid doses estimated by UNSCEAR were corrected by adding a baseline dose to recover the severely underestimated ingestion dose. The conversion coefficients were: k =60~70 from the comparison of the excess absolute risks (EAR) and their dose dependences in Fukushima and in Chernobyl, and k =10~180 from the comparison of excess relative risk per gray (ERR/Gy) in Fukushima with those in Chernobyl. The thyroid doses might have been underestimated by about 1/50~1/100 in UNSCEAR 2020/2021. Conclusion: The dozens-fold increase of childhood thyroid cancer cases after the Fukushima nuclear accident was found to arise from radioactive iodine exposure comparable to that in Chernobyl.

Povidone iodine exposure alters the immune response and microbiota of the gill and skin in koi carp, Cyprinus carpio

Povidone‑iodine (PVP-I) is a disinfectant widely used to prevent and treat bacterial diseases in fish. The use of PVP-I may disturb the microbial community on the fish body surface and thereby facilitate pathogen invasion. We aimed to assess the effects of PVP-I on the immune system and bacterial communities of skin and gill in Cyprinus carpio. Fish were disinfected with 7.5 mL/m3 of PVP-I (1%) for 30 min, and then skin and gill tissues were sampled on days 0, 1, 3, 7, and 14 for the determination of immunity parameters and characterization of surface bacterial communities. Control fish were not disinfected. The results indicated that exposure to PVP-I decreased the activities of gill lysozyme on day 1, and significantly increased the activities of gill SOD and Na-ATPase on day 7. The activity of skin SOD was enhanced on day 3. The PVP-I bath enhanced the mRNA expression of lysozyme, sod, and cat in the gill but decreased lysozyme on days 1–7 and sod on days 7–14 in the skin. The mRNA expression of tight junction proteins was enhanced in both gill and skin tissue. PVP-I decreased gill bacterial richness on days 3 and 7, and reduced bacterial diversity on day 7. The gill microbiota on day 7 was remarkably separate from the control. The skin microbiota on days 1 and 3 was significantly separated from that of the control. In summary, PVP-I elicited shifts in the immune response and changes in the surface microbiota of fish, and the sensitive time windows of microbial fluctuation after PVP-I treatment were three days in the skin and seven days in the gill.

Corrosion of metal parts on satellites by iodine exposure in space

Iodine becomes increasingly popular as alternative propellant for electric propulsion (EP) systems offering several advantages over established xenon. However, iodine is also a reactive and corrosive element. Thus, a careful material selection for the EP system itself, but also for components employed on the satellite is required in the light of typical space mission durations of several years. Here, we carefully define an approach for mimicking long-term interaction of material specimens with iodine in a space environment. The space conditions cover typical iodine atmospheres (10− 1 to 10− 4 Pa), which occur in the vicinity of a satellite employing an iodine-fed EP system, and exposure times, which correspond to 10 years of mission duration. The approach is used to expose a wide range of metal specimens commonly used on spacecraft to iodine. Chemical modifications of the surfaces of the treated samples are analyzed by x-ray photoelectron spectroscopy (XPS). The elemental metals Fe, Ti, Al, and Nb chemically react with iodine, whereas the elemental metals Ni, Cr, Ta, W, and Mo are basically inert. The stainless-steel and aluminum metal alloys show the same behavior as the corresponding dominant elemental specimens, i.e., Fe and Al, respectively. Somewhat surprisingly, Cr as constituent in stainless steel reacts with iodine, in contrast to elemental Cr. Nevertheless, our studies reveal that long-term exposure to low-pressure iodine atmospheres is not critical for the macroscopic structural integrity of all tested specimens even over space mission durations of several years. The reaction with iodine is macroscopically a surface effect, which mainly affects the optical appearance.

The effects of topical iodine containing antiseptics on thyroidal status and early neurodevelopment of preterm infants.

The goal of this study was to determine the quality of these disinfectants' effects on thyroid function and neurological scores in premature newborns aged 28 to 36 gestational weeks (GW). This cohort study was conducted from October 2020 to September 2021 among 28-36GW preterm infants at the neonatal care unit of Jiangnan University Hospital. We divided this 12month period into two consecutive 6month periods. Composite iodine disinfectants and alcohol are used for skin and umbilical cord disinfection of preterm infants, respectively. Urinary iodine concentration (UIC), thyroid hormone levels, and neonatal behavioral and neurological assessment (NBNA) scores were determined in both groups. A total of 126 patients were included in the study, 65 in the iodine exposed group and 61 in the alcohol group. The second UIC and the incidence of serum T4≤5μg/dL and TSH≥10mIU/L in the iodine exposed group were significantly higher than those in the alcohol group (p<0.05). The first NBNA score was lower in the iodine exposed group than in the alcohol group (p<0.05). However, whether it has clinical significance remains to be explored. There was a linear relationship between the two NBNA scores (iodine exposure group, R 2=0.344; alcohol group, R 2=0.227). No sepsis or other adverse outcomes occurred in the two groups of preterm infants after disinfection with different disinfectants. Iodine-containing disinfectants seem to have the potential to cause an increased rate of thyroid dysfunction and a decreased neurological score and should be evaluated in further studies.

Reduced of radiation exposure and iodine load at CT angiography of the aorta before aortic and aortic valve replacement surgery

Objective . The comparison of protocols of computed tomography (CT) angiography of the aorta and their modification in conditions of radiation and iodine load reducing on the patient. Methods . In 95 patients (57 men, 38 women, mean age 61.4 ± 15.6 years) CT angiography of the aorta was performed using two- and three-zone scanning protocols with the voltage value on the X-ray tube (80 and 100kV) depending on the anthropometric measure namely body mass index (BMI). We compared dose length product parameters (DLP), effective dose (E), time and duration of scanning, as well as counting the amount of injected contrast agent (CM) between groups examined using a two-zone and three-zone protocols at an X-ray tube voltage of 80 and 100kV. Results . Analysis of the data obtained showed that the DLP and E values were statistically significantly lower with the CT angiography of the aorta protocol, which consisted of three scanning zones (at 80kV p = 0.008; at 100kV p &lt; 0.001). At the same time, there was no significant difference in the length of the study area in groups with the same voltage on the X-ray tube (p = 0.55), in the group with a three-zone protocol, the scanning time was significantly lower (p &lt; 0.001) and amounted to 9.4 ± 0.5 sec/10.24 ± 0.9 sec (80/100kV), which made it possible to significantly reduce radiation exposure up to 40% and the amount of injected contrast agent by 20%. Conclusions . The use of a three-zone CT-angiography of the aorta protocol with individual selection of voltage of the X-ray tube is justified and allows a significant reduction of radiation and iodine exposure compared to twozone scanning while maintaining the high images quality.