Blood Mercury Levels Research Articles

Blood mercury concentrations in preschool children and potential risk factors in São Paulo, Brazil

Environmental exposure of preschool children to mercury can elevate blood mercury levels (BML) and negatively affect their health. This study aimed to determine BML in preschool children from Brazil's largest city and explore potential associated risk factors. Blood samples were collected in 2013 from 2436 children (age 1–5 years) attending 50 daycare centers (DCC) located in São Paulo, Brazil. Parents or guardians answered questionnaires collecting information on sociodemographics and potential risk factors. BML was determined by Cold Vapor Atomic Absorption Spectrophotometry (CV-AAS) and categorized using a cutoff point of 2.77 μg L⁻1, corresponding to the 75th percentile. Multiple logistic regression was performed (p < 0.05). Data were georeferenced and associations with air pollution, wind frequency and direction were evaluated. The results showed a geometric mean for BML of 1.65 μg L⁻1 (95% CI: 1.60–1.70), arithmetic mean of 2.15 μg L⁻1 (95% CI: 2.09–2.22), 75th percentile of 2.77 μg L⁻1 (95% CI: 2.67–2.91) and 95th percentile of 5.51 μg L⁻1 (95% CI: 5.18–5.92). DCCs located in the Northwest and East zones (p < 0.001) and fish consumption in the past two days (p = 0.04) were associated with high BML. The elevated BML observed in children living in the eastern zone might be attributed to the southeasterly winds passing through a petrochemical complex located nearby. The 95th percentile of BML in this study exceeded the U.S. 95th percentile by five times. BML in São Paulo preschool children was associated with individual and environmental risk factors. This finding highlights the need to identify and control hot spots in São Paulo, Brazil, especially in peripheral and surrounding areas, where individuals are more vulnerable. Further research is needed in Latin America to identify additional sources of urban environmental mercury exposure and guide interventions for protecting the environment and safeguarding children's health.

7439 Mercury toxicity presenting as Pheochromocytoma

Abstract Disclosure: A. Ansar: None. K. McNerney: None. B.A. Marshall: None. Background: Mercury intoxication is a rare cause of hypertension in children and can mimic other endocrinopathies such as pheochromocytoma. Mercury affects catecholamine metabolism and can cause elevated catecholamine levels, thereby incorrectly suggesting a catecholamine-secreting tumor. Clinical Case: An 8-year-old girl presented to the ED with progressive night sweats, intractable migratory myalgias, hypertension and tachycardia. Patient was in her usual state of health until 2 weeks before presentation when she started to have worsening intermittent pains in her chest, arms, back, and knees. She also experienced restlessness and inability to sleep. On presentation she was hypertensive, with blood pressure of 146/116 mm Hg while calm, heart rate 125 bpm, afebrile. She was anxious, irritable, and seemed uncomfortable. Her skin was dry and rough with a scaly eczematous rash on the arms and legs. She had persistently elevated blood pressure in upper and lower extremities, unremarkable echocardiogram and electrocardiogram, and a normal result on fundoscopic examination. Her initial electrolytes, creatinine, and urinalysis were all normal and remained so on serial evaluations. Urine drug screen was negative. Thyroid function panel showed normal TSH with slightly elevated Free T4 2.28 ng/dL (0.9-1.7), but a normal Free T3 3.9 pg/mL (2.0-4.4) and Free T4 by equilibrium dialysis 1.8 ng/dL (0.8 - 2.0). CT of the chest, abdomen and pelvis was negative and did not show any lesions. Plasma renin activity was 4.6 ng/mL/hour, supine, (&amp;lt;2.0) and plasma aldosterone level &amp;lt; 4.0 ng/dL (&amp;lt; 40 supine) were normal. 24-hour urinary norepinephrine was 90 μg/24h (13-65), epinephrine 37 μg/24h (0.2-10), urine metanephrines 195 μg/24h (18-144), urine normetanephrines 305 μg/24h (29-145), all elevated. Further history taking revealed that patient was taking Ayurvedic supplements prepared by hand by medicinal personnel in India for 3 months prior to presentation. These were stopped 2 weeks prior to her presentation, when she first became symptomatic. Her blood mercury level was 11 ng/mL (n &amp;lt;9), and urinary mercury excretion 67 μg/24 hours (n&amp;lt;10), both obtained 3 weeks after stopping supplementation. She was started on oral chelation therapy with succimer 10 mg/kg/day. Her hypertension was controlled with doxazosin. One week after initiation of therapy, her symptoms improved, and she became normotensive. Her acrodynia and irritability resolved. Urine metanephrine levels will be repeated at upcoming clinic follow up. Conclusion: Mercury toxicity should be considered in the differential of pheochromocytoma to avoid extensive diagnostic testing and morbidity associated with it. Lead, mercury, and arsenic have been detected in traditionally prepared Ayurvedic supplements. A careful history of intake of supplements can be important in cases with unusual symptomatology. Presentation: 6/3/2024

Association of maternal blood mercury concentration during the first trimester of pregnancy with birth outcomes.

Exposure to mercury has been associated with adverse effects on pregnancy outcomes. However, there is limited literature on mercury exposure and pregnancy outcomes in Chinese pregnant women. Our study was to investigate the possible association between maternal mercury exposure and spontaneous preterm birth and birth weight. This study was a nested case-control study. The association between blood mercury concentration and both spontaneous preterm birth and birth weight was analyzed using conditional logistic regression and linear regression adjusted for the potential confounding factors, respectively. The dose-response relationship between mercury concentration and birth outcomes was estimated using restricted cubic spline regression. The mean concentration of mercury was 2.8 ± 2.2µg/L. A positive relationship was observed between maternal blood mercury concentration and SPB when analyzed as a continuous variable. However, it was not found to be statistically significant (adjusted OR = 1.10, 95% CI = 0.95-1.26, P = 0.202). Moderate mercury exposure was associated with a higher risk of SPB (Q3 vs. Q1: crude OR = 2.50, 95% CI = 1.16-5.41, P = 0.02; adjusted OR = 3.49, 95% CI = 1.33-9.11, P = 0.011). After considering the combined effects of chemicals other than mercury exposure (including lead, selenium, and cadmium), the results remained consistent. There was no statistically significant association between blood mercury levels and birth weight (adjusted coefficient = 18.64, P-value = 0.075). There were no statistically significant dose-response associations between mercury concentration and birth outcomes (SPB: P = 0.076; birth weight: P = 0.885). Public health policies should focus on reducing environmental releases of mercury, improving food safety standards, and providing education to pregnant women about the risks of mercury exposure and preventive measures.

A Pathway to Screen for Mercury Levels During Pregnancy and Postpartum

BackgroundPrioritizing dietary choices during pregnancy and breastfeeding is a constant concern, as highlighted by the US Food and Drug Administration. Northwestern Ontario (NWO) boasts stunning natural landscapes, including bodies of water such as streams, rivers, and lakes that serve as vital sources of sustenance for local inhabitants. However, these environments, and particularly the fish that inhabit them, harbor naturally occurring levels of mercury, posing ingestion risks. Northern communities face heightened vulnerability to mercury exposure due to their reliance on fish for nutrition and the ecosystems they inhabit. Prolonged mercury exposure can harm the liver and kidneys. Despite the significant health benefits associated with fish consumption, abstaining from it, especially within certain cultural contexts, is often implausible. Consequently, the health care sector must devise strategies for mitigating elevated mercury levels in susceptible individuals. MethodsA descriptive study explored the frequency of primary care providers (PCPs), including family physicians, midwives, and nurse practitioners, screening for elevated mercury levels among their patients in NWO. ResultsConducted via Qualtrics from June 1 to October 1, 2023, the study revealed that 58% of PCPs either infrequently or never inquire about fish consumption, and 86% have never requested blood mercury levels for perinatal patients. Barriers to screening included lack of conversation initiation, language barriers, perceived insignificance, absence of guidelines, inadequate knowledge, and uncertainty about the relevance of discussing fish consumption. Participants called for a screening protocol, easily accessible fish consumption guidelines, and educational workshops. DiscussionImplementing these recommendations and using the suggested screening pathway could empower PCPs to screen for mercury levels in their patient populations efficiently.

P22-05 Associations between blood mercury levels and basic metabolic panel in freshwater fish (Ctenopharyngodon idella)

P22-05 Associations between blood mercury levels and basic metabolic panel in freshwater fish (Ctenopharyngodon idella)

Variance-based sensitivity analysis for weighting estimators results in more informative bounds

Abstract Weighting methods are popular tools for estimating causal effects, and assessing their robustness under unobserved confounding is important in practice. Current approaches to sensitivity analyses rely on bounding a worst-case error from omitting a confounder. In the following paper, we introduce a new sensitivity model called the variance-based sensitivity model, which instead bounds the distributional differences that arise in the weights from omitting a confounder. The variance-based sensitivity model can be parameterized by an R 2 parameter that is both standardized and bounded. We demonstrate, both empirically and theoretically, that the variance-based sensitivity model provides improvements on the stability of the sensitivity analysis procedure over existing methods. We show that by moving away from worst-case bounds, we are able to obtain more interpretable and informative bounds. We illustrate our proposed approach on a study examining blood mercury levels using the National Health and Nutrition Examination Survey (NHANES).

Measurement of lead, mercury, and cadmium in blood donors in Canada.

Fetal and neonatal exposure to lead is associated with irreversible adverse effects on neural development. There is no reliable threshold for lead effect, so limiting exposure is recommended. A significant correlation has been reported between post-transfusion blood lead level (BLL) in infants and lead levels in transfused RBC units. We measured levels of lead, mercury, and cadmium, in Canadian donor blood to investigate if concerning levels for neonatal transfusion exist. Whole blood samples from blood donors (n = 2529) were shipped cold within 7 days of donation. All permanent blood donation clinics across Canada were sampled. Twelve of these permanent clinics and 8 mobile clinics with a greater potential for having higher lead or mercury levels were oversampled. Heavy metals were measured by inductively coupled plasma mass spectrometry. Of all donations, 2.2% (lead) and 0.4% (mercury) had levels higher than the recommended thresholds for safe neonatal transfusion. BLLs were higher in males but there was no significant difference in the blood mercury levels of males versus females. Cadmium levels were higher in females. There was a positive correlation between donor age and levels of heavy metals, with lead having the strongest correlation (r = 0.47, p < .0001). Three clinics in close proximity to two lead-producing mines were among the clinics with the highest BLLs. Significantly higher blood mercury levels were observed in coastal clinics. Our data on donor blood heavy metal levels supports considering blood transfusion as an exposure source to heavy metals and encourages informed selection of blood units for transfusion to vulnerable groups.

Association of aquatic food consumption, long-chain polyunsaturated n-3 fatty acid intake, and blood mercury levels with cognitive function in middle-aged and older adults

Background & aimsAquatic food is rich in nutrients which benefit the human brain and cognitive health; however, concerns about heavy metal accumulation in aquatic food remain. This study evaluated the associations between aquatic food consumption, long-chain n-3 polyunsaturated fatty acids (LC n-3 PUFAs) intake, and blood mercury levels with cognition in middle-aged and older adults. MethodsThis cross-sectional study used baseline data from the Lifestyle and Healthy Aging of Chinese Square Dancer Study. Aquatic food consumption and LC n-3 PUFAs intake were obtained from a food frequency questionnaire. Blood mercury levels were measured using inductively coupled plasma mass spectrometry. A composite z-score was developed to represent global cognition by averaging the z-scores for each cognitive domain. Participants with mild cognitive impairment (MCI) were diagnosed according to Petersen’s criteria. Multivariate linear and logistic regression models were used to examine the association between the exposure factors and cognitive performance including cognitive scores and MCI. ResultsOf 2621 middle-aged and older adults, the mean (SD) age was 63.71 (5.15) years, and 85.73% were females. Compared with the lowest quartile, those in the highest quartile for aquatic food consumption were associated with higher composite z-scores (β=0.156, 95% CI: 0.088–0.225) and lower MCI odds (OR=0.598, 95% CI: 0.425–0.841). A similar positive relationship between LC n-3 PUFAs intake and composite z-score and an inverse association between LC n-3 PUFAs intake and MCI were also observed. In addition, the participants in the highest quartile for blood mercury levels had higher composite z-scores than those in the lowest quartile. ConclusionsIn this cross-sectional study, higher aquatic food consumption, LC n-3 PUFAs intake, and blood mercury levels were related to better cognitive function. Further studies in Chinese populations are required to confirm these findings.

Evaluation of blood mercury levels and a few biochemical marker levels in obese car painters of Iraq

Introduction and Aim: A greater total blood mercury level is associated with obesity; the present study sought to evaluate the association between blood mercury levels and other biological indicators related to. Materials and Methods: The study population included 25 car painters and 25 healthy participants. The height and weight of each participant was recorded and their BMI calculated. Blood drawn from each participant was assessed for their serum levels of mercury and a few other biochemical markers such as TNF-alpha, MDA, Visvatin, Insulin, and Vitamin-D. The data obtained was subjected to statistical analysis. Results: Compared to healthy controls, the mean levels of mercury in the blood as well as other biochemical indicators were found to be greater. On the other hand, the amount of vitamin D was discovered to be lower than average in the control group. A higher quantity of mercury in the blood was shown to be associated with abdominal obesity, as indicated by the findings. Conclusion: Obesity increases the risk of mercury toxicity in car painters and is linked to higher TNF-alpha, visfatin, and MDA levels, as well as lower vitamin D levels.

Association Between Multiple Heavy Metal Exposures and Cholesterol Levels in Residents Living Near a Smelter Plant in Korea.

Considering the interactions between heavy metals, a comprehensive evaluation of the effects of exposure to various types of co-interacting heavy metals on health is required. This study assessed the association between dyslipidemia markers and blood mercury, lead, cadmium, iron, zinc, and nickel levels in residents of an abandoned refinery plant. A total of 972 individuals (exposed group: 567, control group: 405) living near the Janghang refinery plant in the Republic of Korea were included. Blood mercury, lead, cadmium, iron, zinc, nickel, cholesterol, and triglyceride levels were measured. The combined effect of the six heavy metals on dyslipidemia markers was evaluated using a Bayesian kernel machine regression (BKMR) model and compared with the results of a linear regression analysis. The BKMR model results were compared using a stratified analysis of the exposed and control groups. In the BKMR model, the combined effect of the six heavy metals was significantly associated with total cholesterol (TC) levels both below the 45th percentile and above the 55th percentile in the total population. The combined effect range between the 25th and 75th percentiles of the six metals on TC levels was larger in the exposed group than that in the total population. In the control group, the combined effects of the changes in concentration of the six heavy metals on the TC concentration were not statistically significant. These results suggest that the cholesterol levels of residents around the Janghang refinery plant may be elevated owing to exposure to multiple heavy metals.

The long-term effects of water resource development on blood mercury levels and the trophic ecology of Namew (lake sturgeon, Acipenser fulvescens)

The long-term effects of water resource development on blood mercury levels and the trophic ecology of Namew (lake sturgeon, <i>Acipenser fulvescens</i>)

Evaluation of Blood Nitrotyrosine and Nitric Oxide Levels in Acute Mercury Intoxication in Children

Aim: Multiple processes have been demonstrated to elucidate the biological toxicity of mercuric chloride, among which oxidative stress has been identified as a contributing factor. The superoxide radical has the potential to induce peroxidation of lipid membranes, alter the activities of proteins and antioxidant enzymes, and modulate gene transcription. Additionally, it has the ability to swiftly deactivate Nitric Oxide (NO), resulting in impairment of endothelial function and causing harm to macromolecules, membranes, and DNA by generating more harmful radicals including peroxynitrite and hydroxyl radicals. The formation of nitrotyrosine occurs through the interaction between peroxynitrite and tyrosine residues found in proteins. Nitrotyrosine serves as a useful marker for assessing the possible cytotoxic impacts of nitric oxide. While there have been previous animal tests undertaken, the existing literature we have reviewed does not provide evidence regarding the impact of direct mercury exposure and mercury toxicity on nitrotyrosine and NO. In order to achieve our research objectives, we have devised a plan to investigate the presence of nitrotyrosine and NO in the blood serum of children who have been exposed to mercury in our study. Materials and Methods: Our study included 65 patients, 42 girls and 23 boys, who had accidentally come into contact with mercury in the laboratories of some schools in Kahramanmaraş and Gaziantep provinces, and whose blood mercury level was over 10 μg/l and/or whose urine mercury level was over 15 μg/l. The control group of the study included a total of 23 children, 17 girls and 6 boys, who applied to the pediatric clinic with various complaints, without intoxication or neurological findings, and from whom blood samples would be taken for different diagnoses. Results: Nitric Oxide and Nitrotyrosine levels were found to be higher in children exposed to mercury than in the control group (p&lt;0.01). Nitric Oxide, Nitrotyrosine and mercury levels in the patients were high in both genders, and no gender-related difference was detected (p&gt;0.05). The mean duration of mercury exposure was 45 minutes. Of the 65 patients, 20 were asymptomatic and 40 were symptomatic. The most common symptoms were headache and nausea. Conclusion: The existing body of research predominantly focuses on investigating the association between mercury poisoning and oxidative stress biomarkers through animal studies, with a limited number of studies conducted on human subjects. Our study has made a valuable contribution to the existing literature by successfully detecting elevated levels of NO and Nitrotyrosine in children who have been diagnosed with mercury poisoning.

Vitamin C Alleviates the Risk of Gestational Diabetes Mellitus Associated With Exposure to Metals.

Background: Exposure to heavy metals has been suggested to increase the risk of gestational diabetes mellitus (GDM) through the oxidative stress pathway. The study is aimed at examining whether vitamin C could modify the association between exposure to heavy metals and risk of GDM. Methods: We conducted a case-control study in Taiyuan, China, with 776 GDM cases and 776 controls. Data on vitamin C intake from diet and supplements were collected through questionnaires. Concentrations of metals in participants' blood were measured using inductively coupled plasma-mass spectrometry (ICP-MS). Unconditional logistic regression models were applied to estimate effect modification of vitamin C on the association between heavy metals and GDM. Results: Women with higher blood levels of mercury (Hg) (odds ratio (OR) = 2.36, 95% confidence interval (CI): 1.43, 3.92 and 2.04, 95% CI: 1.20, 3.46 for the second and third vs. the first tertile) and arsenic (As) (OR = 2.46, 95% CI: 1.37, 4.43 and 2.16, 95% CI: 1.12, 4.17 for the second and third vs. the first tertile) exposure were associated with increased risk of GDM among women without vitamin C supplement use and having dietary vitamin C intake < 85 mg/day. We found no significant association with metals among women who took vitamin C supplements and/or dietary vitamin C ≥ 85 mg/day. Significant interactions were observed between vitamin C and exposures to metals (i.e., Hg and As) on the risk of GDM (P interaction = 0.048 and 0.045, respectively). Conclusions: Our study, for the first time, suggests that vitamin C supplement use or higher dietary vitamin C intake during preconception and early pregnancy could alleviate the risk of GDM associated with exposure to As and Hg. The results warrant further investigation.

Association of blood metal exposure with age at menarche in Korean women: KNHANES (2008–2017)

Humans are exposed to metals in their daily lives and this metal exposure is responsible for various adverse health effects. Delayed pubertal development has been suggested as an adverse outcome of metal exposure; however, evidence in nationally representative populations, especially in Asia, is limited. We evaluated the association of blood cadmium (Cd), lead (Pb), and mercury (Hg) levels with the age at menarche in Korean females whose blood heavy metals were measured as part of the Korean National Health and Nutrition Examination Survey (KNHANES) 2008–2017. Among the females 16 years of age or older, all measured heavy metals in blood, i.e., Cd, Pb, and Hg, were positively associated with age at menarche. These associations remained significant in a model adjusted for age, survey year, income, education, body mass index, smoking history, and menopausal status as covariates (β: 0.10, 95% confidence interval (CI): 0.03–0.18 for Cd; β: 0.17, 95%CI: 0.06–0.27 for Pb; β: 0.12, 95%CI: 0.05–0.19 for Hg). When the population was separated by age group at the time of the survey, the significance between heavy metal levels and age at menarche became inconsistent, but the general trends were similar. Among those in their 20s and 40s, blood Cd showed a significant association, while Pb was significant among those in their 40s and 50s. A similar trend was observed in the sensitivity analysis in the girls aged 10–15 years at the time of the survey. Blood Cd levels were associated with decreased odds of precocious menarche (OR: 0.57, 95%CI: 0.31–1.03). Delayed menarche is a risk factor for cardiovascular and chronic kidney diseases in later life; hence, public health implication of heavy metal exposure warrants a public health attention.

The use of CytoSorb in acute oral mercuric chloride poisoning at a potentially lethal dose.

The study aims to present a case of acute mercuric chloride poisoning treated successfully with continuous renal replacement therapy using the CytoSorb filter. A 21-year-old female patient after a suicide attempt by intentional ingestion of mercuric chloride, was admitted to the hospital with features of multiple organ damage for specific treatment. The performed laboratory tests confirmed high levels of mercury in the blood (1051 μg/L) and urine (22,960 μg/L). Due to acute renal failure, continuous renal replacement therapy (CRRT) CVVHD Ci-Ca was initiated; the procedure was then converted to CVVHDF Ci-Ca with ultrafiltration to optimise therapy, and CytoSorb was added to the artificial kidney system on day 3. Specific antidote therapy (DMPS) was administered concurrently. The ongoing treatment resulted in a reduction in subjective complaints, a decrease in blood mercury levels to 580 μg/L, and an improvement in parenchymal organ function. In the event of poisoning with inorganic mercury compounds (mercuric chloride), continuous renal replacement therapy using the CytoSorb filter as an extracorporeal blood purification method may be considered.

Basit Febril Nöbetli Çocuklarda Civa, Kadmiyum, Arsenik Düzeyleri ve Nöbet Süresi ile İlişkilerinin Belirlenmesi

Objective: Heavy metals may cause neuronal damage by inducing oxidative stress. This study aims to investigate the levels of mercury, cadmium, and arsenic in children with febrile seizures and their correlation with seizure duration. Materials and Methods: The study was conducted on 40 children who experienced simple febrile seizures and 30 children who had a fever but did not experience seizures. The study analyzed complete blood count, serum high-sensitive C-reactive protein, albumin, whole blood mercury, cadmium, and arsenic levels. The analysis was conducted six hours after the seizure for those who experienced seizures and six hours after the onset of fever for those who did not experience seizures. Results: Our study found that the patient group had significantly higher levels of arsenic in their blood compared to the control group. At the same time, there was no significant difference in the levels of mercury and cadmium. However, we could not establish any relationship between the seizure duration and the heavy metals levels. Conclusion: While mercury and cadmium levels are normal in children with simple febrile seizures, arsenic levels are high. However, the levels of all three heavy metals have no relationship with the duration of seizures.

Prenatal arsenic and mercury levels among women practicing geophagy in areas with artisanal and small-scale gold mining activities, Northwestern Tanzania

BackgroundArtisanal and small-scale gold mining (ASGM) areas potentially pose increased exposure to arsenic and mercury through community contamination, occupations at gold mines, and/or geophagy when soil is locally sourced. This study examined the effects of geophagy, a deliberate soil eating practice, along with community and occupational exposures in ASGM areas on urinary arsenic and blood mercury levels among pregnant women in the Mining and Health Longitudinal Cohort in northwestern Tanzania.MethodsData on maternal arsenic and mercury levels were captured for 1056 pregnant women using an unprovoked morning urine samples and dried blood spots respectively. We used a step-wise generalized linear regression model to retain the most relevant covariates for the model. A generalized linear regression model with identity link function was used to predict the effect of geophagy practices on arsenic and mercury levels separately. The model was adjusted using sociodemographic correlates, including maternal age, education level, whether respondents lived in mining or non-mining area, years of residence, marital status, maternal occupation, individual partner’s education, and occupational, and socioeconomic status.ResultsIn the adjusted regression model, eating soil during pregnancy increased arsenic concentration by almost 23% (β = 1.229, 95% CI: 1.094, 1.38, p < 0.001) and living in mining areas had a 21.2% (β = 1.212; 95% CI: 1.039,1.414, p = 0.014) increased risk. Geophagy significantly increased mercury levels by 13.3% (β = 1.133, 95% CI: 1.022, 1.257, p = 0.018). Living in areas with ASGM activities was associated with a 142% (β = 2.422, 95% CI: 2.111, 2.776, p < 0.0001) increase in blood mercury.ConclusionGeophagy practices increased urinary arsenic and blood mercury levels in pregnant women, which was especially true for arsenic when living in areas with ASGM activities. Working in mining = increased risk for blood mercury levels. Community-based environmental health policies should address reductions in occupational and community exposures, along with strategic geophagy reduction interventions.

Lead, cadmium, and mercury blood levels in schoolchildren in southern Sweden: Time trends over the last decades

To prevent diseases arising from exposure to toxic metals, more knowledge about their temporal changes is needed, especially in children, the most vulnerable group.This study follows temporal changes in blood lead (BPb), mercury (BHg) and cadmium (BCd) levels in schoolchildren (8–11 years old) from two cities in southern Sweden. One blood sample per 773 children was used for time trend analyses between 2007 and 2022. One further blood sample re-sampled after 2 years, were used to assess intra-individual time trends of BPb (n = 377), BCd (n = 102) and BHg (n = 53) between 1979 and 2019.Geometric mean (range) of BPb, BCd and BHg concentrations during 2007–2022 was 9.9 (2.3–59), 0.09 (0.03–0.34) and 0.73 (0.02–8.2) μg/L, respectively. Living close to a Pb smelter resulted in higher levels of all three metals compared with living in the city or rural area. Annually, the concentrations clearly decreased for BPb (−4.9%, p < 0.001) and weakly for BCd (−0.6%, p = 0.013), while BHg slightly increased (+1.4%, p = 0.029). When stratified by residential area, the decrease of BCd and increase of BHg were significant only in the urban area (−1.8% and +2.8%, respectively; p < 0.01). The BPb decrease rate was the highest in the urban area followed by the rural and Pb smelter areas (−5.8% > -4.5% > -3.9%; p < 0.001). For children re-analysed during 1979–2019, a significant decrease was observed only for BPb (−6.8%; p < 0.001), with a 2% higher decrease rate in the period before than after the Pb-gasoline ban in 1994.The preventive measures against Pb pollution are reflected in the constant decrease of BPb levels over time. However, the area close to a Pb smelter, as indicated by a slower Pb decrease rate, might need further and stricter preventive measures. Exposure to Hg and Cd was low, however, the slight increase in BHg and only a minor decrease in BCd, indicate the need for continuous biomonitoring of children.

Increase of blood mercury level with shark meat consumption: A repeated-measures study before and after Chuseok, Korean holiday

Sharks are known to contain high levels of mercury in their meat. However, few studies have directly assessed the changes in mercury concentration in the human body according to shark meat intake. One hundred and ninety-seven participants that traditionally consume shark meat during the Chuseok holiday were recruited from two areas of Gyeongsangbuk-do, South Korea to examine their blood mercury level before and after the holiday season. Blood mercury levels were measured before and after the holiday season. Characteristics such as the consumption of shark meat, intake amount, and the effect on mercury concentration were assessed during the survey. Univariable and multivariable analysis (Linear Mixed Model) were done for assessing the association between shark meat consumption of holiday season and blood mercury level. Among the total participants, 83 consumed shark meat during holiday. In the univariable analysis, a significant increase in blood mercury levels before and after Chuseok was observed only for the group that consumed shark meat during holiday. The multivariable analysis (adjusted for identified confounders that affect both exposure and outcome considering repeated measurements) showed that consuming shark meat was significantly associated with increased blood mercury levels by 3.56 μg/L (95% confidence interval [CI], 2.64–4.67 μg/L). In the model considering the amount consumed as two group, the level of increase was 2.61 μg/L (95% CI, 1.63–3.58 μg/L) for those consuming <100 g, and 6.20 μg/L (95% CI, 4.77–7.62 μg/L) for those consuming ≥100 g compared to group without consuming shark meat. Considering amount consumed as continuous value, 0.02 μg/L (95% CI, 0.01–0.02 μg/L) of blood mercury increase was significantly associated with consuming 1 g. Consumption of shark meat significantly elevated blood mercury levels, exceeding commonly suggested reference concentrations in less than 2 weeks. These findings suggest the need for public health warnings and regulations regarding shark meat consumption.

Some metals and metalloids in the blood of three species of shorebirds increase while foraging during two-week migratory stopover in Delaware Bay, New Jersey

Most migratory shorebird species are declining, some are endangered, and some may be vulnerable to contaminants on long distance travel between wintering grounds and high latitude breeding grounds. We examined whether shorebirds accumulated trace elements at the Delaware Bay (New Jersey) stopover by testing the null hypothesis that there was no difference in the levels of arsenic, cadmium, chromium, lead, mercury, and selenium in blood of three species of shorebirds collected early in their stopover compared to levels in blood collected about two weeks later near the end of the stopover, before departing for breeding grounds. There were significantly higher levels of all metals and metalloids in the blood of ruddy turnstone (Arenaria interpres) later in May than earlier. There were seasonal increases in blood levels of arsenic and selenium for all three species. Chromium and lead levels also increased in red knots (Calidris canutus). These increases occurred although the birds were only present for about two weeks. Levels of arsenic, mercury, and lead in knots and selenium in sanderlings (Calidrris alba), exceeded reported effects levels. These results have potential implications for studying the refueling physiology, energetics, and feeding behavior of migratory shorebirds. However, they also suggest cause for concern because the increased contaminant loads occur in a short period, and the high metal level bolus received all in a few days may result in adverse effects.