[Association of metal/metalloids exposure with abnormal liver function among occupational population in a mining area of Hunan Province:a prospective study].

OBJECTIVE: To investigate the association of metals/metalloids exposure with risk of liver disfunction among occupational population in Hunan Province, and to explore the potential dose-response relationship. METHODS: In 2017, a mining area in Hunan Province was chosen as the research site, and eligible workers were recruited as study subjects. General demographic characteristics, levels of 23 metals/metalloids in plasma and urine, and liver function index(total bilirubin(TBIL), alanine amino transferase(ALT), globulin(GLB) and γ-glutamyl transferase(GGT)) were obtained by questionnaire, physical examination and laboratory tests. Participants were followed up in 2018, 2019 and 2020 respectively. Cox proportional risk model was used to evaluate the relationship between metal/metalloids exposure and risk of liver disfunction, and dose-response relationship curves were plotted by using the restricted cubic spline function. RESULTS: A total of 891 employees were recruited in the study, 576(65.0%)were aged ≤45 years, 832(93.4%) were male and 530(59.5%) worked as smelters. After adjusting various factors such as age, gender, BMI, type of work, education, smoking, alcohol consumption, diet, stress, medical history, exercise and tea consumption, positive correlations were found between plasma tungsten(HR=4.90, 95%CI 1.17-20.48) and urinary barium(HR=1.07, 95%CI 1.02-1.12) levels with abnormally elevated TBIL levels. Additionally, a significant association was observed between plasma thallium and the risk of elevated ALT levels(HR=11.15, 95%CI 1.97-63.29). CONCLUSION: Plasma tungsten and thallium, along with barium found in urine, are risk factors for the development of abnormally elevated liver function indices in occupational groups.

Multi-element Exposure and Cognitive Function in Rural Elderly Chinese.

To investigate the relationship between selenium (Se) based multi-element combined exposure and cognitive function in rural elderly individuals, a cross-sectional study was conducted. The study involved 416 older adults aged 60 and above, residing in four different areas of Enshi county, China, with varying soil Se levels. Inductively coupled plasma mass spectrometry (ICP-MS) was employed to measure the concentrations of Se, copper (Cu), iron (Fe), zinc (Zn), calcium (Ca), magnesium (Mg), cadmium (Cd), arsenic (As), and lead (Pb) in whole blood. Nine standard cognitive tests were applied to assess cognitive function. Analysis of the least absolute shrinkage and selection operator regression (LASSO), covariance (ANCOVA), and generalized linear model (GLM) were utilized to investigate the relationship between element exposure and cognitive function. The results of LASSO revealed that Se, Cu, Fe, Zn, Ca, and Pb were independently identified to be associated with cognition. Both ANCOVA and GLM demonstrated that Se and Ca were correlated with cognitive function. The multi-element model showed higher composite Z scores of 0.32 (95% CI: 0.09 to 0.55) for log-transformed Se (P = 0.007), 0.75 (95% CI: 0.01 to 1.49) for log-transformed Cu (P = 0.048), and a lower score of - 0.67 (95% CI: - 1.26 to - 0.08) for log-transformed Ca (P = 0.025). Furthermore, there was evidence that Se could counteract the negative impact of Ca on cognitive function (P for interaction = 0.031). Our findings suggested that higher levels of Se and Cu were associated with better cognitive function in the elderly and Se can counteract the cognitive damage caused by Ca.

[Associations of plasma metals/metalloids with arrhythmia among occupational population: a prospective study].

OBJECTIVE: To investigate the association between levels of twenty-three plasma metals/metalloids and the risk of arrhythmia among occupational population. METHODS: In 2017, a total of 765 workers aged 18 and above were recruited from a non-ferrous metal factory. The general demographic characteristics were obtained by using questionnaire. Plasma metal/metalloid levels were determined by inductively coupled plasma mass spectrometry(ICP-MS). Participants were followed up in 2018, 2019 and 2020 respectively. After the elements that may affect the incidence of arrhythmia were screened out by least absolute shrinkage and selection operator(LASSO) regression, Cox regression model was used to analyze the relationship between levels of selected elements and risk of arrhythmia occurrence, Quantile g-computation model was used to analyze the effect of element mixture exposure on arrhythmia, and the dose-response curve was estimated by using restricted cubic spline(RCS) function. RESULTS: Of all the research subjects, 386(50.5%) were ≤45 years old; 401(52.4%) had 20 years or more of work experience; 712(93.1%) subjects were male workers. The incidence of arrhythmia was 17.6%. After adjusting for age, seniority, gender, body mass index(BMI), marital status, education level, smoking, drinking, drinking tea, regular exercise, chronic diseases(hypertension, hyperlipidemia), sleep quality and psychological stress, chromium, molybdenum and antimony increased the risk of arrhythmia with HR(95%CI) values of 1.22(1.11-1.34), 1.51(1.20-1.90) and 2.38(1.03-5.49), respectively, while barium reduced the risk of arrhythmia with HR(95%CI) value of 0.98(0.95-1.00). CONCLUSION: Chromium, molybdenum and antimony are the risk factors while barium is the protective factor for arrhythmia.

Exposure to ambient air pollutants is associated with an increased incidence of hyperuricemia: A longitudinal cohort study among Chinese government employees.

BACKGROUND: It is widely recognized that ambient air pollution can induce various detrimental health outcomes. However, evidence linking ambient air pollutants and hyperuricemia incidence is scarce. OBJECTIVES: To assess the association between long-term air pollution exposure and the risk of hyperuricemia. METHODS: In this study, a total of 5854 government employees without hyperuricemia were recruited and followed up from January 2018 to June 2021 in Hunan Province, China. Hyperuricemia was defined as serum uric acid (SUA) level of >420 µmol/L for men and >360 µmol/L for women or use of SUA-lowering medication or diagnosed as hyperuricemia during follow-up. Data from local air quality monitoring stations were used to calculate individual exposure levels of PM10, PM2.5, SO2 and NO2 by inverse distance weightingn (IDW) method. Cox proportional hazard model was applied to evaluate the causal relationships between air pollutant exposures and the risk of hyperuricemia occurrence after adjustment for potential confounders and meanwhile, restricted cubic spline was used to explore the dose-response relationships. RESULTS: The results indicated that exposures to PM10 (hazard ratio, HR = 1.042, 95% conficence interal, 95% CI: 1.028, 1.057), PM2.5 (HR = 1.204, 95% CI: 1.141, 1.271) and NO2 (HR = 1.178, 95% CI: 1.125,1.233) were associated with an increased HR of hyperuricemia. In addition, a nonlinear dose-response relationship was found between PM10 exposure level and the HR of hyperuricemia (p for nonlinearity = 0.158) with a potential threshold of 50.11 µg/m3. Subgroup analysis demonstrated that participants usually waking up at night and using natural ventilation were more vulnerable to the exposures of PM10, PM2.5, NO2, and SO2. CONCLUSION: Long-term exposures to ambient PM10, PM2.5 and NO2 are associated with an increased incidence of hyperuricemia among Chinese government employees.

Dose-response relationship of elements with blood lipids and the potential interaction: A cross-sectional study from four areas with different pollution levels in China.

BACKGROUND: A growing number of researches indicated the association between plasma trace elements and blood lipids. However, the potential interaction and dose-response relationship were less frequently reported. METHODS: In this study, a total of 3548 participants were recruited from four counties in Hunan Province, South China. Demographic characteristics were collected by face-to-face interviews and inductively coupled plasma mass spectrometry (ICPMS) was used to determine the levels of 23 trace elements in plasma. We applied a fully adjusted generalized linear regression model (GLM) and a multivariate restricted cubic spline (RCS) to estimate the correlation, dose-response relationship and possible interaction between 23 trace elements and four blood lipid markers. RESULTS: The results indicated positive dose-response relationships of plasma 66zinc with triglycerides (TG) and low density lipoprotein cholesterol (LDL-C), plasma 78selenium with LDL-C and total cholesterol (TCH), and plasma 59cobalt with high-density lipoprotein cholesterol (HDL-C). There was a negative dose-response relationship between 59cobalt and LDL-C. Further analysis found that 66zinc and 59cobalt had an antagonistic effect on the risk of increased LDL-C level. CONCLUSIONS: This study added new evidence for the potential adverse effects of 66Zn and 78Se on blood lipids, and provided new insight into the threshold value setting for metals as well as the intervention strategy for dyslipidemia.

Effects of ambient air pollution, fresh fruit and vegetable intakes as well as maternal psychosocial stress on the outcome of newborn otoacoustic emission hearing screening.

BACKGROUND: Newborn hearing screening results indicated that more than 40% of the detected infants had no recognized risk factors. To determine whether maternal exposure to ambient air pollutants and experience of stressful life event, as well as lack of fresh fruit and vegetable during pregnancy are associated with the abnormal hearing development among newborns. METHODS: A total of 1193 newborns and their mothers were recruited in this study. Personal information and covariates were collected by face to face interview. Medical examination results of newborns and their mothers were extracted from medical record. We estimated personal air pollutant exposure level through inverse distance weighted method based on data from air quality monitoring stations and assessed the auditory development of newborns via distortion product otoacoustic emission (DPOAE). Unconditional logistic regression model was used to estimate the relationship between DPOAE screening result and the potential influential factors as well as the combined effect. RESULTS: The results indicated that PM10 exposure during the second trimester and stressful life event during the third trimester could increase the risk of not passing DPOAE test among newborns. However, frequent intakes of fruit and vegetable significantly reduced the risk. There was a synergetic interaction between PM10 exposure and stressful life event on neonatal hearing development. CONCLUSIONS: To alleviate abnormal auditory development among fetus, pregnant woman should decrease the exposures to ambient air pollutant and negative life event and at the same time, intake sufficient fresh fruit and vegetable.

MBP-activated autoimmunity plays a role in arsenic-induced peripheral neuropathy and the potential protective effect of mecobalamin.

Intake excessive arsenic (As) is related to the occurrence of peripheral neuropathy. However, both the underlying mechanism and the preventive approach remain largely unknown. In the present study, As treatment significantly decreased the mechanical withdrawal threshold and increased the titer of anti-myelin basic protein antibody in rats, accompanied with damaged BNB. The levels of inflammatory cytokines and proteolytic enzymes were also significantly upregulated. However, administration of MeCbl in As-treated rats significantly reversed the decline in hindfoot mechanical withdrawal threshold, as well as BNB failure and sciatic nerve inflammation. Repeated As treatment in athymic nude mice indicated that sciatic nerve inflammation and mechanical hyperalgesia were T cell-dependent. These data implicated that MBP-activated autoimmunity and the related neuroinflammation probably contributed to As-induced mechanical hyperalgesia and MeCbl exerted a protective role probably via maintenance the integrity of BNB and inhibition of neuroinflammation.