Association between exposure to lead, cadmium, and arsenic and blood pressure in workers from a smelter / 环境与职业医学

Background Occupational exposure to lead, cadmium, or arsenic is a potential risk factor for blood pressure elevation. Current studies mainly focus on the relationship between a single metal and blood pressure. However, mixed metal exposure often exists in the actual working environment, and the interactive effects of polymetallic interactions on blood pressure and the dose-effect relationship remain unclear yet. Objective To explore the influence proportion of occupational exposure to lead, cadmium, or arsenic on blood pressure and their interactive effects. Methods From January to December 2021, workers from a smelter in southern China were selected. Demographic characteristics, height, weight, and blood pressure of workers were collected through questionnaire and physical examination. At the same time, their urine samples were collected and the levels of urinary lead, urinary cadmium, and urinary arsenic were detected by inductively coupled plasma mass spectrometry, and corrected by urinary creatinine (Cr). Linear regression and logistic regression were used to analyze the relationship between urinary lead, cadmium, and arsenic and blood pressure. Weighted quantile sum (WQS) regression was applied to evaluate the dose-effect relationship between urinary lead, cadmium, and arsenic exposures and blood pressure and the effect weight of each metal on blood pressure. Generalized linear regression and additive/multiplicative scaling were used to identify interactive effects of the three metals on blood pressure. Results A total of 1075 workers were included in this study, with a mean age of (44.68±5.11) years and mean working seniority of (24.66±5.23) years. There were 891 males (88.9%) and 184 were females (17.1%); 24.7% workers were drinkers and 45.7% workers were smokers; 302 workers (28.1%) reported hypertension and 37 of them were taking antihypertensive drugs. The P50 (P25, P75) levels of urinary lead, urinary cadmium, and urinary arsenic were 6.11 (3.71, 11.08), 3.88 (2.68, 5.44), and 26.04 (19.99, 35.11) μg·g−1, respectively. After adjusting for gender, age, working seniority, body mass index, smoking, drinking, and the usage of antihypertensive drugs, systolic and diastolic blood pressure increased by 0.772 and 0.418 mmHg respectively for 10% increase in lead, cadmium, and arsenic mixed exposure. Urinary cadmium, among the three single exposures, had the greatest effect on systolic and diastolic blood pressure, weight (w)=0.523 and 0.551 respectively. The interaction of urinary lead and urinary cadmium was positively correlated with the occurrence of hypertension, multiplicative interaction OR (ORint)=1.88 (95%CI: 1.09, 3.63), attributable proportion due to interaction (AP)=1.19 (95%CI: 0.40, 8.18). Conclusion This study shows that mixed exposure to lead, cadmium, and arsenic has a positive relationship with blood pressure, in which cadmium plays a major role. Co-exposure to lead and cadmium has a positive interactive effect on hypertension development and systolic blood pressure elevation.

Benchmark dose estimation based on Bayesian model averaging and its application to evaluation of cadmium exposure of population in Baiyin / 环境与职业医学

Background The optimal model method for estimation of benchmark dose (BMD) does not consider the uncertainty of model selection. There is a lack of studies on using Bayesian model averaging (BMA) to estimate BMD. Objective To apply BMA to the exposure assessment of cadmium pollution in China, discuss the role of BMA in estimating BMD based on dose-response models, and to provide methodological support for health risk assessment of hazardous substances. Methods The parameters of five dose-response models (Gamma, Log-logistic, Log-probit, Two-stage, and Weibull models) estimated from the data from a cadmium-contaminated area in Baiyin City of Gansu Province and the urinary cadmium ranges in five cadmium-contaminated areas in China were used to simulate the data of varied correct models with different numbers of dosage groups (5 and 8) and different sample sizes (50, 100, and 200), then the performance of BMA and traditional optimal model were compared. The case analysis used the cadmium exposure data in Baiyin, Gansu Province. All analyses set urinary cadmium as the indicator of cadmium exposure, the abnormal rate of β2-microglobulin as the effect indicator, and the benchmark response to 10%. The correct model (the model used when simulating data), optimal model [the model with smallest Akaike information criterion (AIC)], and BMA were used to estimate BMD and lower confidence limit of benchmark dose (BMDL); the BMDs, BMDLs, and relative deviations from different methods were compared. Results In the simulation study, with increasing sample size or the number of dosage groups, the intervals of the 5th percentile and the 90th percentile of BMD tended to be narrower; when the correct model was a single model, the relative deviation of BMD estimation by BMA was greater than that of the traditional optimal model; when the correct model was an equal weight mixed model, the relative deviation of BMD estimation by BMA was less than that by the traditional optimal model. For the data of cadmium-contaminated areas, the optimal model was a Log-probit model (AIC=1814.46), followed by a Log-logistic model (AIC=1814.57); the BMDs (BMDLs) estimated by the Log-probit model, the Log-logistic model, and BMA were 3.46 (2.68), 3.16 (2.33), and 2.92 (2.07) μg·g−1, respectively. Conclusion The traditional optimal model is still recommended when the correct model is known. However, when the dose-response relationship of a hazardous substance is uncertain or with different sources or exposure grouping, compared with the traditional optimal model, BMA theoretically provides more stable estimation of BMD and BMDL by considering multiple possible alternative models.

Association between heavy metal exposure level and physical development indicators among school-age children / 环境与职业医学

Background Heavy metals are widely present in the environment, difficult to degrade, and bioaccumulative. Children's physical development are not mature, and exposure to heavy metals which may cause irreversible harm to them. However, the current research conclusions are still inconsistent. Therefore, it is very important to pay attention to the impact of heavy metal pollutants on physical development. Objective To detect the level of heavy metal exposure of school-age children in Laizhou Wan, Shandong Province, and to explore the relationship between heavy metal exposure level and physical development indexes of school-age children. Methods The subjects of this study were 318 children born to pregnant women recruited from Laizhou Wan Birth Cohort in Shandong Province from September 2010 to December 2013. The school-age children at age 7 were followed up from July to September 2019. Their urine samples were collected and the levels of arsenic (As), cadmium (Cd), lead (Pb), and mercury (Hg) in urine were detected by inductively coupled plasma mass spectrometry (ICP-MS). At the same time, the height, weight, body mass index (BMI), waist circumference, and body fat percentage of the children were evaluate to analyze the relationship between the four heavy metals in children's urine and the indicators related to children's physical development. Results Among the 318 school-age children with an age (\begin{document}$\bar x \pm s $\end{document}) of (7.77±0.67) years, the median (P25, P75) levels of As, Cd, Pb, and Hg in urine were 73.98 (44.81, 124.61), 0.40 (0.27, 0.58), 1.20 (0.71, 1.72), and 2.38 (1.32, 4.80) µg·g−1 (of creatinine), respectively. The children’s urinary Cd level was positively correlated with their weight, BMI, and waist circumference (P<0.05), and corresponding regression coefficients (b) and its 95% confidence intervals (CI) were 0.99 (0.14-1.83), 0.43 (0.06-0.81), and 1.35 (0.27-2.42), respectively; while the other heavy metals were not related to the above physical development indicators (P>0.05). After sex stratification, it was found that boys’ urinary Cd level was positively correlated with their height, weight, BMI, and waist circumference (P <0.05) with associated b (95%CI) of 1.73 (0.53-2.93), 2.03 (0.60-3.47), 0.75 (0.11-1.38), and 2.66 (0.85-4.47), respectively; such associations were not found in girls. After further stratification of boys’ BMI according to normal, overweight, and obesity, it was found that a higher urinary Cd level was correlated with an increased risk of obesity in boys (P<0.05), and the associated b (95%CI) was 2.34 (1.02-5.36). Conclusion The level of urinary Cd exposure of boys in Laizhou Wan, Shandong Province is positively correlated with their height, weight, BMI, and waist circumference, and may be related to obesity in boys.

Effects of occupational cadmium exposure on workers' cardiovascular system / 中华劳动卫生职业病杂志

Objective@#To investigate the effects of cadmium exposure on cardiovascular system of occupational workers.@*Methods@#Cross-sectional study was applied to 992 workers in a nickel-cadmium battery plant in November, 2011, of which 749 were cadmium exposed workers and 243 were controls without cadmium and other expose. Urinary cadmium、electrocardiogram (ECG) and blood pressure were examined simultaneously among 992 workers. The risk factors of ECG abnormality rate and hypertension rate were analyzed by Logistic regression.@*Results@#The level of urinary cadmium in cadmium exposed workers was significantly higher than controls (8.89±4.00 vs 1.34±1.18 μg/g creatinine, P<0.01) . Urinary cadmium level in women was significantly higher than men in both exposure and control group (P<0.05) . According to the group of working years, Urinary cadmium level raised with the increase of working years (F=28.272, P<0.001) . The ECG abnormality rate and hypertension rate of cadmium exposed workers were higher than that of control group, the differences were all statistically significant (P<0.01) . The abnormal rate of ECG and the hypertension rate increased with the prolonging of working years and demonstrated dose-response relationship. With the increase of urinary cadmium level, the abnormal rate of ECG and hypertension rate raised (OR=1.11, P<0.01) and (OR=1.15, P<0.01) respectively.@*Conclusion@#Occupational cadmium exposure increased the abnormal rate of ECG and blood pressure and therefore damaged cardiovascular system of workers. This study provided base data for protecting health of cadmium exposed workers.

Study on the dosage of GMDTC for removing cadmium / 中国职业医学

OBJECTIVE: To explore different doses of sodium(s)-2-(dithiocarboxylato((2R,3R,4R,5R,6R)-2,3,4,5,6-pentahydroxyhexyl) amino)-4-(methylthio) butanoate(GMDTC) for removing cadmium. METHODS: Thirty-five male New Zealand rabbits were randomly divided into blank control group,GMDTC high dose control group,model control group,ethylene diamine tetraacetic acid(EDTA) control group and GMDTC low,medium and high dose groups,five rabbits in each group. The blank control group and GMDTC high dose control group were given 0. 90% normal saline solution intravenously; model control group,EDTA control group and GMDTC low,medium and high dose group were given 2 μmol/kg of cadmium chloride(CdCl_2) and 40 μmol/kg of β-mercaptoethanol mixed solution intravenously,5. 0mL/kg body weight(bw),once a day for five days. On the forty-one day of the experiment(the fist day of GMDTC treatment),the control group and the model control group were injected 0. 90% normal saline solution 250 mL via ear vein,the EDTA control group was given EDTA solution at the dose of 93. 5 mg/kg bw with 250 mL 0. 90% normal saline solution,also via ear vein; the GMDTC high dose control group,and the GMDTC low,medium and high dose groups were given 250 mL GMDTC solution at the concentration of 108.0,12.0,36.0 and 108. 0 mg/kg bw with 0. 90% normal saline by intravenous infusion,once a day,6 times a week for four consecutive weeks. The urine β_2-microglobulin(MG),renal cadmium,blood cadmium,and urinary cadmium before and after the treatment were detected. RESULTS: The body weight of New Zealand rabbits increased with the increasing feed time(P < 0. 01). The levels of β_2-MG before treatment increased in model control group,EDTA control group,GMDTC low,medium and high dose groups than that in the blank control group(P < 0. 01). The levels of renal cadmium after treatment in GMDTC medium and high dose groups decreased compared with those in the blank control group and EDTA control group respectively(P < 0. 05). The blood cadmium after treatment in EDTA control group,GMDTC low,medium and high dose groups were decreased compared with those before treatment in the same group respectively(P < 0. 05),meanwhile decreased than the blood cadmium after treatment in the model control group respectively(P < 0. 05). The blood cadmium after treatment had not a statistically significant difference among the EDTA control group,GMDTC medium and high dose groups(P < 0. 05). At all the time points(1,6,8,13,15,20,22 and 28 days after treatment),the urinary cadmium after treatment in EDTA control group and the three GMDTC dose groups increased compared to the model control group at the same time(P < 0. 05). The urinary cadmium after treatment increased with GMDTC dose increased at the other six time points,expect on 20 and 22 days after treatment(P < 0. 05). The blood cadmium removal rates after treatment were 70. 06%,74. 86% and 78. 05% and the renal cadmium removal rates were 14. 27%,27. 95% and 61. 24% in GMDTC low,medium and high dose groups,respectively. CONCLUSION: The intravenous infusion of GMDTC at the dose of 108. 0 mg/kg bw effectively removed cadmium in cadmium poisoning rabbit. This dose had no obvious toxic effect and was equivalent to human dose of 36. 0mg/kg bw which meets the requirement of new drug property.

Epidemiological survey of urinary Cadmium in Shengyang urban children / 中华实用儿科临床杂志

Objective To evaluate the body burden of Cadmium(Cd) in normal children from Shenyang city,and to analyze the effect of Cd on kidney.Furthermore,to investigate the influences of living factors on the level of Cd in children,so as to make recommendations for children's health.Methods The subjects was composed of 1 170 healthy children recruited from 0 to 17 years old by cluster random sampling method.They were divided into three groups(0-5 years old group,6-11 years old group,12-17 years old group).Questionnaires were used to obtain essential information about age,gender,weight,socioeconomic status,medication,and so on.Second morning urine samples were collected to make routine analyses,urinary Cd(Cdob),urine microalbumin(MALB) and α1-microglobulin(α1-MG).Results 1.A total of 1 070 children including 544 males and 526 females were enrolled.2.The concentration of Cdob increased with age,in agreement with the level of urinary Cd corrected by urine specific gravity (Cdsg).However,the level of Cd in urine corrected by urinary creatinine(Cdcr) presented the opposite status with the age increasing.3.Cdcr and urine MALB adjusted by urinary creatinin(MALBcr) revealed a positive correlation(rs =0.45,P ＜ 0.01).4.Preference values for Cdob and Cdsg,Cdcr respectively were:0-5 years old ＜0.56 μg/L,＜0.83 μg/L and ＜2.17 μg/g Cr;6-11 years old ＜0.65 μg/L,＜1.01 μg/L and ＜1.23 μg/g Cr;12-17 years old ＜0.74 μg/L,＜1.15 μg/L and ＜ 1.25 μg/g Cr.Conclusions There is an age-dependent cumulative increases in Cdob.Although renal damage was not found in this study,the uptake of Cd should be reduced as much as possible and it is necessary to strengthen the follow-up study of Cdob in body burden.

Renal impairment and stone risk in inhabitants environmentally exposed to cadmium in Mae Sot District of Tak Province, Thailand

Objective: Cadmium (Cd) is a cumulative poison. Long-term exposure to environmental Cd causes oxidative stress, renal dysfunction and bone defects. The present study aimed to investigate the status of renal impairment and risk of urolithiasis in inhabitants environmentally exposed to Cd in Mae Sot District, Tak Province of Thailand. Methods: A total of 77 non-smoking women were recruited to the study, 40 subjects from high Cd-polluted areas (Group 1), 17 subjects from the vicinity of Cd-polluted areas (Group 2) and 20 control subjects from non Cd-polluted areas living outside the Mae Sot District (Group 3). Blood and 24-hr urine samples were collected. Plasma creatinine (Cr), calcium (Ca), magnesium (Mg) and zinc (Zn) were measured. Levels of Cd, Zn, Mg, Ca, Cr, proteins and N-acetyl-β-glucosaminidase (NAG) activity were determined from urine samples. Results: Group 1 and Group 2 excreted urinary Cd significantly higher than Group 3. The prevalence of urinary Cd \> 2 mg/g Cr in Group 1, Group 2 and Group 3 were 25%, 11.8% and 0%, respectively. Creatinine clearance (CCr) of Group 1 was significantly lower than that of Group 2. Urinary excretions of proteins, Ca and Zn in Group 1 were significantly higher than in Group 2. Urinary levels of NAG activity and proteins in Group 1 were significantly higher than in Group 3. The urinary level of Ca in Group 1 was significantly higher than in Group 3. In contrast, urinary Mg in Group 1 was significantly lower than that in Group 3. In Group 1, urinary Cd was positively correlated with urinary NAG activity, proteins and Zn, but it was inversely correlated with CCr. Conclusion: The residents of high Cd-polluted areas had renal impairment, increased urinary Ca and decreased urinary Mg. Subjects who resided in the vicinity, manifested kidney damage. These local populations are at risk for kidney diseases, particularly urolithiasis.

Blood and Urinary Cadmium Concentration of Residents around Abandoned Metal Mines in Busan and Gyeongsangnam-do / 대한산업의학회지

OBJECTIVES: To evaluate the blood and urinary cadmium concentration levels of around abandoned metal mines in comparison with a control group. METHODS: Blood and urinary cadmium concentration levels were analyzed through investigations of the dietary habits and dietary water of subjects living near abandoned metal mines (exposure group) (n=190) in comparison with those living in designated control areas (control group) (n=256). RESULTS: The blood cadmium (1.93 microgram/l) and urinary cadmium (2.41 microgram/g cr) concentrations of the exposure group were significantly higher than those of the control group (blood cadmium: 1.19 microgram/l, urinary cadmium: 1.94 microgram/g cr). Both concentrations were significantly higher in vegetarians in both groups. CONCLUSIONS: The exposure group had higher blood and urinary cadmium concentrations than the control group. We attributed the elevated blood and urine cadmium levels in the abandoned mine residents to the influence of the abandoned mine sites.

Trend of the Changes in the Level of Blood Lead, Urinary Arsenic and Urinary Cadmium of Children in Ulsan: 3-year Follow-up Study / 예방의학회지

OBJECTIVES: To obtain basic data on blood lead level and urinary level of arsenic and cadmium of children living near a petrochemical estate and a suburban area in Ulsan, Korea and to observe the trend of the changes in the level of these metals in these children. METHODS: The study subjects comprised 626 children living near a petrochemical estate and 299 children living in a suburban area of Ulsan. We analyzed the level of lead, arsenic and cadmium using atomic absorption spectrometer. RESULTS: The mean levels of blood lead in children living near the petrochemical estate were 5.25 microgram/dl, 5.24 microgram/dl, and 7.24 microgram/dl in the years 1997, 1999, and 2000, respectively, whereas those of children living in the suburban area were 3.81 microgram/dl, 4.75 microgram/dl, and 7.19 microgram/dl respectively. The mean levels of urinary arsenic in children living near the petrochemical estate were 4.57 microgram/g creatinine, 4.78 microgram/g creatinine, and 6.02 microgram /g creatinine in the year 1997, 1999, and 2000 respectively, whereas those of children living in suburban area were 2.35 microgram/g creatinine, 4.75 microgram/g creatinine, and 7.07 microgram/g creatinine, respectively. The mean levels of urinary cadmium in children living near the petrochemical estate were 1.15 microgram/g creatinine, 1.05 microgram/g creatinine, and 1.71 microgram/g creatinine in the year 1997, 1999, and 2000, respectively, whereas those of the children living in the suburban area were 0.74 microgram/g creatinine, 1.29 microgram/g creatinine, and 1.48 microgram/g creatinine, respectively. There were increasing trends in the level of blood lead, urinary arsenic and cadmium of children in Ulsan, and the differences in the level of these metals were disappearing between the children living in other areas year by year. CONCLUSIONS: These results suggest that the amount of exposure to lead, arsenic, and cadmium is increasing from year to year, and there is a need for periodic biological and atmospheric monitoring of these metals in Ulsan.

A Study on Urinary Cadmium Concentration and Renal Indices of Inhabitant in an Abandoned Mine Area / 예방의학회지

Urinary cadmium is used as a sensitive indicator for internal Cd dose, and increased excretion of N-acetyl-beta-D-glucosaminidase(NAG), beta(2)microglobulin(MG) and total protein are useful indices for renal dysfunction by chronic exposure to Cd. The target group was 184 inhabitant(82 men and 102 women) in an abandoned mine area known as exposure to low level Cd. The control group was took 160 individuals(64 men and 96 women) in Cd not-exposed area. Urinary Cd concentration was significantly higher in the target group than the control. The geometric mean of urinary Cd for male was 2.56ng/l, 2.80ng/g creatinine and 2.50ng/S.G. in the target group and 1.19ng/l, 1.36ng/g creatinine and 1.17ng/S.G. in the control. For female 2.69ng/l, 3.94ng/g creatinine and 2.63ng/S.G. in the target group and 1.27ng/l, 1.97ng/g creatinine and 1.25ng/S.G. in the control, respectively. In addition, urinary Cd of the target group had affected by the period of residence and dietary habit for the rice and the vegetables from the target area. These findings suggest the chronic exposure to Cd of the target population. Mean excretion of urinary NAG, beta(2)MG and total protein were not significant between two groups. In the target group, urinary NAG activity and total protein were significantly correlated with urinary Cd, but beta(2)MG was not related. Urinary excretion of NAG, beta(2)MG and total protein were significantly increased in 10 than in <2 of urinary Cd level. In 2~10 group of urinary Cd level, the excretion of NAG significantly increased while not showed for beta(2)MG. In present study, urinary excretion of NAG was relatively sensitive than beta(2)MG in chronic exposure population to low level Cd.

Changes of Renal Cadmium Accumulation Levels and Urinary Cadmium Excretion Levels Induced by Long-term Cadmium Exposure in Rats / 대한산업의학회지

This study was performed to compare the cadmium accumulation levels in kidney with urinary cadmium excretion levels according to the duration of cadmium exposure in rats. Total 120 male rats, 6 weeks of age, were administered 0.5 mg/day of Cd to subcutaneously, intraperitoneally and orally 6 times per week for 12 weeks. The animals were sacrificed in the 1st day of 2nd, 4th, 6th, 8th, 10th and 12th week after beginning of cadmium administrations. Body weight, hematologic values, enzyme activities, renal Cd levels, urinary Cd and proteins were calculated and each value was compared according to the Cd administration routers. The Cd accumulation levels in the kidney of rats increased remarkably for 6-8th weeks which were experimented and urinary Cd excretion levels and urinary protein levels showed the tendency of increasing with the Cd accumulations in kidneys, especially in the subcutaneous injected rats. On the other hand, there was a significant positive correlation among the total Cd administration, the Cd accumulation in the kidneys, the urinary Cd excretion and protein.