Exposure assessment of dietary cadmium: findings from Shanghainese over 40 years, China.

BACKGROUND: Environmental exposure to cadmium causes renal dysfunction and bone damage. Cadmium contamination in food is regarded as the main environmental source of non-occupational exposure. The aim of this study was to assess the contribution of dietary cadmium exposure in environmental cadmium exposure and its health risk among adults in Shanghai, China. METHODS: A cross-sectional survey about food consumption was conducted in 2008 among 207 citizens aged over 40 years in Shanghai, China. The food frequency questionnaire was combined with food, tobacco and water cadmium exposure to estimate the daily environmental cadmium exposure in both point and probabilistic estimations. Urine and blood samples of the participants were analyzed for internal exposure to total cadmium. Correlation analysis was conducted between the internal cadmium exposure and environmental cadmium exposure. RESULTS: According to the point estimation, average daily environmental cadmium exposure of the participants was 16.7 µg/day and approached 33.8% of the provisional tolerable daily intake (PTDI). Dietary and tobacco cadmium exposure approached 25.8% and 7.9% of the PTDI, respectively. Males had higher levels of dietary cadmium exposure than females (p?=?0.002). The probabilistic model showed that 93.4% of the population did not have any health risks from dietary cadmium exposure. By sensitivity analysis, tobacco consumption, tobacco cadmium level, cadmium in vegetables and cadmium in rice accounted for 27.5%, 24.9%, 20.2% and 14.6% of the total cadmium exposure, respectively. The mean values of urinary and blood cadmium among the study population were 0.5 µg/L and 1.9 µg/L, respectively. Positive correlations were observed between environmental cadmium exposure and blood cadmium (R?=?0.52, P<0.01), tobacco cadmium intake and blood cadmium excluding non-smokers (R?=?0.26, P?=?0.049<0.05), and urine cadmium and age (R?=?0.15, P?=?0.037). CONCLUSIONS: It has been suggested that there is no increased health risk among adult residents in Shanghai, China because of recent total cadmium exposure. Vegetables and rice were the main sources of dietary cadmium intake. Tobacco cadmium exposure, which accounted for approximately 25% of the total dietary cadmium exposure, was another important source of non-occupational cadmium exposure.

[Risk assessment of fluoride exposure to pork and offal products of pigs in Shanghai City].

OBJECTIVE: To estimate the exposure of fluoride to pork and offal products of pigs and assess their health risks in Shanghai residents. METHODS: Conducting a dietary survey in 1630 residents cluster sampled from four districts in Shanghai. Detecting fluoride in 872 pork and offal samples, and using Monte Carlo method to estimate the chronic daily intake (CDI) and hazard quotient (HQ) of fluoride in Shanghai residents caused by eating pork and offal products of pigs. RESULT: The CDI of fluoride is less than the tolerable daily intake (TDI), and the HQ is less than 1. The intake of pork and offal product is less in elder people than young people (P < 0.05), and that is less in female than male (P < 0.05). The fluoride content in offal is higher than that in pork (P < 0.05), the fluoride in kidney (P < 0.05) and liver (P < 0.05) is higher than that in other viscera. CONCLUSION: The intake of fluoride from pork and offal products in Shanghai residents is lower than the TDI of fluoride and not reaching the risk level of fluoride causing dental fluorosis, unhealthy of bone and osteofluorosis.

[Risk assessment of nerve conduction velocity in workers exposed to lead].

OBJECTIVE: To explore the dose-effect relationship between lead exposure and nerve conduction velocity, and to assess risk characteristics of nerve conduction velocity induced by lead exposure. METHODS: The external dose, internal dose (blood lead, urine lead) and the conduction velocity of peripheral nerve were examined. The benchmark dose of a population exposed to occupational lead was estimated to develop risk assessment of nerve conduction velocity in worker exposed to lead by use of BMDS (version 1.3.3). The BMDL in terms of blood lead and urine lead was calculated. RESULTS: There was correlation between blood lead and urine lead. The sense nerve conduction velocity was decreased significantly in the group of lead exposure workers (P < 0.05). The BMDLs-05 for median nerve conduct velocity, ulnar nerve conduction velocity, and superficial peroneal nerve conduction velocity in terms of blood lead were 456.99, 332.36 and 468.38 microg/L respectively; the BMDLs-05 in terms of urine lead were 14.1, 9.2 and 13.6 microg/gCr respectively. CONCLUSION: The internal dose is the better index to reflect the level of lead exposure. Blood lead is identified as a specific and sensitive biomarker for sense nerve conduction velocity reduction. Ulnar nerve conduction velocity can be used as highly sensitive biomarkers to screen the high risk population of lead exposure.

[Risk assessment of renal dysfunction caused by occupational lead exposure].

OBJECTIVE: To assess the risk of renal dysfunction caused by occupational lead exposure through epidemiological investigation. METHODS: The workers in a battery factory were selected as the subjects for the exposure and effect assessment. The occupational environmental monitoring data was collected and used to calculate the total external dose of lead. The relationship between external dose and internal dose of lead was analyzed. The external dose, blood lead (BPb) and urinary lead (UPb) were used as exposure biomarkers while the urinary N-acetyl-D-glucosaminidase (UNAG), and urinary albumin (UALB) were used as the effect biomarkers for the renal dysfunction caused by lead. Software of BMDS (BMDS 11311) was used to calculate BMD. RESULTS: The external and internal does of lead was positively correlated (BPb: r = 0.466, P < 0.01; UPb: r = 0.383, P < 0.01). The levels of BPb, UPb in exposure group (654.03 microg/L, 143.45 microg/g Cr) were significantly higher than those in the control group (57.12 microg/L, 7.20 microg/g Cr), so were UALB, UNAG; in addition, all of them presented significant dose-response relationship. The BPb BMD of UALB, UNAG were 607.76, 362.56 microg/L respectively and the UPb BMD of UALB, UNAG were 117.79, 78.79 microg/gCr respectively. CONCLUSION: Occupational lead exposure can cause renal dysfunction, which presents dose-response relationship; the risk assessment of renal dysfunction caused by occupational lead exposure is performed by BMD calculation of BPb and UPb.

Higher urinary 1-hydroxypyrene concentration is associated with cooking practice in a Chinese population.

Urinary 1-hydroxypyrene (1-OHP) is a biomarker of polycyclic aromatic hydrocarbons (PAHs) exposure. We examined urinary 1-OHP concentrations in 328 non-occupational exposed health subjects (108 females and 220 males). Each subject was questionnaired for the information of cigarette smoking and the habit of cooking practice including the cooking frequency in the kitchen (times per week), range hood opened for cooking, and fuel used for cooking. Concentrations of urinary 1-OHP (geometric mean, mumol/mol creatinine) were significantly higher in females than in males (0.50 versus 0.34, P<0.001). Cooking frequency in the kitchen had significant influence on the urinary 1-OHP concentrations in females. In females who did cooking practice in the kitchen, the urinary 1-OHP excretions were significantly higher in those who did not install the range hood compared to those who always opened the hood when cooking (0.75 versus 0.42, P=0.020). In males, cooking frequency in the kitchen and cigarette smoking were interacted on urinary 1-OHP levels. Those results imply that it is necessary for females with higher frequency of cooking and males with heavy smoking habits to improve their cooking conditions in order to reduce the risks of getting diseases including cancer.

Risk assessment on renal dysfunction caused by co-exposure to arsenic and cadmium using benchmark dose calculation in a Chinese population.

Arsenic and cadmium are important inorganic toxicants in the environment. Humans certainly have the potential to be exposed to the mixtures of arsenic and cadmium, but the toxicological interactions of these inorganic mixtures are poorly defined. A general population co-exposed to arsenic and cadmium, was selected in China. The total number of participants was 245, made up of 122 in the arsenic-cadmium polluted area, 123 in the non polluted area. Urinary arsenic (UAs) and cadmium (UCd) were determined by atomic absorption spectrometry as exposure biomarkers and beta2-microglobulin (Ubeta2MG), albumin (UALB), N-acetyl-beta2-glucosaminidase (UNAG) in urine were determined as effect biomarkers. The benchmark dose (BMD) and the lower confidence limit on the benchmark dose (LBMD) were calculated to estimate the critical concentration of UAs and UCd. UAs and UCd concentrations in the polluted area were significantly higher than those in the non polluted area (P < 0.01). The levels of Ubeta2MG, UALB and UNAG in the polluted area were significantly higher than those in the non polluted area (P < 0.01). The BMD/LBMD of UAs and UCd for a 10% level of risk above the background level were estimated as 121.91/102.11 microg/g creatinine and 1.05/0.88 microg/g creatinine. It was suggested that the lower confidence limit of population critical concentration of UAs and UCd for renal dysfunction for 10% excess risk level above the background, which is obtained from LBMD, may need to be kept below 102 and 0.88 microg/g creatinine in order to prevent renal damage in general population co-exposed to arsenic and cadmium. It is indicated that combined effect of arsenic and cadmium were additive effect and/or synergistic effect, and cadmium may potentiate arsenic nephrotoxicity during the long-term and co-exposure to arsenic and cadmium in humans.