Dietary exposure to lead of adults in Shenzhen city, China.

Lead, a ubiquitous heavy metal, can be found in the environment and food. The present study is the first to estimate the lead dietary exposure of Shenzhen adults (≥ 20 years old) in various age-gender subgroups, and to assess the associated health risk. Food samples that represented the Shenzhen people's dietary pattern were collected and prepared for analysis. Lead was determined in 13 food groups using 276 individual cooked samples by inductively coupled plasma-mass spectrometry (ICP-MS). Dietary exposures were estimated by combining the analytical results with the local food consumption data of Shenzhen adults. The mean and 95th percentile lead exposure of Shenzhen adults were 0.59-0.73 and 0.75-0.94 µg kg(-1) bw day(-1), respectively. In all food groups, the highest lead exposure was from 'Eggs and their products' (42.4-51.6% of the total exposure); preserved eggs being the main contributor. The other major contributors to lead exposure of Shenzhen adults were 'Fish and seafood, and their products' (14.3-16.7% of the total exposure) and 'Vegetables and their products' (15.5-16.2% of the total exposure). The margin of exposure (MOE) approach was used for the risk assessment of lead, and the results showed that the risk was considered to be low in all age-gender groups for Shenzhen adults. However, having considered a number of toxic effects of lead, it is suggested that more efforts should be made to reduce the lead levels in foodstuff for Shenzhen adults.

[Health risk assessment on pesticide residues in drinking water in Shenzhen].

OBJECTIVE: To conduct a health risk assessment of pesticide residues and its annual trend analysis in drinking water in Shenzhen City. METHODS: The water quality monitoring data of product water, pipe water and secondary supply water during from 2011 to 2013 were collected and analyzed. The risk evaluation models recommended by the U. S. Environmental Protection Agency (USEPA) were employed to perform health risk assessments for children and adults on the 12 non-carcinogenic materials (namely, heptachlor, pentachlorophenol, hexachlorocyclohexane, hexachlorobenzene, DDT, malathion, glyphosate, dimethoate, bentazone, atrazine, chlorothalonil, furadan). Results The results of the analysis for water quality from 84 factory samples, 11 peripheral samples and one secondary supply water sample showed that all of the measured indicators in the above mentioned water samples met the National Health Standards (GB 5749-2006) published by Ministry of Health of the People's Republic of China. The adults and children' s health indices (HIs) of the 12 non-carcinogenic materials were greater than 1 (2. 323 - 6. 312). Dimethoate in factory and peripheral water samples posed the largest risks of harm among the non-carcinogenic pollutants measured. And its HIi were also greater than 1 (1. 995 - 5. 094) and followed by hexachlorobenzene and heptachlor. Annual rising trend on health risk of the 12 pesticide residues indicated that their HIT on adults was 2323. 18 x 10(-3) in 2011, 2340. 18 x 10(-3) in 2012 and 2431. 97 x 10(-3) in 2013, and on children 2965. 07 x 10 (-3) in 2011, 2986. 77 x 10(-3) in 2012 and 3103. 93 x 10(-3) in 2013, respectively. This study also suggested that the average risk of peripheral water samples (HIT was equal to 2619. 64 x 10(-3) was greater than that of factory samples (HIT was same as 2366. 92 x 10(-3), and more children' s health risk than adults' risk. CONCLUSION: Health risks of pesticide residues in drinking water in Shenzhen have exceeded the threshold value and dimethoate was the main hazard and more children's health risk than adults' risk. Furthermore, there was an annual rising slowly trend on health risks of pesticide residues in drinking water.

[Determination of 8 elements in food by inductively coupled plasma optical emission spectrometer simultaneously].

OBJECTIVE: To establish a method for determination of 8 elements including K, Na, Ca, Mg, Fe, Zn, Cu and Mn in food by inductively coupled plasma optical emission spectrometer (ICP-OES). METHODS: After high-pressure digestion by HNO3 in closed-vessel, 8 elements were simultaneously determined by ICP-OES. RESULTS: The detection limits of 8 elements ranged from 0. 02 to 6 mg/kg(solid samples), 0. 005 mg/L to 2 mg/L(liquid samples). The average correlation coefficients were; ≥0. 999 with good linearity. The precision ranged from 0. 1% to 9. 6%, the recoveries ranged from 88% to 115%. The results of analyzing standard materials were in the certificate values. CONCLUSION: The method is rapid and accurate with less interference which meets the technical requirements of food testing and can be applied to the determination of 8 elements in food simultaneously.

[Effect of ambient air PM10 concentration on the hospital outpatient visit of respiratory diseases in Shenzhen City].

OBJECTIVE: To explore quantitatively the impact of the ambient air PM10 concentration (inhalable particulate matter) on the hospital outpatients for respiratory diseases. METHODS: Daily hospital visits data in 2008 was collected from a hospital in Shenzhen, meteorological data and air pollution data were collected from Shenzhen Meteorological Bureau and Shenzhen Environmental Protection Bureau, respectively. There was a time serial analysis using semi-parameter generalized additive model extend Poisson regression, after controlled with long-term tend, the-day-of-week, meteorological factors and other air pollutants. Excess relative risks (ER) of daily hospital visits associated with increased PM10 level were estimated. RESULTS: Ambient air PM10 concentration were no association with the increase of outpatients for respiratory in the same day. The lagged effect of 5 days with an ER of 1.113% (95% CI 0.613% - 1.616%) was observed. Except (PM10 + CO) model, the ER value increased when SO2, NO2, CO concentrations were introduced. CONCLUSION: The ambient air PM10 concentration could positively associated with the increase of daily hospital visits for respiratory diseases in Shenzhen.

[Flow injection analysis method for hygienic examination of volatile phenol compounds in the air of residential area].

OBJECTIVE: To establish a flow injection analysis for hygienic examination of volatile phenol compounds in the air of residential area. METHOD: Volatile phenol compounds in the air was sampled by a fritted glass bubbler with 10 ml 0.1 mol/L sodium hydroxide inside and analyzed by a flow injection analyzer. The samples were reacted with 4-aminoantipyrine after online distillation in the presence of potassium ferricyanide. RESULTS: There was a linear relationship in the range of 0 - 1500 microg/L. The samples could be stored in a 4 degrees C refrigerator at least for 7 days. This method showed a high reproducibility with relative standard deviations of 0.84% - 1.0%. The recoveries of standard addition of the method were 100.3% - 103.3%. The detection limit was 0.0003 mg/m3 and the linear range was 0.0009 -0.25 mg/m3. The absorption efficiencies were 96.1% - 97.2%. CONCLUSION: This method meets the requirements for the analysis of volatile phenol compounds in the air of residential area.

[Analysis of pulmonary function of primary students living in air pollution areas].

OBJECTIVE: To explore the changes of lung function of primary students living in the regions of different air pollution. METHODS: Nanshan District and Longgang District were decided respectively as a relatively heavy air pollution region and as a relatively light air pollution region in Shenzhen according to their air pollutant concentrations. The daily monitoring values on atmospheric SO2, NO2, PM10 and CO from 2006 to 2008 in the two districts were collected. PM2.5 monthly monitoring was started in Jan. 2008. Pulmonary functions of primary students were performed in the two schools within the scope of the surrounding 3km of the PM2.5 monitoring points. RESULTS: Average concentrations of atmospheric SO2, NO2, CO, PM10 and PM2.5 in Nanshan District were more high than those in Longgang District. Their concentrations were 0.0285 mg/m3 vs 0.0227 mg/m3, 0.0649 mg/m3 vs 0.0473 mg/m3, 2.278 mg/m3 vs 1.478 mg/m3, 0.0724 mg/m3 vs 0.0713 mg/m3 and 0.0665 mg/m3 vs 0.0524 mg/m3 (P < 0.05) respectively except PM10. Levels of the key indicators of lung function (VC, VC%, FVC, FVC%, MVV, MVV%, FEV1.0, FEV1.0/FVC, PEF, PEF%, FEF25, FEF50 and FEF75) increased with ages in the primary students. Means of the most indicators in Nanshan District were higher than those in primary students in Longgang District. Significant difference existed in the same grade of students on lung function in the two regions (P < 0.05). CONCLUSION: Air pollution could affect pulmonary function of primary students.

Elevated body burdens of PBDEs, dioxins, and PCBs on thyroid hormone homeostasis at an electronic waste recycling site in China.

A cross-sectional study of 25 sample sets (each set consisted of maternal serum and cord whole blood) from 50 pregnant women in zone A (n = 25 from exposed group) and zone B (n = 25 from reference group) was conducted to examine the association between thyroid hormone (TH) levels and PBDE, PCDD/F, and PCB exposures. Thyroid hormones TT3, TT4, and TSH levels were measured in maternal serum at 16 weeks of gestation. The concentrations of PBDEs, PCDD/Fs, and PCBs were determined by isotope dilution HRGC/HRMS in cord blood samples. Body burdens of the three contaminants in cord blood in zone A (median: summation sigma TEQ-PCDD/Fs 0.041, summation operator TEQ-PCBs 0.022 pg WHO-TEQ/g, summation operator PBDEs 23.4 pg/g whole weight, respectively) were significantly higher than those from the reference area (median: summation sigma TEQ-PCDD/Fs 0.014, summation sigma TEQ-PCBs 0.0041 pg WHO-TEQ/g, summation sigma PBDEs 16.15 pg/g, respectively) (p < 0.05). Levels of TT4 and TSH in serum in zone A were significantly lower than those in zone B (p < 0.05). A negative correlation was found between TT4 levels and body burdens of PCDD/Fs and PCBs. However, there was no significant association of concentration of PBDEs and levels of the three thyroid hormones. Our results suggest that electronic waste (e-waste) recycling contributes to high body burdens of PBDEs, PCDD/Fs, and PCBs and affects thyroid hormone homeostasis in humans. The potential health risk for neonates still needs further investigation.

[Epidemiological studies on Clonorchis sinensis infection along the Zhujiang River in Lou village of Shenzhen].

OBJECTIVE: To study the transmission route and epidemiological features of Clonorchis sinensis infection in Shenzhen area--the biggest immigration city of Southern China. METHODS: In this study, we examined 1473 individuals (710 males and 763 females) to determine the current status of C. sinensis infection among the people in one village in Zhujiang river region, Guangdong province, China. Blood samples were detected on antibody of C. sinensis with enzyme linked immunosorbent assay,and stool specimens from sera positive cases were examined by modified Kato-Katz thick smear to confirm the density of infection. People were interviewed on their life styles under the structured questionnaire which was administered by trained staff members. Major content of the questionnaire included eating raw fish, using the same utensils for both raw fish and cooked food, using feces of domestic animals and human feces to feed fish and so on. RESULTS: Among 1473 people examined, 70 (4.75%) were found infected with C. sinensis. By counting eggs per gram feces (EPG), it was found that heavy intensities of infection in males was stronger than that of females,and the overall average EPG was 41.87. Of 1473 interviewees, 54% of them did not know about fluke disease or its transmission route, 12% of those who knew about the fluke but believed that the infection caused no harm or only slight harm to their health. 27% of the interviewees ate raw fish at least 1-2 times per months with 5% of the families using the same utensils for both raw fish and cooked food. 40% of the fish ponds owners fed their fish with the feces of domestic animals and human feces. CONCLUSION: Together with these results, unhealthy behaviors, poor knowledge, inappropriate farming/fishery practices, eating raw fish were important factors influencing the C. sinensis prevalence in humans.