The status and health risk assessment of dietary fipronil contamination among 20 provinces of China / 中华预防医学杂志

Objective@#To understand the status and health risk assessment of dietary fipronil contamination among 20 provinces of China.@*Methods@#A total of 13 kinds of dietary samples in Chinese total diet study include cereals, legumes, potatoes, meats, eggs, aquatics, dairies, vegetables, fruits, sugars, beverages and water, alcohols, condiments and their corresponding products. Among them, condiments were used in the preparation of 12 other sample categories; thus, the actual mixed dietary samples of each province covered 12 groups. A total of 240 mixed dietary samples were collected from 20 provinces in China from 2009 to 2013. After the sample extraction and cleanup, dietary samples were analyzed for the residues of fipronil and its metabolites to obtain the contamination levels of fipronil residues using liquid chromatography-high resolution mass spectrometry. The dietary intake of adult residents was estimated based on food consumption of general population of China.@*Results@#Among the 240 dietary samples, the detection rate of fipronil was 10.4% (25 samples), and the detection rates of fipronil metabolites, i.e. fipronil desulfinyl, fipronil sulfone and fipronil sulfide were 20.4% (49 samples), 40.0% (96 samples) and 8.8% (21 samples), respectively. According to the dietary exposure analysis, the average lower and upper dietary exposure levels of fipronil residues in adult residents of China were 11.34 and 12.35 ng·kg-1·d-1, accounting for 5.7% and 6.2% of acceptable daily intake (ADI), respectively. The highest adult dietary intake of fipronil residues was found in Hunan province, with a value of 72.98 ng·kg-1·d-1, accounting for 36.5% of ADI. Vegetables were the main dietary source of fipronil residues, which contributed to 71.0% of the total intake dose.@*Conclusion@#Fipronil residues were detected in varying degrees in dietary samples, yet the health risk caused by the dietary intake of adult residents among 20 provinces of China is low.

Comparison of food allergy prevalence of food allergy in children with or without bronchial asthma in cite of China / 中华实用儿科临床杂志

Objective To explore the prevalence and clinical characteristics of food allergy in bronchial asth-matic children less than 14 years old in China. Methods A case - controlled study was designed. The questionnaires were given to children,who were diagnosed to be asthmatic during the national epidemiological survey of asthma in chil-dren in 31 cities from September 2009 to August 2010. Non - asthmatic children,matched with the cases in age and gender,were selected during the same survey as control subjects if they were matched with the cases in age and sex. In-formation regarding the food allergen and symptom of food - induced anaphylaxis was analyzed. The difference in food allergy was compared between children with or without bronchial asthma. Results As a result,9235 asthmatic children and 11391 control subjects were enrolled in the case - control study. There were 14. 66％(1354 / 9235 cases)of the asthmatic children who had food allergy,compared to 3. 99％(455 / 11391 cases)of the non - asthmatics children, and the findings showed a significant difference (χ2 = 725. 25,P < 0. 001). The most common food allergens were fish and shrimp in both groups,and the difference was not significant [44. 09％ (597 / 1354 cases)vs. 42. 20％ (192 / 455 cases),χ2 = 0. 50,P > 0. 05]. The rate of peanut allergy was 4. 58％ (62 / 1354 cases)and 1. 54％ (7 / 455 cases) (χ2 = 8. 58,P < 0. 05),respectively. And the rates of fruit allergy in the asthmatic group and the non - asthmatic group were 14. 03％(190 / 1354 cases)and 27. 69％(126 / 455 cases)(χ2 = 44. 01,P < 0. 05),respectively. Cutaneous and nasal symptoms were common clinical manifestations. The rates of rash,pruritus,and swelling sympions were 47. 27％(640 / 1354 cases)and 61. 32％(279 / 455 cases)(χ2 = 26. 90,P < 0. 001),respectively for asthmatic group and non -asthmatic group. Rates of nasal symptoms were 17. 13％(232 / 1354 cases)and 10. 55％(48 / 455 cases)(χ2 = 11. 29, P = 0. 001),respectively in the asthmatic group and the non - asthmatic groups. Respiratory symptoms,such as cough and wheezing,were 25. 33％(343 / 1354 cases)and 5. 49％(25 / 455 cases)(χ2 = 80. 72,P < 0. 001)in 2 groups. Twenty cases of 1354 asthmatic children had severe food allergy,while such severe conditions occurred only 1 child without asthma (455 cases)occurred severe condition (1. 48％ vs. 0. 22％,χ2 = 4. 96,P < 0. 05). Conclusion The-rate of food allergen sensitization is highly prevalent in the children with asthma. Compared to those without asthma, and their types of food allergen and clinical symptoms are different from the latter.

Epidemiology of food allergy in children from 31 cities in China / 国际儿科学杂志

Objective To investigate the prevalence of food allergy among children living in metropoli-ses aged 0-14 years. Methods In this cross-sectional study a questionnaire was distributed to parents taking care of children aged 0-14 years from China′s 31 metropolises to get the parents reported prevalence. Results A total of 337560 children aged 0-14 years participated in the survey. There are 19676 children reported with food aller-gy(5. 83%). In different regions,the parents reported prevalence of food allergy had significant difference(χ2 =657. 01,P<0. 001). It was highest in the eastern (7. 38%,5259) and the northeastern (7. 03%,2916) part of China,and was lowest in the northwestern part of China,which was 4. 35%. Of all the 31 surveyed metropolises, the parents reported prevalence of food allergy was highest in Qingdao,and lowest in Lhasa,which was 9. 11%(917/10066),and 2. 33% (116/4984)respectively. The prevalence of food allergy in males and females was 5. 87% and 5. 79% respectively,with no significant difference (χ2 =1. 078,P=0. 299). The prevalence of food allergy in preschool children (3-5 years old,6. 65%) was higher than other ages (χ2 =46. 469,P<0. 001). Of children reported to have food allergy,38. 5% had a history of eczema,23. 0% had a history of allergic rhinitis, and 37. 7% had a family history of allergic diseases. Conclusion The parents reported prevalence of food aller-gy among children 0-14 years old from 31 metropolises in China was 5. 83%. In different regions cities and a-ges,there′s significant difference of the reported prevalence. There′s no significant difference of parents reported prevalence between males and females. The study would have great significance in reflecting and evaluating the prevalence of food allergy among children.

Epidemiology of food allergy in children from 31 cities in China / 国际儿科学杂志

Objective To investigate the prevalence of food allergy among children living in metropoli-ses aged 0-14 years. Methods In this cross-sectional study a questionnaire was distributed to parents taking care of children aged 0-14 years from China′s 31 metropolises to get the parents reported prevalence. Results A total of 337560 children aged 0-14 years participated in the survey. There are 19676 children reported with food aller-gy(5. 83%). In different regions,the parents reported prevalence of food allergy had significant difference(χ2 =657. 01,P<0. 001). It was highest in the eastern (7. 38%,5259) and the northeastern (7. 03%,2916) part of China,and was lowest in the northwestern part of China,which was 4. 35%. Of all the 31 surveyed metropolises, the parents reported prevalence of food allergy was highest in Qingdao,and lowest in Lhasa,which was 9. 11%(917/10066),and 2. 33% (116/4984)respectively. The prevalence of food allergy in males and females was 5. 87% and 5. 79% respectively,with no significant difference (χ2 =1. 078,P=0. 299). The prevalence of food allergy in preschool children (3-5 years old,6. 65%) was higher than other ages (χ2 =46. 469,P<0. 001). Of children reported to have food allergy,38. 5% had a history of eczema,23. 0% had a history of allergic rhinitis, and 37. 7% had a family history of allergic diseases. Conclusion The parents reported prevalence of food aller-gy among children 0-14 years old from 31 metropolises in China was 5. 83%. In different regions cities and a-ges,there′s significant difference of the reported prevalence. There′s no significant difference of parents reported prevalence between males and females. The study would have great significance in reflecting and evaluating the prevalence of food allergy among children.

The contamination and dietary exposure analysis for seven mycotoxins in the Fifth Chinese Total Diet Study / 中华预防医学杂志

Objective@#To investigate the contamination levels and dietary intakes of seven mycotoxins in Chinese diets.@*Methods@#In Chinese Total Diet Study, food aggregation was based on the food consumption of local residents, thus generating the sampling scheme. According to the sampling scheme, the food items were sampled at three survey points in each province and then mixed in the same proportion. The mixed dietary samples were prepared after being cooked and processed. The samples comprised of 13 categories of food: cereals, beans, potatoes, meat, eggs, aquatic products, milk, vegetables, fruits, saccharides, beverages and drinking water, alcohol, and condiments. Condiments were used in cooking, so there were in total 12 varieties of samples for determination. Altogether, the study included 240 mixed dietary samples from 20 provinces with 12 varieties. The contamination levels of the seven mycotoxins, including sterigmatocystin (SMC), citrinin (CIT), cyclopiazonic acid (CPA), moniliformin (MON), gliotoxin (GLIO), mycophenolateacid (MPA) and verruculogen (Verru), were analyzed by UPLC-MS/MS method, and dietary intakes of residents were estimated as well.@*Results@#Among the detected seven mycotoxins, MPA,GLIO and Verru were not detected. The content range of CPA in beans was 0.47-1.57 μg/kg and in alcohol was 0.19-2.26 μg/kg, and the detection rate of CPA was 7.1% (17/240). The content of SMC in aquatic products of Guangxi, in saccharides of Beijing, and in beverages of Liaoning was 2.88 μg/kg, 0.01 μg/kg, and 0.53 μg/kg, respectively. The content range of SMC in aquatic products was 0.70-1.76 μg/kg, and the detection rate was 2.9% (7/240). In addition, the content of CIT in fruit of Sichuan was 5.31 μg/kg, and the content of MON in milk of Jilin was 3.60 μg/kg. According to the dietary exposure analysis, the exposure levels of the seven mycotoxins in China's general population were low. MPA, GLIO and Verru were not detected, and the exposure range of the other four mycotoxins were 0.000-8.132 (CIT), 0.000-27.448 (SMC), 0.000-3.026 (CPA), and 0.000-62.847 ng·kg-1·d-1 (MON), respectively.@*Conclusion@#In the detected seven mycotoxins, CPA, SMC, CIT and MON were detected only in the individual diet in some areas with a low dietary exposure level. However, the contamination level of CPA in alcohol merits attention.

Determination of Total Fatty Acid Esters of Chloropropanols in Edible Vegetable Oils by Gas Chromatography-Mass Spectrometry / 分析化学

A method was established for the simultaneous determination of the total fatty acid esters of chloropropanols in edible oils by gas chromatography-mass spectrometry combined with isotope dilution technology. The samples were hydrolyzed with sodium methylate-methanol, and then purified by diatomite cartridge. After being derivatized with heptafluorobutyrylimidazole ( HFBI ), the target analytes were determined by GC-MS with the deuteriumchloropropanols esters as the internal standards. An excellent linear correlation in the range of 0. 050-2. 000 mg / L was acquired for 3-monochloropropane-1,2-diol (3-MCPD) esters, 2-MCPD esters, dichloropropan-2-ol (1,3-DCP) esters and 2,3-dichloropropan-1-ol (2,3-DCP) esters, with all the correlation coefficients (r) higher than 0. 9995. The limits of detection (LODs) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0. 015, 0. 015, 0. 030, and 0. 030 mg / kg, respectively, and the limits of quantitation (LOQ) were 0. 050, 0. 050, 0. 100, and 0. 100 mg / kg, respectively. The average spike recoveries of the four kinds of chloropropanols esters in blank extra virgin olive oil matrix were typically in a range of 87. 0% -110. 5% with the relative standard deviations (RSDs) less than 10. 1% . The detection rates of 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters in 74 edible oil samples were 94. 6% , 63. 5% , 5. 4% , and 0% , respectively. The contamination levels of 3-MCPD esters, 2-MCPD esters and 1,3-DCP esters were in the range of not detected (ND) to 10. 646 mg / kg, ND to 3. 617 mg / kg and ND to 0. 089 mg / kg, respectively. This method is accurate and rugged for the simultaneous determination of total fatty acid esters of chloropropanols in edible vegetable oils.

Long-term effect of cadmium exposure on residents' renal dysfunction: An epidemiologic study / 中华预防医学杂志

<p><b>OBJECTIVE</b>To study long-term effect on renal function exposed to environmental cadmium.</p><p><b>METHODS</b>Stratified random sampling and cluster sampling method of epidemiological investigations were carried out in northern Guangdong province between April, 2011 and August, 2012. A total of 167 residents who lived in high cadmium exposure area for more than 15 years, aged above 40 were selected in exposed group. Moreover, A total of 145 residents who had similar living and economic conditions and lived in local for more than 15 years, aged above 40 were selected in control group. We used health questionnaires and medical examinations in order to acquire their health status. Home-harvested rice and vegetables were collected using quartering method for detection of cadmium level. Urine specimens of residents were collected for detection of cadmium level and creatinine as well as renal dysfunction biomarkers, namely, N-acetyl-beta-D-glucosamidase (NAG), β2-microglobulin (β2-MG), and retinol binding protein(RBP), respectively. The analysis of spearman rank correlation and multiple regression were used to investigate the relationships between age, urinary cadmium levels and renal injury biomarkers.</p><p><b>RESULTS</b>The cadmium levels in rice and vegetables of exposed group were 0.75 and 0.10 mg/kg, both were significantly higher than 0.07 and 0.01 mg/kg in the control group (Z values were -6.32 and -7.84, all P values < 0.001). The urinary cadmium level of exposed group was 8.29 µg/g · cr, which was higher than that of the control group 2.03 µg/g · cr with significant difference (Z value was -11.39, P < 0.001). After stratified the total population by age, the urinary cadmium level in 40-49 years, 50-59 years and ≥ 60 years subgroups were 7.22, 8.71, and 13.10 µg/g · cr, which both were significantly higher than 1.80, 2.04, and 2.05 µg/g · cr in the control group (Z values were -5.22, -7.41, and -7.14, all P values < 0.001). After stratified the total population by gender, the urinary cadmium level of male and female were 5.12 and 12.36 µg/g · cr, which both were significantly higher than 1.79 and 2.16 µg/g · cr in the control group (Z values were -7.68 and -9.03, all P values < 0.001). Comparing the differences of renal dysfunction biomarkers (NAG, β2-MG, RBP) between two groups. The level of urinary β2-MG and RBP of exposed group were 0.21 and 0.04 µg/g · cr, which were higher than 0.05 and 0.00 µg/g · cr of the control group with significant difference (Z value was -7.08 and -9.65, all P values < 0.001). Pearson correlation analysis showed that NAG, β2-MG and RBP were positively correlated with urinary cadmium and age, the correlation coefficients were 0.57, 0.49, 0.21 and 0.22, 0.26, 0.23 respectively (all P values < 0.001). After adjusting the effect of age, it was appeared that urinary cadmium levels contributed most to the alteration of NAG, β2-MG and RBP, the standardized regression coefficients were 0.57, 0.49 and 0.20 (all P values < 0.001), and suggested that the cadmium body burden was one of the most important factors for renal dysfunction.</p><p><b>CONCLUSION</b>Residents, who had cadmium contaminated rice and vegetables for a long time, would take the risk of increasing body burden of cadmium and urinary early biomarkers of renal tubular injury that referred to occurrence of renal dysfunction.</p>

Analysis of perfluoroalkyl substances and their precursors in eighteen market milk / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the level of perfluoroalkyl substances (PFASs) and their precursors in 18 market milk samples of China.</p><p><b>METHOD</b>The 18 milk samples were selected in 8 provinces of China, including Ningxia, Neimeng, Beijing, Tianjin, Hebei, Shanxi, Chongqing, and Guangdong. 8 PFASs and 11 PFAS precursors were measured by ultra-high performance liquid chromatography-tandem quadruple mass spectrometry (UPLC-MS/MS). The dietary exposure assessment was made.</p><p><b>RESULTS</b>Three PFASs were detected in milk samples which were PFOA, PFUdA, and PFOS. The numbers of detected samples were 5, 12, and 14, respectively. Their concentration ranges were < Limit of determination (LOD)-431.94 pg/ml, < LOD -15.95 pg/ml and < LOD -126.98 pg/ml, respectively. Three PFAS precursors were also found above the detection limits, namely, 4:2 FTS, 6:2 FTS, and 6:2 diPAP. Only one sample was detected 4:2 FTS at the concentration of 3.75 pg/ml. The detected samples of 6:2 FTS and 6:2 diPAP were 12 and 3. Their concentration ranges were < LOD -2.49 pg/ml and < LOD -24.56 pg/ml, respectively. The ranges estimated daily intake of PFOA and PFOS of the detected samples were 2.49 × 10⁻³-405.89 × 10⁻³ ng · kg⁻¹ · d⁻¹ and 36.10 × 10⁻³-119.32 × 10⁻³ ng · kg⁻¹ · d⁻¹.</p><p><b>CONCLUSION</b>Our results suggested that there were different contamination levels of PFASs and their precursors in the 18 market milk produced from different regions in china. The estimated daily intake of PFASs from the milk in our study were far below the tolerable daily intake set by European Union (PFOS: 150 ng · kg⁻¹ · d⁻¹, PFOA: 1 500 ng · kg⁻¹ · d⁻¹).</p>

Analysis of perfluoroalkyl substances precursors in human milk from 12 provinces of China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the level of perfluoroalkyl substances (PFASs) precursors in Chinese human milk samples.</p><p><b>METHODS</b>The human milk samples were collected during the performance of Stockholm convention on survey of human milk in China in 2007. Based on the geographical location and dietary habits, China was divided into the south area and north area which 6 provinces were chosen from each area and there were 12 provinces in all. In each province, one urban site and two rural sites were selected to collect 80-110 samples. Mothers were randomly selected in each site to collect their breast milk. There were 1 237 individual human milk samples in all. For each province, the individual samples from the urban areas and the rural areas were pooled separately resulting in 24 pooled human milk samples. 11 PFAS precursors were measured in pooled samples by ultra-high performance liquid chromatography-tandem quadruple mass spectrometry (UPLC-MS/MS). The dietary exposure assessment of newborns was made.</p><p><b>RESULTS</b>Three PFAS precursors were found above the detection limits, namely, 6:2 FTS, FHUEA, and 6:2 diPAP. Their concentration ranges were < Limit of determination (LOD) -47.46 pg/ml, < LOD -70.68 pg/ml and < LOD -35.08 pg/ml, respectively. The highest total PFAS precursor concentration 77.70 pg/ml was found in urban area samples from Shannxi Province. Rural area samples from Hubei had the lowest total PFAS precursor concentration, which was below the LOD. There were significant differences between rural and urban areas in many provinces, such as Shannxi (rural: 1.51 pg/ml; urban: 77.70 pg/ml), Shanghai (rural: 1.13 pg/ml; urban: 71.88 pg/ml), Jiangxi (rural: 65.39 pg/ml; urban: 0.55 pg/ml) and so on. The ranges estimated daily intake of 6:2 FTS, FHUEA and 6:2 diPAP of the samples from 12 provinces were 0.05-4.51, 1.13-6.72 and 1.15-3.34 ng · kg⁻¹ · d⁻¹.</p><p><b>CONCLUSION</b>The results suggested the human exposure of PFAS precursors in China and the potential health impact of postnatal exposure through breastfeeding to infants. The level of PFAS precursors showed differences in regions, rural and urban places.</p>

Development of gas chromatography-mass spectrometry for determination of fatty acid esters of chloropropanols in milk powder and the pollution level of infant formula / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish a method for determination of fatty acid esters of chloropropanols (chloropropanols esters) in milk powder by isotope dilution-gas chromatography-mass spectrometry (GC-MS), and to acquire the pollution level of chloropropanols esters in infant formula and evaluate the dietary exposure risk of chloropropanols esters in infant formula for infants.</p><p><b>METHODS</b>A total of 111 infant formula samples were collected from supermarkets in Beijing, and the infant formula with no chloropropanols esters detected was served as the blank sample. The samples were ultrasonically extracted with hexane, followed by ester-bond cleavage reaction with sodium methylate-methanol and purification by matrix solid-supported liquid-liquid extraction, then being derivatived with heptafluoro butyrylimidazol. After extracted by sodium chloride solution, the derivatives were determined by GC-MS. The concentration of chloropropanols esters were quantified using the deuterium chloropropanols esters as the internal standards. The accuracy of the method was assessed by the recoveries of the blank spiked samples, and the relative standard deviations (RSD) of the recoveries represent the precision of the method. The contamination level of chloropropanols esters and the intake amount of the infant formula of the 6-month infant were used to estimate the dietary exposure assessment, and x (95% CI) and P97.5 of the contamination level of chloropropanols esters were used to represent the average dietary exposure and the high-end dietary exposure.</p><p><b>RESULTS</b>The satisfied linear correlations in the range of 0.010-0.800 mg/L was acquired for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters with coefficient correlations of 0.999 9, 0.999 8, 0.999 5 and 0.999 6, respectively. The limits of detection (LOD) and the limits of quantitation (LOQ) for 3-MCPD esters, 2-MCPD esters, 1,3-DCP esters and 2,3-DCP esters were 0.005, 0.005, 0.015, 0.015 mg/kg, and 0.015, 0.015, 0.045, 0.045 mg/kg. The average recoveries of the four chloropropanols esters spiked at 0.025, 0.050 and 0.100 mg/kg in blank matrix were in a range from 80.3% to 111.9%, with relative standard deviations (RSD) less than 11.4%. Of the 111 infant formula samples, the detection rates and the contamination levels of 3-MCPD esters and 2-MCPD esters were 77.5% (86/111), 11.7% (13/111) with the contamination levels in the range of ND-0.230 mg/kg and ND-0.039 mg/kg, respectively, and χ (95% CI) and P97.5 of 3-MCPD esters and 2-MCPD esters were 0.020 (0.003-0.113) and 0.006 (0.005-0.025) mg/kg, 0.113 and 0.025 mg/kg, respectively. 1,3-DCP esters and 2,3-DCP esters were not detected in the 111 samples. x (95% CI) and P75 of the six-month old infants to 3-MCPD esters were 0.304 (0.038-1.735) and 1.735 µg · kg⁻¹ · d⁻¹, respectively, which accounted for 15.2% and 86.7% of the PMTDI (2 µg · kg⁻¹ · d⁻¹) of 3-MCPD.</p><p><b>CONCLUSION</b>This GC-MS method was accurate and rugged for the determination of chloropropanols esters in milk powder. Based on the exposure assessment results, the health risk of chloropropanols esters for infants caused by the intake of infant formula was acceptable.</p>

The application of UPLC-MS/MS to detect precursors of perfluorooctanoic acid and perfluoroalkyl carboxylatesin serum / 中华预防医学杂志

<p><b>OBJECTIVE</b>We established a method of UPLC-MS/MS that was to detect fifteen precursors of perfluoroalkyl sulfonates (PFSA) and perfluoroalkyl carboxylates (PFCA) in serum.</p><p><b>METHODS</b>Briefly, TBAS solution was added to sera, then the mixed solution was extracted with aliquots of MTBE. The MTBE aliquots were combined, evaporated to dryness under nitrogen, and reconsituted in 0.25 ml of methanol and water (1:1). Then the reconstituted solution through 0.2 µm nylon syringe filter was collected. Chromatographic separation was performed using a Waters ACQUITY (TM) BEH ¹⁸C column (50 mm × 2.1 mm × 1.7 mm). Analyte quantitation was performed in the negative electrospray ionization mode and multiple reaction monitoring (MRM).</p><p><b>RESULTS</b>Three target substances, 6: 6PFPi, 6: 8PFPi, 8: 8PFPi, were externally confirmed by standard addition. Rates of recovery for these three chemicals were from 41.01% to 112.13% in two standard levels. And the relative standard deviations (RSD) were lower than 11.63% and higher than 1.80%. The other twelve substances were quantified with internal standard. Moreover in two standard levels, rate of recovery for these chemicals ranged from 70.25% to 127.51%. And RSD were more than 1.23% and less than 15.45%. And the corresponding limit of detection (LOD) and limit of quantitation (LOQ) for all target substances were 0.1-5.0 pg/ml and 0.2-10.0 pg/ml. Then we detected these target substances in ten different human serum samples. The levels of few substances were higher than LOD. And the ranges of FOSA-M, N-EtFOSA-M, N-MeFOSAA, N-EtFOSAA were respectively < LOD-0.94 pg/ml, < LOD-10.08 pg/ml, < LOD-6.74 pg/ml, < LOD-1.04 pg/ml.</p><p><b>CONCLUSION</b>The method, with high sensitivity and accuracy, could meet the actual testing requirements.</p>

Analysis of molecular features of clinical Vibrio parahaemolyticus strains in China / 中华预防医学杂志

<p><b>OBJECTIVE</b>To explore the phenetic and genetic features of clinical Vibrio parahaemolyticus strains from 2007-2009 in China.</p><p><b>METHODS</b>A total of 135 clinical Vibrio parahaemolyticus strains, isolated from Zhejiang, Jiangsu, Sichuan, Guangxi, Liaoning Provinces during 2007 to 2009, were selected for the research. The occurrence of virulence genes thermostable direct hemolysin (tdh) and TDH-related hemolysin (trh), species-specific genes thermolabile hemolysin (tlh), toxR, VPM and gyrB, the pandemic clone gene markers(GS-PCR, PGS-PCR, orf8 and HU-α) in 135 Vibrio parahaemolyticus strains was detected by PCR. The antimicrobial susceptibilities to eight antimicrobial agents of the experimental strains were determined by the broth microdilution method. All strains were serotyped and underwent the cluster analysis with pulsed-field gel electrophoreses.</p><p><b>RESULTS</b>The results of PCR methods claim that all experiment strains carry species-specific genes such as tlh, toxR, gyrB, VPM. Among clinical strains, 85.9% (116/135) carry tdh and/or trh. 85.2% (115/135) were positive for tdh, and 3.0% (4/135) were positive for trh; while 3 strains carried both.66.7% (90/135) , 80.7% (109/135) , 65.2% (88/135) , 66.7% (90/135) clinical strains carried the genes of GS-PCR, PGS-PCR, orf8, HU-α, respectively. The results of antibiotics susceptibility test showed that 8.1% (11/135) strains were resistant to at least one agent, including 9 strains were resistant to ampicillin, 2 strains were resistant to trimethoprim and sulphamethoxazole, and 1 strain were resistant to tetracycline. All clinical strains were sensitive to cefotaxime, ceftazidime, gentamicin, ciprofloxacin and chloromycetin.Serological analysis of the O and K antigens claimed that a total of 29 serotypes were identified for clinical strains, predominantly O3, O4 and O1 groups, accounting for 89.6% (121/135). O3: K6 was dominant serotype, accounting for 56.3% (76/135). The pandemic flora in China included O3: K6, O4: K68, O1: K36, O1: K25, O1: K5 and O3: K29 serotypes.Genomic DNAs of 135 clinical strains were digested with SfiI and NotI, the molecular size of PFGE restriction fragments used for analysis mainly ranged from 30-700 kb.When subjected to UPGMA clustering, 6 and 9 clusters were grouped by SfiI and NotI, and the minimal similarity was 52.6% and 58.7%, and pandemic flora were located in C groups and D group, respectively.</p><p><b>CONCLUSION</b>Most of Vibrio parahaemolyticus strains isolated from clinical sources in China were pathogenic. The pandemic clone, especially O3: K6 was prevalent. The GS-PCR and HU-α genes were reliable markers to identify the pandemic flora. The serotype by PFGE was reliable to distinguish the pandemic flora and the sporadic strains.</p>

Ocuurence of organophosphorus pesticides in animal foods and their diet exposure assessment / 中华预防医学杂志

<p><b>OBJECTIVE</b>To investigate the levels of organophosphorus pesticides (OPPs) in animal foods and to assess the diet exposure risk of OPPs to Chinese population.</p><p><b>METHODS</b>115 samples, including pork, beef, mutton, chicken, fish, eggs, and milk were collected from 13 provinces in China, were analyzed by dual gas chromatography-dual pulsed flame photometry (GC-PFPD) for the contamination of 58 organophosphorus pesticide residues including their metabolites. The cumulative exposure assessment and high-end exposure assessment were used to assess the diet exposure risk of OPPs to Chineses population.</p><p><b>RESULTS</b>The contamination levels of OPPs in animal foods were in the range of not detected (ND)-0.343 mg/kg, and the total detection rate was 37.4% (43/115). OPPs were frequently detected in samples of milk, fish and pork compared with other animal foods with the detection rate of 12/19, 9/16 and 7/16, respectively. The cumulative exposure amount of 10 OPPs to Chinese population was 0.12 µg×kg(-1)·d(-1), which accounted for 7.29% of the ADI.</p><p><b>CONCLUSION</b>The residue levels of OPPs were low in animal food in the surveyed areas in China with some banned individual OPPs, such as methamidophos and monocrotophos, were detected. The dietary exposure risk of OPPs raised by the intake of animal foods in surveyed areas of China was low.</p>

A systematic review on food lead concentration and dietary lead exposure in China / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>By synthesizing results from primary studies, systematic review can provide empirical information of concerned problems. This study aimed to review the available surveillance data from studies reporting the contamination surveillance of food lead in China.</p><p><b>METHODS</b>Relevant studies were identified by systematically searching Chinese Biological Medicine Database and China National Knowledge Infrastructure using the key term of "lead" for surveillance data published in Chinese between 2006 and 2012. To avoid potential selection bias, all articles were evaluated by two independent reviewers, and the disagreements were resolved by discussion or the third author was asked to arbitrate.</p><p><b>RESULTS</b>Among 269 identified publications on surveillance data of lead in food, 43 articles met the defined inclusion criteria. The food samples were divided into 11 groups (cereal grains and pulses, fish, eggs, vegetables, meat, edible fungi, milk and dairy products, fruits, offal, tea and preserved egg). Surveillance data of publications were reviewed to calculate the weighted mean and rate exceeding maximum levels. Our results indicated that the highest lead concentration was 1.937 mg/kg in tea. The total percentage of samples exceeding the maximum levels was 5.57%. Dietary exposure to lead was assessed by combining the weighted mean concentration of surveillance data with national consumption data in 2002. In this review, dietary intake of lead was 1.232 µg/kg b.w./day.</p><p><b>CONCLUSION</b>Further control measures should be taken to reduce exposure to lead, from both dietary and non-dietary sources.</p>

Particle-bound PCDD/Fs in the atmosphere of an electronic waste dismantling area in China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>Particulate samples from the atmosphere in an electronic waste dismantling area were collected to investigate the levels and sources of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs).</p><p><b>METHODS</b>Particulate samples including total suspended particulates (TSP) and particulate matter <2.5 μm diameter (PM(2.5)) were collected on selected non-rainy days in summer (Jul 10-12, 2006) and winter (Jan 11-13, 2007) from Fengjiang (FJ), an electronic waste (e-waste) dismantling area in eastern China, and an adjacent area Luqiao (LQ). The samples were analyzed by isotope dilution - high resolution gas chromatography / high resolution mass spectrometry (HRGC/HRMS).</p><p><b>RESULTS</b>In FJ, the mean PCDD/F concentrations (mean TEQ values) were 280.6 pg Nm(-3) (3.432 pg WHO-TEQ Nm(-3)) for the TSP samples and 223.3 pg Nm(-3) (3.180 pg WHO-TEQ Nm(-3)) for the PM(2.5) samples. The total PCDD/F concentrations and TEQs in the PM(2.5) samples were about 66.8%-108.0% of the TSP samples, indicating that the fine particles contained higher levels of PCDD/Fs than coarse particles. The PCDD/F levels in FJ were much higher than those detected in common urban areas around the world, suggesting that the study area was heavily polluted by PCDD/Fs. Furthermore, the total average daily PCDD/F intake in FJ was estimated at 62.11 pg WHO-TEQ kg(-1)·day(-1) for adults and 110.11 pg WHO-TEQ kg(-1)·day(-1) for children, which greatly exceeds the WHO (1998) tolerable daily intake of 1-4 pg of WHO-TEQ kg(-1)·day(-1).</p><p><b>CONCLUSION</b>The PCDD/F homologues and congener profiles confirmed that the PCDD/Fs in FJ originated from crude e-waste recycling activities. The severe dioxin pollution present in FJ has also substantially influenced the adjacent area of LQ through atmospheric transport. Open burning of medical waste was another source of PCDD/Fs identified in LQ.</p>

Exposure level of total N-nitroso compounds in residents of high-and low-risk areas for esophageal cancer in southern / 中华预防医学杂志

<p><b>OBJECTIVE</b>To assess the exposure level of total N-nitroso compounds (TNOCs) in the residents of high- and low-risk areas for esophageal cancer in southern China.</p><p><b>METHODS</b>Samples of duplicate plate diets and 12 hr overnight urine were collected from 120 male adults in each of the 2 areas, a high-risk area (Nanao county) and a low-risk area (Lufeng county) for esophageal cancer. The 240 male healthy subjects (35 - 64 years old) were selected by a 3-stage random cluster sampling procedure. Levels of TNOC, N-nitrosamino acids (NAAs) and volatile N-nitroso compounds (VNOC) in the samples were measured by Thermo Energy Analyzer.</p><p><b>RESULTS</b>The detectable rate (95%) of diet TNOC, daily dietary TNOC intake (4.25 +/- 0.84) micromol/day, 12-hr urinary TNOC excretion levels (1.76 +/- 0.23 ng/12 h) and daily dietary intake of VNOC (266 +/- 31.2 microg/day) in the high-risk area were all significantly higher than those of the low-risk area. Oesophageal cancer mortality rates were positively and significantly associated with daily dietary TNOC intake and 12-hr urinary TNOC excretion. Urinary NAAs excretion levels were not different in the two areas.</p><p><b>CONCLUSION</b>The results suggest that TNOCs may be implicated in the etiology of esophageal cancer in southern China.</p>

A PRELIMINARY STUDY ON THE ACTIVE CONSTITUENTS OF TEA MODIFYING N-NITROSATION REACTION / 营养学报

The contents of tea polyphenolic compounds, ascorbic acid, flavones and tea catechins in 17 kinds of Chinese tea were reported.In multivariable analysis, both factor analysis and regression technique were used to assess the realationship between blocking rate (transferred into In odd, dependent variable) and tea active constituents (independent variable) . It has been shown that the correlation coefficient between each pair of independent variables is comparatively high. One main factor could explain 80% of variation among independent variables, of which the factor loadings were 0.951 (tea catechins), 0.88 (tea polyphenolic compounds), 0.842 (ascorbic acid). It has been found that tea polyphenolic compounds had a higher contribution to the blocking rate. The blocking rates on NPRO formation were 88% for 2 ml green tea extract, 74% for tea polyphenolic compounds extracted from 2 ml green tea, and 75% for 20 mg of tea catechins, the same amount as contained in 2ml of tea extract. The blocking rate -was 28% for the same amount of ascorbic acid contained in 2 ml of tea extract, and therefore ascorbic acid in tea didn't play an important role in the blocking of NPRO formation. Tea polyphenolic compounds and tea catechin affected NPRO formation in the same manner as tea extract, i.e. inhibtion in higher level and promotion in lower level. Thus, it might be concluded that blocking effect on NPRO formation was mainly due to tea polyphenolic compounds especially tea catechin in tea.