Probabilistic evaluation of dietary exposure to lead and age-related exposure centile for residents in Jiangsu / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish a probabilistic model for evaluation of dietary exposure to lead and construct age-related exposure centiles for the residents in Jiangsu.</p><p><b>METHODS</b>Lead contamination data were obtained from the national food contamination monitoring program during 2001 - 2006 and 2791 samples from 232 food products in Jiangsu were included. Food consumption data were from the national diet and nutrition survey conducted in 2002, including 3938 subjects in Jiangsu. A non-parametric probabilistic model using Monte Carlo simulation was applied to derive the intake distribution. The intake data was then analyzed using the LMS method, which constructs exposure percentiles adjusted for the median (M), the coefficient of variation (S) and the skewness (L) of the intake distribution.</p><p><b>RESULTS</b>The median and P(99) of the lead exposure for the residents in Jiangsu were 1.02 µg×kg(-1)×d(-) and 9.29 µg×kg(-1)×d(-1), respectively.6.38% of the total population showed to have a lead intake exceeding the tolerable limit, which for the urban and rural population were 4.31% and 7.06%, respectively. The exceeding rate for children of 2 - 10 years old from the urban and rural areas were 13.17% and 17.70%, respectively.</p><p><b>CONCLUSION</b>There was a large variation in the lead exposure level of the population in Jiangsu; People in rural areas are in greater risk for higher lead exposure than urban people; The dietary exposure to lead for children and the high-end population was serious.</p>

Establishment of non-parametric probabilistic model for evaluation of Chinese dietary exposure / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish a non-parametric probabilistic model for evaluation of Chinese dietary exposure and to improve the assessment accuracy while integrating into the global risk assessment on food safety.</p><p><b>METHODS</b>Contamination data was from the national food contamination monitoring program during 2000 - 2006, including heavy metals, pesticides and mycotoxins, amounting to 135 contaminants with 499 commodities and 487 819 samples. Food consumption data was obtained from the national diet and nutrition survey conducted in 2002 with three consecutive days by 24-hour recall method, and 66 172 consumers were included. Monte Carlo simulation was applied to derive the intake distribution, and the uncertainty of each percentile was estimated using the Bootstrap sampling.</p><p><b>RESULTS</b>Different non-parametric probabilistic models for dietary exposure evaluation on heavy metals, pesticides and some of the toxins were established for Chinese people, and intake distributions with 95% confidence intervals of these contaminants were estimated. Taking acephate as an example, the results of its model shows that, for the 7 - 10 year-old children, the median dietary exposure in urban and rural areas were 1.77 microg x kg(-1) x d(-1) and 2.48 microg x kg(-1) x d(-1) respectively, with a 95% confidence interval of (1.59 - 2.06) microg x kg(-1) x d(-1) and (2.33 - 2.80) microg x kg(-1) x d(-1) respectively.</p><p><b>CONCLUSION</b>The non-parametric probabilistic model can quantify the variability and uncertainty of exposure assessment and improve the assessment accuracy.</p>

Establishment of database for food classification and coding in Chinese dietary exposure assessment / 中华预防医学杂志

<p><b>OBJECTIVE</b>To establish the basis for Chinese dietary exposure assessment database by classifying and coding the data from the national dietary survey and pollutant surveillance.</p><p><b>METHODS</b>The method, which combined CODEX food classifying and coding of Codex Alimentarius Commission (CAC) with Chinese food classification of food composition table, was applied to classify and code the data of 1 810 703 Chinese dietary consumption and 487 819 pollutant surveillance. The coding system was according to the first two letters of the respective food group that represent the type or source of foods, the last four digits represent the serial number of the food in the CAC food classification. If the foods can be found in CAC food code system, its original food code is used. The new codes corresponding with the foods which are not exist in CAC food code system, is added according to CAC coding methods.</p><p><b>RESULTS</b>Dietary consumption data were divided into 6 major categories, 19 types, 75 groups, the agricultural products of pollutant surveillance corresponding to 499 codes. Comparing with CAC food coding system, Chinese dietary consumption data have added F (candy snacks) and G (beverages) 2 major categories, 4 types, 33 groups, 302 new codes. The additional groups most were the processing food groups with Chinese characteristics, such as canned, beverages, candy, meat products.</p><p><b>CONCLUSION</b>The foundation of data communication to dietary exposure assessment has been established, and the connection of Chinese food classifying and coding with CAC data have been achieved.</p>

Development and verification of Chinese dietary exposure evaluation model software / 中华预防医学杂志

<p><b>OBJECTIVE</b>To develop the dietary exposure evaluation model software accredited of Chinese intellectual property rights and to verify the rationality and accuracy of the results from the probabilistic model in Chinese dietary exposure evaluation model software according to international standards.</p><p><b>METHODS</b>The software of SAS was used to build various evaluation model based on the data from Chinese dietary survey and the chemical compound in food surveillance and to design an operation interface. The results from probabilistic dietary exposure model for children 2 - 7 years old were compared with that from duplicate portion study of 2-7 years children dietary exposure in Jinhu, Jiangsu province in order to analyze the rationality of model. The results from probabilistic model of dietary exposure were compared with the results from @Risk software to verify the correction of the probabilistic model by using the same data of randomly selected 10 000 study subjects from national dietary survey. While, the mean drift was used as an internal index to illustrate the accuracy of the computation.</p><p><b>RESULTS</b>Chinese dietary exposure evaluation software was developed successfully. On the rationality, the results from probabilistic model were lower than that from the point estimation (e.g., cucumber: the result of point estimation of acephate was 4.78 microg x kg(-1) x d(-1), while the results of probabilistic model which was 0.39 microg x kg(-1) x d(-1)). Meanwhile the results from probabilistic model were higher than the results of duplicate portion study (on the P95, the result of probabilistic model of Pb exposure in children was 11.08 microg x kg(-1) x d(-1), while the results of duplicate portion study was 5.75 microg x kg(-1) x d(-1)). On accuracy, the results from @Risk and the probabilistic model were highly consistent (on the P95, the result of probabilistic assessment of acephate diet exposure was 4.27 microg x kg(-1) x d(-1), while the results of duplicate portion study was 4.24 microg x kg(-1) x d(-1)), and the mean drift was of random distribution, the drift region varied from 0.05% to 11.9%.</p><p><b>CONCLUSION</b>The results computed by the software of Chinese dietary exposure evaluation model are reliable and reasonable, which is a meaningful step to improve the dietary exposure evaluation technique in China.</p>

Evaluation on the case management program of hypertension in Zhongguancun community, Beijing / 中华流行病学杂志

<p><b>OBJECTIVE</b>To explore a suitable model regarding community-based case management of hypertension in the urban areas.</p><p><b>METHODS</b>Based on the guidelines set by the Chinese Hypertension League (CHL), the goal of case management of hypertension was set as: to maintain blood pressure at the normal range. Family doctors were guided to take care of case management. Hypertension patients who had been contracted to the family doctors were followed by a team of family doctors for half a year.</p><p><b>RESULTS</b>After the 6-month intervention, the rate of hypertension under control had increased from 50.44% to 69.84% (P < 0.0001) while the means of systolic blood pressure decreased by 3.72 mm Hg and diastolic blood pressure decreased by 2.67 mm Hg (P < 0.0001) respectively. The means of SBP decreased by 8.59 mm Hg and diastolic blood pressure decreased by 5.26 mm Hg in patients whose baseline blood pressure were not under control. The rates of smoking, higher salt intake and no physical exercise had significantly decreased (P < 0.05). The mean number of hospital visits in the six-month follow-up period was 7.69 +/- 2.37. The "rate of control" among those who had followed schedule was higher than that of those who were not on schedule (P < 0.0001). The rate among those who had followed the schedule tended to have increased with aging and the level of education (P < 0.001).</p><p><b>CONCLUSION</b>The community-based case management program on hypertension played an important and effective role in the control of hypertension in urban areas. Patients received great benefit when following the guidance from their doctors.</p>