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Foodborne diseases are major global public health issues. Among microbial hazards， foodborne diseases are the most serious problem caused by pathogenic bacteria. Under the risk-based food safety management system， identifying the priority hazards and their important food sources is the premise and key to the prevention and control foodborne diseases. Currently， Europe， the United States， and other countries have established two categories of source attribution methods based on microbial subtyping. The results of these methods were transformed on a scientific basis to formulate food safety risk control measures. China is in the preliminary exploration stage of source attribution method research of foodborne disease. This study aimed to systematically sort the methodological principles and models of source attribution methods widely used internationally， combine the basis and current situation of foodborne disease source attribution research in China， and suggest four work directions for constructing the next stage of foodborne disease source attribution system in China. These directions include developing methods， combining data， building platforms and strong exchanges， which involves the development of localized source attribution model based on microbial subtyping to solve the challenges associated with confirming control and preventing and controlling foodborne diseases in China， and achieving food safety and protecting the lives and health of individuals.

Dicyclohexyl phthalate （DCHP） is a phthalic acid esters. It has been widely used in plastic processing and as a component in printing ink， paints， coatings， adhesives， and so on. DCHP can be detected in food， water， soil， air and dust. The application and management of DCHP was introduced， and its pollution characteristics based on existing research at home and abroad was described in this paper. And the research progress of DCHP’s metabolic processes in vivo and the hazard of liver， reproductive system， endocrine system and related mechanisms were further elaborated. And the existing problems and further research directions will be discussed.

ObjectiveTo explore the absorption， distribution， accumulation， and excretion after oral exposure to lanthanum and the effects of lanthanum on the blood element spectrum of rats.Methods48 female SPF-grade rats were randomly divided into 8 groups with a one-time gavage of 700 mg/kg·BW lanthanum nitrate solution using single oral exposure experiment. And the blood， heart， liver， spleen， lung， kidneys， brain， femur， and fecal of rats were collected and measured by ICP-MS after gavage for 1， 2， 4， 8， 16， 32， 64， and 128 h. Another 48 SPF-grade rats were randomly divided into 4 groups （half male and female）， each group with a control and an experimental group was observed in experimental time-point in repeat oral exposure experiment. The experimental group repeatedly gavage lanthanum nitrate solution containing lanthanum 66 mg/kg·BW， and the control group gavage an equal amount of physiological saline. Then， on the 7th， 14th， 21st and 28th days， the rats （including the control group and the experimental group） were taken to determine the contents of 44 elements in blood and the contents of lanthanum in liver， kidney， femur， feces and urine by ICP-MS.ResultsAfter single oral exposure to lanthanum， lanthanum peaked in blood for 2 h， the elimination half-life was 69.315 h， and the overall clearance rate was 1.733 L/h/kg. Lanthanum was widely distributed in the heart， liver， spleen， lung， kidneys， brain， and femur with blood， and the level in the femur was the highest （P0.05）.ConclusionIn this experiment， lanthanum can be rapidly absorbed into the blood after oral exposure and is widely distributed in the heart， liver， spleen， lung， kidneys， brain， and femur. After repeat oral exposure to lanthanum， lanthanum is easily deposited in the liver and femur， feces excretion is the main route of elimination， and no effect of lanthanum on the blood element spectrum of rats has been observed.

ObjectiveThis study aimed to provide scientific evidence for precise prevention measures by utilizing a frequency matching model to identify the primary food sources contributing to sporadic cases of nontyphoidal Salmonella （NTS） in a Chinese province from 2016 to 2020.MethodsData on NTS serotypes from both patients and food sources were collected and analyzed through the Foodborne Disease Surveillance Report System and the Food Contaminant Risk Surveillance System. Source attribution was determined using the Hald model， considering serotypes common to human cases and food sources.ResultsThe analysis revealed that livestock meat was responsible for 35.67% of NTS sporadic cases， with pork contributing significantly at 22.37%. Eggs and egg products accounted for 33.83% of NTS sporadic cases， while poultry and aquatic animals contributed 19.28% and 11.22%， respectively. According to the source attribution analysis， monophasic Salmonella typhimurium appeared to be the dominant serotype causing NTS cases in the province.ConclusionThis study concluded that pork plays a crucial role as an etiological food source for sporadic NTS cases in the province， as determined by the Hald model. These findings provide valuable insights into the prevention and control of NTS-related contamination. Moreover， the application of frequency matching models to address source attribution in sporadic cases can be extended to other provinces for similar investigations.

ObjectiveTo provide scientific basis for the development and utilization of edible pigment Monascus red， the analysis of its key components and toxicological evaluation were carried out.MethodsIdentification test and physicochemical indexes test were carried out based on the samples according to the method in National food safety standard GB 1886.181—2016. The content of citrinin （CIT） and Monacolin K were detected through high performance liquid chromatography （HPLC）. UPLC-Orbitrap-MS2 were used for chemical composition and content determination， in which the molecular structure was also characterized. The 14-day oral toxicity test of SD rats was carried out， based on the acute oral toxicity test of Monascus red by the limited method.ResultsThe quality and specification of test samples conformed to the provisions of China National Food Safety Standard. The content of CIT and Monacolin K was 0.030 8 mg/kg （converted as one color value） and 0.166 mg/g. Twenty compounds were separated in Monascus red by UPLC-Orbitrap-MS2， red pigment， orange pigment and yellow pigment of it accounted for 88.38%， 2.04% and 5.96%， respectively. The results of acute oral toxicity showed that Monascus red was innocuous （LD50>20 g/kg·BW）. In the 14-day repeated oral dose toxicity test， compared with the control group， rats in 5 g/kg·BW dose group exhibited no significant differences in the general clinical observation， growth and development， hematology， blood biochemistry， routine urine detection， gross anatomy，organ weight，organ-to-body ratio， and histopathological examinations.ConclusionMonascus red is composed of multiple components characterized by red pigments. There is no obvious toxic effects found in the preliminary safety evaluation， which can provide reference for further long-term research.

ObjectiveTo investigate the contamination status and dietary exposure risk of 3 perfluorinated substances and 2 chlorine substituted perfluoroalkyl ether sulfonate acids in fresh vegetables planted in the vicinity of typical fluorine chemical industry parks located in Guangdong province.MethodsNinety six vegetables were collected from the vicinity of 3 typical fluorine chemical industry parks and local markets in 2019. The concentrations of 3 perfluorinated substances ［perfluorooctane sulfonate acid （PFOS）， perfluorooctanoic acid （PFOA）， perfluorohexanesulfonic acid （PFHxS）］ and 2 chlorine substituted perfluoroalkyl ether sulfonate acids （6：2 Cl-PFESA and 8：2 Cl-PFESA） in fresh vegetables were detected using isotope dilution method by UPLC-QqQ-MS， and the point estimate was employed to estimate the levels of dietary exposure from fresh vegetables.ResultsPFOS and PFOA were detected in all samples， while chlorine substituted perfluoroalkyl ether sulfonates were detected in 2 leafy vegetable samples. The sum of average concentration of PFASs and Cl-PFESAs in vegetable samples was 0.792 ng/g fw （fresh weight， fw）， and it was two-fold higher compared the samples around the fluorine chemical industrial with the samples from local markets. The average concentration of 5 chemicals （1.11 ng/g fw） was the highest in leafy vegetables. The results of dietary exposure assessment indicated that the exposure levels of 3 perfluorinated compounds by consumption of fresh vegetables which planted surrounding fluorine chemical industry parks were 0.185-2.35 ng/kg·BW. The hazard indexes （HI） of PFOS and PFOA were greater than 1. The exposure level of chlorine substituted perfluoroalkyl ether sulfonate acids were lower.ConclusionThe exposures of PFOS and PFOA of local general population exceeded the established thresholds for the adult residents. The risks of 2 chlorine substituted perfluoroalkyl ether sulfonate acids exposure from vegetables were low， which still need to be concerned.

Objective: To survey the residents for their understanding of Coronavirus Disease 2019 (COVID-19)-related knowledge, attitude and practices (KAP) in two hard hit provinces of China to facilitate the governmental decisions on strategies against the disease., Methods: We invited the participants from Hubei and Henan Provinces of China for an internetbased survey starting from 12:00 on February 21, 2020 to 12:00 on February 23. The survey included the general conditions, KAP of COVID-19, psychological status and living conditions of the residents., Results: The effective response rate of the questionnaire was 98.9%. The mean (P25, P75) age of the participants was 19 (16, 40) years, and 54.3% of them were students. Social media were the most important source of information concerning the pandemic of the respondents. The respondents had a high awareness of person-to-person transmission of the virus through the respiratory tract or droplets but showed a relatively low level of awareness of the population susceptible to COVID-19 and its specific symptoms. The results of multivariate analysis showed that women, undergraduate students (including college students) and higher degree holders had better knowledge of COVID-19 ( P < 0.05); the proportion of respondents who expressed to have different levels of psychological stressed such as worry, anxiety and panic reached 77.2%; 16.7% of the responders considered psychological interventions necessary for their psychological conditions; 63.6% of the respondents confessed a bias against the people returning from Hubei and Henan provinces, while 22.4% worried that they might be biased because of their residence in Hubei and Henan. The rate of personal protective equipment shortage was as high as 69.4%; the rates of the responders who would "covering the mouth and nose when coughing or sneezing", "properly use masks in accordance with regulations", "maintain proper hand hygiene ", "avoid gatherings with relatives and friends" and "refrain from going to public places" were 92.4%, 95.9%, 93.5%, 88.8% and 93.1%, respectively. Women and groups with good knowledge of the disease reported better protective behaviors against the diseases ( P < 0.05)., Conclusions: The residents in Hubei and Henan Provinces have generally good KAP related to COVID-19, and the online platforms plays a positive role to in circulating epidemic-related information. It is essential to further increase the supply of the protective materials and pay more attention to the mental health of the residents during the pandemic, and psychological counseling and psychological protection should be provided if necessary.

Objective: To study long-term effect on renal function exposed to environmental cadmium., Methods: 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., Results: 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., Conclusion: 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.

Objective: To investigate possible joint toxic effects of diazinon, propoxur and bisphenol A (BPA) on proliferation of RAW264.7 cells in vitro., Methods: Cytotoxicity was assessed by MTT assay. The median inhibiting concentration values (IC50) and 95% confidence interval (CI) of diazinon, propoxur and BPA individually and in mixture (mixed according to ratio of IC50) were established by weighted probit method. The types of toxic interaction of diazinon & BPA and propoxur & BPA were assessed by three methods commonly used for binary mixtures, which were Additional Index Method, Equivalent Effect Curve Method and Logistic Regression Method., Results: After 24-hour expoxure, the IC50 and 95% CI of diazinon, propoxur and BPA to RAW264.7 cells were 194.1 microg/ml (173.4 microg/ml-217.4 microg/ml), 448.4 mg/L (358.2 microg/ml-573.2 microg/ml) , and 37.5 microg/ml (35.3 microg/ml-39.9 microg/ml), respectively. Those of mixtures of diazinon & BPA and propoxur & BPA were 168.8 microg/ml (160.1 microg/ml-178.2 microg/ml) and 253.4 microg/ml (236.0-273.0 microg/ml). In the interaction assessment, three methods all demonstrated an antagonistic action of diazinon & BPA and an addition action of propoxur & BPA., Conclusion: It is concluded that the interaction of diazinon & BPA on proliferation of RAW264.7 cells is antagonistic, and that of propoxur & BPA is additive.

Objective: To study effects of alginate on Th1/Th2 cytokines in vivo and in vitro of mice spleen lymphocytes., Methods: In vivo test: Fifteen C57BL/6 mice were randomly divided into one negative control group and two Alginate groups, which were respectively given purified water or 0.50, 1.50 g/kg bw alginate everyday. After 30 days, mice spleen lymphocytes were separated and cultured for 48h. Culture supernatant were gathered for analysis of IL-2, IL-4, IL-5, TNF and IFN-gamma with cytometric bead array (CBA). In vitro test: C57BL/6 mice spleen lymphocytes were separated and respectively cultured with 25 mg/ml or 50 mg/ml alginate for 48h, and then culture supernatants were gathered for analysis of IL-2, IL-4, IL-5, TNF and IFN-gamma with cytometric bead array (CBA)., Results: In vivo test: Compared with the negative control, the IFN-gamma of 0.5 g/kg bw and 1.5 g/kg bw alginate groups showed marked elevation (P < 0.01), while IL-2 and IL-4 were both decreased (P < 0.05, P < 0.01). In vitro test: Compared with control group, TNF, IL-2 and IL-4 of 25 mg/ml and 50 mg/ml alginate groups (P < 0.05, P < 0.01) and IL-5 of 50 mg/ml alginate group (P < 0.01) were all increased., Conclusion: No matter in vivo or in vitro, alginate both can affect the Th1/Th2 cytokines of mice spleen lymphocytes.

For reasons of animal welfare and better science, a series of in vitro methods, including assays based isolated eye or cornea, Chorioallantoic membrane, cultured tissue or cell, had been established and evaluated to replace the Draize eye irritation test. This paper provides a brief review of the recent progress in the in vitro alternatives to Draize eye irritation test, and the principles of scientific validation of these alternatives were also discussed.

The purpose of this study was to explore the effect of zinc on reproductive function in rats. The results revealed that the sperm count, sperm motility and reproductive function appeared to be enhanced in male rats by 60 days successive administration of low dose zinc (12 mg/kg) or medium dose zinc (120 mg/kg), whereas reproductive system damages characterized by lowering of reproductive function would be resulted by high dose zinc(240 mg/kg). However, no effect on the growth and development of the second generation was shown, suggesting that the injury was just limited to certain extent.