Food-borne Listeria monocytogenes risk assessment

Listeria monocytogenes is ubiquitous in the environment and in food processing plants. Consequently, foods are frequently contaminated. However, the occurrence rate of listeriosis is only about five cases per million people per year. Listeriosis primarily strikes immunocompromised individuals, pregnant women and the elderly with a fatality rate of 20-25%. The FDA is in the process of finishing a risk assessment that is being conducted as an initial step in reviewing its approach to maximizing the public protection from foodborne L. monocytogenes . The risk assessment evaluated the presence and quantitative levels of L. monocytogenes in 21 groups of ready-to-eat foods. The potential growth of L. monocytogenes between retail point-of-sale, where contamination data originated, and consumption was modelled. The frequency and amount of consumption of these foods completed the data for the exposure assessment. For the hazard characterization or dose response part of the risk assessment, data from animal studies, virulence assays and epidemiological investigations were used to estimate the likelihood of illness for different human groups from consuming different numbers of L. monocytogenes . This risk assessment is a virtual review of current scientific knowledge. Quantitative modelling provides greater insight than a qualitative review and also indicates the uncertainty about our knowledge. The risk assessment does not attempt to define an acceptable or tolerable level of L. monocytogenes consumption or propose changes in regulations. These decisions are the responsibility of risk managers who consider additional factors such as food preferences, technical feasibility and societal values when evaluating regulatory policies.     

Preliminary evaluation of fumonisins by the Nordic countries and occurrence of fumonisins (FB1 and FB2) in corn-based foods on the Danish market

Experts from the Nordic countries (Denmark, Norway, Sweden, Finland and Iceland) have carried out an evaluation of fumonisins. The working group members concluded that, at that time point, it was not possible to carry out a complete risk assessment. However, it was recommended that the human daily' intake of fumonisins should be less than 1 microg/kg bw/day. Subsequently, the presence of the Fusarium mycotoxins fumonisin B1 and B2 (FB1 and FB2) in corn-based food on the Danish retail market has been determined. A total of 70 samples were analysed and 37% contained FB1 and 21% contained FB2. No fumonisins were found in sweet corn (canned or frozen), corn-on-the-cob, corn starch or gruel powder for babies. FB1 was found in about half of the corn flakes, corn snack and popcorn (not popped) samples, whereas FB2 was seen to a lesser extent. Both FB1 and FB2 were found in 75% or more of the corn flour, tacos and polenta samples. In general, the content of FB1 was in the range of 1-1000 micro/kg and the content of FB2 was in the range of 4-250 microg/kg. Corn-based foods are consumed in rather low amounts and irregularly among the Danish population and therefore it is not meaningful to calculate an average daily funonisin intake. An estimate for an 'eater' shows that the intake of fumonisins will not exceed 0.4 microg/kg bw/day.     

中国带壳鸡蛋中沙门氏菌定量危险性评估的初步研究--Ⅰ.危害识别与暴露评估

为控制由食用鸡蛋而导致的沙门氏菌食物中毒 ,利用中国的资料与信息建立了带壳鲜鸡蛋沙门氏菌定量危险性评估模型 ,对中国带壳鲜鸡蛋的沙门氏菌污染情况进行定量评估。模型计算每年以带壳鲜蛋形式被消费的带染鸡蛋数量平均为 2 5× 10 8(5 th～ 95 th百分位点值 :1 9× 10 6～1 1× 10 9)个 ,消费前每个污染鸡蛋中的沙门氏菌菌量平均 70CFU(5 th～ 95 th百分位点值 :14CFU与172CFU) ,该定量危险性评估的框架为中国每年沙门氏菌病暴发的危险性提供了评估依据。     

中国带壳鸡蛋中沙门氏菌定量危险性评估的初步研究--Ⅱ.危害特征的描述与危险性特征的描述

为控制由沙门氏菌污染鸡蛋引起的食物中毒 ,对我国带壳鲜鸡蛋的沙门氏菌污染引起人群感染的危险性进行定量评估。带壳鲜蛋沙门氏菌定量危险性评估模型模拟了从农场到餐桌 (即从生产到消费 )由于消费带壳鲜鸡蛋引起沙门氏菌病的危险性。模型计算每年因食用被沙门氏菌污染的带壳鲜蛋而引起沙门氏菌病的人数平均为 5 3× 10 7人 (5 th～ 95 th百分位点值 :4 0× 10 5～ 2 2× 10 8)。与全国疾病监测点的监测数据预测的沙门氏菌病例数据吻合 ,表明该模型可以合理地预测危险性。通过改变该模型的重要参数 ,评估了几种降低危险性措施的效果 ,发现控制鲜蛋贮存的温度与时间是影响危险性结果的最重要因素。该评估方法的框架为我国今后进行其它类似的定量危险性评估提供了参考。     

食品中重金属的健康风险评估研究进展

重金属作为受关注的污染物,其毒性具有刺激性、靶器官毒性和致癌性等特点。食品中的重金属是进入人体的主要途径之一。因此,使用精确的方法评估食品对人体的健康风险具有重要意义。重金属的人体生物可利用性可以较为贴近人体重金属暴露的实际情况,通过模拟体外生物可利用性实验模型是现有获取重金属人体生物可利用性数据的通用方法。利用生物可利用性数据评估人体重金属暴露的健康风险相比直接利用食品重金属含量更为准确。本文综述了食品的人体生物可利用性实验方法及现行的重金属健康风险评估方法,分析对比了各种方法的优点和局限性,为科研人员确定不同污染物在食品中的生物可利用性提供思路和方向,以加强食品安全评估和人体重金属暴露评估的准确性。     

基于抽检数据的重大活动中供应食品的安全风险评估分级研究

目的 针对重大活动中供应食品分级抽检缺乏理论和数据依据的问题,评估粮食、油脂、肉类、乳品、蔬菜、水产及其制品共6类主要供应食品中49项风险因子级别,指导构建重大活动中供应食品的科学监测防控体系.方法 整理分析2015—2019年国家市场监督管理总局(原国家食品药品监督管理总局)和各地方监管部门(食药监部门)的监督抽检数...     

上海市零售梭子蟹中副溶血性弧菌的污染状况及风险评估

目的 研究上海市场零售梭子蟹中副溶血性弧菌的污染状况,并对副溶血性弧菌可能引发的公共卫生风险进行初步评估.方法 采用最可能数(MPN)法检测上海和宁波市售梭子蟹中副溶血性弧菌的带菌量,采用膳食回顾性调查方法对上海居民梭子蟹消费量进行调查,采用Risk Ranger软件对梭子蟹中副溶血性孤菌进行丰定量风险评估.结果 上海和宁波市零售梭子蟹中副溶血性弧菌阳性率分别为60.5%和13.3%,阳性试样平均菌量分别为0.75 MPN/g和5.50 MPN/g.膳食调查结果显示,上海居民梭子蟹人均日摄入量为2.95 g/d.风险评估结果显示,风险评分为36分,梭子蟹食用者每人每天的发病概率为8.22×10-9,每年上海地区预期发生42.5例副溶血性弧菌感染病例.通过改变评估模型中某些风险的选择,如采取良好的控制措施,风险可降低至原来的1/10.结论 上海市售梭子蟹副溶血性弧菌污染状况较为严重,可能对人群健康造成较高的风险,未来有必要进一步加强监测.     

Cumulative risk assessment of the intake of organophosphorus and carbamate pesticides in the Danish diet

The aim of the study is to evaluate the potential cumulative effects of organophosphorus and carbamate pesticides that act through a common mechanism of toxicity, and to assess the long- and short-term risks for the Danish population. The intake estimates are based on dietary intake data collected in the Danish nation-wide food consumption survey in 1995. The pesticide data are based on the Danish pesticide residue-monitoring programme from 1996-2001. The amount of 35 organophosphorus pesticides and carbamates were included in the cumulative risk assessment. Processing factors, such as reduction of pesticide levels by rinsing and peeling, were applied in the exposure assessment. The "Toxicity Equivalence Factor" (TEF) approach was used to normalise the toxicity of the different organophosphorus and carbamate pesticides. Cumulative chronic exposure of organophosphorus and carbamates pesticides via fruit, vegetables and cereals is for adults 0.8-2% of the Acceptable Daily Intake (ADI) in chlorpyrifos equivalents, and 0.03-11% of the ADI in methamidophos equivalents; and for children 2-5% of the ADI in the chlorpyrifos equivalents, and 0.07-27% of the ADI in methamidophos equivalents. Neither Acute Reference Dose (ARfD) nor ADI was exceeded for any of the compounds studied. The results indicate that the Danish population is neither exposed to any cumulative chronic risk, nor at risk of acute exposure, from consumption of organophosphorus and carbamate pesticides from fruit, vegetables and cereals.     

Carbonyl compounds in different stages of vinification and exposure risk assessment through Merlot wine consumption

ABSTRACT

The objective of this research was to estimate for the first time the transformations that the free form of some target carbonyl compounds may undergo during winemaking and assess the exposure risk to these compounds through the consumption of the Merlot commercial wines under study. Acrolein and furfural were found in grapes and the respective wines, although levels were observed to decline throughout the winemaking process. Formaldehyde was found in all stages of wine production in levels lower than the limit of quantification of the method and ethyl carbamate was not found in samples. Acetaldehyde seems to be a precursor of acetoin and 2,3-butanediol, since the levels of this aldehyde decreased along winemaking and the formation of the ester and alcohol was verified. Furfural levels decreased, while the occurrence of furan-containing compounds increased during winemaking. The formation of acetaldehyde during alcoholic fermentation and the potential environmental contamination of grapes with acrolein and furfural are considered as the critical points related to the presence of toxic carbonyl compounds in the wine. Acrolein was found in the samples under study in sufficient quantities to present risk to human health, while other potentially toxic carbonyl compounds did not result in risk. This study indicated for the first time the presence of acrolein in grapes suggesting that environmental pollution can play an important role in the levels of this aldehyde detected in wines. Reduction of the emission of this aldehyde to the environment may be achieved by replacing wood burning by another heat source in fireplaces or wood stones, and abandoning the practice of burning garbage and vegetation.     

Occurrence of heterocyclic aromatic amines in the Swiss diet: analytical method, exposure estimation and risk assessment

A total of 86 meat samples, prepared in restaurants or homes, ready to eat (including poultry and fish) and 16 commercial samples such as bouillon (cubes) were analysed for heterocyclic aromatic amines (HAA). The analytical method consisted of an acidic extraction, clean-up on a cation exchange cartridge followed by an analogous HPLC step to recover the following HAA: IQ, MeIQ, MeIQx, 4,8-DiMeIQx, PhIP and 7,8-DiMeIQx. The HAA containing HPLC-fractions were collected, the HAA identified and quantified using two RP-HPLC-systems of different retention properties (UV-detection). The limit of quantitation was in the range of 0.2-0.4ng/g and the relative repeatability 6-15%. The recovery of PhIP was lower than for the other HAA analysed (less than 80%) and a correction factor was applied. No significant differences of the HAA-concentration were found in samples from homes and restaurants. half of the total samples contained HAA at the following frequencies: PhIP and MeIQx 33% (each), 4,8-DiMeIQx 11% and MeIQ 4%; 7,8- DiMeIQx and IQ were not detected. The frequencies in commercial products were for MeIQx 31%, 7,8- DiMeIQx 19%, IQ 13% and PhIP 6%; MeIQ and 4,8-DiMeIQx were not found. Based on these data, the average exposure of Swiss adults to HAA was estimated to be 5ng/kg body mass per day, commercial products contributing less than 10%. The theoretical excess cancer risk due to this intake was estimated on the base of the carcinogenic potency of the HAA in long-term animal experiments by linear extrapolation. The resulting risk in the order of 10^-4 at the maximum is discussed in terms of Swiss epidemiological data.     

快速微生物定量风险评估工具及其改进在海产品中副溶血性弧菌风险分级中应用

目的使用快速微生物定量风险评估(sQMRA2)工具对海产品中副溶血性弧菌(Vibrio parahaemolyticus,VP)风险开展定量分级,观察预测模型的选择对sQMRA2分级结果的影响。方法利用sQMRA2工具,综合2017年大连市海产品微生物监测数据、海产品消费量调查数据、海产品储存/交叉污染/烹调习惯等专家咨询数据,对大连市不同海产品-致病性VP组合开展定量风险分级。通过改变食品-致病微生物组合的生长和灭活模型表达式对sQMRA2工具加以改进,观察预测模型的改变对分级结果的影响。结果 sQMRA2工具定量风险分级结果发现,虾类-致病性VP组合导致的每餐发病风险和发病人数最高,分别为1. 2×10-5和5 000人。改变生长和灭活预测模型表达式可在一定程度上影响sQMRA2工具的风险分级结果。结论虾类是导致大连市普通人群2017年6～9月感染VP的高风险食品,交叉污染是各种组合导致人体感染VP的主要途径,使用风险分级工具时需要考虑预测模型的影响。