核科学助力塞舌尔保障消费者权益

塞舌尔是印度洋上一个由115个岛屿组成的群岛,由于使用了核技术,塞舌尔的10万居民现在可以更好地信赖他们购买的食品。

塞舌尔公共卫生实验室的一名科技人员正在进行牛奶检测。(图/塞舌尔公共卫生实验室S. Labrosse)

塞舌尔是印度洋上一个由115个岛屿组成的群岛,由于使用了核技术,塞舌尔的10万居民现在可以更好地信赖他们购买的食品。

2016年由原子能机构牵头、与联合国粮食及农业组织(粮农组织)合作启动的一个为期四年的技术合作项目,帮助塞舌尔提高了粮食安全控制能力。因此,塞舌尔公共卫生实验室现在能够检测进口牛奶和乳制品中的黄曲霉毒素M1,这是一种致癌物质。同时,政府还加强了国家法律框架,针对这些污染物更好地保护消费者健康。

许多小岛屿发展中国家由于面积小、地形和气候等原因,不适合从事农业生产,因而依赖食品进口。为了保持消费者的安全和信赖,监测和控制进口食品中的霉菌毒素、生物毒素和有毒金属等污染物以及食品生产中使用的兽药和农药的残留至关重要。

塞舌尔公共卫生实验室首席实验室技术专家Leon Biscornet说:“得益于原子能机构和粮农组织的支持,我们现在有能力对食品中的一系列残留物和污染物进行痕量分析,这意味着我们有能力更好地保护消费者免受进口产品的潜在危害。”他补充说,对出口食品的安全进行认证的能力,也有助于改善食品出口市场的准入和维护,并促进农产品出口。

检测牛奶和乳制品中的黄曲霉毒素

塞舌尔消费的牛奶和乳制品90%以上是进口的。经过与原子能机构和粮农组织一年的合作,实验室在12种进口奶制品中检测到了不可接受的黄曲霉毒素M1含量。疑似产品被立即召回,等待国际参考实验室的诊断确认,该实验室确认90%以上的疑似样品确实含有黄曲霉毒素M1。这证明了塞舌尔公共卫生实验室建立的检测能力的可靠性。

黄曲霉毒素由真菌产生,是全球公共卫生和贸易关注的主要问题。根据世界卫生组织(世卫组织)的数据,黄曲霉毒素会增加患癌症特别是肝癌的风险;它们还可能导致人类急性疾病和中毒。因此,粮农组织/原子能机构粮农核技术联合处食品安全专家James Sasanya认为,它们在食品中的存在应受到可靠实验室的监管和监测。

在塞舌尔受污染牛奶事件发生之前,关于食品或饲料中污染物和毒素的国家食品条例并没有对牛奶和奶制品中的黄曲霉毒素M1含量规定任何限值。现在,随着2019年国家《食品安全法》的修订,这一情况已有所改变。塞舌尔公共卫生专员Jude Gédéon说:“根据新规定,从批发和零售市场上清除受污染的奶制品现在有了明确的法律依据,并立即生效。”

该修订案还要求进口商通过卫生证书向公共卫生局提供合法证明,证明其进口的牛奶不含黄曲霉毒素M1、医疗和农药残留等不安全水平的污染物。

食品安全、人员和技术设备

“小国面临的两个挑战是专业人力资源有限和缺乏必要的设备来促进食品安全检测和实验室的运作。通过我们的项目,我们能够解决其中的一些需求,通过改善国家食品控制系统,为加强消费者安全作出贡献。”负责该项目的原子能机构计划管理官员Sulafa Karar说。

在项目期间,原子能机构和粮农组织提供了培训和设备,并与实验室工作人员分享了最佳实践。设备包括一台放射性受体分析仪,这是一种最先进的工具,可以分析十多组兽用抗菌素、霉菌毒素和杀虫剂。

五名实验室工作人员接受了霉菌毒素和相关污染物分析培训。此外,还就如何解读检测结果,特别是如何确定饲料、动物及动物产品中不可接受的黄曲霉毒素水平向实验室提供了技术指导。实验室还从随后的实践培训中受益,培训内容包括分析仪器的最佳使用,以及有效分析食品——不仅是牛奶,还有坚果和香料——中霉菌毒素的样品制备。

这种支持的结果是建立了快速、具有成本效益和敏感的核分析能力,有助于对多种食品和动物饲料进行危害测试,这些食品和饲料也会通过食用动物产品影响人们的健康。黄曲霉毒素M1最近已被列入可在实验室进行检测的化合物清单中。

塞舌尔公共卫生实验室目前正处于建立同位素确认分析能力的后期阶段。这意味着,目前在海外进行的确认测试将很快在国内进行。这将进一步加强国家食品安全管理体系,对进出口食品消费质量产生积极影响。

Detection of aflatoxin in milk and dairy products

Over 90% of the milk and dairy products consumed on the archipelago are imported. After a year of collaboration with the IAEA and FAO, the laboratory was able to detect levels of aflatoxins M1 above the acceptable limit in 12 types of imported milk products. The suspected products were immediately recalled, pending confirmation of the lab’s diagnosis from an international reference laboratory. More than 90% of the suspected samples were confirmed positive to aflatoxins M1 by the reference laboratory, demonstrating the reliability of the testing capabilities now established at the Seychelles Public Health Laboratory.

Produced by fungi, aflatoxins are a major public health and trade concern globally, as they increase the risk of cancer, especially liver cancer, according to the World Health Organization (WHO). Aflatoxins can also cause acute sickness or toxicity in humans. Therefore, their presence in food products should be regulated and monitored using reliable laboratories, said James Sasanya, Food Safety Specialist at the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture.

Before the incident with contaminated milk, the national food regulations on contaminants and toxins in food or feed in the Seychelles did not include any limit of aflatoxin M1 concentration in milk and milk products. This has now changed with the amendment in 2019 of the national Food Safety Act.  “Under the new provisions, there is now a clear legal basis for removing contaminated milk products from the market, both wholesale and retail, with immediate effect,” said Jude Gédéon, Public Health Commissioner.

The amendment also requires importers to provide the Public Health Authority legitimate proof, through a health certificate, that their imported milk is free of contaminants, such as unsafe levels of aflatoxin M1 as well as residues.

Food safety, staff and technical equipment

“Two challenges for small countries are limited availability of specialized human resources and lack of necessary equipment to facilitate food safety testing and operation of laboratories. Through our project, we were able to address some of these needs, contributing to enhanced consumer safety through the improvement of the national food control system,” said Sulafa Karar, the IAEA Programme Management Officer in charge of the project. 

The IAEA and FAO delivered training and equipment and shared best practices with lab staff. Equipment included a radio receptor assay instrument, a state-of-the-art tool that can analyze more than 10 groups of veterinary antimicrobials, mycotoxins and pesticides (see The Science).

Five laboratory staff were trained on the analysis of mycotoxins and related contaminants. Technical guidance was also provided to the laboratory on the interpretation of test results, especially levels of total aflatoxins in feed, animals and animal products considered unacceptable. The laboratory also benefited from subsequent hands-on training on optimum use of analytical instrumentation, as well as sample preparation for effective analysis of mycotoxins in foods – not only milk, but also nuts and spices.

This support resulted in the establishment of rapid, cost-effective and sensitive nuclear analytical capabilities that facilitate the testing of hazards in a broad range of foods and animal feed – which can also affect people’s health through the consumption of animal products . Facilitating testing for aflatoxins M1 was the most recent addition to the growing list of compounds that can be screened at the laboratory.

The Seychelles Public Health Laboratory is now in advanced stages of establishing isotopic confirmatory analytical capabilities. This means that confirmatory tests currently conducted overseas will soon be conducted domestically. This will further boost the country’s food safety control system and positively impact the quality of imported and exported food products consumed.