Zearalenone-Contaminated Cereals in African Communities, Probabilistic Exposures and Adverse-Health Outcomes: A Meta-Analysis

Zearalenone, a mycotoxin produced by Fusarium spp., is one of the exposomes that elicits global public health concern. However, its exposure and health risks are least studied among cereal-growing communities in Africa. It has been well documented to possess estrogenic activities among female populations in humans and animals. Uncertainties are associated with using the permissible maximum tolerable daily intake as a health-based guidance value. This poses a challenge to quantifying reliable exposures and risks for age-related consumers globally and typically in Africa, where cereal consumption is predicted to increase in the next decade. This meta-analysis used probabilistic approaches to leverage uncertainties in zearalenone concentrations in various cereals reported in the scarce studies published across the continent. Using EFSA recommended guidelines, exposures to zearalenone and health risks, indexed as hazard quotient, were quantified among age-related consumer populations in Africa. Exposures were simulated at 100,000 iterations, benchmarked against the regulatory PMTDI (0.25 μg/kg) and quantified as hazard quotient (HQ) to describe risk of adverse health outcomes.
The results presented zearalenone concentrations ranging from 0.90 to 1032 μg/kg and high prevalence in rice and rice-based products (75%). Simulated modal and 95th percentile zearalenone exposures ranged respectively from 5.33×10-3 to 9.70×10-2, and 1.91 to 31.60 μg/kg(bw)-day. Infants recorded the highest modal (9.70×10-2 μg/kg(bw)-day, <0.25 μg/kg EFSA limit), and top 5% (95th percentile) exposures (31.60 μg/kg(bw)-day) which exceeded the regulatory threshold and consequently presented risk (HQ>1). In older age groups, 95th percentile exposures ranked in descending order as: toddlers (13.11 μg/kg(bw)-day) > other children (6.84 μg/kg(bw)-day) > adolescent (3.65 μg/kg(bw)-day) > young adult (2.57 μg/kg(bw)-day) > adult females (2.33 μg/kg(bw)-day) > elderly group (2.09 μg/kg(bw)-day) > adult males (1.91 μg/kg(bw)-day)
The results show a severe risk (HQ >1) among all consumer groups but especially for infants, which seems consistent with global observations in Europe, South America, and the Far East. Infants were more vulnerable to risks arising from zearalenone contaminations and exposures. They are very likely to be exposed to this mycotoxin that exhibits estrogenic traits throughout their lifetime and thus, concerted mitigation strategies for zearalenone must be encouraged to control risk among this age group. Though caution must be exercised in interpreting the results obtained in this study, the probabilistic approach based on the 95th percentile exposure suggests severe zearalenone burden among all consumers, especially infants and children in Africa.

玉米赤霉烯酮 (zearalenone) 是由镰孢菌属 (Fusarium spp.) 产生的真菌毒素，亦是一类引发全球公共健康关切的暴露组相关危害物。然而，在非洲谷物种植产区的人群中，针对其暴露情况与健康风险的研究最为匮乏。已有充分研究证实，该毒素对人类与动物的雌性群体具有雌激素样活性。将最大可耐受每日摄入量作为基于健康的指导值时，存在诸多不确定性。这给全球范围内、尤其是非洲各年龄层消费者的可靠暴露与风险量化工作带来了挑战——预计未来十年非洲的谷物消费量将持续增长。本项荟萃分析采用概率学方法，对非洲大陆已发表的有限研究中报道的各类谷物内玉米赤霉烯酮浓度的不确定性进行了表征与分析。本研究依据欧洲食品安全局 (European Food Safety Authority, EFSA) 推荐的指南，对非洲各年龄层消费者的玉米赤霉烯酮暴露情况以及以危害商数 (hazard quotient, HQ) 为指标的健康风险进行了量化。研究通过10万次迭代模拟暴露情况，以监管机构设定的暂定最大可耐受每日摄入量 (Provisional Maximum Tolerable Daily Intake, PMTDI，0.25 μg/kg) 为基准，将风险量化为危害商数 (HQ)，以表征不良健康结局的发生风险。
研究结果显示，玉米赤霉烯酮的浓度范围为0.90~1032 μg/kg，其中大米及大米制品的污染检出率高达75%，污染水平较为突出。模拟得到的玉米赤霉烯酮暴露众数范围为5.33×10^-3~9.70×10^-2 μg/(kg·体重·天)，95分位暴露范围为1.91~31.60 μg/(kg·体重·天)。婴儿群体的暴露众数最高，达9.70×10^-2 μg/(kg·体重·天)（低于欧洲食品安全局设定的0.25 μg/kg限值），而其前5%高暴露人群（95分位）的暴露量达31.60 μg/(kg·体重·天)，超过了监管阈值，因此存在健康风险 (HQ>1)。在其他年龄组中，95分位暴露量由高到低依次为：学步儿童 (13.11 μg/(kg·体重·天)) > 其他儿童群体 (6.84 μg/(kg·体重·天)) > 青少年 (3.65 μg/(kg·体重·天)) > 年轻成年人 (2.57 μg/(kg·体重·天)) > 成年女性 (2.33 μg/(kg·体重·天)) > 老年群体 (2.09 μg/(kg·体重·天)) > 成年男性 (1.91 μg/(kg·体重·天))
研究结果显示，所有消费者群体均面临严重健康风险 (HQ>1)，其中婴儿群体的风险尤为突出，这与欧洲、南美及远东地区的全球观测结果一致。婴儿群体对玉米赤霉烯酮污染与暴露引发的健康风险更为易感。婴儿在其一生中均极有可能接触这种具有雌激素样特性的真菌毒素，因此必须推动制定协同管控策略，以降低该年龄群体面临的玉米赤霉烯酮健康风险。尽管解读本研究结果时需谨慎行事，但基于95分位暴露量的概率学分析结果表明，非洲所有消费者均面临较重的玉米赤霉烯酮暴露负担，其中婴儿与儿童群体的情况尤为严峻。