Chloramphenicol has been used in veterinary medicine, where its residues can remain in food of animal origin, thus potentially causing adverse health effects. This facilitated the ban for its use in food-producing animals globally, but its residues have remained ubiquitous. In this study, food commodities possibly contaminated with chloramphenicol, including livestock meat, poultry, edible viscera, fish, shrimp and crab, molluscs, milk, and eggs, were collected from domestic retail shops in all the 11 districts of Guangzhou and tested for its residue. Probabilistic risk assessment model calculations for its dietary exposure, and the margin of exposure (displayed as mean values and 5th percentile to 95th percentile ranges) were performed by using @RISK software based on a Monte Carlo simulation with 10,000 iterations. The results indicated the detection of chloramphenicol in 248 out of 1454 samples (17.1%), which averaged to a level of 29.1 μg/kg. The highest average value was observed in molluscs (148.2 μg/kg, with the top value as 8196 μg/kg); meanwhile, based on the dietary structure of a typical Cantonese, pond fish, pork, and poultry meat contributed most (about 80%) to the residents’ dietary exposure to chloramphenicol. The margin of exposure for dietary chloramphenicol exposure in Guangzhou residents was 2489, which was apparently below 5000 (the borderline for judging a health risk), particularly low in preschool children (2094, suggesting an increased risk). In conclusion, the study suggests that chloramphenicol exposure in Guangzhou residents is considerable, and its relevant health hazard, especially for preschool children, is worthy of further investigation.

Pentachlorophenol (PCP) is a ubiquitous environmental contaminant commonly existing as its sodium salt (NaPCP), which enters the human body primarily through long term but low-level dietary exposure. PCP contributes to chemical carcinogenesis and teratogenesis. In this study, the probabilistic risk of dietary exposure to PCP in Guangzhou citizens was investigated. In total, 923 food samples in the categories of pork, livestock (beef and lamb), poultry, offal, eggs, and freshwater fish (considered to be relatively susceptible to PCP contamination) were collected from various markets in Guangzhou and tested for PCP. Probabilistic risk assessment model calculations for PCP dietary exposure and margin of exposure (MOE) values were performed using @RISK software, based on a Monte Carlo simulation with 10,000 iterations. The overall detection rate of PCP (above 1 μg kg⁻¹, the detection limit) was 19.9% (184/923), with an average of 7.9 μg kg⁻¹. The highest rate of PCP detection, 28.2%, was in livestock (beef and lamb). The MOE value for dietary PCP exposure in general Guangzhou residents averaged 400, which was far below 5,000 (the borderline for judging a health risk). The lowest MOE value, 190, was observed in the 3- to-6-year old population and indicates a significant risk. In conclusion, this study suggests that PCP exposure in Guangzhou residents is of considerable health risk, especially for the pre-school young children.

Cadmium (Cd) and its compounds are hazardous environmental pollutants with renal toxicity and human carcinogenicity, with ingestion of contaminated foods representing the major mode of exposure. There have been a number of reports evaluating the Cd content in various foods; however, regarding the actual risk posed by dietary cadmium exposure, only a few reports are available in which single point evaluation (less accurate than multiple point evaluation) was employed. In this study, we used a margin of exposure (MOE) model and @RISK software (for multiple evaluation) to evaluate Cd-related health risk in the local Guangzhou residents at varying ages, through a comparison between the estimated monthly exposures and the provisional tolerable monthly intake (0.025 mg/kg body weight (b.w.)), based on the Cd contents in various food categories available locally (a total of 3964 food samples were collected from each of the 13 districts of Guangzhou between 2015 and 2019), which were determined by using inductively coupled plasma mass spectrometry. In this study, Cd was detected in 69.6% of the samples (averaged 0.120 mg/kg), and rice and its products, leafy vegetables, bivalves, and shrimp and crabs contributed most to Cd exposure (8.63, 3.18, 2.79, and 1.48 ng/kg b.w./day, respectively). The MOE values demonstrated the following tendency: the younger age group, the lower MOE, and its 95% confidence range for the (youngest) 3~6 year old group started from 0.92, indicating a health risk of young children, while that for the other age groups were all above 1.0. Our preliminary findings warrant further clarification using biomarker assays in the relevant population.

Per- and polyfluoroalkyl substances (PFASs), known for their environmental persistence and adverse health effects, pose an elevated risk to vulnerable populations through dietary exposure. Yet, there is limited research on PFAS concentrations in market basket meats and offal from Guangzhou, China. We examined the distribution of 16 PFAS in 166 market basket samples (beef, pork, and offal (pork liver)) from Guangzhou. Age-specific dietary exposure and related health risk were assessed for 3-6-year-old children, 7-17-year-old adolescents, adults, and seniors, integrating local food consumption data and probabilistic risk models. The results demonstrated a variable distribution of PFAS based on food species, with offal exhibiting the highest level of contamination (mean Ʃ₁₆PFAS: 6.209 ng·g^-1). Perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) were identified as the most predominant compounds contributing to dietary exposure of total PFAS. For the estimated weekly intake (EWI) of Ʃ₄PFAS [PFOA, PFOS, Perfluorononanoic acid (PFNA), and Perfluorohexanesulfonic acid (PFHxS)] from meats and offal, the average EWI ranged from 3.252 to 5.710 ng·kg^-1 body weight (bw) per week in four age groups. The probability of exceeding tolerable weekly intake (4.4 ng·kg^-1 bw per week) is 51% in children, 45% in adolescents, and 39% in both adults and seniors. Offal was identified as the predominant source of the total PFAS exposure. This study provides the first insights into the age-specific health risk of PFAS from market meats and offal from Guangzhou, highlighting the urgent need for further research to establish safety benchmarks or consumption advisory values for these compounds in the Chinese diet.

Aflatoxins are widespread hepatotoxic food contaminants, yet age-specific cumulative exposure to multiple aflatoxins and associated health risks remain poorly characterized. This study assessed cumulative dietary exposure to aflatoxin B₁ (AFB₁), B₂, G₁, and G₂, and hepatocellular carcinoma (HCC) risk across five age groups, evaluating the influence of packaging and retail sources on contamination. Contamination data of 1179 food samples and consumption data were integrated to calculate the margin of exposure (MoE) and annual HCC incidence. AFB₁ was most frequently detected and often co-occurred with other aflatoxins; bulk vegetable oils showed the highest total aflatoxin detection rate. Roasted peanuts contributed most to aflatoxin exposure, particularly among children aged 3–6 (MoE 900–1206). Rice, rice products, and coarse grains were primary contributors to aflatoxin-attributable HCC risk (0.008 cases per 100,000 person-years). Overall contamination was significantly higher in bulk products than in pre-packaged foods (p < 0.05) and in samples from farmers’ markets and grocery stores than in other sites (p < 0.05). These findings reveal non-negligible aflatoxin-related health risks for Guangzhou residents, especially young children and frequent consumers of staple grains and nuts. Targeted monitoring of high-risk foods and retail environments and age-specific dietary guidance are recommended to reduce population-level aflatoxin exposure and HCC risk.

Background: Although antibiotics have a wide range of applications in medical clinical practice and possess significant clinical value, their inevitable contribution to gut microbiome dysbiosis warrants attention. Our previous research has confirmed that the combined intervention of exercise and konjac glucomannan (KGM) has a better regulatory effect on gut dysbiosis in mice compared with individual interventions. Methods: This study aims to further investigate whether this effect can be transmitted through fecal microbiota transplantation (FMT), and to compare the recovery effects of autologous FMT (a-FMT), fecal microbiota transplantation after exercise combined with KGM intervention (EK-FMT), and combinative intervention with exercise and KGM (EXE-KGM) on gut microbiome dysbiosis. Sample sizes ranged from five to six animals. Results: The results showed that the a-FMT group recovered α diversity the fastest, including Chao, Shannon, and Simpson indices(p < 0.05), within 2 weeks after transplantation when compared with the CTL group. At the end of the experiment, the Bray–Curtis distance of the a-FMT group was closest to the CTL group, while the EXE-KGM group had delayed recovery, there was no significant difference between the EK-FMT group and the EXE-KGM group. Metagenomic analysis and metabolomics analysis indicated that the arginine synthesis and metabolism pathways (KEGG: map00471, map00473, arginine biosynthesis) played a core role in the restoration of the microbiota. Conclusions: The results of this experiment indicate that EK-FMT group can partially transfer the regulatory effects of combined exercise and KGM intervention, a-FMT accelerates the recovery speed of the gut microbiome and arginine metabolism may play an important role in it. This finding provides a theoretical basis and practical direction for special populations to receive special donor fecal treatment.