Chemical hazards in pork and health risk: A review

Pork is consumed daily at large quantities in many countries in the world and global pork consumption accounted for 36% of all meat consumed in 2007 and 75% for Viet Nam in 2013 (GSO, 2013). Currently, the issue of toxic chemicals in pork and pork products is of concern by organizations and consumers. A number of studies have documented elevated levels of chemicals found in pork and pork products, which potentially result in negative impacts on consumers' health. However, in developing countries, including Viet Nam, chemicals in pork and health risks have been given inadequate attention. There have been currently very few publications on international peer-reviewed literature and little research on the impacts of chemicals in pork on consumers' health in the country. This review summarizes data available on ScienceDirect database and Vietnamese scientific journals to synthesize information about chemical hazards in pork, pork products and related health risks. The chemical hazards mentioned in this review are mostly common toxic chemicals such as heavy metals, residues of veterinary drugs, dioxin, additives and toxic substances generated during meat processing. In addition, the review also provides recommendations for future research

Antibiotic residues and heavy metals in pork at wet markets in Vietnam

From April 2014 to January 2015, a total of 190 fresh pork samples at wet markets were collected to produce 18 pooled samples that represent 18 studied communes in Hung Yen and Nghe An provinces. Tetracycline, fluoroquinolones, sulfonamide, chloramphenicol groups were firstly screened by ELISA and positive samples were quantified by liquid chromatography–mass spectrometry/mass spectrometry (LCMS/MS). Lead, cadmium and arsenic were determined by Atomic Absorption Spectrometer (AAS). While pooled samples for tetracycline and fluoroquinolones (0/18) were negative tested we found positive test results for sulfonamide (50%, 9/18) and chloramphenicol (16.7%, 3/18). The average residue levels were 155.5 (25.6-263.2) µg/kg for sulfadimidine, higher than Vietnamese MRL (100 µg/kg) and 0.54 (0.34- 0.76) µg/kg for chloramphenicol, which is prohibited in veterinary drugs in Vietnam. Regarding heavy metals, there were 5/18 (27.8) of pooled samples being positive for lead, while cadmium and arsenic were not detected. The average concentration of lead in pork was 74.1 (70.1-78.7) µg/kg, which was still lower than the standard level applied for lead in pork (100 µg/kg). There were no significance differences on the prevalence and concentrations of antibiotic and heavy metal residues between the two studied provinces. The results highlight the presence of sulfadimidine and chloramphenicol in pork available at wet markets. This finding is a component of an ongoing food safety project (PigRISK), which is assessing the health risks of chemical hazards in pork and developing incentive-based innovations to improve management of human and animal health risks in smallholder pig value chains in Vietnam

Exposure assessment of chemical hazards in pork meat, liver, and kidney, and health impact implication in Hung Yen and Nghe An provinces, Vietnam

Objectives This study assesses the risk of exposure to hazardous chemical residues in pork meat, liver, and kidney collected at wet markets in Nghe An and Hung Yen provinces and discusses health impact implication. Methods 514 pig feed, kidney, liver, and pork samples were pooled and qualitatively and quantitatively analyzed for tetracyclines, fluoroquinolones, sulphonamide, chloramphenicol, β-agonists, and heavy metals. We compare the results with current regulations on chemical residues and discuss health implications. Results Legal antibiotics were found in feed. Tetracycline and fluoroquinolones were not present in pork, but 11% samples were positive with sulfamethazine above maximum residue limits (MRL); 11% of packaged feed and 4% of pork pooled samples were positive for chloramphenicol, a banned substance; two feed, two liver, and one pork samples were positive for β-agonists but did not exceed current MRL; 28% of pooled samples had lead, but all were below MRL; and all samples were negative for cadmium and arsenic. Thus, the health risks due to chemical hazards in pork in Hung Yen and Nghe An seemed not as serious as what were recently communicated to the public on the mass media. Conclusions There is potential exposure to sulphonamide, chloramphenicol, and β-agonists from pork. Risk communication needs to focus on banned chemicals, while informing the public about the minimal risks associated with heavy metals

Antimicrobial residues, non-typhoidal Salmonella, Vibrio spp. and associated microbiological hazards in retail shrimps purchased in Ho Chi Minh city (Vietnam)

We investigated antimicrobial residues, non-typhoidal Salmonella (NTS), Vibrio spp. and their associated antimicrobial resistance (AMR), in shrimps locally purchased in Ho Chi Minh City (Vietnam). In addition, we investigated the relationship between AMR in NTS, Vibrio spp. and antimicrobial residue in the same sample. A total of 40 samples of shrimp heads/shells from different retail sources was cultured using ISO 6579-1:2017 (NTS) and ISO/TS 21872-1:2007 (Vibrio spp.). Phenotypic antimicrobial susceptibility was investigated using Vitek (NTS, 34 antimicrobials) and disk diffusion (Vibrio spp., 12 antimicrobials). A total of 9 (22.5%) samples contained antimicrobial residue, including tetracyclines, fluoroquinolones, sulfonamides and macrolides (in 7.5%, 7.5%, 2.5% and 2.5% of samples, respectively). Shrimp samples from supermarkets had a higher prevalence of antimicrobial residue than those purchased in street markets (50% vs. 13.3%) (p = 0.049). A total of 30 (75%) samples were contaminated with NTS. All samples contained Vibrio spp., with V. parahaemolyticus being most common (87.5% samples). A total of 58.9% NTS isolates were multidrug resistant. With regards to the highest priority, critically important antimicrobials, the highest resistance corresponded to quinolones (14.4-47.8%), followed by 3rd and 4th generation cephalosporins (3.3-7.8%). Vibrio spp. isolates were characterised by their high resistance against ampicillin (82.7%) and 3rd generation cephalosporins (8.3-16.5%). Extended Spectrum Beta-Lactamase (ESBL) activity was detected in 28.1% V. parahaemolyticus isolates. Half of ESBL-positive V. parahaemolyticus strains harboured bla CTX-M1. We found an association between the presence of residues and the number of resistances for NTS (p = 0.075) and Vibrio spp. isolates (p = 0.093) from the same sample. These findings suggest that the presence of residues may contribute to the selection of AMR in foodborne pathogens in shrimps. Authorities should strengthen policies aiming at restricting inappropriate antimicrobial usage in shrimp farming, and step up monitoring of antimicrobial residues and food-borne pathogens at retail in Vietnam