Dietary exposures to eight metallic contaminants of the Hong Kong adult population from a total diet study

Dietary exposures to eight metallic contaminants, aluminium (Al), antimony (Sb), cadmium (Cd), lead (Pb), methylmercury (MeHg), nickel (Ni), tin (Sn) and vanadium (V), of the Hong Kong adult population were estimated using the total diet study (TDS) approach. The estimated mean exposures of Al (0.60 mg kg^–1 bw week^–1), Sb (0.016–0.039 µg kg^–1 bw day^–1), Cd (8.3 µg kg^–1 bw month^–1), Pb (0.21 µg kg^–1 bw day^–1), MeHg (0.74 µg kg^–1 bw week^–1), Ni (3.1 µg kg^–1 bw day^–1), Sn (0.029–0.031 mg kg^–1 bw week^–1) and V (0.13 µg kg^–1 bw day^–1) were well below the relevant health-based guidance values (HBGVs) where available. However, dietary exposures to MeHg of women aged 20–49 years (child-bearing age) accounted for 150% of the provisional tolerable weekly intake (PTWI) and to Al and Cd of some high consumers were found exceeding or approaching the HBGVs. The major food contributors of MeHg were fish and seafood (90%), of Al were non-alcoholic beverages including tea (33%), and of Cd were vegetables (36%). MeHg exposure during pregnancy was a public health concern in Hong Kong due to potential health risks to the foetus. Results suggest that there is a need to continue monitoring the exposures to metallic contaminants, especially Al, Cd and MeHg, of the Hong Kong population.     

Impact of refining the assessment of dietary exposure to cadmium in the European adult population

Exposure assessment constitutes an important step in any risk assessment of potentially harmful substances present in food. The European Food Safety Authority (EFSA) first assessed dietary exposure to cadmium in Europe using a deterministic framework, resulting in mean values of exposure in the range of health-based guidance values. Since then, the characterisation of foods has been refined to better match occurrence and consumption data, and a new strategy to handle left-censoring in occurrence data was devised. A probabilistic assessment was performed and compared with deterministic estimates, using occurrence values at the European level and consumption data from 14 national dietary surveys. Mean estimates in the probabilistic assessment ranged from 1.38 (95% CI = 1.35–1.44) to 2.08 (1.99–2.23) µg kg^–1 bodyweight (bw) week^–1 across the different surveys, which were less than 10% lower than deterministic (middle bound) mean values that ranged from 1.50 to 2.20 µg kg^–1 bw week^–1. Probabilistic 95th percentile estimates of dietary exposure ranged from 2.65 (2.57–2.72) to 4.99 (4.62–5.38) µg kg^–1 bw week^–1, which were, with the exception of one survey, between 3% and 17% higher than middle-bound deterministic estimates. Overall, the proportion of subjects exceeding the tolerable weekly intake of 2.5 µg kg^–1 bw ranged from 14.8% (13.6–16.0%) to 31.2% (29.7–32.5%) according to the probabilistic assessment. The results of this work indicate that mean values of dietary exposure to cadmium in the European population were of similar magnitude using determinist or probabilistic assessments. For higher exposure levels, probabilistic estimates were almost consistently larger than deterministic counterparts, thus reflecting the impact of using the full distribution of occurrence values to determine exposure levels. It is considered prudent to use probabilistic methodology should exposure estimates be close to or exceeding health-based guidance values.     

Dietary exposure and risk assessment to lead of the population of Jiangsu province,China

The paper’s main purpose is to estimate the dietary exposure to lead for the inhabitants of Jiangsu province, China. Lead concentration data were obtained from the national food contamination monitoring programme during 2007–10. Food samples (n = 2077) were collected from 23 food categories in Jiangsu province. Consumption data were derived from Chinese national nutrition and health survey in 2002, which included 3938 inhabitants from 1451 households in Jiangsu province. Concentration data were combined with consumption data to estimate the dietary intake for the inhabitants of 2–6, 7–17 and 18–80 years, respectively. The β-binomial–normal (BBN) model was used to estimate the long-term intake for the population in Jiangsu province. The distribution of individual margin of exposure (IMoE) was introduced to assess the health effect. Uncertainty of IMoE was quantified by Monte Carlo and bootstrap methods. The mean levels of dietary exposure to lead were estimated at 3.019 µg kg^?1 bw day^?1 for children aged 2–6 years, 2.104 µg kg^?1 bw day^?1 for teenagers aged 7–17 years, and 1.601 µg kg^?1 bw day^?1 for adults aged 18–80 years. The mean intakes for the urban and rural populations were 1.494 and 1.822 µg kg^?1 bw day^?1, respectively. From the 25th to 99.9th percentiles, IMoE was 0.125–2.057 for 2–6 years and 0.473–7.998 for 18–80 years, respectively. The distribution of IMoE could indicate a public health concern on lead for the Chinese population in Jiangsu. Control measures should be taken to reduce lead exposure in Jiangsu province.     

Widespread occurrence of perchlorate in water,foodstuffs and human urine collected from Kuwait and its contribution to human exposure

Perchlorate is a thyroid hormone-disrupting compound and is reported to occur widely in the environment. Little is known on human exposure to perchlorate in Kuwait. In this study, 218 water samples, 618 commonly consumed foodstuffs and 532 urine samples collected from Kuwait were analysed to assess the exposure of the Kuwaiti population to perchlorate. For the estimation of daily intake of perchlorate, food consumption rates were obtained from the National Nutrition Survey in the State of Kuwait (NNSSK). The results showed that leafy vegetables accounted for a major share of perchlorate exposure among the Kuwaiti population at 0.062 µg kg^–1 bw day^–1 (36.2%), followed by fruits at 0.026 µg kg^–1 bw day^–1 (15.3%) and non-leafy vegetables at 0.017 µg kg^–1 bw day^–1 (10.1%). The urinary perchlorate geometric mean (GM) concentrations ranged from 8.51 to 17.1 µg l^–1 for the five age groups, which were higher than those reported in other countries. The estimated urinary perchlorate exposure for the Kuwaiti general population was 0.42 µg kg^–1 bw day^–1, which was higher than that reported for the United States. The dietary intake of perchlorate for the Kuwaiti population ranged from 0.14 to 0.67 µg kg^–1 bw day^–1 for the five age groups, with a mean total daily intake of 0.17 µg kg^–1 bw day^–1 for the general population. The highest estimated dietary mean daily intake of perchlorate (0.67 µg kg^–1 bw day^–1) was found for children at 3–5 years. The estimated dietary perchlorate exposure in Kuwait is higher than the recommended mean reference dose (RfD) but lower than that of provisional maximum tolerable daily intake (PMTDI) set by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).     

Aflatoxin B1 in betel nuts (Areca catechu L.) imported to Pakistan from different regions of South Asia

Aflatoxin B₁ (AFB₁) levels were evaluated in betel nuts (Areca catechu L.) being imported to Pakistan during 2010–2011. In total, 278 betel nut samples (India = 21, Indonesia = 51, Sri-Lanka = 34 and Thailand = 172) were received from the Department of Customs and were analysed by thin layer chromatography (TLC). All Indian origin betel nuts showed AFB₁ contamination ranging from 11.7–262.0 µg kg^?1 with a mean of 92.5 µg kg^?1. Among Indonesian and Sri Lankan shipments, 80.4% and 73.5% betel nuts were contaminated with AFB₁ ranging between 3.3–39.2 and 6.5–103.4 µg kg^?1 with a mean of 11.6 and 35.0 µg kg^?1, respectively. However, only 30.2% of Thailand origin samples showed AFB₁ contamination ranging 3.3–77.0 µg kg^?1 with a mean of 6.6 µg kg^?1. The widespread occurrence of AFB₁ increases the hazard associated with betel nuts. Thus, strict control is a pre-requisite for the production and import/export of psychoactive substances as betel nuts.     

Aflatoxins and ochratoxin A in export quality raisins collected from different areas of Pakistan

During 2012–2014, 170 samples of export quality raisins were collected from different vendors in Pakistan. The collected samples were analysed for the presence of aflatoxins (AFs) and Ochratoxin A (OTA) contamination using high-performance liquid chromatography technique. The limit of detection and limit of quantification of AFs/OTA were 0.12/0.10 and 0.36/0.30 µg kg^?1, respectively. Only 5% of the samples were contaminated with AFs, ranging 0.15–2.58 µg kg^?1 with a mean of 0.05 ± 0.26 µg kg^?1. None of the raisin samples exhibited AFs contamination above the maximum limit (ML = 4 µg kg^?1) as set by the European Union (EU). About 72% of the samples were contaminated with OTA, ranging 0.14–12.75 µg kg^?1 with a mean of 2.10 ± 1.9 µg kg^?1. However, in 95.3% of the tested samples, OTA level was lower than the ML of 10 µg kg^?1 as regulated by the EU. Apparently, a strict and continuous monitoring plan, including regulatory limits, improves food safety and quality for all types of commodities.     

Polycyclic aromatic hydrocarbons in Italian preserved food products in oil

A method based on gas chromatography/ tandem mass spectrometry was used to assess levels of 16 EU priority polycyclic aromatic hydrocarbons (PAHs) in 48 preserved food products in oil including foods such as vegetables in oil, fish in oil and oil-based sauces obtained from the Italian market. The benzo[a]pyrene concentrations ranged from <0.04 to 0.40 µg kg^?1, and 72.9% of the samples showed detectable levels of this compound. The highest contamination level was observed for chrysene with three additional PAHs (benzo[a]anthracene, benzo[b]fluoranthene and benzo[c]fluorene) giving mean values higher than the mean value for benzo[a]pyrene. Chrysene was detected in all the samples at concentrations ranging from 0.07 to 1.80 µg kg^?1 (median 0.31 µg kg^?1). The contamination expressed as PAH4 (sum of benzo(a)pyrene, chrysene, benzo(a)anthracene and benzo(b)fluoranthene), for which the maximum tolerable limit has been set by Commission Regulation (EU) No. 835/2011, varied between 0.10 and 2.94 µg kg^?1.     

Dietary exposure to trace elements and health risk assessment in the region of Valencia,Spain: a total diet study

ABSTRACT

Dietary exposure of the Valencian region population to lead, cadmium, inorganic arsenic (iAs), chromium, copper, tin and methylmercury (meHg) was assessed in a total diet study carried out in the region of Valencia in 2010–11. A total of 8100 food samples were collected and analysed. Occurrence data were combined with consumption data to estimate dietary exposure in adults (> 15 years of age) and young children (6–15 years of age). The estimated intake was calculated by a probabilistic approach. Average intake levels (optimistic scenario) for lead, iAs, chromium and tin were 0.21, 0.08, 1.79 and 1.87 µg kg^?1 bw day^?1 respectively; for Cd and meHg average intake levels were 0.77 and 0.54 µg kg^–1 bw week^?1, respectively, and for Cu, 1.60 mg day^?1. In terms of risk characterisation, the results showed that 2.84% of the adult population may exceed the BMDL₁₀ (benchmark dose lower confidence limit) established for Pb, which is linked to renal effects; whereas 28.01% of the young children population may exceed the BMDL₀₁ related to neurodevelopment effects. In addition, 8.47% of the adult population and 12.32% of young children exceeded the meHg tolerable weekly intake (TWI).     

Bisphenol A contamination in soft drinks as a risk for children’s health in Italy

Bisphenol A (BPA) was determined in sugary carbonated, non-carbonated and milk-based beverages, through HLPC-fluorescence detection and confirmed by LC-MS/MS, in a selection of brands that are mostly consumed by Italian children. The daily intake was determined through the WHO budget method (BM). BPA was found at detectable levels in 57% of carbonated beverages, in 50% of non-carbonated and in 100% of milk-based beverages. The median concentrations were 1.24 µg l^–1 (range = < LOD–4.98 µg l^–1) in canned carbonated beverages and 0.18 µg l^–1 (< LOD–1.78 µg l^–1) in non-canned carbonated beverages. In non-carbonated beverages, median concentrations were 0.80 µg l^–1 (< LOD–2.79 µg l^–1) and 0.18 µg l^–1 (< LOD–3.58 µg l^–1), respectively, for canned and non-canned beverages; in milk-based products the BPA median concentration was 3.60 µg l^–1 (1.00–17.65 µg l^–1). BPA daily intake from sugary drink consumption in children ranged from 0.008 to 1.765 µg kg^–1 bw day^–1. The median exposure values for the ‘best’ and ‘worst’ cases were 0.16% and 0.47% respectively of the EFSA t-TDI for BPA (4 µg kg^–1 bw day^–1), and 10.59% and 35.30% of the t-TDI when the maximum levels were considered.     

Determination and surveillance of hydrocortisone and progesterone in livestock products by liquid chromatography-tandem mass spectrometry

A simple analytical method for the determination of hydrocortisone and progesterone in bovine, swine, and chicken muscle and eggs was developed. Hydrocortisone and progesterone were extracted with acetonitrile and subsequently cleaned-up using an Oasis^® HLB mini-cartridge. The method was validated in accordance with Japanese guidelines and exhibited trueness from 86.6% to 104.3% and precision (relative standard deviations (RSDs) of repeatability and within reproducibility were under 8.7% and 11.7%, respectively). The method was applied to 103 bovine muscle, 137 swine muscle, 69 chicken muscle and 52 egg samples that were commercially available in Tokyo, Japan. The hydrocortisone concentration was 0.9–41.2 µg kg^?1 in all bovine muscle samples, with an average of 7.7 µg kg^?1 and a median of 6.2 µg kg^?1. The progesterone concentration in 50 samples exceeded the limit of quantification (LOQ) and reached a maximum of 95.4 µg kg^?1. Hydrocortisone was also detected in all swine muscle samples at concentrations of 2.0–56.0 µg kg^?1. Its average and median concentrations amounted to 13.1 and 11.3 µg kg^?1, respectively. Twenty-three samples contained progesterone levels surpassing the LOQ, with a maximum concentration of 107.0 µg kg^?1. No chicken muscle samples contained any of the analytes. The progesterone concentration was 15.5–200.0 µg kg^?1 in all egg samples, with an average of 95.4 µg kg^?1 and a median of 90.5 µg kg^?1.     

Deoxynivalenol in wheat,maize, wheat flour and pasta: surveys in Hungary in 2008–2015

Among Fusarium mycotoxins, deoxynivalenol (DON) is the most common contaminant in case of cereals and cereal-based foods in Hungary. In this study, Hungarian wheat (n = 305), maize (n = 108), wheat flour (n = 179) and pasta (n = 226) samples were analysed (N = 818). The samples were collected during 2008–2015 in Hungary. Applied methods of analysis were enzyme-linked immunosorbent assay and liquid-chromatography coupled with a mass spectrometer. Results were compared and evaluated with Hungarian weather data. Among cereal samples, in 2011, wheat was contaminated with DON (overall average ± standard deviation was 2159 ± 2818 µg kg^?1), which was above the maximum limit (ML). In case of wheat flour and pasta, no average values above ML were found during 2008–2015, but higher DON contamination could be observed in 2011 as well (wheat flour: 537 ± 573 µg kg^?1; pasta: 511 ± 175 µg kg^?1).     

Exposure to polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) through the consumption of prepared meals in Italy

Diet is a relevant source of exposure to environmental pollutants. Dietary intake of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), dioxin-like polychlorinated biphenyls (DL-PCBs) and polybrominated diphenyl ethers (PBDEs) by the Italian population was assessed through a duplicate diet study on prepared meals. Baby food composite representative of the diet of toddlers aged 9–12 months and school canteen servings from four towns in Italy representing the diet of children aged 4–9 years were collected on a 5-day basis. Similarly, 5-day lunches from an office canteen, 7-day lunches from a hotel-school, three fast food meals, and eight duplicate 1-day meals of individuals (one vegetarian) were selected to represent the diet of adults aged above 18 years. Servings from each diet were then pooled to form a composite and analysed. Dietary intake was estimated from the resulting contaminant levels in composites combined with age-related food consumption data from national survey. The mean upper bound (UB) intakes for cumulative PCDDs, PCDFs, and DL-PCBs were 0.67, 0.63–0.92, and 0.27–0.63 pg WHO₂₀₀₅-TE kg^?1 body weight (bw) day^?1 for toddlers, children and adults, respectively. BDE-47 (UB) ng kg^?1 bw day^?1 estimates were 2.75 in toddlers, 0.08–0.16 in children and 0.03–0.09 in adults. Similarly, for BDE-99 higher UB intakes (ng kg^?1 bw day^?1) resulted in toddlers (1.26), than those in children (0.06–0.08) and adults (0.03–0.10), respectively. The above estimates fall below the tolerable weekly intake (TWI) (14 WHO₂₀₀₅-TE kg^?1 bw day^?1) established by the European Union Scientific Committee on Food (SCF) for PCDD/Fs and DL-PCBs. The margin of exposure (MOE = 3) of toddlers to BDE-99 clearly indicates this age group as target for a risk-oriented approach. This study is proposed as a first cost-effective screening in PCDD, PCDF, DL-PCB and PBDE intake assessment, with a focus also on time trends.     

Unravelling a vicious circle: animal feed marketed in Costa Rica contains irregular concentrations of tetracyclines and abundant oxytetracycline-resistant Gram-positive bacteria

Diverse tetracyclines are used to prevent and control bacterial infections in livestock and farmed fish. These drugs are administered through the diet, but farmers seldom check whether feed contains antibiotic-resistant bacteria that may colonise their crops or transfer their resistance traits to species of veterinary relevance. To examine whether antibiotic dosage defines the abundance of antibiotic-resistant bacteria in animal feed, we determined the concentration of parental compounds and epimers of oxytetracycline (OTC), doxycycline, tetracycline and chlortetracycline, as well as the abundance and resistance level of OTC-resistant bacteria in samples of fish (n = 21), poultry (n = 21), swine (n = 21), and shrimp feed (n = 21) marketed in Costa Rica. Fish feed contained the highest amounts of tetracyclines (119–8365 mg kg^?1) and the largest proportion of bacteria resistant to 10 μg ml^?1 (1.8–92.4%) or 100 μg ml^?1 of OTC (12.5–63.8%). Poultry (78–438 mg kg^?1) and swine (41–1076 mg kg^?1) feed had intermediate concentrations of tetracyclines and OTC-resistant bacteria (0.2–66% and 0.3–49%, respectively), whereas shrimp feed showed the lowest amounts of tetracyclines (21.5–50.3 mg kg^?1), no OTC and no culturable OTC-resistant bacteria. In line with these results, the MIC₅₀ of OTC for 150 isolates from fish and poultry feed was > 256 µg ml^?1, while that of 150 bacteria isolated from swine feed was 192 µg ml^?1. Phenotypic tests, fatty acid profiles and proteotypic analyses by matrix-assisted laser desorption/ionisation-time of flight mass-spectroscopy revealed that most OTC-resistant isolates were Gram-positive bacteria of low G+C% content from the genera Staphylococcus and Bacillus. Clear correlations between OTC dosage and feed colonisation with OTC-resistant bacteria were seen in medicated feed for fish (r = 0.179–0.651). Nonetheless, some unmedicated feed for fish, swine and poultry contained large populations of OTC-resistant bacteria, suggesting that raw materials and manufacturing processes may also influence carriage of OTC-resistant bacteria in animal feed.     

Toxic and essential elements in butter from the Black Sea region,Turkey

In this study, 88 randomly selected samples of butter produced in the Black Sea region of Turkey were purchased from different retail markets during different periods and investigated for toxic and essential elements content. Quantitative analyses of elements in the samples were performed using an inductively coupled plasma-mass spectroscopy (ICP-MS). Mean concentrations of As, Cr, Cu, Fe, Mn, Ni, Pb, Se and Zn in the butter samples were 18.93, 100.32, 384.66, 4199.1, 887.47, 168.64, 56.13, 16.34 and 384.66 µg kg^?1, respectively. Cd and Co were detected in 19 (mean content 0.29 µg kg^?1) and 81 (mean content 3.81 µg kg^?1) samples of 88 butter samples, respectively. However, the dietary intake of these elements by the population of the Black Sea region is currently well below the dietary reference intake (DRI) and provisional tolerable weekly intake (PTWI) levels of essential and toxic elements.     

Dietary intake of arsenic by children and adults from Jinhu area of China

The aim of this study was to estimate the dietary intake of arsenic (As) by children and adults from Jinhu area of China. A duplicate diet approach was used to collect diet samples in November and December 2007. The As content was measured by hydride generation atomic fluorescence spectrometry. The As intakes (median) for different group were: children: 0.6 µg kg^?1 bw day^?1 or 6.7 µg kg^?1 bw week^?1; adults: 0.5 µg kg ^?1 bw day^?1 or 3.8 µg kg ^?1 bw week^?1, none of which exceeded the provisional tolerable weekly intake (PTWI) of 15 µg kg ^?1 bw week^?1 for As proposed by the World Health Organization (WHO). The median and maximum of the children group amounted to 44.7% and 125.3% of the PTWI; the values for adults were 25.3% and 118.7%, respectively. There were 3.3% of children whose weekly As intake exceeded the PTWI, and there were 6.7% of adults whose weekly As intake exceeded the PTWI. It is concluded that dietary As intake was safe for most people in Jinhu area, but the high dietary As intake for a minority of people in this area deserves attention.     

Aflatoxins in animal feed in Iran

One hundred and forty-six samples of animal feed (barley, n = 60; wheat bran, n = 22; wheat dry pulp, n = 29; and canola meal, n = 35) were collected in 2011 from Mashhad (Khorasan, Iran). Aflatoxins (AFs) were determined in these samples after immunoaffinity column clean-up by high-performance liquid chromatography (HPLC) with fluorescence detection. Aflatoxin B₁ (AFB₁) contamination was found in 28 samples: in five of the barley samples (8.3%) at a mean level of 0.48 µg·kg^?1, in two wheat bran samples (9.0%) at a mean level of 0.88 µg·kg^?1, in 10 wheat dry pulp samples (34.5%) at a mean level of 0.30 µg·kg^?1 and in 11 canola meal samples (31.4%) at a mean level of 0.92 µg·kg^?1. AFB₁ levels were below the maximum levels of Iran regulations (5 µg·kg^?1) and the EU maximum limit (5 µg·kg^?1).     

Dietary exposure of Hong Kong secondary school students to total mercury and methylmercury from fish intake

Fish is the main source of dietary exposure to methylmercury (MeHg), which is a public health concern owing to its potential neurotoxicity. To evaluate the public health risk, this study estimated the total mercury (tHg) and MeHg exposure from fish intake in Hong Kong secondary school students. Median tHg and MeHg concentrations of 280 samples purchased from different commercial outlets (covering 89 species of whole fish and three types of canned tuna), together with the local food consumption data of secondary school students obtained by semi-quantitative food frequency questionnaire in 2000, were used to estimate dietary exposure from fish intake for the average and high consumer (95th percentile exposure). For tHg, the median concentration was 63 µg kg^–1 (range 3–1370 µg kg^–1) and estimated exposures ranged 0.5–0.6 µg kg^–1 body weight (bw) week^–1 for an average consumer and 1.6–1.9 µg kg^–1 bw week^–1 for a high consumer. For MeHg, median concentration was 48 µg kg^–1 (range 3–1010 µg kg^–1) and estimated dietary exposures were 0.4–0.5 µg kg^–1 bw week^–1 for an average consumer and 1.2–1.4 µg kg^–1 bw week^–1 for a high consumer. These values are below the respective provisional tolerable weekly intake (PTWI) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA). The health risk is greater for high consumers since MeHg exposures may approach or exceed the PTWI when other dietary sources are taken into account.     

Occurrence of bound 3-monochloropropan-1,2-diol content in commonly consumed foods in Hong Kong analysed by enzymatic hydrolysis and GC-MS detection

The aim of this study was to determine the level of bound 3-monochloropropan-1,2-diol in foodstuffs commonly consumed in Hong Kong, China, by an enzymatic hydrolysis indirect method which proved to be free from interferences. A total of 290 samples were picked up randomly from the local market and analysed. About 73% of these samples were found to contain detectable amounts of bound 3-MCPD. Amongst the 73 food items, bound 3-MCPD was not detected in 13 food items, including extra virgin olive oil, beef ball/salami, beef flank, ham/Chinese ham, nuts, seeds, soy sauce, oyster sauce, butter, yoghurt, cream, cheese and milk. For those found to contain detectable bound 3-MCPD, the content ranged up to 2500 µg kg^?1. The highest mean bound 3-MCPD content among the 14 food groups was in biscuits (440 [50–860] µg kg^?1), followed by fats and oils (390 [n.d.–2500] µg kg^?1), snacks (270 [9–1000] µg kg^?1), and Chinese pastry (270 [n.d.–1200] µg kg^?1). Among the samples, the highest bound 3-MCPD content was in a grape seed oil (2500 µg kg^?1), followed by a walnut flaky pastry (1200 µg kg^?1) and a grilled corn (1000 µg kg^?1). Basically, the results of this study agreed well with other published results in peer-reviewed journals, except for cheese, cream, ham, nuts and seeds.     

Mycotoxin contamination of home-grown maize in rural northern South Africa (Limpopo and Mpumalanga Provinces)

The aim of this study was to assess mycotoxin contamination of crops grown by rural subsistence farmers over two seasons (2011 and 2012) in two districts, Vhembe District Municipality (VDM, Limpopo Province) and Gert Sibande District Municiality (GSDM, Mpumalanga Province), in northern South Africa and to evaluate its impact on farmers’ productivity and human and animal health. A total of 114 maize samples were collected from 39 households over the two seasons and were analysed using a validated liquid chromatography-tandem mass spectrometry mycotoxins method. Aflatoxin B₁ (AFB₁) occurrence ranged from 1 to 133 µg kg^?1 in VDM while AFB₁ levels in GSDM were less than 1.0 µg kg^?1 in all maize samples. Fumonisin B₁ levels ranged from 12 to 8514 µg kg^?1 (VDM) and 11–18924 µg kg^?1 (GSDM) in 92% and 47% positive samples, respectively, over both seasons. Natural occurrence and contamination with both fumonisins and aflatoxins in stored home-grown maize from VDM was significantly (p < 0.0001) higher than from GSDM over both seasons.     

Deposition and depletion of maduramicin residues in eggs after oral administration to laying hens determined by LC-MS

The coccidiostat maduramicin has been approved as a feed additive for chickens and turkeys, although it is prohibited for use in laying hens. In the present study, laying hens were divided into three groups and fed for 14 days with medicated feed containing maduramicin, at three different concentrations: 50, 100 and 500 µg kg^?1. Eggs were collected during treatment and for 26 days after the end of feeding with medicated feed. Maduramicin residues were found exclusively in egg yolk, with the highest concentration in egg yolk of 459 µg kg^?1 for the highest dose. The maximum concentration of maduramicin in whole egg was 16.6 µg kg^?1 for the group receiving feed containing the maximum permitted level of maduramicin in feed (50 µg kg^?1). The half-life of elimination of maduramicin, calculated for post-treatment days 1–10, was 6.5 days. Twelve days after drug administration, the concentration of the maduramicin in egg yolk for Group 3 (fed with 500 µg kg^?1 maduramicin) still exceeded 20 µg kg^?1, while the concentrations for Groups 1 and 2 were 1.2 and 2.7 µg kg^?1, respectively.