Brominated flame retardants in animal derived foods in the Netherlands between 2009 and 2014.

Polybrominated diphenylethers (PBDEs), hexabromocyclododecanes (HBCDDs) and tetrabromobisphenol A (TBBPA) were monitored in various foods from terrestrial and aquatic animal origin (>850 samples), collected in the Netherlands between 2009 and 2014. The terrestrial samples included meat/fat from 7 animal species (including bovines, pigs, broilers and sheep), bovine milk and hen eggs. Dominant PBDE congeners in these samples were BDE-47, -99, -100, -153 and -183. The meat/fat generally contained the highest ∑PBDE concentrations compared to eggs and milk, with meat from deer, horse and sheep containing the highest concentrations. Generally declining ∑PBDE concentrations were observed between 2009 and 2014, however, this was only significant in pig meat and hen's eggs. The aquatic samples included fillets from 18 species (including herring, haddock and salmon), brown crab parts, shrimp and mussels, and the highest ∑PBDE concentrations were seen in body parts of brown crab, herring, mackerel, salmon and sea bass (on wet weight basis). Patterns generally contained more congeners (i.e., BDE-28, -49 and -66) additional to the aforementioned congeners found in terrestrial samples. Herring, sea bass and brown crab (body parts) contained among the highest PBDE concentrations. TBBPA was only detected in 3 individual samples (bovine and broiler meat and haddock), while α-HBCDD was the dominant diastereomer detected in several terrestrial and aquatic samples. When detected, TBBPA and HBCDD concentrations were generally in the same order as ∑PBDE concentrations in the same sample types.

Carry-over of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) in dairy cows fed smoke contaminated maize silage or sugar beet pulp.

Fires and improper drying may result in contamination of feed with PCDD/Fs and PCBs. To predict the impact of elevated feed levels, it is important to understand the carry-over to edible products from food producing animals. Therefore, a carry-over study was performed with maize silage contaminated by a fire with PVC materials, and with sugar beet pulp contaminated by drying with coal, containing particles from a plastic roof. Levels of PCDD/Fs and dl-PCBs in the maize silage were 0.93 and 0.25 ng TEQ kg(-1), those in beet pulp 1.90 and 0.15 ng TEQ kg(-1) (both on 88% dry matter (DM)). Dairy cows (3 per treatment) received either 16.8 kg DM per day of maize silage or 5.6 kg DM per day of sugar beet pellets for a 33-d period, followed by clean feed for 33 days. This resulted in a rapid increase of PCDD/F levels in milk within the first 10 days with levels at day 33 of respectively 2.6 and 1.7 pg TEQ g(-1) fat for maize silage and beet pulp. Levels of dl-PCBs at day 33 were lower, 1.0 and 0.5 pg TEQ g(-1) fat. In the case of the maize silage, the carry-over rates (CORs) at the end of the exposure were calculated to be 25% and 32% for the PCDD/F- and dl-PCB-TEQ, respectively. For the dried beet pulp the CORs were 18% and 35%. This study shows that the carry-over of PCDD/Fs and dl-PCBs formed during drying processes or fires can be substantial.

Carryover of cadmium from feed in growing pigs.

Growing male pigs were exposed to cadmium (Cd) at levels around 1 and 10 mg kg(-1) feed for up to 12 weeks, administered as CdCl2 or Cd-cysteine (CdCys). Pigs exposed to 10 mg kg(-1) showed decreased growth during the last 3 weeks. Liver and kidney concentrations of Cd continuously increased over the entire 12-week exposure, exceeding the European Union limits of 1.0 mg kg(-1) (kidney) and 0.5 mg kg(-1) (liver) within 3 weeks at the feed level of 10 mg kg(-1). A switch to clean feed after 3 weeks for 5 or 9 weeks resulted in steadily decreased levels in kidney and liver, which could be completely attributed to organ growth. At the lower feed level, the level in kidney exceeded the limit almost twofold after 12 weeks, but not after 3 weeks. Liver levels remained below the limit. Metallothionein (MT) levels in livers showed a steady decrease in both untreated and treated animals over time. In kidney such a decrease was only observed in control animals, whereas in the highest-dosed animals the MT concentrations steadily increased. The observed carryover of Cd from feed to liver and kidney was modelled by means of a simple transfer model relating levels in feed via MT levels to accumulation of Cd. Using this model, it was shown that the exposure period of growing pigs to feed containing the European Union limit of 0.5 mg kg(-1) feed should be less than 12 weeks in order to prevent Cd levels in the kidneys to exceed the European Union limit.

Accumulation of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in livers of young sheep.

A major part of sheep livers contains levels of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) above the former but to some extent also the new maximum levels (MLs) in the EU. In order to investigate the relationship between the intake of these contaminants and their accumulation in livers, kidney fat and meat, young blackhead sheep were fed with grass pellets containing PCDD/Fs at 2.5 times the maximum level. Levels of PCDD/Fs in livers were already quite high at the start of the exposure but increased 3-fold within 56d, exceeding the new product based MLs. Levels in meat and fat also increased but did not exceed the MLs. Although less elevated in the grass, both dl- and ndl-PCB levels also increased in liver and fat. Their kinetics in the tissues was less clear, potentially caused by increased levels in the straw given to the sheep during the whole experimental period. There was a clear difference in the behavior of the various congeners, the PCDFs and especially the higher chlorinated PCDFs and PCDDs showing a higher accumulation in the liver. In the case of the PCBs, this was particularly true for PCB 126. When switched to clean grass after 56d, the levels in livers and other tissues decreased to about the levels in the control sheep within 56d. This offers a potential solution for decreasing the intake of consumers.

Levels of polychlorinated dibenzo-p-dioxins, dibenzofurans (PCDD/Fs) and dioxin-like PCBs in free range eggs from Vietnam, including potential health risks.

Chicken and duck eggs collected from three different areas in Vietnam were examined for polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). These regions included a background area, an area sprayed with Agent Orange and the Bien Hoa airbase area where Agent Orange was handled by the US Army. The latter area now is inhabited and people keep their own laying hens. Egg samples were first screened with an in vitro reporter gene bioassay and a selection was analyzed by GC/HRMS. Samples from Bien Hoa airbase showed very high PCDD/F levels, up to 249 pg dioxin-equivalents (TEQ)/g fat, mainly due to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In the sprayed areas, levels (3.2-8.2 pg TEQ g(-1)) were comparable to those observed in background areas (3.2-8.2 pg TEQ g(-1) fat). The estimated average consumption of 22 g d(-1) of the highly contaminated eggs will result in a 2-fold exceedance of the current exposure limits for adults and 5-fold for children, even without considering other contaminated food sources. This indicates a potential health risk from consumption of these highly contaminated eggs, which were not yet considered as a source for exposure to PCDD/Fs of people living in the highly contaminated areas.

Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans) in traditional clay products used during pregnancy.

Geophagy, the practice of consuming clay or soil, is encountered among pregnant women in Africa, Eastern Asia and Latin America, but also in Western societies. However, certain types of clay are known to contain high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The aim of this study was to determine the PCDD/F contents of orally consumed clays purchased from Dutch and African markets. Congener patterns were compared with those of pooled human milk samples collected in eight African countries, to investigate a possible relationship with clay consumption. From the Dutch market thirteen clay products were examined, seven of African and six of Suriname origin. From seven African countries, twenty clay products were collected. All 33 clay products were screened with a cell-based bioassay and those showing a high response were analyzed by GC/HRMS. High PCDD/F concentrations were measured in three clay products from the Dutch market, ranging from 66 to 103 pg TEQ g(-1), whereas clay products from African countries were from 24 to 75 pg TEQ g(-1). Patterns and relatively high concentrations of PCDD/Fs in human milk samples from the Democratic Republic of the Congo and Côte d'Ivoire suggest a relationship with the consumption of contaminated clay. Frequent use of PCDD/F contaminated clay products during pregnancy may result in increased exposure of the mother and subsequently the developing fetus and new-born child. The use of these contaminated clays during pregnancy should be carefully considered or even discouraged.

Dietary exposure to dioxins and dioxin-like PCBs in The Netherlands anno 2004.

In this study, representative occurrence data for PCDD/Fs and dioxin-like PCBs in food were obtained and used to estimate dietary exposure of the Dutch population. Food composite samples were analyzed as well as single fish and vegetables samples. Total dioxin concentrations in animal products ranged from 0.05 pg TEQ/g product in poultry to 2.5 pg TEQ/g product (using TEF(2006)) in fish (shrimp), with 0.12pg TEQ/g product being the lowest concentrations measured in fish (tuna). In vegetable products, concentrations ranged from 0.00002 pg TEQ/g product (white kale) to 0.19 pg TEQ/g (oils and fats). A long-term dietary exposure distribution was calculated using Monte Carlo Risk Assessment software. The lower bound median exposure of the Dutch population to PCDD/Fs and dioxin-like PCBs was estimated at 0.8 pg WHO-TEQ/kgbw/d, half of which were dioxin-like PCBs. Dairy was the main source (38%) due to its high consumption. Time-trend analysis shows that the exposure to dioxins has further decreased by 35% over the past five years. This is due to lower levels of dioxin-like compounds in most of the foods, mainly influenced by lower levels in meat and milk. The use of the new TEFs gives an exposure reduction of 10% with respect to TEF(1998). Still, 4% of the Dutch population exceeds the exposure limit of 14 pg/kgbw/week as set by the EU.

Qualitative screening and quantitative determination of pesticides and contaminants in animal feed using comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry.

A method has been developed for the target analysis of over 100 pesticides and contaminants in a complex feed matrix. The method is based on extraction with ethyl acetate, cleanup by gel permeation chromatography (GPC) and dispersive solid-phase extraction (SPE) with primary secondary amine phase (PSA), and analysis by comprehensive two-dimensional gas chromatography with full scan time-of-flight mass spectrometric detection (GC x GC-TOF-MS). Parameters studied during method development included a dispersive SPE cleanup step after GPC, large volume injection into the GC system and the GC x GC separation. Qualitative and quantitative performance of the GC x GC system was evaluated by analyzing spiked extracts in the range equivalent to 1-100 microg/kg in feed. At levels of 50 microg/kg and higher, all compounds targeted for could be identified fully automatically by the software based on their mass spectra. At lower levels the hit rate decreased with the concentration. System linearity was excellent in solvent and only slightly affected by matrix (correlation coefficients r>or=0.995 for 90% of the compounds). Limits of quantification were in the 1-20 microg/kg range for most compounds. The overall method was validated for 106 compounds at the 10 and 100 microg/kg level. Recoveries between 70% and 110% and RSDs below 20% were obtained for the majority of the compounds.