Complete mass balance of dietary polychlorinated dibenzo-p-dioxins and dibenzofurans in dairy cattle and characterization of the apparent synthesis of hepta- and octachlorodioxins

Mass balances of 2,3,7,8-substituted dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) were measured in cows following administration of pentachlorophenol (PCP)-treated wood. Fecal excretion accounted for the major fraction of all congeners. Recovery in feces increased with increasing chlorination, while storage in body fat and excretion in milk decreased with increasing chlorination. The PCDFs with no chlorines in the 4- and 6-positions were apparently metabolized because residues were not detected in milk and body fat. Storage and excretion of 1,2,3,4,6,7,8-HpCDD and 1,2,3,4,6,7,8,9-OCDD exceeded intake by factors of 1.7 and 3.4, but recovery of other PCDD/Fs did not exceed intake significantly. Excess excretion of OCDD, but not HpCDD, was confirmed in a follow-up study. Synthesis of HpCDD and OCDD did not occur when PCP-treated wood was fermented with rumen microorganisms, and enhanced concentrations of HpCDD and OCDD were not found in gastrointestinal tract contents of dosed animals. Formation of OCDD during incubation of feces spiked with PCP-treated wood led to the conclusion that synthesis was postexcretion during sample preparation.     

Ion-trap tandem mass spectrometry for the analysis of polychlorinated dibenzo-p-dioxins, dibenzofurans, and dioxin-like polychlorinated biphenyls in food

This paper reports on the applicability of gas chromatography coupled to ion-trap tandem mass spectrometry (GC/ITMS/MS) for the analysis of polychlorinated dibenzo- p-dioxins (PCDDs), dibenzofurans (PCDFs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in food. MS/MS parameters were selected to achieve the high sensitivity and selectivity required for food analysis. Good precision (RSD=5-18% for PCDD/Fs and 6-14% for dl-PCBs) and low limits of detection for PCDD/Fs (0.1-0.93 pg/g of fat) and dl-PCBs (0.1-0.89 pg/g of fat) were obtained. A comparative study of the congener-specific determination using both GC/ITMS/MS and GC-high resolution mass spectrometry (GC/HRMS) was performed by analyzing several matrices such as milk, fish oil, chicken, pork, fish, eggs, and a chicken compound feed, at low pg/g levels. The results using GC/ITMS/MS were in good agreement with those obtained by GC/HRMS. Consequently, GC/ITMS/MS is proposed for the analysis of PCDD/Fs and dl-PCBs in food and feed samples.     

Uptake and transfer of PCDD/Fs by cattle fed naturally contaminated feedstuffs and feed contaminated as a result of sewage sludge application. 2. Nonlactating cows.

The dietary absorption and tissue distribution of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) was investigated in 4 nonlactating Simmental cows. During Phase 1 the dietary uptake and fecal excretion of these chemicals were measured over 10 days using feed containing background levels of PCDD/Fs that were primarily of atmospheric origin. Following this, two of the animals were sacrificed and samples of different fat, muscle, and organ tissues were collected. In Phase 2 the remaining two animals were fed grass silage from a field which had a history of repeated sewage sludge applications. During the last 10 days of the 27-day feeding period, the dietary uptake and fecal excretion of PCDD/Fs were again quantified, after which these two animals were also sacrificed and sampled. The dietary absorption of the PCDD/Fs in the nonlactating cows agreed well with values reported in Part I of this series for lactating cows. In the two animals sacrificed at the end of Phase 1 that were close to a contaminant steady state, the lipid-normalized concentrations were similar in almost all tissues. The exceptions were the liver, and to a lesser extent the lungs and the spleen, which had higher levels; and the degree of elevation increased with the degree of chlorination of the PCDD/Fs. During Phase 2, the animals' body burden of several of the PCDD/F congeners increased markedly. The tissue analyses indicated that the chemicals were initially sequestered primarily in the liver, from where they were redistributed to the other tissues and organs. The rate of redistribution was related to the perfusion of the organ/tissue and decreased in the order lung>spleen>kidney>muscle>fat tissue. The rate of redistribution also decreased with increasing degree of chlorination of the PCDD/F congeners. Whereas virtually all of the 1,2,3,7,8-Cl(5)DD taken up during Phase 2 had been deposited in fat tissue by the end of the 27-day feeding period, three-quarters of the Cl(8)DD was still in the liver.     

Toxic potency of polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and polychlorinated biphenyls in food samples from Catalonia (Spain)

A surveillance program on polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) in 29 foodstuff samples produced all over the four provinces in Catalonia (Spain) is presented. The study included the analyses of milk, egg, meat (beef, chicken, and pork), mussel, and olive oil samples. A previously developed method for the simultaneous analysis of the 2,3,7,8-substituted PCDDs/PCDFs and the dioxin-like PCBs, as well as the indicator PCBs, was employed. Total toxicity equivalent (TEQ) values were calculated using the toxicity equivalent factors (TEFs) proposed by the World Health Organization (WHO) for dioxin-like PCBs, PCDDs, and PCDFs. The TEQ(PCDD/F) levels were below the limits proposed in the draft of the EC regulation for food commercialization in the European countries. These limits are the following: 2 pg WHO-TEQ/g fat for pork, 3 pg WHO-TEQ/g fat for milk and chicken, 5 pg WHO-TEQ/g fat for egg and beef, and 3 pg WHO-TEQ/g whole product for fish. The contributions of PCDDs/Fs and dioxin-like PCBs in the total toxicity of the samples were calculated for each matrix. The results showed that the TEQ(PCB) contribution varied from 27% in olive oil samples to 81% in mussel samples. These findings suggest that the regulation of TEQ contents in food should include not only the TEQ(PCDD/F), but also the TEQ(PCB).     

Milk--blood transfer of (14)C-tagged polycyclic aromatic hydrocarbons (PAHs) in pigs

Polycyclic aromatic hydrocarbons (PAHs) are lipophilic organic pollutants occurring widely in the terrestrial environment. To study the transfer of PAHs in the food chain, pigs have been fed with milk spiked either with [(14)C]phenanthrene or with [(14)C]benzo[a]pyrene. The analysis of blood radioactivity showed that both PAHs were absorbed with a maximum concentration at 5--6 h after milk ingestion, similar to fat metabolism. The blood radioactivity then decreased to reach background levels 24 h after milk ingestion. Furthermore, the blood radioactivity was higher for phenanthrene (even if the injected load was the lowest) than for benzo[a]pyrene, in agreement with their solubility difference. These findings suggest that milk fat and PAHs were absorbed during the same time period.     

Associations Between Dioxins/Furans and Dioxin-Like PCBs in Estuarine Sediment and Blue Crab

The objective of the present study was to evaluate the relationships between the quantity, toxicity, and compositional profile of dioxin/furan compounds (PCDD/Fs) and dioxin-like polychlorinated biphenyls (DL-PCBs) in estuarine sediment and in the blue crab (Callinectes sapidus). Sediment and blue crab samples were collected in three small urban estuaries that are in relatively close proximity to each other. Results show that differences between PCDD/F and DL-PCB mass concentrations and total toxic equivalents (TEQ) toxicity in sediments of the three estuaries are reflected in those of the blue crab. TEQs are higher in the hepatopancreas of the crabs than in the sediment, but the concentration factor is inversely proportional to the TEQ in the sediments. Congener profiles in the crabs are systematically different from those in the sediments, and the difference is more pronounced for PCDD/Fs than for DL-PCBs, possibly due to differences in metabolization rates. Compared with sediment profiles, more lesser-chlorinated PCDD/Fs that have higher TEFs accumulate in crab hepatopancreas. This selective bioaccumulation of PCDD/Fs results in a TEQ augmentation in crab hepatopancreas compared with sediments. The bioaccumulation in the blue crab is also selective for PCDD/Fs over DL-PCBs.     

Levels and trends of polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) and dioxin-like polychlorinated biphenyls (PCBs) in Spanish commercial fish and shellfish products, 1995-2003

The polychlorinated dibenzo-p-dioxin (PCDD), dibenzofuran (PCDF), and polychlorinated biphenyl (PCB) contents of 123 Spanish commercial salmon, tuna fish, sardine, oyster, mussel, and clam samples from 1995 to 2003 were investigated. A significant decrease of dioxin and non-ortho PCB concentrations in the studied species was found over the years. The decrease was greater in the case of dioxins than in that of non-ortho PCBs, especially during the early years of the study. PCB and PCDD/F concentrations in the years 2001-2003 were comparable to those reported in the literature for similar species collected after 1999. Mean PCB concentrations ranged from 3.46 ng/g of fresh weight (fw) in clams to 100 ng/g of fw in tuna fish. PCDD/F mean current levels ranged from 0.62 pg/g of fw in clams to 2.89 pg/g of fw in oysters. Toxic equivalent quantities (WHO-TEQ) ranged from 0.05 pg of WHO-TEQ(PCDD/Fs)/g of fw in clams to 0.5 pg of WHO-TEQ(PCDD/Fs)/g of fw in salmon (in the upper bound determination levels). When coplanar PCBs were included, the WHO-TEQ(PCDD/Fs+cop) (PCBs) values increased by a range of 1.7 times in oysters to 14.1 times in tuna fish. The decrease in dioxin concentrations suggests that efforts to control dioxin emissions and to reduce human exposure through foodstuffs are succeeding. The high contribution of PCBs to total WHO-TEQs in the fish and shellfish species investigated suggests that it is important to determine PCBs in foodstuffs, and especially in fish products, and they should be included in further research and future legislation.     

Freely dissolved PCDD/F concentrations in the Frierfjord,Norway: comparing equilibrium passive sampling with “active” water sampling

Introduction  

Equilibrium passive samplers consisting of 55-μm polyoxymethylene (POM) and 170-μm polydimethylsiloxane were tested for the analysis of polychlorinated dibenzodioxin/furan (PCDD/F) in the pore water and overlying water of the Frierfjord, a bay in southern Norway. This fjord is heavily polluted with PCDD/Fs due to emissions from a former Mg smelter.     

长江三角洲地区土壤环境质量与修复研究I.典型污染区农田土壤中多氯代二苯并二噁英/呋喃(PCDD/Fs)组成和污染的初步研究

通过同位素稀释高分辨率气相色谱-质谱方法(HRGC/HRMS)对长江三角洲地区某典型污染区农田土壤中多氯代二苯并二英(PCDDs)/呋喃(PCDFs)组成、含量及毒性当量进行了初步研究。结果表明,该地区农田土壤中PCDD/Fs总含量的平均值达2639·1pgg-1dw,并检测出PCDD/Fs的四氯~八氯多种异构体。根据世界卫生组织毒性当量(TEQ,哺乳动物)计算结果显示,农田土壤中PCDD/Fs的毒性当量为TEQ20·8~21·3pgg-1dw,超过加拿大国家居住环境土壤二英含量控制标准的5倍多,其中2,3,4,7,8-PCDF和1,2,3,7,8-PCDD对PCDD/Fs的TEQ值贡献最大。该地区农田土壤中已经出现一定程度的二英/呋喃污染。     

Bioaccumulation of PCDD/Fs and Co-PCBs in Lower-Trophic-Level Organisms in Sendai Bay,Japan

In Sendai Bay, Japan, the total PCDD, PCDF, and Co-PCB (dioxins) concentrations in phytoplankton were equivalent to 150, 12, and 51 pg/g wet weight (ww), respectively. The average concentrations in seaweed were 3, 0.095, and 2.1 pg/g ww, respectively. The total concentrations in phytoplankton were much higher than those in seaweed, even though both groups are algae. The concentrations in zooplankton were 11, 1.1, and 110 pg/g ww, respectively. The total PCDD/F concentrations in zooplankton (primary consumers and lower-trophic-level invertebrates) were lower than in phytoplankton (primary producers), but the total Co-PCB concentration in zooplankton was higher than that in phytoplankton. The concentrations in mysids (secondary consumers and higher-trophic-level invertebrates) were 190, 18, and 290 pg/g ww, respectively. The average concentrations in shrimp (secondary consumers and higher-trophic-level invertebrates) were 120, 17, and 410 pg/g ww, respectively. The concentrations in higher-tropic-level invertebrates were higher than those in lower-trophic-level invertebrates. The average concentrations in sand lance were 4.5, 1.7, and 550 pg/g ww, respectively. The total PCDD concentration in sand lance was lower than that in zooplankton (prey of sand lance), but the total Co-PCB concentration in sand lance was higher than that in zooplankton. The bioaccumulation of PCDD congeners in sand lance differed from that of Co-PCB congeners. The bioaccumulation of PCDD/Fs from lower- to higher-trophic-level invertebrates through the food web differed from that from lower-trophic-level invertebrates to fish.     

Levels of polychlorinated dibenzo-p-dioxins and dibenzofurans in food of animal origin. The Swiss dioxin monitoring program

Between 1997 and 1999, several cases of dioxin contaminations in foodstuffs of animal origin occurred in Europe due to feed contaminated by several independent sources: citrus pulp pellets, fat containing polychlorinated biphenyls (PCB), and kaolinitic clay as anti-caking agent in feedingstuffs. As a consequence of the latter, a survey on polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) in food of animal origin was initiated by the Swiss authorities to assess the extent of PCDD/F contamination and to document the efficiency of the measures taken to ensure the decontamination of the food supply. Investigation of a total of 128 samples of cow's milk, poultry, eggs, and meat revealed several cases of residue levels distinctly above the background exposure limit of approximately 2.5 ng of I-TEQ/kg (fat basis). Particularly, elevated concentrations were found in eggs (maximum 13 ng of I-TEQ/kg), poultry (maximum 3.9 ng of I-TEQ/kg), and pork (maximum 7.5 ng of I-TEQ/kg). On the basis of the observed PCDD/F congener pattern, the contamination could be attributed to PCDD/F-contaminated kaolin that was used as an anti-caking agent in particular feedstuffs.     

An assessment of the concentrations of PCDDs/Fs in contaminated bottom sediments and their sources and ecological risk

Purpose

The purpose of the study was to determine the levels of polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran (PCDD/F), two types of persistent organic pollutant (POP), in an urban retention reservoir located in an industrial zone within a coal-mining region. It also assesses the potential ecological risk of the PCDDs/Fs present in bottom sediments and the relationship between their content and the fraction of organic matter.

Materials and methods

The sediment samples were collected from Rybnik Reservoir, located in the centre of the Rybnik Coal Region, Silesia, one of Poland’s major industrial centres. Seventeen PCDD/F congeners in the surface of the sediments were analysed using high-resolution gas chromatography and high-resolution mass spectrometry (HRGC/HRMS).

Results and discussion

The toxic equivalency (TEQ) of the PCDDs/Fs in the sediments ranged from 1.65 to 32.68 pg TEQ g^?1. PCDDs constituted 59–78% of the total PCDDs/Fs, while the PCDFs accounted for 22–41%. The pattern of PCDD/F congeners in the sediments was dominated by OCDD. However, the second-most prevalent constituents were OCDF and ∑HpCDFs in the low TOC sediment (< 10 g TOC kg^?1), but HpCDD in the rich TOC samples (> 10 g TOC kg^?1). PCDD/F concentrations in the sediment samples were 2- to 38-fold higher than the sediment quality guidelines limit, indicating high ecological risk potential. Although a considerable proportion of PCDDs/Fs in the bottom sediments from the Rybnik Reservoir were derived from combustion processes, they were also obtained via transport, wastewater discharge, high-temperature processes and thermal electricity generation. The PCDD/F concentrations were significantly correlated with all fractions of organic matter; however, the strongest correlation coefficients were found between PCDDs/Fs and humic substances. Besides organic matter, the proportions of silt/clay fractions within sediments played an important role in the transport of PCDDs/Fs in bottom sediments.

Conclusions

The silt/clay fraction of the bottom sediments plays a dominant role in the movement of PCDDs/Fs, while the organic matter fraction affects their sorption. The results indicate that the environmental behaviour of PCDDs/Fs is affected by the quantity and quality of organic matter and the texture of sediments.

     

白银市不同功能区表层土壤中PCDD/Fs分布特征研究

采用高分辨气相色谱高分辨质谱联用仪（HRGC/HRMS）对白银市不同功能区土壤样品中的17种2,3,7,8-PCDD/Fs的含量进行了测试,探讨了白银市典型区域表层土壤中PCDD/Fs的来源、分布特征。结果表明,白银市各类表层土壤中17种2,3,7,8-PCDD/Fs的I-TEQ浓度范围为0.42～8.56pg（I-TEQ）·g-1,均值为2.28pg（I-TEQ）·g-1,其中,工业区土壤中PCDD/Fs含量为0.42～8.56pg（I-TEQ）·g-1,均值为3.37pg（I-TEQ）·g-1;城市生活区PCDD/Fs的含量为0.50～1.83pg（I-TEQ）·g-1,均值为1.31pg（I-TEQ）·g-1;农业区含量为0.49～1.33pg（I-TEQ）·g-1,均值为1.01pg（I-TEQ）·g-1;两个背景点PCDD/Fs的含量分别为0.60和1.10pg（I-TEQ）·g-1。研究区域内PCDD/Fs的含量呈现工业区〉城市生活区〉农业区〉背景区的趋势,高氯代的PCDD/Fs异构体对土壤中二恶英毒性当量的贡献率较大。     

Survey of persistent organochlorine contaminants (PCBs, PCDD/Fs, and PAHs), heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic in food samples from Huelva (Spain): levels and health implications

Concentrations of PCBs, PCDDs, and PCDFs, heavy metals (Cu, Cd, Zn, Pb, and Hg), and arsenic have been determined in a great variety of food samples purchased in different markets across the city of Huelva, located in southwestern Spain and under strong industrial activity. All samples analyzed presented concentrations below the maximum allowed by the European Community regarding PCDD/Fs, with the exception of samples within the meat group. An estimation of the daily intake resulted in 1.15 pg of WHO(PCDD/Fs)-TEQ/kg of body weight/day for a 70 kg person and 2.63 pg of WHO-TEQ/kg of body weight/day when PCBs were included, therefore accounting for a similar or even higher percentage than PCDD/Fs and showing the importance of their inclusion in monitoring studies. Meat and meat products, together with vegetable oils and dairy products, were the major food groups contributing to the estimated daily intake. For heavy metals and arsenic, the concentrations found were under the value proposed by European regulations, and estimated daily intakes were well below those proposed by the WHO for all metals investigated. PAHs have been analyzed in food samples from marine origin, values ranging from 8.22 to 71.4 ng/g of fresh weight. Pyrene was the most abundant compound, accounting for >80% in the samples investigated. The most carcinogenic PAHs, such as benzo[a]pyrene and dibenz[a,h]anthracene, were in all cases below the limits of detection. Therefore, the samples analyzed in this survey can be considered as safe with regard to the levels obtained and the in-force legislation.     

长江三角洲地区土壤环境质量与修复研究 Ⅱ.典型污染区农田生态系统中二噁英/呋喃(PCDD/Fs)的生物积累及其健康风险

对长江三角洲地区某典型污染区农田生态系统和部分农产品中多氯代二苯并二嘿英（PCDDs）／呋喃（PCDFs）的污染特征、生物富集及潜在健康风险进行了初步研究。结果表明，该地区局部农田土壤中PCDD／Fs含量及毒性当量平均达556 pg g^-1dw和TEQ 20．2 pg g^-1dw，已在不同农产品中明显积累，其中稻米中PCDD／Fs含量及毒性当量为50．7 pg g^-1dw和TEQ6．4 pg g^-1dw，蔬菜茎叶中为35．2 pg g^-1dw和TEQ6．7 pg g^-1dw；当地家禽鸡肉中PCDD／Fs含量及毒性当量为30．9 pg g^-1ww和TEQ5．7 pg g^-1ww。日允许摄入量（TDI）计算结果表明，经稻米-蔬菜、稻米-蔬菜-鱼腥草、稻米-蔬菜-鱼腥草-鸡肉三种暴露途径至人体的PCDD／Fs日摄入量分别为TEQ67．4、72．1、83．5Pg kg^-1d^-1，均远远超过世界卫生组织（WHO）制定的TDI标准（TEQ 1-4pg ks^-1d^-1）。该地区局部农田生态系统及部分农产品中存在二嘿英类（PCDD／Fs）污染，已构成较大的人体健康风险。     

Comparison of nosespace,headspace, and sensory intensity ratings for the evaluation of flavor absorption by fat

The goal of this study was to better understand the correspondence between sensory perception and in-nose compound concentration. Five aroma compounds at three different concentrations increasing by factors of 4 were added to four matrixes (water, skim milk, 2.7% fat milk, and 3.8% fat milk). These were evaluated by nosespace analysis with detection by proton transfer reaction mass spectrometry (PTR-MS), using five panelists. These same panelists evaluated the perceived intensity of each compound in the matrixes at the three concentrations. PTR-MS quantification found that the percent released from an aqueous solution swallowed immediately was between 0.1 and 0.6%, depending on the compound. The nosespace and sensory results showed the expected effect of fat on release, where lipophilic compounds showed reductions in release as fat content increases. The effect is less than that observed in headspace studies. A general correlation between nosespace concentration and sensory intensity ratings was found. However, examples of perceptual masking were found where higher fat milks showed reductions in aroma compound intensity ratings, even if the nosespace concentrations were the same.     

Effects, quenching mechanisms, and kinetics of water soluble compounds in riboflavin photosensitized oxidation of milk

To protect the nutrient and flavor stability of milk under light, the effects of 0, 0.01, 0.03, and 0.05 M 1,4-diazabicyclo[2,2,2]octane (DABCO) and 2,5-dimethylfuran (DMF) on the riboflavin photosensitized oxidation of milk were studied. The oxidation of milk was studied by measuring the headspace oxygen in sample bottles after 3 h of light exposure at 3000 lux. As the concentration of DABCO and DMF, which are water soluble compounds, increased in the sample from 0, 0.01, and 0.03 to 0.05 M, the depleted headspace oxygen content significantly decreased (P < 0.05). Steady state kinetic studies of singlet oxygen oxidation showed that the antioxidant activity of DABCO and DMF was due to singlet oxygen quenching. The reaction rate constant of singlet oxygen with milk fat was 8.1 x 10(5) M(-1) s(-1). Total singlet oxygen quenching rates of DABCO and DMF were 1.5 x 10(7) and 2.6 x 10(7) M(-1) s(-1), respectively. DABCO and DMF could be used to slow the reaction between singlet oxygen and milk components to protect nutrients, especially riboflavin, and to improve the oxidative stability of milk fat during storage or processing under light.     

Disposition of doramectin milk residues in lactating dairy sheep

Doramectin (DRM) is a broad spectrum macrocyclic lactone antiparasitic drug not approved for use in dairy animals. However, DRM and other endectocide compounds are widely used extra-label to control endo- and ectoparasites in dairy sheep. The plasma disposition kinetics and the pattern of DRM excretion in milk were characterized following its subcutaneous administration to lactating dairy sheep. DRM concentration profiles were measured in plasma and milk samples after validation of a specific HPLC-based methodology. DRM was detected between 1 h and 30 days post-treatment. DRM concentrations of 0.48 ng.mL(-1) (plasma) and 1.03 ng.mL(-1) (milk) were measured at 30 days post-treatment. DRM was extensively distributed from the bloodstream to the mammary gland, and large concentrations were excreted in milk. The peak concentrations and total amount of DRM recovered in milk (expressed as area under the concentration versus time curve) were 3-fold higher than those measured in plasma; 2.44% of the total DRM dose was excreted in milk. The long persistence of DRM milk residues should be seriously considered before its extra-label use in dairy animals is recommended.     

Adequacy of vitamin A and fat in the breast milk of lactating women in south Sri Lanka

OBJECTIVE: To determine vitamin A (retinol) and fat concentrations in breast milk during early lactation. METHODS: Healthy lactating women (n 88) aged between 18 and 35 years were randomly selected for the study from urban, semi-urban, rural and estate (plantation) sectors of Galle District. Their anthropometry was recorded; breast milk samples were collected from the right breast one hour after the last feed. Breast milk retinol was determined by HPLC and fat content by the crematocrit method. RESULTS: Subjects were in the 2nd to 9th month of lactation. Retinol concentrations of the breast milk samples ranged from 0.10 to 2.46 micromol/l, with a mean of 0.50 micromol/l, and correlated positively with parity (Pearson correlation coefficient, r = 0.307; P = 0.01) and negatively with period of lactation (r = -0.209; P = 0.05). The fat content of breast milk ranged between 5.09 and 56.46 g/l with a mean of 26.95 g/l. A significant difference in either breast milk fat or retinol content and mean birth weight of the babies was not seen between the groups. The ratio of retinol to fat in breast milk was positively correlated with weight (r = 0.274; P = 0.01) and height (r = 0.328; P < 0.001) of the mothers. CONCLUSIONS: In this primary investigation on breast milk quality the fat content was found to be marginal; the majority of lactating mothers (92.0%) were not providing the minimum daily requirement (1.05 micromol/l) of retinol to their babies.     

Effect of exposure to soil-bound polycyclic aromatic hydrocarbons on milk contaminations of parent compounds and their monohydroxylated metabolites

The aim of this study was to determine the transfer kinetics of soil-bound polycyclic aromatic hydrocarbons to milk in lactating cows. Soil (500 g/day) fortified with fluorene (104 microg/g dry soil), phenanthrene (82 microg/g), pyrene (78 microg/g), and benzo[a]pyrene (33 microg/g) was administered to three dairy cows via a rumen cannulas for 28 consecutive days. Parent compounds and their major metabolites in milk were measured using gas chromatography-mass spectrometry. Secretion of parent compounds in milk did not increase significantly (P > 0.05) over the control values measured before supply. Target monohydroxylated metabolites were not detected in control samples, but 2-hydroxy fluorene, 3-hydroxy phenanthrene, and 1-hydroxy pyrene were present in milk by the second day of dosing. The highest concentrations of metabolites in milk (31-39 ng/mL) were for 1-hydroxy pyrene at days 7 and 14 of dosing. The observed plateaus for 3-hydroxy phenanthrene and 2-hydroxy fluorene were lower (respectively, 0.69 and 2.79 ng/mL) but significantly increased in comparison to the control samples. Contrarily, 3-hydroxy benzo[a]pyrene was not detected in milk at any sampling time. These results suggested a notable metabolism of the parent compounds after their extraction from soil during the digestive transfer. Thus, the metabolization of fluorene and pyrene can lead to higher concentrations of metabolites than of parent compounds in milk. Despite the absence of a significant transfer of parent PAHs to milk, the appearance of metabolites raises the questions of their impact on human health.