Petra Schrey

Decrease of PCDD/F levels in human blood from Germany over the past ten years (1989-1998)

744 whole blood samples of normal subjects from Germany collected in 1989-1998 have been analyzed for polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF) by capillary gas chromatography/high resolution mass spectrometry. Over the examined time period a continuous decrease of the PCDD/F concentrations in human blood was observed. The mean levels found were 43.7 pg I-TEq/g (lipid basis) in 1989 and 20.7 pg I-TEq/g (lipid basis) in 1996/98 [median: 42.2 and 19.4]. The reduction to about the half was found for most congeners. Each one-year subset of the collective and the entire collective shows a positive correlation of the PCDD/F blood levels with age for most of the congeners, the sum values and the calculated toxicity equivalents. For statistical evaluation a multiplicative model was used: Concentration = A x Age(B). The correlation is mostly pronounced for lower chlorinated PCDD and for 2,3,4,7,8-PentaCDF. The PCDD/F concentrations in human blood in relation to the year of examination and the age of the subjects can be described by a linear model: I-TEq [pg/g (lipid basis)] = 6176 - 3.097 x Year + 0.6482 x Age or by a multiplicative model: I-TEq [pg/g(lipid basis)] = 10(89.08-0.04415 x Year + 0.008468 x Age).

Dietary intake of cadmium by children and adults from Germany using duplicate portion sampling

The dietary intake of cadmium was studied among children and adults from Germany. The study area comprised the highly industrialized Ruhr district as well as the North Sea island Amrum. A total of 229 duplicate samples were collected from 49 individuals between December 1994 and May 1995. The sampling period for each participant was either 3 or 7 days. Cadmium concentrations in duplicate samples were measured by atomic absorption spectrometry. The daily cadmium intakes (geometric mean) for 4 different groups of individuals distributed as follows: for small children (mean age: 1.8 years) from the Ruhr district 0.17 microg/(kg(bw) x day) [range: 0.02-1.62 microg/(kg(bw) x day)], for children (mean age: 3.8 years) from the Ruhr district 0.49 microg/(kg(bw) x day) [range: 0.11-2.06 microg/(kg(bw) x day)], for children (mean age: 3.9 years) living on the North Sea island Amrum 0.35 microg/(kg(bw)-day) [range: 0.09-1.13 microg/ (kg(bw) x day)] and for adults (mean age: 40.9 years) from the Ruhr district 0.37 microg/(kg(bw) x day) [range: 0.05-1.32 microg/(kg(bw) x day)]. Compared to the provisional tolerable weekly intake (PTWI) of 7 microg/(kg(bw) x week) proposed by the WHO the dietary intake of cadmium was rather high. The geometric mean and maximum intake values for the different groups ranged between 24.3-55.7% and 62.7-120.7 respectively of the PTWI. We therefore conclude, that the cadmium exposure of the population needs to be reduced in order to minimize the risk of adverse health effects related to this metal.

Dietary intake of lead, cadmium, copper and zinc by children from the German North Sea island Amrum

The dietary intake of metals was studied in seven male and seven female children at the age of 1.5 to 5.3 years living in a remote area of Germany, the North Sea island Amrum. The dietary intake of lead and cadmium was measured by a seven-day-duplicate study using atomic absorption spectrometry. The dietary intake of copper and zinc were calculated from food diaries. The median lead and cadmium intakes were 2.1 micrograms/(kgbw x week) [range: 0.63-5.1 micrograms/(kgbw x week)] and 2.7 micrograms/(kgbw x week) [range: 1.7-4.4 micrograms/(kgbw x week)]. The median daily intake of copper and zinc were 1.1 mg/d (range: 0.54-2.5 mg/d) and 5.7 mg/d (range: 2.7-14 mg/d). Compared to the provisional tolerable weekly intake (PTWI) of 25 micrograms/(kgbw x week) proposed by the WHO the dietary intake of lead was low. The median amounted to 8.5% and the maximum to 20% of the PTWI. The cadmium intake was comparatively high. The median amounted to 39% and the maximum to 63% of the PTWI [7 micrograms/(kgbw x week)]. The median intake of copper was in the range of the values recommended by the German Society of Nutrition (0.7-1.0 mg/d and 1.0-1.5 mg/d for children at the age of 1-< 4 years and 4-< 7 years). Twenty-three percent of the calculated intakes were below these values. The median intake of zinc however did not reach the recommended dietary intake of 7 and 10 mg/d for children at the age of 1-< 4 years and 4-< 7 years.

Human fecal PCDD/F-excretion exceeds the dietary intake

A mass balance of human dietary PCDD/F-intake and fecal PCDD/F-excretion was carried out. The participants of the study were seven male and seven female adults between the ages of 24 to 64 years, living in North Rhine-Westphalia, Germany. The PCDD/F-intake was measured using the duplicate method. Sampling time of each food duplicate covered three days. The fecal PCDD/F-excretion was measured by collecting the feces which corresponded to the food duplicates. The mean daily dietary PCDD/F-intake was 49 pg I-TEq/d (range: 23-96 pg I-TEq/d) and therewith lower than that estimated in the past. The mean daily fecal PCDD/F-excretion was 98 pg I-TEq/d (40-200 pg I-TEq/d). This is twice the amount of the PCDD/F-intake. The fecal excretion of OCDD was especially higher than the dietary intake (mean: 7 fold, range: 1.2-21 fold). The differences between PCDD/F-intake and PCDD/F-excretion may be caused by a reduction of the body burden as a consequence of decreasing PCDD/F-intake. Other explanations were additional sources of exposure to PCDD/F or de novo formation of PCDD/F in the human body.

Dietary intake of PCDD/F by small children with different food consumption measured by the duplicate method.

The dietary intake of PCDD/F by 42 small children, 21 boys and 21 girls in the age range 14-47 months, with different food consumption behaviour living in urban and rural areas of Germany was measured by the duplicate method with a 7 day sampling period from May to September 1998. The PCDD/F-levels in the food duplicates were in the range 39.2-325 fg I-TEq/g(dry weight) (median: 90.7; arithmetic mean: 96.6) and the doses were in the range 0.681-5.43 with a median of 1.56 and an arithmetic mean (AM) of 1.60 pg I-TEq/(kg(body weight) x d). Children living in an urban industrialized area with food consumption including products from the family owned vegetable gardens or the surrounding area and/or products from domestic animals showed no statistically significant different concentrations in the food duplicates or in the dietary intake of PCDD/F, calculated as I-TEq, than children living in a rural area with similar food consumption behavior or than children consuming exclusively food from the supermarket.

Dietary intake of nickel and zinc by young children - results from food duplicate portion measurements in comparison to data calculated from dietary records and available data on levels in food groups.

The daily dietary intake of nickel (Ni) and zinc (Zn) by 42 young children, 21 boys and 21 girls, from 4 to 7 years of age, living in urban and rural areas of Germany and having different food consumption behaviour, was determined by the duplicate method with a 7-day sampling period. Dietary records were also kept by the childrens parents for the 7-day sampling period. Individual reported food items were identified, assigned to food groups and, together with known Ni and Zn concentrations of foodstuffs, daily intake rates were calculated. The same method was used for calculations of the energy, fat, protein and carbohydrate intake rates. The levels in the food duplicates, determined by atomic absorption spectrometry, were in the range of 69-2000 microg Ni/kg(dry weight) (geometric mean (GM): 348) and 7.1-43 mg Zn/kg(dry weight) (GM: 17.5). Daily intake rates based on the 294 individual food duplicate analyses were 12-560 microgNi/d (GM: 92.3) and 1.5-11 mgZn/d (GM: 4.63). The results from the dietary records were 35-1050 microg Ni/d (GM: 123) and 1.7-15 mg Zn/d (GM: 5.35). The results of the daily intake rates from both methods showed a correlation with regard to Zn (r=0.56), but no correlation was found between either the Ni intake rates determined with both methods or between the Ni intake rates measured by the duplicate method and calculated intake rates from the dietary records of energy, fat, protein, carbohydrates or drinking water. In the case of nickel, the discrepancies between the methods lead one to suppose that the main factors influencing Ni intake by food are not directly caused by easily assessable food ingredients themselves. It is possible that other factors, such as contaminated drinking water or the transition of Ni from kettles or other household utensils made from stainless steel into the food, may be more relevant. In addition there are some foodstuffs with great variations in concentrations, often influenced by the growing area and environmental factors. Further, some food groups naturally high in Nickel like nuts, cocoa or teas might not have been kept sufficient within the records. In summary, the dietary record method gave sufficient results for Zn, but is insufficient for Ni. Based on the food duplicate analysis, children living in urban areas with consumption of food products from a family-owned garden or the surrounding area and/or products from domestic animals of the surrounding area had about one-third higher Ni levels in their food than children either living in an urban area or children consuming products exclusively from the supermarket. Only slight differences were found with regard to Zn. Compared to the recommendations of the German Society of Nutrition (DGE) (25-30 microgNi/d and 5.0 mgZn/d), the participants of the study had a clearly increased Ni and, in view of the geometric mean value, a nearly adequate Zn intake. Health risks are especially given with regard to the influence of nickel intake by food on dermatitis for nickel-sensitive individuals.

Dietary intake of arsenic, mercury and selenium by children from a German North Sea island using duplicate portion sampling

The dietary intake of arsenic, selenium and mercury was studied for children living on the North Sea island Amrum, Germany. Altogether, 98 duplicate portions were collected from 14 children (age 1.5-5.5 years) in April and May 1995 over a sampling period of 7 days, respectively. The element concentrations in duplicate samples were measured by atomic absorption spectrometry. The weekly As and Hg intake (median and range) was 2.31 and 0.89-6.75 microg/(kg(bw) x week) for As and 0.13 and 0.060-0.62 microg/(kg(bw) x week) for Hg. Compared with the provisional tolerable weekly intake (PTWI) for As and Hg as proposed by the WHO, German children from coastal areas reveal no health risks due to As and Hg dietary intake. The daily Se intake (median and range) was 19 and 6-160 microg/day. The appropriate Se intake of 10-40 microg/day, as recommended by the Austrian, German, and Swiss Nutrition Councils for 1-4 years-old children, was not reached in 8 out of 49 cases (16.3%), whereas the recommended Se intake, fixed at 15-45 microg/day for the 4-7 years-old children, was not reached in 15 out of 48 cases (31.3%).

Polychlorinated Dibenzo-p-Dioxins/Polychlorinated Dibenzofurans (PCDD/Fs), Polychlorinated Biphenyls (PCBs), and Organochlorine Pesticides in Human Blood of Pregnant Women from Germany

Blood samples from 226 pregnant women aged between 19 and 41 yr, living in an industrialized area of Germany (Duisburg birth cohort study), were collected between September 2000 and November 2002 and analyzed for their content of persistent organic pollutants (POPs). Levels of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) were in the range of 4.34–97.3 pg WHO 1998 TEq/glipid base (median: 25.96) or 3.77–63.56 pg WHO 2005 TEq/glipid base (median: 19.38), respectively. Whole blood volume-based concentrations of organochlorine pesticides and their metabolites were 0.036–0.53 μg/L (median: 0.15) hexachlorobenzene (HCB), 4.5–1300 ng/L (median: 67) β-hexachlorocyclohexane (HCH), 0.6–520 ng/L (median: 18) 4,4′-dichlorodiphenyltrichloroethane (DDT), and 0.1–9.1 μg/L (median: 0.54) 4,4′-dichlorodiphenyldichloroethene (DDE). Parameters influencing the POP levels in human blood were examined using multiple regression models. Levels and the levels scatter widths of most PCDD/F and PCB congeners and HCB increased significantly with age. Within the multiple regression model a weak age dependence was also found for β-HCH and DDT, whereas blood levels of α- and γ- HCH and DDE were not age dependent. The total lactation period for earlier born children decreased most POP blood levels, except for α- and γ-HCH. Over the study period of 27 mo only a low decreasing effect on human POP blood levels was observed. The body mass index had in general no or a low positive influence on contaminant levels. Because exposure to PCDD/F and PCB is higher in most industrialized countries in comparison to less industrialized ones, lower levels of these substances were detected in blood samples of women who had lived outside Western Europe for a longer period. In contrast, these women showed higher blood levels of organochlorine pesticides, indicating that these chemicals are still in use outside Western Europe.

Dietary intake of persistent organic pollutants (POPs) by German children using duplicate portion sampling.

The dietary intake of persistent organic pollutants (POPs) was studied in 14 German children at the age of 1.5 to 5.3 years from the North Sea island Amrum. A total of 98 duplicate samples were collected between April and May 1995. The sampling period for each participant was 7 days. Concentrations of POPs were measured by capillary gas chromatography and electron capture detection. The median daily intake [ng/(kgbw.day)] for the different compounds were as follows: 1.9 for alpha-HCH, 1.2 for beta-HCH, 9.5 for gamma-HCH, 4.6 for HCB, 3.4 for DDT, 11.2 for DDE, 1.1 for PCB 101, 5.1 for, PCB 138, 5.2 for PCB 153 and 2.2 for PCB 180. Compared to acceptable or tolerable daily intake (ADI/TDI) proposed by WHO and other organizations the dietary intake of POPs was low. The median values of the ADI/TDI for the POPs was less than 2.2%. The highest percentage of tolerable intake was found for the sum of PCB and amounted to 20.4%. However, compared with minimal risk levels (ATSDR), the percentage of dietary intake was much higher, especially for gamma-HCH (based on median intake: 95%), for HCB (23.1%) and for PCB (69%).

Myeloperoxidase-catalyzed formation of PCDD/F from chlorophenols

Chlorophenols (CP) are transformed in vitro to polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) by a biochemical-catalyzed oxidation. This is shown for 2,4,5-tri-, 2,3,4,6-tetra-and pentachlorophenol with myeloperoxidase recovered from human leucocytes in the presence of hydrogen peroxide. The yield, the reaction, and the PCDD/F-pattern found depend on the CP. The formation rates are in the micromol-per-mol range for all substrates. The experiments confirm the suspicion that a biochemical formation of PCDD/F from precursors such as CPs can take place in the human body and that this metabolic pathway may lead to a higher inner exposure with PCDD/F than is now assumed.