Pilot study on the perfluorooctanesulfonate and perfluorooctanoate exposure of the German general population

Perfluorinated chemicals (PFCs) are used in a wide variety of consumer products. Major fields of application include surfactants, surface protection (e.g., for textiles, carpets, and upholstery), paper treatment (e.g., for food packages), and lubricants. Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are raw materials or manufacturing aids for some PFCs and can be released of those by biotic and/or metabolic decomposition. Due to their widespread use, persistence and bioaccumulative properties they are taken up by the general population from different sources. This might be a problem for environmental medicine because in animal studies PFOS and PFOA provoked various types of cancer and showed developmental toxic potential besides other adverse health effects.

We determined the PFOS and PFOA plasma concentrations of 105 non-smokers out of the German general population as a first estimate of the exposure situation in Germany. We employed an analytical method based on serum protein precipitation followed by HPLC with MS/MS-detection. The median plasma concentrations of all participants were 22.3 and 6.8 μg/l, the 95th percentiles 54.3 and 14.6 μg/l for PFOS and PFOA, respectively. These values are comparable with those of other biomonitoring studies. In our study, men were higher burdened both with PFOS (median: 27.1 vs. 19.9 μg/l) and PFOA (median: 8.3 vs. 5.8 μg/l) than women. No significant influence of age on PFOS and PFOA plasma concentrations could be observed. A strong correlation (r=0.82) between PFOS and PFOA plasma levels indicates the same exposure sources. The ubiquitous internal exposure of the general population to PFOS and PFOA must lead to further activities primarily regarding clarification of sources, metabolism, pharmacokinetics, and health effects.     

Historical comparison of perfluorooctanesulfonate, perfluorooctanoate, and other fluorochemicals in human blood

The purpose of this investigation was to determine whether there has been a change in the human blood concentration of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and five other fluorochemicals since 1974. Blood samples were collected in 1974 (serum) and 1989 (plasma) from volunteer participants of a large community health study. The study included a total of 356 samples (178 from each time period). These samples were analyzed by high-pressure liquid chromatography/tandem mass spectrometry methods. The median 1974 and 1989 fluorochemical concentrations, respectively, were as follows: PFOS, 29.5 ng/mL vs. 34.7 ng/mL; PFOA, 2.3 ng/mL vs. 5.6 ng/mL; perfluorohexanesulfonate (PFHS), 1.6 ng/mL vs. 2.4 ng/mL; and N-ethyl perfluorooctanesulfonamidoacetate (PFOSAA), less than the lower limit of quantitation (LLOQ; 1.6 ng/mL, vs. 3.4 ng/mL). For N-methyl perfluorooctanesulfonamidoacetate (M570), perfluorooctanesulfonamide, and perfluorooctanesulfonamidoacetate, median serum concentrations in both years were less than the LLOQ values (1.0, 1.0, and 2.5 ng/mL, respectively). Statistical analysis of 58 paired samples indicated that serum concentrations of PFOS, PFOSAA, PFOA, PFHS, and M570 were significantly (p < 0.001) higher in 1989 than in 1974. The data from 1989 were then compared with geometric mean fluorochemical concentrations of serum samples collected in 2001 from 108 American Red Cross adult blood donors from the same region. Except for M570, there were no statistically significant (p < 0.05) geometric mean fluorochemical concentration differences between the 1989 and 2001 samples. In conclusion, based on this study population, PFOS and other serum fluorochemical concentrations have increased between 1974 and 1989. Comparison with other regional data collected in 2001 did not suggest a continued increase in concentrations since 1989.     

Prenatal exposure to PFOA and PFOS and risk of hospitalization for infectious diseases in early childhood

Objectives

To examine whether prenatal exposure to perfluorooctanesulfonate (PFOS) or perfluorooctanoate (PFOA) is associated with the occurrence of hospitalization for infectious diseases during early childhood.

Methods

We randomly selected 1400 pregnant women and their offspring from the Danish National Birth Cohort (1996–2002) and measured PFOS and PFOA levels in maternal blood during early pregnancy. Hospitalizations for infection of the offspring were identified by the linkage to the National Hospital Discharge Register through 2008.

Results

Hospitalizations due to infections were not associated with prenatal exposure to PFOA and PFOS. On the contrary, the relative risks of hospitalizations ranged from 0.71 to 0.84 for the three higher quartiles of maternal PFOA levels compared with the lowest, but no dose-response pattern was found. No clear pattern was observed when results were stratified by child’s age at infection, with the exception of an inverse association between maternal PFC levels and risk of hospitalization during the child’s first year of life.

Conclusions

These findings suggest that prenatal exposure to PFOA or PFOS is not associated with increased risk of infectious diseases leading to hospitalization in early childhood.     

Transplacental exposure of neonates to perfluorooctanesulfonate and perfluorooctanoate: a pilot study

Objectives Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) can be released of perfluorinated compounds by biotic and/or metabolic decomposition. Due to their ubiquitous occurrence, persistence and bioaccumulative properties they can be found in blood of the general population all over the world. In animal studies PFOS and PFOA provoked cancer and showed developmental toxic potential besides other adverse health effects. On the basis of the comparison of maternal and umbilical cord plasma sample pairs we wanted to examine whether infants are exposed to PFOS and PFOA via their mothers’ blood. Methods We determined PFOS and PFOA in 11 plasma samples of mothers and the 11 corresponding cord plasma samples of neonates. An analytical method based on plasma protein precipitation followed by HPLC with MS/MS-detection was employed. As internal standards we used 1,2,3,4-¹³C₄-PFOS and 1,2-¹³C₂-PFOA. Results We found PFOS and PFOA in every plasma sample analysed. In maternal plasma samples PFOS concentrations were consistently higher compared to those of the related cord plasma samples (median: 13.0 μg/l vs. 7.3 μg/l). In the case of PFOA we observed only minor differences between PFOA concentrations within the analysed sample pairs (median: 2.6 μg/l vs. 3.4 μg/l for maternal and cord plasma samples, respectively). Discussion For both substances a crossing of the placental barrier could be shown. For PFOS we observed a decrease from maternal to cord plasma concentrations by a factor of 0.41–0.80. To the contrary, PFOA crosses the placental barrier obviously unhindered. These findings show that neonates are exposed to PFOS and PFOA via their mothers’ blood. Given the current situation that only little is known about the consequences of PFOS and PFOA exposure in the early state of development of humans and the fact that in animal studies both substances showed developmental toxic effects further research regarding human health effects is indispensable.     

Epidemiologic assessment of worker serum perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) concentrations and medical surveillance examinations

Perfluorooctanesulfonyl fluoride (POSF, C8F17SO2F) is used to create applications for surfactants and paper, packaging, and surface (e.g., carpets, textiles) protectants. Such POSF-based products or their residuals may degrade or metabolize to PFOS (C8F17SO3-). PFOS concentrates in liver and serum and results in hypolipidemia as an early effect of cumulative dosages. Male and female employees of two perfluorooctanyl-manufacturing locations (Antwerp, Belgium and Decatur, Alabama) participated in a periodic medical surveillance program that included hematology, clinical chemistry, thyroid hormone, and urinalysis testing. Serum concentrations of PFOS and perfluorooctanoate (PFOA, C7F15CO2-, used as a fluoropolymer emulsifier) were measured via mass spectrometry methods. The mean serum PFOS and PFOA concentrations for 263 Decatur employees were 1.32 parts per million (ppm; geometric mean 0.91, range 0.06-10.06 ppm) and 1.78 ppm (geometric mean 1.13, range 0.04-12.70 ppm), respectively. Mean concentrations were approximately 50% lower among 255 Antwerp workers. Adjusting for potential confounding factors, there were no substantial changes in hematological, lipid, hepatic, thyroid, or urinary parameters consistent with the known toxicological effects of PFOS or PFOA in cross-sectional or longitudinal analyses of the workers' measured serum fluorochemical concentrations.     

Assessment of lipid,hepatic, and thyroid parameters with serum perfluorooctanoate (PFOA) concentrations in fluorochemical production workers

Objectives Perfluorooctanoic acid (PFOA) results in peroxisome proliferator mediated effects in rats and mice resulting in hypolipidemia but not in monkeys. Counterintuitive modestly positive associations between PFOA and cholesterol levels in production workers have been inconsistently reported. The purpose of this assessment was to examine this association in male workers who manufactured or used PFOA at three facilities. Methods Subjects were male employee voluntary participants of a fluorochemical medical surveillance program who provided blood samples for serum measurement of PFOA (perfluorooctanoate) and various lipid, hepatic, and thyroid parameters. Statistical analyses included multiple and logistic regression and analysis of covariance. Results A total of 506 employees, who did not take cholesterol-lowering medications (93% of all male participants), were analyzed. Serum PFOA concentrations ranged from 0.007 to 92.03 μg/ml [arithmetic mean 2.21 μg/ml (95% confidence interval 1.66–2.77), median 1.10 μg/ml]. Adjusted for age, body mass index, and alcohol usage in regression analyses, PFOA was not statistically significantly (P > 0.05) associated with total cholesterol or low-density lipoproteins (LDL). High-density lipoproteins (HDL) were significantly negatively (P < 0.01) associated with PFOA for the three facilities combined but not by individual sites, indicating the overall result was likely a consequence of residual confounding due to different demographic profiles at these sites. Serum triglycerides were significantly positively associated with PFOA but not consistently by locations. There were no statistically significant associations observed between PFOA and hepatic enzymes for the three facilities combined although some modest positive associations were observed between PFOA and hepatic enzymes at one of the three facilities. Analyses of all locations showed no associations with TSH or T4 and PFOA. A negative association was observed for free T4 and positive association for T3; however, the findings were well within these assays’ normal reference ranges. Conclusion There was no evidence that employees’ serum PFOA concentrations were associated with total cholesterol or LDL. A negative association with HDL was explained by demographic differences across the three locations. Several explanations are offered for the inconsistent triglyceride associations with PFOA including both methodological as well as biological possibilities.     

Two-year follow-up biomonitoring pilot study of residents’ and controls’ PFC plasma levels after PFOA reduction in public water system in Arnsberg,Germany

Residents in Arnsberg, Germany, had been supplied by drinking water contaminated with perfluorooctanoate (PFOA). Biomonitoring data from 2006 evidenced that plasma PFOA concentrations of residents from Arnsberg were 4.5–8.3 times higher than those in reference groups. The introduction of charcoal filtration in July 2006 distinctly reduced PFOA concentrations in drinking water. Our one-year follow-up study showed a 10–20% reduction of PFOA plasma levels in residents from Arnsberg. Here we report the first results of the two-year follow-up study Arnsberg 2008. Additionally, the results of the two-year follow-up examination of the reference group are included. Paired plasma samples of 138 study participants (45 children, 46 mothers and 47 men) collected in 2006 and 2008 were considered in the statistical analyses. Within the two years plasma concentrations of PFOA, perfluorooctanesulfonate (PFOS) and perfluorohexanesulfonate (PFHxS) decreased in residents from Arnsberg and in control groups. The geometric means of PFOA plasma levels declined by 39% (children and mothers) and 26% (men) in Arnsberg and by 13–15% in the corresponding subgroups from the reference areas. For the population from Arnsberg a geometric mean plasma PFOA half-life of 3.26 years (range 1.03–14.67 years) was calculated. Our results confirm an ongoing reduction of the PFOA load in residents from Arnsberg. The decline of PFC levels in plasma of participants from the reference areas reflects the general decrease of human PFC exposure during the very recent years.     

Cord serum concentrations of perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) in relation to weight and size at birth

BACKGROUND: Recent studies have reported developmental toxicity among rodents dosed with perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA). OBJECTIVES: We examined the relationship between concentrations of PFOS and PFOA in cord serum (surrogates for in utero exposures) and gestational age, birth weight, and birth size in humans. METHODS: We conducted a hospital-based cross-sectional epidemiologic study of singleton deliveries in Baltimore, Maryland. Cord serum samples (n = 293) were analyzed for PFOS and PFOA by online solid-phase extraction, coupled with reversed-phase high-performance liquid chromatography-isotope dilution tandem mass spectrometry. Maternal characteristics and anthropometric measures were obtained from medical charts. RESULTS: After adjusting for potential confounders, both PFOS and PFOA were negatively associated with birth weight [per ln-unit: beta = -69 g, 95% confidence interval (CI), -149 to 10 for PFOS; beta = -104 g, 95% CI, -213 to 5 for PFOA], ponderal index (per ln-unit: beta = -0.074 g/cm(3) x 100, 95% CI, -0.123 to -0.025 for PFOS; beta = -0.070 g/cm(3) x 100, 95% CI, -0.138 to -0.001 for PFOA), and head circumference (per ln-unit: beta = -0.32 cm, 95% CI, -0.56 to -0.07 for PFOS; beta = -0.41 cm, 95% CI, -0.76 to -0.07 for PFOA). No associations were observed between either PFOS or PFOA concentrations and newborn length or gestational age. All associations were independent of cord serum lipid concentrations. CONCLUSIONS: Despite relatively low cord serum concentrations, we observed small negative associations between both PFOS and PFOA concentrations and birth weight and size. Future studies should attempt to replicate these findings in other populations.     

Effects of perfluorooctanesulfonate exposure on plasma lipid levels in the Inuit population of Nunavik (Northern Quebec)

Background

Perfluorooctanesulfonate (PFOS) was used as a surfactant in various commercial products. In rodents, exposure to this compound induced various health effects, including hypolipidemia. In human populations, the potential toxicity of PFOS is not yet fully characterized, but indications of effects on lipids are reported. A recent study reported an increase in plasma cholesterol associated with exposure to perfluorinated compounds in humans exposed through drinking water, but similar effects were not reported in all exposed human populations. PFOS is widely distributed in the environment, including the arctic biota. The Inuit of Nunavik are exposed to environmental contaminants through the consumption of fish and game. This diet is also a source of ω3-polyunsaturated fatty acids (n-3 PUFAs) that are known to lower plasma triacylglycerols.

Objective

This cross-sectional epidemiologic study aims at assessing the relationship between PFOS exposure and plasma lipids, while taking account of the concomitant hypolipidemic effect exerted by n-3 PUFAs.

Methods

Plasma concentrations of PFOS and lipids were assessed in Nunavik Inuit adults (n=723) in the framework of a large-scale environmental health study. Associations of exposure levels to age, gender and selected wild food consumption associated with n-3 PUFAs intake, as well as the exposure on lipid levels were investigated by multivariate linear modeling.

Results

In the Inuit population, PFOS exposure and n-3 PUFAs intake are related to traditional food consumption. Triacylglycerol and ratio of total cholesterol to high density lipoprotein cholesterol (HDL-C) levels were negatively associated with PFOS plasma levels, while HDL-C levels were positively associated, after adjustment for circulating levels of n-3 PUFAs and for the interaction between gender and PFOS plasma levels. Other plasma lipids, such as low density lipoprotein-cholesterol and non-HDL-C were not related to PFOS plasma concentrations.

Conclusion

The results of this study show a relationship between PFOS and plasma lipid levels in an environmentally exposed human population, and this effect appears distinct from that of n-3 PUFAs.     

Perfluorooctanesulfonate and other fluorochemicals in the serum of American Red Cross adult blood donors

Perfluorooctanesulfonyl fluoride-based products have included surfactants, paper and packaging treatments, and surface protectants (e.g., for carpet, upholstery, textile). Depending on the specific functional derivatization or degree of polymerization, such products may degrade or metabolize, to an undetermined degree, to perfluorooctanesulfonate (PFOS), a stable and persistent end product that has the potential to bioaccumulate. In this investigation, a total of 645 adult donor serum samples from six American Red Cross blood collection centers were analyzed for PFOS and six other fluorochemicals using HPLC-electrospray tandem mass spectrometry. PFOS concentrations ranged from the lower limit of quantitation of 4.1 ppb to 1656.0 ppb with a geometric mean of 34.9 ppb [95% confidence interval (CI), 33.3-36.5]. The geometric mean was higher among males (37.8 ppb; 95% CI, 35.5-40.3) than among females (31.3 ppb; 95% CI, 30.0-34.3). No substantial difference was observed with age. The estimate of the 95% tolerance limit of PFOS was 88.5 ppb (upper limit of 95% CI, 100.0 ppb). The measures of central tendency for the other fluorochemicals (N-ethyl perfluorooctanesulfonamidoacetate, N-methyl perfluorooctanesulfonamidoacetate, perfluorooctanesulfonamidoacetate, perfluorooctanesulfonamide, perfluorooctanoate, and perfluorohexanesulfonate) were approximately an order of magnitude lower than PFOS. Because serum PFOS concentrations correlate with cumulative human exposure, this information can be useful for risk characterization.     

Contribution to the evaluation of reference values for PFOA and PFOS in plasma of children and adults from Germany

Perfluorinated compounds (PFC) are a large group of chemicals produced for several decades and widely used for many industrial and consumer applications. Human Biomonitoring studies reveal a background exposure of the general population to perfluorooctanoic acid (PFOA) and pefluorooctane sulfonate (PFOS) in many parts of the world. Reference values for PFOS and PFOA in the German population are currently not available. However, the data of three PFC human biomonitoring studies are taken as basis for deriving a preliminary reference value. The first two studies were performed in southern Germany with 105 (sampling period 2003-2004) and 356 adults (sampling period 2005). The third study was performed in North Rhine-Westphalia (sampling period October and November 2006) in connection with the high PFOA contamination of drinking water in the Sauerland region. Non PFOA exposed control groups comprised of 80 children and 153 females from Siegen and 103 men from Brilon. The whole study which could be taken as a basis for PFOS reference considerations comprised of 170 children, 317 females and 204 men. Though the studies are not representative for the German population, they provide at present the best available data basis for deriving reference values. The 95th percentile values of the studies were used and the following preliminary reference values are recommended: PFOA, 10microg/l for all groups; for PFOS 10microg/l for children at school beginner age, 15microg/l for adult females and 25microg/l for adult males.     

陕西省一般人群全血和尿液中铬、镉和铅负荷水平分析

目的了解陕西省一般人群血液和尿液中铬、镉和铅的内暴露水平及其分布特点。方法 2017年采用分层随机抽样方法,选取陕西省5个县(区、市) 720名3～79岁人群为监测对象,采集血液和尿液样品,采用电感耦合等离子体质谱法检测样品中铬、镉和铅的含量。检测结果定量资料组间比较,符合正态分布采用方差分析,不符合正态分布采用独立样本非参数检验。结果陕西省一般人群中,血铬和尿铬几何均数分别为0.31μg/L和0.51μg/L,男性尿铬高于女性(χ²=7.276,P <0.05);血镉和尿镉几何均数分别为0.20μg/L和0.19μg/L,男性均高于女性(χ²=14.022、5.698,P <0.05);血铅和尿铅几何均数分别为16.24μg/L和0.47μg/L,男性均高于女性(χ²=50.157、5.173,P <0.05)。城镇地区血铬和血镉几何均数高于乡村地区(χ²=36.815、17.222,P <0.05),乡村地区尿铬和尿铅高于城镇地区(χ²=53.492...     

Methodological considerations for the accurate determination of lead in human plasma and serum

Studies which accurately measure plasma or serum lead (Pb) are needed to evaluate the ‘biologically active’ fraction of Pb in the circulation, and to clarify the role of plasma in the transportation of Pb between different compartments of the body. We evaluated several methodological aspects which influence the determination of Pb in plasma and serum. Generally, venous blood was obtained by different sampling methods (routine and ultraclean) from 3 subjects without history of Pb exposure. After centrifugation (800g) for 10 min, the plasma or serum was analyzed by inductively coupled plasma-high-resolution mass spectrometry (ICP-MS). Several evaluations were conducted, including 1) comparison of an ultraclean serum collection method with a plasma collection method that used a commercial Vacutainer®-type tube for trace metals (EDTA anticoagulant); 2) the effect of whole blood standing time prior to centrifugation on plasma or serum Pb concentration; and 3) comparison of a method using commercial heparinized Vacutainer® tubes to an ultraclean plasma sampling method that utilized a low-Pb heparin anticoagulant. Plasma or serum iron (Fe) levels were also measured to evaluate hemolysis. The 3 subjects had whole blood Pb (blood-Pb) levels of 1.8, 2.0, and 2.7 μg/dl. Their corresponding ultraclean serum-Pb levels were 0.40%, 0.30%, and 0.48% of their whole blood-Pb levels, respectively. By comparison, the EDTA Vacutainer® method plasma-Pb values were 1.7%, 1.5%, and 2.4% of whole blood-Pb, respectively. Whole blood standing (clotting) times of 15, 40, and 70 min before centrifugation resulted in increasing ultraclean serum-Pb levels of 0.21%, 0.81%, and 1.2% of whole blood-Pb (1.8 μg/dl), respectively. Whole blood standing time had no effect on plasma-Pb levels when heparin Vacutainers® were used, or when a low-Pb heparin was used to obtain ultraclean plasma. However, plasma collected using the commercial heparin Vacutainer® method contained consistently higher and more variable Pb levels than samples collected using the ultraclean plasma-Pb method. Hemolysis, when present, contributed significantly to both plasma-Pb and serum-Pb levels. In conclusion, plasma-Pb and serum-Pb levels are dependent upon methodologic processing techniques, including Pb contamination control, redistribution due to EDTA anticoagulant, hemolysis, and time dependency in sample processing. While true plasma-Pb and serum-Pb levels by any method have yet to be defined, these data provide a methodological basis from which to investigate variation in Pb partitioning between whole blood and plasma within individuals. Am. J. Ind. Med. 33:430–438, 1998. © 1998 Wiley-Liss, Inc.     

Intestinal absorption of lycopene from different matrices and interactions to other carotenoids, the lipid status, and the antioxidant capacity of human plasma

Summary Background: The bioavailability of carotenoids has been investigated in animal studies as well as in human studies, so far mostly for β-carotene. Only few results exist for lycopene. In recent studies, lycopene was significantly better available from processed tomatoes compared to raw tomatoes, when using daily intakes between 16.5 mg and 75 mg lycopene. Aim of the study In a comparative study the availability of a low oral lycopene dosage of 5 mg/d from different food matrices versus soft gel capsules containing tomato oleoresin was assessed. In addition to the plasma carotenoid content, the effect of lycopene ingestion on other plasma carotenoids, the lipid status parameters, and the antioxidant activitys was estimated. Methods Twenty-two female adults (20 – 27 y) were randomized in three groups and were advized to minimize their carotenoid intake for two weeks. After this initial period, two groups received a portion of tomatoes or tomato juice adjusted to a lycopene dose of 5 mg/d, the third group ingested the same dose comprized in soft gel capsules containing tomato oleoresin. During the test period of 6 weeks, the participants continued reducing the intake of carotenoids from food. Fasting blood samples were withdrawn prior to the study, before supplementation started, and then weekly while supplemented. Seven-day dietary records were prepared before the study started and after one week of supplementation. Carotenoids were analyzed by reversed phase HPLC with diode array detection. Dietary records were evaluated using the computer software EBIS 2.1. The plasma total cholesterol, HDL cholesterol, and triglycerides were determined enzymatically. In addition, the antioxidant activity of plasma was estimated by using the TEAC and the TRAP assays. Results The basal levels of lycopene in plasma were comparable for all groups (0.2 – 0.3 μmol/l) and decreased significantly during the two weeks of depletion to approximately 50 % of the basal values. Other plasma carotenoids such as β-carotene and β-cryptoxanthin decreased significantly, too, whereas lutein and zeaxanthin remained unchanged. After supplementation with tomato oleoresin capsules or tomato juice, the plasma lycopene increased significantly, while it remained unchanged during intake of tomatoes. Normal dietary habits were practized of all volunteers before and during the study except vitamin C whose intake was significantly lower during the study period, because the probands were recommended to reduce the intake of fruits and vegetables. Lycopene supplementation did not affect the lipid status parameters of the three groups. After ingestion of lycopene the antioxidant activity of the plasma was not altered. Mean TEAC values were estimated to 0.33 ± 0.05 mmol/l and TRAP values to 1.0 ± 0.1 mmol/l and showed no significant differences in all groups during the whole study period. Conclusions The bioavailability of lycopene varied significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tomato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes. The daily intake of 5 mg lycopene, an intake comparable to the usual daily carotenoid intake, did not affect cholesterol and triglycerides in plasma or its antioxidant capacity. Received: 1 March 1999, Accepted: 30 April 1999     

A new HPLC-method for the simultaneous determination of B1-, B2- and B6-vitamers in serum and whole blood

Considering that the B1-, B2- and B6-vitamers in whole blood and serum are partly protein bound and partly in phosphorylated form as co-enzyme, we developed a sample treatment which is able to transduce all three vitamers in their free forms. After cleaning the sample on solid-phase-extraction columns (SPE-column) we are able to separate all three vitamers in one run with HPLC and to quantify them with simultaneous detection (UV and Fluorescence). The following reference values were obtained: (ng/ml) Serum: Thiamin 6.55 +/- 2.38, Riboflavin 4.92 +/- 1.01, vitamin B6 11.21 +/- 3.17. Whole blood: Thiamin 62.3 +/- 20.8, riboflavin 69.8 +/- 20.9, vitamin B6 59.5 +/- 22.4.     

Reference intervals for blood Cd and Pb in the general population of Sardinia (Italy)

The reference values (RVs) for blood Cd and Pb of 215 adult subjects non-occupationally exposed and living in Sardinia (insular Italy) were assessed. Age, sex, smoking, alcohol drinking and living area were used to stratify the reference group. After collection from volunteers, samples were acid digested in a microwave oven and metals were determined by sector field inductively coupled plasma mass spectrometry. The RVs expressed as 5th-95th percentiles (geometric mean, GM) were 0.24-1.82 μg/l (0.53 μg/l) for blood Cd and 13.2-87.3 μg/l (33.4 μg/l) for blood Pb. Females had GM levels of Cd (0.58 μg/l) higher than males (0.49 μg/l); subjects aged <40 years had less Cd (0.44 μg/l) than old subjects (>60 years; 0.56 μg/l); Cd in smokers (1.23 μg/l) was 3-times higher than in non-smokers (0.42 μg/l) and correlated with the number of cigarettes per day. The alcohol intake and place of living did not influence blood Cd. The GM values of blood Pb in males (44.4 μg/l) were higher than in females (24.7 μg/l); subjects less than 40 years-old (27.5 μg/l) showed lower Pb than elderly individuals (>60 years, 41.2 μg/l); drinkers (42.2 μg/l) had Pb 2-times higher than non-drinkers (24.4 μg/l). Blood Pb was not significantly affected by smoking and place of living. As revealed by multiple linear regression, the predictor variables were, in order of weight, smoke ? age for blood Cd levels, and sex = age ? alcohol for blood Pb levels.