Population biomonitoring of micronutrient intakes in children using urinary spot samples.

PURPOSE: Urinary spot samples are a promising method for the biomonitoring of micronutrient intake in children. Our aim was to assess whether urinary spot samples could be used to estimate the 24-h urinary excretion of potassium, phosphate, and iodine at the population level. METHODS: A cross-sectional study of 101 children between 6 and 16 years of age was conducted. Each child collected a 24-h urine collection and three urinary spot samples (evening, overnight, and morning). Several equations were used to estimate 24-h excretion based on the urinary concentrations of each micronutrient in the three spot samples. Various equations and spot combinations were compared using several statistics and plots. RESULTS: Ninety-four children were included in the analysis (mean age: 10.5 years). The mean measured 24-h urinary excretions of potassium, phosphate, and iodine were 1.76 g, 0.61 g, and 95 µg, respectively. For potassium, the best 24-h estimates were obtained with the Mage equation and morning spot (mean bias: 0.2 g, correlation: 0.27, precision: 56%, and misclassification: 10%). For phosphate, the best 24-h estimates were obtained with the Mage equation and overnight spot (mean bias: - 0.03 g, correlation: 0.54, precision: 72%, and misclassification: 10%). For iodine, the best 24-h estimates were obtained with the Remer equation and overnight spot (mean bias: - 8 µg, correlation: 0.58, precision: 86%, misclassification: 16%). CONCLUSIONS: Urinary spot samples could be a good alternative to 24-h urine collection for the population biomonitoring of iodine and phosphate intakes in children. For potassium, spot samples were less reliable.

Effects of feed iodine concentrations and milk processing on iodine concentrations of cows' milk and dairy products, and potential impact on iodine intake in Swiss adults.

The contribution of milk and dairy products to daily iodine intake is high but variable in many industrialised countries. Factors that affect iodine concentrations in milk and dairy products are only poorly understood. Our aim was to: (1) assess the effect of feed iodine concentration on milk iodine by supplementing five groups of five cows each with one of five dosages from 0-2 mg iodine/kg DM; (2) quantify iodine losses during manufacturing of cheese and yogurt from milk with varying iodine concentrations and assess the effect of cellar-ripening; and (3) systematically measure iodine partitioning during heat treatment and skimming of milk. Milk iodine reached a near-steady state after 3 weeks of feeding. Median milk iodine (17-302 µg/l for 0-2 mg iodine/kg DM) increased linearly with feed iodine (R2 0·96; P < 0·001). At curd separation, 75-84 % of iodine was lost in whey. Dairy iodine increased linearly with milk iodine (semi-hard cheese: R2 0·95; P < 0·001; fresh cheese and yogurt: R2 1·00; P < 0·001), and cellar-ripening had no effect. Heat treatment had no significant effect, whereas skimming increased (P < 0·001) milk iodine concentration by only 1-2 µg/l. Mean daily intake of dairy products by Swiss adults is estimated at 213 g, which would contribute 13-52 % of the adults' RDA for iodine if cow feed is supplemented with 0·5-2 mg iodine/kg DM. Thus, modulation of feed iodine levels can help achieve desirable iodine concentrations in milk and dairy products, and thereby optimise their contribution to human iodine nutrition to avoid both deficiency and excess.

The main determinants of iodine in cows' milk in Switzerland are farm type, season and teat dipping.

Milk and dairy products are important iodine sources and contribute about 30-40 % of total iodine in the Swiss diet. Information about variation in milk iodine concentration (MIC) in Switzerland is limited. We examined MIC and its potential determinants in milk from organic and conventional farms. We collected bulk milk samples at 3-month intervals over 1 year from thirty-two farms throughout Switzerland and Aosta valley, North-West Italy. We sampled all feed components including tap water, collected information on farm characteristics, feeding and teat disinfection practices by questionnaire and estimated the cows' winter and summer iodine intake. Iodine in milk and feed components was measured using inductively coupled plasma MS. The overall median MIC was 87 (range 5-371) µg/l. In multivariate analysis, predictors of MIC were as follows: (1) farm type: median MIC from organic and conventional farms was 55 and 93 µg/l (P=0·022); (2) season: 53, 97 and 101 µg/l in September, December and March (P<0·002); and (3) teat dipping: 97 µg/l with v. 56 µg/l without (P=0·028). In conclusion, MIC varied widely between farms because of diverse farming practices that result in large differences in dairy cow exposure to iodine via ingestion or skin application. Standardisation of MIC is potentially achievable by controlling these iodine exposures. In order for milk to be a stable iodine source all year round, dietary iodine could be added at a set level to one feed component whose intake is regular and controllable, such as the mineral supplement, and by limiting the use of iodine-containing teat disinfectants.

Study design and baseline characteristics of a combined educational and environmental intervention trial to lower sodium intake in Swiss employees.

BACKGROUND: Blood pressure is a primary cardiovascular disease risk factor. Population-wide governmental strategies aim to reduce lifestyle and dietary risk factors for hypertension, one of which is an unbalanced diet with high sodium and low potassium intakes. Nutrition interventions in the workplace are considered a promising approach in encouraging health-promoting behaviors. We developed and conducted the health promoting sodium reduction trial "Healthful & Tasty: Sure!" in worksites in the German-speaking part of Switzerland from May 2015 to Nov 2016, for which we present the study protocol and baseline characteristics. METHODS: Healthful & Tasty, a cluster nonrandomized single-arm trial with calibration arm, aimed to demonstrate the effectiveness of a combined educational and environmental intervention in the workplace in reducing employees' average daily sodium/salt intake by 15%. To this end, health and food literacy of employees and guideline compliance among the catering facility team needed to be improved. The primary outcome measure was sodium/salt intake estimated from sodium excretion in a 24-h urine sample. Secondary outcome measures included changes in the overall qualitative diet composition, blood pressure, anthropometric indices, and health and food literacy. Of eight organizations with catering facilities, seven organizations took part in the nutrition education and catering salt reduction interventions, and one organization participated as a control. Overall, 145 consenting employees were included in the staggered, one-year four-phase trial, of which 132 participated in the intervention group. In addition to catering surveys and food sampling, the trial included five follow-up health assessments including questionnaires, blood pressure measurements, anthropometrics, and sodium, potassium, and iodine intake measurements obtained from 24-h and spot urine samples, and a food record checklist. Exploratory and hypothesis generating baseline statistical analysis included 141 participants with adequate 24-h urine samples. DISCUSSION: Despite practice-driven limitations to the study design and small cluster and participant numbers, this trial has methodological strength and will provide important insights into the effectiveness of a combined educational and environmental intervention to reduce salt intake among female and male Swiss employees. TRIAL REGISTRATION: German Clinical Trials Register, DRKS00006790 . Registered 23 September 2014.

Probing the Kinetic Parameters of Plutonium-Naturally Occurring Organic Matter Interactions in Freshwaters Using the Diffusive Gradients in Thin Films Technique.

The interaction of trace metals with naturally occurring organic matter (NOM) is a key process of the speciation of trace elements in aquatic environments. The rate of dissociation of metal-NOM complexes will impact the amount of free metal available for biouptake. Assessing the bioavailability of plutonium (Pu) helps to predict its toxic effects on aquatic biota. However, the rate of dissociation of Pu-NOM complexes in natural freshwaters is currently unknown. Here, we used the technique of diffusive gradients in thin films (DGT) with several diffusive layer thicknesses to provide new insights into the dissociation kinetics of Pu-NOM complexes. Results show that Pu complexes with NOM (mainly fulvic acid) are somewhat labile (0.2 ≤ ξ ≤ 0.4), with kd = 7.5 × 10(-3) s(-1). DGT measurements of environmental Pu in organic-rich natural water confirm these findings. In addition, we determined the effective diffusion coefficients of Pu(V) in polyacrylamide (PAM) gel in the presence of humic acid using a diffusion cell (D = 1.70 ± 0.25 × 10(-6) cm(2) s(-1)). These results show that Pu(V) is a more mobile species than Pu(IV).

Prevalence of iodine inadequacy in Switzerland assessed by the estimated average requirement cut-point method in relation to the impact of iodized salt.

OBJECTIVE: To assess the iodine status of Swiss population groups and to evaluate the influence of iodized salt as a vector for iodine fortification. DESIGN: The relationship between 24 h urinary iodine and Na excretions was assessed in the general population after correcting for confounders. Single-day intakes were estimated assuming that 92 % of dietary iodine was excreted in 24 h urine. Usual intake distributions were derived for male and female population groups after adjustment for within-subject variability. The estimated average requirement (EAR) cut-point method was applied as guidance to assess the inadequacy of the iodine supply. SETTING: Public health strategies to reduce the dietary salt intake in the general population may affect its iodine supply. SUBJECTS: The study population (1481 volunteers, aged ≥15 years) was randomly selected from three different linguistic regions of Switzerland. RESULTS: The 24 h urine samples from 1420 participants were determined to be properly collected. Mean iodine intakes obtained for men (n 705) and women (n 715) were 179 (sd 68.1) µg/d and 138 (sd 57.8) µg/d, respectively. Urinary Na and Ca, and BMI were significantly and positively associated with higher iodine intake, as were men and non-smokers. Fifty-four per cent of the total iodine intake originated from iodized salt. The prevalence of inadequate iodine intake as estimated by the EAR cut-point method was 2 % for men and 14 % for women. CONCLUSIONS: The estimated prevalence of inadequate iodine intake was within the optimal target range of 2-3 % for men, but not for women.

Biomonitoring of ochratoxin A, 2'R-ochratoxin A and citrinin in human blood serum from Switzerland.

Biomonitoring of mycotoxins and their metabolites in biological fluids is increasingly used to assess human exposure. In this study, biomarkers of ochratoxin A (OTA) and citrinin (CIT) exposure were determined in a large number of serum samples from healthy blood donors in Switzerland. In 2019, 700 samples from different regions were obtained. From 240 donors, a second sample (taken 2-9 months later) was available for analysis. Moreover, 355 blood donor samples from 2005 from all regions in Switzerland and 151 additional samples from the southern Swiss region of Ticino from 2005 could be analysed.OTA, 2'R-ochratoxin A (2'R-OTA), ochratoxin alpha (OTα), CIT and dihydrocitrinone (DH-CIT) were analysed using validated targeted methods including precipitation and online SPE clean-up.OTA and 2'R-OTA were frequently detected (OTA in 99%; 2'R-OTA in 51% of the tested samples). The mean concentration in all positive samples was 0.4 ng/mL for OTA and 0.2 ng/mL for 2'R-OTA. OTα was not detected in any sample above the limit of quantification (LOQ). In contrast to OTA, CIT and DH-CIT were only quantifiable in 2% and 0.1% of the samples, respectively. No significant trend was observed between the samples from 2005 and the more recent samples, but OTA concentrations were usually higher in serum samples from the southern Swiss region of Ticino and in males compared to females.Our extensive data fit well within the framework of previously published values for the healthy adult European population.

Comparison of nutritional composition between plant-based drinks and cow's milk.

The high decline in liquid milk consumption in Western countries has been compensated by the increased consumption of processed dairy products and the rapidly increasing number of new plant-based beverages constantly introduced in the market, advertised as milk substitutes and placed on shelves near milk products. To provide better understanding about the nutritional value of these drinks compared with cow's milk, 27 plant-based drinks of 8 different species and two milk samples were purchased from two big retailers in Switzerland, and their composition regarding protein, carbohydrate, fat, vitamin, and mineral contents and residue load [glyphosate, aminomethylphosphonic acid (AMPA), and arsenic] was analyzed quantitatively and qualitatively. Energy and nutrient intakes were calculated and compared with the dietary reference values for Germany, Austria and Switzerland (D-A-CH). In addition, the digestible indispensable amino acid score (DIAAS) was calculated to estimate the quality of the proteins. Milk contained more energy; fat; carbohydrate; vitamins C, B2, B12, and A; biotin; pantothenic acid; calcium; phosphorus; and iodine than most plant-based drinks. Soy drinks provided slightly more protein and markedly more vitamins B1 and B6, folic acid, and vitamins E and D2 (with supplemented vitamin D2) and K1, magnesium, manganese, iron, and copper than milk and the other plant-based drinks. However, with the exception of cow's milk and soy drinks, which had > 3% protein, most milk alternatives contained ≤ 1% protein; therefore, they cannot be considered good protein sources. In regard to protein quality, milk was outstanding compared with all plant-based drinks and exhibited higher calculated DIAASs. Our results show that the analyzed plant-based drinks are not real alternatives to milk in terms of nutrient composition, even if the actual fortification is taken into account. Improved fortification is still an issue and can be optimized using the most bioavailable and soluble derivatives. Complete replacement of milk with plant-based drinks without adjusting the overall diet can lead to deficiencies of certain important nutrients in the long term.

Uranium exposure of the Swiss population based on 24-hour urinary excretion.

AIM OF THE STUDY: Important regional differences in uranium exposure exist because of varying uranium concentrations in soil, water and food. Comprehensive data on the exposure of the general population to uranium is, however, scarce. Based on the 24-hour urinary excretion, the uranium exposure of the adult Swiss population was assessed in relation to age, sex, place of residence, body mass index (BMI), smoking habit and type of drinking water, as well as risk factors in relation to kidney impairment and indicators of a possible renal dysfunction. METHODS: Uranium was quantified in 24-hour urine from a nationwide population-based sample (n = 1393). The ratio 238U/233U was measured for isotope dilution calibration with a sector field inductively coupled plasma mass spectrometer (HR-ICP-MS). RESULTS: Overall median and 95th percentile were 15 and 67 ng/24 h, respectively. The place of residence significantly influenced urinary uranium excretion. However, most of the highest urinary uranium excretion levels could not be associated to areas known for their elevated uranium concentrations in the drinking water. Sources other than the local drinking water (e.g., bottled water) might be important, too. Gender as well as albumin excretion also had a significant effect on uranium excretion. The latter was, however, strongly dependent on the presence of diabetes mellitus. No association was found for age, BMI, smoking habit or the other examined kidney related variables. CONCLUSIONS: On the basis of uranium exposure, assessed via 24-hour urinary uranium excretion, and current knowledge of the toxicity of naturally occurring uranium, a substantial corresponding health risk for the general adult population is unlikely. However, as long as no specific sensitive biomarker for the biological impact of low-dose chronic uranium exposure has been identified and validated, assessing subtle health impact of such exposure will remain difficult.

Increase of iodine content in brine-salted soft, semi-hard and hard cheeses by diffusion of iodide.

Iodised salt (supplemented with potassium iodide) is the primary source of iodine in Switzerland, but it is rarely used in the manufacture of cheese. In the present study, the diffusion of iodide and chloride in experimentally produced soft, semi-hard and hard cheeses was investigated after brine-salting and subsequent ripening with iodised or non-iodised salt. Diffusion of iodide (I-) and chloride (Cl-) into the cheeses was monitored by zonal analyses at different times of ripening. The concurrent diffusion of the two ions in the aqueous phase of cheeses was modelled using Fick's law and the apparent diffusion coefficients (Dapp) were determined. The results showed that iodide diffuses more slowly into the interior of the cheeses than chloride. Although the ripened cheeses still showed a concentration gradient between rind and centre, an average increase of 402 ± 30 µg kg-1 iodine was achieved in the edible part of the cheeses treated with iodised salt. Based on a national food survey, the hypothetical contribution of cheese to the dietary iodine intake was estimated. If cheese was produced with iodised salt, it would cover approximately 10% of the recommended daily iodine intake (150 µg d-1). Therefore, the use of iodised salt in cheese production would make an important contribution to a iodine supply for population groupswith borderline iodine deficiency.

Use of day and night urinary iodine excretion to estimate the prevalence of inadequate iodine intakes via the estimated average requirement cut-point method.

The objectives were to determine urinary iodine concentration (UIC) in day and night samples collected over a 24-hour period and evaluate the usual dietary iodine intake distribution from this collection. We propose a method by which the prevalence of inadequacy can be calculated from a single 24-hour collection, reducing the burden on participants and the study costs. The samples from 1128 participants were collected between 2009 and 2013 within the framework of the Swiss Kidney Project on Genes observational cohort study; 1024 samples were suitable for statistical evaluation of iodine analysis. Participants were over 18, resident in Switzerland and of European ancestry. Over 24 hours, urine was collected as night-time (bedtime until and including first morning urine) and day-time (the remainder) samples. Associations with variables, in particular to estimated glomerular filtration rate (eGFR), were investigated using mixed models. The 24-hour median UICs were 73 and 96 µg/l for women (n = 542) and men (n = 482), respectively; 24-hour median intakes (derived from the corresponding excretion) were 127 and 156 µg/d, respectively. Day and night excretions were normalised to 24-hour excretion values and the usual intake distribution calculated by the US National Cancer Institute method. The Estimated Average Requirement cut-point method was used to calculate the prevalence of inadequacy, estimated at 14% for women and 4% for men; above the target of 2-3%. We conclude that segregating 24-hour urine into day and night collections is sufficient to determine the prevalence of iodine inadequacy in the population and reduces the burden on participants by sparing a second 24-hour collection. No association between iodine intake and eGFR was found.

Iodine bioavailability from cow milk: a randomized, crossover balance study in healthy iodine-replete adults.

BACKGROUND: Milk and dairy products are considered important dietary sources of iodine in many countries. However, to our knowledge, iodine bioavailability from milk has not been directly measured in humans. OBJECTIVE: The aim of this study was to compare iodine bioavailability in iodine-replete adults from: 1) cow milk containing a high concentration of native iodine; 2) milk containing a low concentration of native iodine, with the addition of potassium iodide (KI) to assess a potential matrix effect; and 3) an aqueous solution of KI as a comparator; with all 3 containing equal amounts of total iodine (263 µg/250 mL). We also speciated iodine in milk. DESIGN: We conducted a 3-wk, randomized, crossover balance study in adults (n = 12) consuming directly analyzed, standardized diets. During the 3 test conditions - high intrinsic iodine milk (IIM), extrinsically added iodine in milk (EIM), and aqueous iodine solution (AIS) - subjects collected 24-h urine over 3 d and consumed the test drink on the second day, with 3- or 4-d wash-out periods prior to each treatment. Iodine absorption was calculated as the ratio of urinary iodine excretion (UIE) to total iodine intake. Milk iodine speciation was performed using ion chromatography-mass spectrometry. RESULTS: Iodine intake from the standardized diet was 195 ± 6 µg/d for males and 107 ± 6 µg/d for females; the test drinks provided an additional 263 µg. Eleven subjects completed the protocol. There was a linear relation between iodine intake and UIE (ß = 0.89, SE = 0.04, P < 0.001). There were no significant differences in UIE among the 3 conditions (P = 0.24). Median (range) fractional iodine absorption across the 3 conditions was 91 (51-145), 72 (48-95), and 98 (51-143)% on days 1, 2, and 3, respectively, with day 2 significantly lower compared with days 1 and 3 (P < 0.001). In milk, 80-93% of the total iodine was inorganic iodide. CONCLUSION: Nearly all of the iodine in cow milk is iodide and although fractional iodine absorption from milk decreases with increasing dose, its bioavailability is high. The trial was registered at clinicaltrials.gov as NCT03590431.

Plutonium from above-ground nuclear tests in milk teeth: investigation of placental transfer in children born between 1951 and 1995 in Switzerland.

BACKGROUND: Occupational risks, the present nuclear threat, and the potential danger associated with nuclear power have raised concerns regarding the metabolism of plutonium in pregnant women. OBJECTIVE: We measured plutonium levels in the milk teeth of children born between 1951 and 1995 to assess the potential risk that plutonium incorporated by pregnant women might pose to the radiosensitive tissues of the fetus through placenta transfer. METHODS: We used milk teeth, whose enamel is formed during pregnancy, to investigate the transfer of plutonium from the mother's blood plasma to the fetus. We measured plutonium using sensitive sector field inductively coupled plasma mass spectrometry techniques. We compared our results with those of a previous study on strontium-90 ((90)Sr) released into the atmosphere after nuclear bomb tests. RESULTS: Results show that plutonium activity peaks in the milk teeth of children born about 10 years before the highest recorded levels of plutonium fallout. By contrast, (90)Sr, which is known to cross the placenta barrier, manifests differently in milk teeth, in accordance with (90)Sr fallout deposition as a function of time. CONCLUSIONS: These findings demonstrate that plutonium found in milk teeth is caused by fallout that was inhaled around the time the milk teeth were shed and not from any accumulation during pregnancy through placenta transfer. Thus, plutonium may not represent a radiologic risk for the radiosensitive tissues of the fetus.

Selenium status of the Swiss population: assessment and change over a decade.

A monitoring study of serum selenium concentration was carried out on healthy blood donors from different regions of Switzerland. With an overall mean serum concentration of 98 microg/L (n=1847), the selenium status of the healthy adults can be assessed as adequate. The lowest measured concentration of 62 microg/L denotes that the risk of a marginal selenium deficiency in the Swiss population is small. Compared to a similar study carried out in 1993, the status improved for both genders, although the increase is higher among women. It is noteworthy that the supplementation practice has increased during this period with ca. 2% of the population taking Se-micronutrients. No correlation between the age and the serum concentration is detected, even though the age-range was enlarged in this study to 18-68 years for the women and to 19-72 years for the men. The place of residence only marginally influences the selenium concentration, which implies a certain uniformity of the dietary habits between the various regions of the country.

Iodine in Swiss milk depending on production (conventional versus organic) and on processing (raw versus UHT) and the contribution of milk to the human iodine supply.

The iodine content in milk depends on various factors, including the season, production system, and location of milk production. The aim of this study was 1) to obtain data on the iodine concentration of conventional and organically produced milk and according to seasons; 2) to compare these actual data with previous measurement data; 3) to study the influence of UHT treatment on the iodine content and 4) to estimate the contribution of organic and conventional milk to the consumer's iodine intake. A total of 110 samples of conventional and organic ultra-heat treated (UHT) whole milk were collected in the period between 1 May 2013 and 30 April 2014 from two large-scale companies, processing milk from two regions in Switzerland. The iodine concentration in organic milk (average 71 ±â€¯25 µg/l) was significantly lower than in conventional milk (average 111 ±â€¯26 µg/l) and varied between suppliers. Milk iodine concentration varied according to the month of collection in organic and conventionally produced milk, with lowest values between August and October (organic milk 42 µg/l; conventional milk 75 µg/l) and highest values in January (organic milk 99 µg/l; conventional milk 145 µg/l). Heat treatment did not influence iodine concentration. Since milk and dairy products are significant source of food-related iodine intake in Switzerland, consumers who prefer organic milk and dairy products are likely to have an inferior iodine status.

Arsenic species in rice and rice-based products consumed by toddlers in Switzerland.

Inorganic arsenic (iAs) is a contaminant present in food, especially in rice and rice-based products. Toxicity of arsenic compounds (As) depends on species and oxidative state. iAs species, such as arsenite (As(III)) and arsenate (As(V)), are more bioactive and toxic than organic arsenic species, like methylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)) or arsenosugars and arsenobetaine. An ion chromatography-inductively coupled-plasma-mass spectroscopy method was developed to separate the four following arsenic anions: As(III), As(V), MMA(V) and DMA(V). Sample preparation was done in mild acidic conditions to ensure species preservation. The predominant arsenic species found in rice and rice-based products, except for rice drinks, was As(III), with 60-80% of the total As content, followed by DMA(V) and As(V). MMA(V) was measured only at low levels (<3%). Analyses of rice products (N = 105) intended for toddlers, including special products destined for infants and toddlers, such as dry form baby foods (N = 12) or ready-to-use form (N = 9), were done. It was found in this study that there is little or no margin of exposure. Risk assessment, using the occurrence data and indicated intake scenarios compared to reference BMDLs as established by EFSA, demonstrated toddlers with a high consumption of rice based cereals and rice drinks are at risk of high iAs exposure, for which a potential health risk cannot be excluded.

Urinary Cadmium Excretion Is Associated With Increased Synthesis of Cortico- and Sex Steroids in a Population Study.

Context: Urinary cadmium (Cd) excretion is associated with cancer and cardiovascular morbidity. A potential mechanism could be disturbance of steroidogenesis in gonads and adrenal glands. Objective: We tested whether urinary excretion of Cd is correlated with that of cortico- and sex steroid metabolites in the general adult population. Setting: The Swiss Kidney Project on Genes in Hypertension is a multicentric, family-based population study. Measures: Urinary excretions of steroid hormone metabolites and Cd were measured with separate day and night collections. Associations were analyzed by mixed linear models. Results: Urinary Cd and testosterone excretions in men were significantly correlated (respective day and night ß values [standard error (SE)], 1.378 [0.242], P < 0.0005; and 1.440 [0.333], P < 0.0005), but not in women [0.333(0.257), P = 0.2; and 0.674 (0.361), P = 0.06]. Urinary Cd and cortisol excretions were positively associated in both sexes [day: ß = 0.475 (SE, 0.157), P = 0.0025, and 0.877 (SE, 0.194), P < 0.0005, respectively; night: ß = 0.875 (SE, 0.253), P < 0.0005 and 1.183 (SE, 0.277), P = 0.00002, respectively]. Cd excretion was correlated with mineralocorticoid metabolites excretion, except tetrahydroaldosterone, in both sexes (P < 0.01). There was an independent effect of Cd on sex hormone and corticosteroid synthesis and an interdependent effect on gluco- and mineralcorticoid production. Conclusion: Our findings provide evidence for a global stimulating effect on steroid synthesis already at low-dose Cd exposure. These findings might explain the association of Cd with diseases such as steroid-sensitive cancers or metabolic disorders.

Optimization of a New Mass Spectrometry Method for Measurement of Breast Milk Iodine Concentrations and an Assessment of the Effect of Analytic Method and Timing of Within-Feed Sample Collection on Breast Milk Iodine Concentrations.

BACKGROUND: Breast milk iodine concentration (BMIC) may be an indicator of iodine status during lactation, but there are few data comparing different analytical methods or timing of sampling. The aims of this study were: (i) to optimize a new inductively coupled plasma mass spectrometry (ICP-MS) method; and (ii) to evaluate the effect of analytical method and timing of within-feed sample collection on BMIC. METHODS: The colorimetric Sandell-Kolthoff method was evaluated with (a) or without (b) alkaline ashing, and ICP-MS was evaluated using a new (129)I isotope ratio approach including Tellurium (Te) for mass bias correction (c) or external standard curve (d). From iodine-sufficient lactating women (n = 97), three samples were collected within one breast-feeding session (fore-, mid-, and hind-feed samples) and BMIC was analyzed using (c) and (d). RESULTS: Iodine recovery from NIST SRM1549a whole milk powder for methods (a)-(d) was 67%, 24%, 105%, and 102%, respectively. Intra- and inter-assay coefficients of variation for ICP-MS comparing (c) and (d) were 1.3% versus 5.6% (p = 0.04) and 1.1% versus 2.4% (p = 0.33). The limit of detection (LOD) was lower for (c) (0.26 µg/kg) than it was for (d) (2.54 µg/kg; p = 0.02). Using (c), the median [95% confidence interval (CI) obtained by bootstrap] BMIC (µg/kg) in foremilk (179 [CI 161-206]) and in mid-feed milk (184 [CI 160-220]) were not significantly different (p = 0.017), but were higher than in hindmilk (175 [CI 153-216]; p < 0.001). In foremilk using (d), BMIC was 199 ([CI 182-257]; p < 0.001 vs. (c)). The variation in BMIC comparing (c) and (d) (13%) was greater than variation within feeding (5%; p < 0.001). CONCLUSIONS: Because of poor recoveries, (a) and (b) should not be used to measure BMIC. Compared with (d), (c) has the advantages of higher precision and a lower LOD. In iodine-sufficient women, BMIC shows low variation within a breast-feeding session, so timing of sampling is not a major determinant of BMIC.

Cadmium body burden of the Swiss population.

Urinary cadmium (Cd) excretion was measured within a representative Swiss collective. With a median of 0.23 µg/24 h (n = 1409) and the 95th percentile at 0.81 µg/24 h, no increased health risk for the general non-exposed population was identified. The independent variables Age, BMI and Smoking habit had a significant effect on urinary Cd excretion. No association was found with the region of residence and sex. A subsample comparison between 24-h and spot urines of the same subjects (n = 90) did not reveal an evident concentration difference for both creatinine-adjusted sample types. Dependencies on age and gender were observed for creatinine, which consequently impacts on the creatinine normalisation of urine samples.

Depleted uranium in Kosovo: an assessment of potential exposure for aid workers.

BACKGROUND: During the Kosovo conflict approximately 11 tons of depleted uranium munitions were used against armored targets, predominantly in the west. Potential exposure to uranium amongst employees of the International Red Cross and Red Crescent Movement in western Kosovo was assessed. METHODS: Individuals (n = 31) who had resided at least 3 mo in western Kosovo provided 24-h urine collections and completed an administered questionnaire. Specimens were analyzed for creatinine concentration, and uranium concentration was determined using inductively coupled mass spectrometry. FINDINGS: Subjects ranged in age from 22 to 45 y, and 77% were male. Mean duration of residency was 11 mo, and 14 individuals were in western Kosovo throughout the hostilities. Almost three quarters of subjects reported seeing destroyed tanks or vehicles, predominantly while passing by within a vehicle. Two individuals spent time within 50 m of a destroyed tank or vehicle while outside of a vehicle. Urinary uranium concentrations ranged from 3.5 to 26.9 ng of uranium per liter of urine (median 8.9 ng L(-)). Creatinine normalized values ranged from 2.9 to 21.1 ng of uranium per gram of creatinine (median 7.4 ng g(-1) creatinine). These results fall toward the lower end of urinary uranium determinations made amongst non-exposed populations drawn from a literature review. INTERPRETATION: These results do not indicate an increased exposure to uranium amongst adults living and working in western Kosovo who do not spend time in proximity to destroyed vehicles. Environmental sampling and replication of these results amongst a sample including children and individuals reporting intensive exposure to destroyed vehicles would further develop the exposure assessment.