Monitoring of trace elements in breast milk sampling and measurement procedures.

The aims of this study were to test analytical procedures for the determination of Cd, Cu, Mn, Pb, Se and Zn in breast milk and to establish optimum sampling conditions for monitoring purposes. Two population groups were analysed: (1) Seven women from Prague whose breast milk was sampled on days 1,2, 3, 4, 10, 20 and 30 after delivery; (2) 200 women from four (two industrial and two rural) regions whose breast milk was sampled at defined intervals. All samples were mineralised in a microwave oven in the mixture of HNO3 + H2O2 and analysed by atomic absorption spectrometry. Conditions for the measurement of the elements under study (i.e. those for the electrothermal atomisation for Cd, Mn and Pb, flame technique for Cu and Zn, and hydride generation technique for Se) were optimized. Using optimized parameters the analysis was performed and the following conclusion has been made: the concentrations of zinc and manganese decreased very sharply over the first days, that of copper slightly increased within the first two days and then slightly decreased, that of selenium did not change significantly. Partial "stabilisation" was achieved after the second decade. No correlation among the elements was found. A significant difference between whole and skim milk was only found for selenium (26% rel. higher in whole milk). The majority concentrations of cadmium and lead were below the detection limit of the method (0.3 microg x l(-1) and 8.2 microg x l(-1), respectively, as calculated for the original sample). To provide biological monitoring, the maintenance of sampling conditions and especially the time of sampling is crucial.

Effects of age, BMI, smoking and contraception on levels of Cu, Se and Zn in the blood of the population in the Czech Republic.

Variations in the levels of Cu, Se and Zn in blood were analyzed in relation to gender, age, BMI, smoking and hormonal contraception. The blood samples were collected from 3,207 blood donors (2,362 men, 845 women) during years 1996-2003. Blood concentrations of these elements were in the same range as those found for populations of other European countries. Significant differences exist between men and women, in blood concentration, for Cu (840 microg Cu.l(-1) vs. 970 microg Cu.l(-1), p<0.01) and Zn (6,780 microg Zn.l(-1) vs. 6,235 microg Zn.l(-1), p<0.01) only. The level of Cu in relation to age is increasing in men, but decreasing in women. The level of Se in relation to age increases regardless of sex. Concentrations of Zn rise with age in women group, only. Positive correlation was found between BMI and level of Cu only for group of men. For Se levels and BMI differences exist only in men namely between groups <20 and >35 (82 microg Se.l(-1) vs. 92 microg Se.l(-1)). Slight positive correlations exist between Zn concentration and BMI in women only. The significant differences were found between smokers and non-smokers for Cu in men (850 microg Cu.l(-1) vs. 830 microg Cu.l(-1)) and Se (81 microg Se.l(-1) vs. 84 microg Se.l(-1)). The smoking has not significant influence on concentration of Zn in the blood. The hormonal contraception significantly increases the concentration of Cu in blood (920 microg Cu.l(-1) vs. 1,270 microg Cu.l(-1), p<0.01). The levels of Se and Zn in blood are not influenced using hormonal contraception.

Determination of normal concentration levels of Cd, Cr, Cu, Hg, Pb, Se and Zn in hair of the child population in the Czech Republic.

Knowledge of normal levels of concentrations of trace elements (Cd, Cr, Cu, Hg, Pb, Se and Zn) in the population serve, among others, in the designing of regulations of exposure limits and prevention of diseases caused by deficiency in essential trace elements. Concentrations of the named elements in the hair of children in the Czech population were determined by means of atomic absorption spectrometry. The samples of hair were collected during 1994- 2001 from 3,556 children (1,741 boys and 1,815 girls, average age 9.9 years). Mineralization in a microwave digestion system was used following a washing procedure. The accuracy of results was checked by means of the control materials CRM Human Hair GBW 07601. Values of concentrations of the trace elements in hair found for children were (in medians) 0.14 microg Cd.g(-1), 0.22 microg Cr.g(-1), 12 microg Cu.g(-1), 0.19 microg Hg.g(-1), 1.6 microg Pb.g(-1), 0.22 microg Se.g(-1) and 124 microg Zn.g(-1), respectively. Statistically significant differences between boys and girls were found for Cd, Cu and Zn. Concentrations of the elements under study correspond to the published values for the non-exposed population.

Determination of normal concentration levels of Cd, Pb, Hg, Cu, Zn and Se in urine of the population in the Czech Republic.

Knowledge of normal levels of concentrations of trace elements (Cd, Pb, Hg, Cu, Zn, and Se) in the population serves, among others, in design of regulations concerning health protection, determination of exposition limits and prevention of diseases caused by deficiency of trace elements. Concentrations of the named elements in urine of the Czech population were determined by means of atomic absorption spectrometry. The urine has been collected during 1996-2000 from 1192 individuals (816 males and 376 females, average age 34.6 years) and 2008 children (1052 boys and 956 girls, average age 9.9 years). Mineralization in a microwave digestion system was used in sample preparation. The accuracy of results was checked by means of the Control Materials Seronorm 403,125 and BioRad 69,041. Values of concentrations of the trace elements in urine found for adult (medians) were 0.36 microgram Cd.g-1 creatinine, 10.6 micrograms Cu.g-1 creatinine, 0.68 microgram Hg.g-1 creatinine, 3.3 micrograms Pb.g-1 creatinine, 6.2 micrograms Se.g-1 creatinine, and 397 micrograms Zn.g-1 creatinine, respectively. Statistically significant differences between men and women have been found in the concentrations of Cu and Hg. In the juvenile population following concentrations have been found: 0.29 microgram Cd.g-1 creatinine, 16.1 micrograms Cu.g-1 creatinine, 0.32 microgram Hg.g-1 creatinine, 4.8 micrograms Pb.g-1 creatinine, 10.2 micrograms Se.g-1 creatinine and 460 micrograms Zn.g-1 creatinine. Statistically significant differences between boys and girls were found only in Cu and Hg concentrations. Concentrations of the studied elements correspond to the published values concerning population not exposed professionally.

Reference values for lead and cadmium in blood of Czech population.

This study aimed at determining blood concentrations of lead (B-Pb) and cadmium (B-Cd) in a group of 1215 healthy blood donors (895 males, 320 females) and 758 children (397 boys, 361 girls) aged 10 years, sampled in 1996-1998 in four districts of the Czech Republic. The analysis was performed using atomic absorption spectrometry. The median B-Pb values were lower in children (34 mg/L) than in adults. In the group of adults, the level was significantly higher in men (46 mg/L) than in women (29 mg/L). In none of the groups the 90th percentile exceeded the value of 100 mg/L. The B-Cd values in adults depended on smoking habit (median non-smokers: 0.5 mg/L, male smokers--1.2 mg/L, female smokers--1.0 mg/L). In children, more than 50% of values were under the limit of detection. The obtained values were used to propose reference values for the Czech population.

Health risk of urban soils contaminated by heavy metals.

The paper presents the results of geochemical investigations carried out in the city of Prague. Czech Republic, between the years 1994-1997, by the Czech Geological Institute, National Institute of Public Health and Hygiene Stations of Prague. Exposure assessment for children as the most sensitive population, based on soil ingestion pathway, indicates that lead is the major pollutant of concern, especially in the central regions of the city. Direct exposure assessment was done by analyzing blood and urine samples collected from children aged 3-6 years. Blood lead levels were the only biomarker significantly higher as compared to the control group (32.1 +/- 17.4 microg/l, 25.1 +/- 15.4 microg/l). This pilot study supports the establishment of a new sub-system within the already existing System of Monitoring the Environmental Impact on Population Health of the Czech Republic.

Retrospective study of concentration levels of Pb, Cd, Cu and Se in serum of the Czech population in time period 1970-1999.

The retrospective study evolution of trends in concentrations of Cd, Pb, Cu and Se in the population of the Czech Republic over 30 years period could be useful in design of regulations concerning health protection, prevention of diseases caused by deficiency of trace elements and have considerable economic importance. Concentrations of the named elements in the serum were determined by means of atomic absorption spectrometry (AAS) after mineralisation in a microwave digestion system. The 1433 samples of serum (730 males and 703 females, average age 48.7 and 49.1 years respectively) from a time period 1970-1995 were obtained from the Serum bank of National Institute of Public Health and volunteers (1999). Serum samples from the years 1970, 1975, 1980, 1985, 1990, 1995 and 1999 were examined. The accuracy of the results was checked by means of the Control material Seronorm Whole Blood 404,107 and Seronorm Serum 704,121, Nycomed. The concentration of Cd had a decreasing trend for the years 1975-1999 (0.82 microgram Cd.l-1 vs 0.47 microgram Cd.l-1). The levels of Pb are falling in the interval 1970-1980 (15.6 micrograms Pb.l-1 vs. 6.6 micrograms Pb.l-1). In year 1985 concentration of Pb increased (10.7 micrograms Pb.l-1) but subsequently decreased again (1995--6.4 micrograms Pb.l-1). In year 1999, it was 8.9 micrograms.l-1. The concentration of Cu decreased in period 1970-1990 (1525 micrograms Cu.l-1 vs. 990 micrograms Cu.l-1). From 1990 to 1999 the levels of Cu had an increasing tendency (1999--1060 micrograms Cu.l-1). Levels of Se in the interval 1970-1985 were surprisingly equal (58.1 micrograms Se.l(-1)-54.4 micrograms Se.l-1). However in the interval 1986-1990 the level of Se sharp declined (38.3 micrograms Se.l-1). Since 1990 levels of Se in serum increased again, up to 67.1 micrograms Se.l-1 in 1999. Statistically significant differences between men and women were found only in Cu and Pb concentrations. Concentrations of under study elements corresponded to the published values concerning unexposed population.

Determination of thirty-two elements in human autopsy tissue.

Inductively coupled plasma-mass spectrometry (ICP-MS) was used to determine the concentrations of 32 elements in the human liver and kidney and 20 elements in the bone, obtained from 70 autopsied dead individuals (54 males, 16 females) between 18 and 76 yr of age from the North Bohemia territory of the Czech Republic. Geometric means, median, minimal-maximal range, as well as distribution and correlation analysis were calculated. Some significant differences among tissue concentrations of trace elements of the women and men were found. In the liver, medians of the concentrations of some elements were higher for men than that for women (Al: 770 vs 610 microg/kg; As: 42 vs 27 microg/kg; Cd: 1800 vs 1390 microg/kg; Rb: 3955 vs 3210 microg/kg; V: 160 vs 105 microg/kg). On the contrary, the content of other elements for men was lower (Bi: 0.8 vs 3.2 microg/kg; Cr: 57 vs 72 microg/kg; Hg: 228 vs 325 microg/kg; Zn: 57.1 vs 68.5 mg/kg). In the kidney of men, there were higher contents of Al (360 vs 245 microg/kg) and Hg (135 vs 75 microg/kg) and lower contents of Zn (47.7 vs 59.7 mg/kg) and I (135 vs 220 microg/kg) than those of women. In the case of bone, the concentrations of Cu and Rb were higher for men (1410 microg Cu/kg and 405 microg Rb/kg, respectively) than for women (655 microg Cu/kg and 285 microg Rb/kg, respectively). On the contrary, the content of Mn was considerably lower for men (110 microg Mn/kg) than for women (215 microg Mn/kg).

The concentration levels of Cd, Pb, Hg, Cu, Zn and Se in blood of the population in the Czech Republic.

Knowledge of normal levels of concentrations of trace elements (Cd, Pb, Hg, Cu, Zn, and Se) in the population serves, among others, in design of regulations concerning health protection, determination of exposure limits and prevention of diseases caused by deficiency of trace elements. Concentrations of the named elements in whole blood of the Czech population were determined by means of atomic absorption spectrometry. The blood was collected during 1996-1998 from 1,216 blood donors (896 males and 320 females, average age 33 years) and 758 children (397 boys and 361 girls, average age 9.9 years). Mineralisation in a microwave digestion system was used in sample preparation. The accuracy of results was checked by means of the Control material Seronorm Whole Blood 404107 and Seronorm Serum 704121, Nycomed. Values of concentrations of the trace elements in blood found for adult (medians) were 0.7 microgram Cd.l-1, 800 micrograms Cu.l-1, 0.78 microgram Hg.l-1, 41 micrograms Pb.l-1, 76 micrograms Se.l-1, and 5,800 micrograms Zn.l-1, respectively. Statistically significant differences between men and women have been found in the concentrations of Cu, Hg, Pb, and Zn. In the juvenile population following medians of concentrations have been found: 0.15 microgram Cd.l-1, 1,047 micrograms Cu.l-1, 0.46 microgram Hg.l-1, 34 micrograms Pb.l-1, 69 micrograms Se.l-1, and 8,180 micrograms Zn.l-1. Statistically significant differences between boys and girls were found only in Pb and Zn concentrations. Concentrations of the studied elements correspond to the published values concerning population not exposed professionally.

Population-based biomonitoring in the Czech Republic--the system and selected results.

In the framework of the system of monitoring the environmental impact on population health, the concentration of lead, cadmium and selenium in blood and cadmium in urine was measured in adults (n = 670), children (n = 599) and umbilical blood (n = 549) using atomic absorption spectrophotometry. Furthermore, cytogenetic analysis of peripheral lymphocytes in all population groups under study was investigated. The median blood Pb level for the overall group of adults (47.8 micrograms/l, i.e. 0.23 mumol/1) was significantly higher in men (51.5 micrograms/l, i.e. 0.25 mumol/l). Smoking significantly influenced the blood Pb level in women. The 90th percentile in no group exceeded the value of 100 micrograms/l (0.48 mumol/l). The median blood Cd level in adults (0.9 microgram/l, i.e. 0.008 mumol/l) depends on smoking habit (1.25 micrograms/l, i.e. 0.01 mumol/l). The median urine Cd level was 0.585 microgram/g creatinine (0.59 mumol/mole creatinine) in adults and 0.37 microgram/g creatinine (0.37 mumol/mole creatinine) in children. The median blood Se level (53.5 micrograms/l, i.e. 0.68 mumol/l) was found to be higher in the group of non-smokers (57.5 micrograms/l, i.e 0.73 mumol/l). Lead and selenium level were significantly lower in the umbilical blood. Cytogenetic analysis results showed age-dependent average percentages of aberrant cells: 1.1% in umbilical blood, 1.27% in children and 1.71 in adults in line with the reference values for the Czech population.

Determination of some metals in biological samples for monitoring purposes.

The biological monitoring of toxic and essential metals in biological material is important for the study of influence of environmental conditions on the human body. In this work, the determination of Cd, Pb and Hg in blood, urine and hair of children has been performed by atomic absorption spectroscopy. The electrothermal atomisation with Zeeman background correction was used for Pb and Cd determination and mercury was determined using Trace Mercury Analyser TMA 254. Methylmercury in hair was determined simultaneously. To check the method, SRM Lyphochek Urine Metal control--Biorad, Seronorm Trace Elements--Nycomed and GWB Human Hair (China) were used. The group of more than 100 children were chosen for the study. Statistical tests were used for the evaluation of the obtained results. The concentrations of all elements in all types of samples correspond to the "normal contents" published for the non-exposed population.

Comparison of concentration of Cu and Zn in children population.

The biological monitoring of essential metals in blood, urine and hair became important for the control of biological processes and for the study of the influence of environmental conditions on the human organism. To determine the normal level of copper and zinc in the children population group of Central Bohemia (Benesov), 98 samples of whole blood, 133 samples of urine and 135 samples of hair have been analysed by means of atomic absorption spectroscopy. The mineralisation of blood and hair samples in the microwave oven and 3-fold dilution of urine were used for the sample preparation. Arithmetic and geometric means as well as median and ratio Zn/Cu were calculated. The concentration of the elements under study in all samples did not differ from the values published in the literature. Some differences between girls and boys have been found.