Blood and urine levels of Pb, Cd and Hg in the general population of the Czech Republic and proposed reference values

The Human Biological Monitoring (HBM) project was launched in the Czech Republic in 1994 as a part of the nation-wide Environmental Health Monitoring System to assess the exposure of the Czech general population to a broad spectrum of environmental contaminants. Over the years 2001-2003, the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) were determined in whole blood of 1188 adults (blood donors) and 333 children and in urine of 657 adults and 619 children. In adults, the median blood lead (B-Pb) level was 33microg/l. Men had higher B-Pb levels than women (medians 37microg/l vs. 25microg/l). Significantly higher B-Pb levels were observed in smokers compared to non-smokers (36microg/l vs. 31microg/l). In children, no sex-dependent differences were observed (median 31microg/l). In total, the median blood Cd level (B-Cd) in adults was 0.5microg/l. Smokers showed a median B-Cd level about 3 times as high as non-smokers (1.3microg/l vs. 0.40microg/l). Neither sex- nor age-related differences were observed in B-Cd levels. In 65% of children, B-Cd levels were below the limit of detection (LOD). The overall median urinary cadmium level (U-Cd) in adults was 0.31microg/g creatinine. Significantly higher U-Cd levels were found in women (median 0.39microg/g creatinine) compared to men (0.29microg/g creatinine). No significant differences were found between smokers and non-smokers. In more than 50% of children, the U-Cd level was below the LOD (=0.2microg/l). The median blood mercury (B-Hg) level in adults was 0.89microg/l. Significant differences were found between smokers (0.80microg/l) and non-smokers (0.92microg/l), and between men and women (0.86microg/l vs. 0.94microg/l). The median B-Hg level in children was 0.42microg/l and no sex-related differences were observed. The median urinary mercury (U-Hg) levels were 0.63microg/g creatinine in adults and 0.37microg/g creatinine in children. Significantly higher U-Hg levels were obtained in women and non-smokers compared to men and smokers, respectively. The B-Pb, B-Hg, U-Cd, and U-Hg levels significantly correlated with age. The following reference values were recommended for the period 2001-2003: 80, 65 and 55microg/l for B-Pb and 3.1, 4.0 and 1.5microg/l for B-Hg in men, women and children, respectively; 1.1microg/l and 1.2microg/g creatinine for B-Cd and U-Cd, respectively, in adult non-smokers; 5.4 and 12.0microg/g creatinine for U-Hg in men and women, respectively, and 3.7 and 5.5microg/g creatinine for U-Hg in boys and girls, respectively. The previous reference values for B-Pb and B-Cd needed revision and were reduced.     

Reference values for blood benzene in the occupationally unexposed general population

Blood benzene was determined by gas chromatography-mass spectrometry in 431 "normal" subjects, subdivided into 155 rural subjects and 276 urban subjects. Blood benzene (mean value 262 ng/l) was significantly lower in rural (200 ng/l) than in urban (296 ng/l) workers, as well as differing significantly between 293 non-smokers and 138 smokers (205 ng/l and 381 ng/l, respectively). Among non-smokers, values were significantly higher (307 ng/l) in 76 chemical workers. In the total study population, in 95% of cases blood benzene was less than 718 ng/l, the 95th percentile being 514 ng/l in non-smokers vs 901 ng/l in smokers and 576 ng/l in rural vs 822 ng/l in urban subjects. Within each population subgroup, the difference between non-smokers and smokers was statistically significant, except among office workers (non-smokers 234 ng/l, smokers 304 ng/l). Blood benzene (y) was directly proportional to the number of cigarettes smoked (x) (y = 201 + 12x; r = 0.44; n = 431), and inversely proportional to the interval between the last cigarette and the time at which the blood samples was taken (z) (log y = 6.167-0.0015z; r = -0.461; n = 135). The blood half-life of benzene was about 8h. The multiple correlation between blood benzene (Cb), number of cigarettes per day (x) and time since the last cigarette (z) is: Cb = 417 + 7.2x - 0.41z (n = 135; R = 0.20; P less than 0.00001).     

Comparison of breath,blood and urine concentrations in the biomonitoring of environmental exposure to 1,3-butadiene, 2,5-dimethylfuran,and benzene

OBJECTIVES: To investigate and compare alveolar, blood, and urine concentrations of 1,3-butadiene, 2,5 dimethylfuran, and benzene, in non-occupational exposure to these products. METHODS: Benzene, 2,5-dimethylfuran and 1,3-butadiene were measured in the breath, blood, and urine samples of 61 subjects living in small mountain villages. All 61 were regularly employed as forestry workers. Sampling was done during the long winter-season non-working period. Samples were collected after overnight rest and analysed by headspace and GC-mass spectrometry methods. RESULTS: The median 1,3-butadiene level was 1.2 ng/l (range: <0.8-13.2 ng/l) in alveolar air, 2.2 ng/l (range: <0.5-50.2 ng/l) in blood, and 1.1 ng/l (range: <1-8.9 ng/l) in urine. The median benzene level was 5.7 ng/l (range: <1-24.9 ng/l) in alveolar air, 62.3 ng/l (range: 33.5-487.2 ng/l) in blood, and 63.4 ng/l (range: 25.8-1099.1 ng/l) in urine. The median 2,5-dimethylfuran level was 0.5 ng/l (range: <1-12.5 ng/l) in alveolar air, 2.5 ng/l (range: <5-372.9 ng/l) in blood, and 51.8 ng/l (range: <5-524.9 ng/l) in urine. In several cases, 2,5-dimethylfuran levels were below the detection limit in alveolar air and blood, especially in non-smokers. 1,3-Butadiene, 2,5-dimethylfuran and benzene levels were significantly higher in smokers than non-smokers in all biological media. CONCLUSIONS: 1,3-Butadiene and benzene, as ubiquitous pollutants, are detectable and quantifiable in human alveolar air, blood and urine. 2,5-Dimethylfuran, which is not a usual environmental pollutant, is almost always detectable in biological media, but only in smokers.     

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.     

Levels of benzene and other volatile aromatic compounds in the blood of non-smokers and smokers

The concentrations of benzene, toluene, ethylbenzene, and o-, m-and p-xylene were measured in venous blood samples collected from 13 non-smokers and 14 cigarette smokers. The blood samples were analysed by a purge and trap technique followed by gas chromatography/mass spectrometry/computer analysis. The above-mentioned volatile organic compounds (VOC) could be detected in measurable amounts in all blood samples. This finding seems to reflect the ubiquitous exposure of humans to these agents in the urban environment, in non-smokers as well as in smokers. Smokers were found to have significantly higher blood concentrations of benzene (median 547 ng/l) and toluene (median 2201 ng/l) than non-smokers (median 190 ng/l and 1141 ng/l, respectively). The concentrations of ethylbenzene and xylenes also tended to be higher in smokers when compared to non-smokers. The different concentrations of these compounds in the blood of non-smokers appear to reflect the common concentration pattern found in outdoor urban air as well as in indoor air and also seem to be influenced by the different blood/air partition coefficients of these compounds. The results indicate that smoking is associated with a significant additional exposure to VOC, in particular to benzene and toluene.     

Determination of lead and arsenic in tobacco and cigarettes: an important issue of public health

Contents of lead and arsenic were determined in 617 tobacco samples and 80 samples of cigarettes. The mean content of lead in tobacco was 0.93 microg/g (range 0.02-8.56 microg/g) and arsenic was 0.15 microg/g (range < 0.02-2.04 microg/g). The mean content of lead in cigarettes was 1.26 microg/g (range 0.02-6.72 microg/g) and arsenic was 0.11 microg/g (range < 0.02-0.71 micro/g). There was a large variability in lead and arsenic content among samples of tobacco and samples of cigarettes. Positive correlation between lead and arsenic contents in tobacco was found (r = 0.22; p < 0.0001). Based on our data and data from literature we compare the content of lead and arsenic in tobacco and cigarettes in other studies and discuss the influence of smoking to lead and arsenic exposure and health. In conclusion, at the same time with the implementation of tobacco use prevention programmes it is advisable to implement continuous monitoring of lead and arsenic in tobacco and cigarettes in order to reduce the health risk due to exposure of these metals.     

Determinants of chronic mucus hypersecretion in a general population with special reference to the type of tobacco smoked

Data from a prospective study of 3884 smokers and 3676 non-smokers followed for five years were analysed to investigate the determinants of chronic mucus hypersecretion (CMH). During the follow-up 414 (10.7%) smokers and 140 (3.8%) non-smokers developed CMH. The influence of the type of tobacco smoked (plain cigarettes, filter cigarettes, pipe and cheroots/cigars), lifetime tobacco consumption, age, alcohol consumption, and socioeconomic status on the development of CMH was assessed in men and women separately using multiple logistic regression. In smokers of both sexes, the risk of developing CMH increased significantly with lifetime tobacco consumption and almost significantly with age. In male smokers, the risk of developing CMH increased with alcohol consumption but was not significantly related to the type of tobacco smoked. In female smokers, the risk of CMH increased significantly with short school education and was, after adjustment for the amount of tobacco smoked, approximately twice as high in cigarette smokers as in cheroot smokers. However, as female cheroot smokers on the average consumed much more tobacco than female cigarette smokers the incidence of CMH was almost the same in the two groups. Among current non-smokers, the risk of developing CMH increased with age and previous tobacco consumption. It is concluded that although a number of factors are associated with the development of CMH, tobacco smoking, regardless of the type of tobacco, is a major determinant of CMH.     

Smoking and passive smoking as conditioners of folate status in young women

OBJECTIVE: For women of fertile age, an adequate supply of folate is important for preventing a range of health problems, especially congenital malformations in their offspring. Since congenital deformities are more common in children of mothers who smoke, the objective was to analyse the folate status of smokers, passive smokers and non-smokers. METHODS: Folate intake was monitored in 319 women aged 18-35 (112 smokers, 100 passive smokers and 107 non-smokers) using a three day food record. Serum and erythrocyte folate concentrations were measured by radioimmunoassay. Exposure to tobacco smoke was established by a questionnaire on present and past tobacco consumption, the number of hours in contact with smokers, and by assessing urine cotinine concentrations. RESULTS: The folate intake of smokers (S) (159.1 +/- 65.7 microg/day) and passive smokers (PS) (165.2 +/- 66.6 microg/day) was lower than that of non-smokers (N) (181.7 +/- 72.4 microg/day) (p < 0.05 between S and N). No subject fully met the recommended intake of the vitamin, but S and PS subjects both took less than N subjects (39.8 +/- 16.4% and 41.3 +/- 16.6% compared to 45.4 +/- 18.1% respectively). Serum folate concentrations were also lower in S and PS subjects grouped together (16.6 +/- 5.9 nmol/L) compared to N subjects (18.4 +/- 6.7 nmol/L) (p < 0.05). CONCLUSIONS: None of the studied women took the 400 microg/day of folate recommended. 6.7% had serum folate concentrations of < 9.2 nmol/L. The situation was worse in S and PS subjects, which might contribute to an increased risk of developing certain diseases and to giving birth to children with congenital deformations.     

Urinary nickel excretion in populations living in the proximity of two russian nickel refineries: a Norwegian-Russian population-based study.

The Russian nickel refineries located in the cities of Nikel and Zapolyarny close to the Norwegian border are responsible for extensive sulfur dioxide and nickel pollution, as well as severe ecological damage in both countries. The aim of our study was to investigate human nickel exposure in the populations living on both sides of the Norwegian-Russian border. The design was a cross-sectional population-based study of adults aged 18-69 years residing in Sor-Varanger municipality, Norway, and Nikel and Zapolyarny, Russia, during 1994 and 1995. Individual exposure to nickel was assessed by measurements of nickel in urine using electrothermal atomic absorption spectrometry. For controls, urine was collected from adults in the Russian cities of Apatity and Umba (Kola Peninsula) and the Norwegian city of Tromso, all of which are locations without nearby point sources of nickel. Altogether 2,233 urine specimens were analysed for nickel. People living in Nikel had the highest concentrations (median 3.4 microg/l), followed by Umba (median 2.7 microg/l), Zapolyarny (median 2.0 microg/l), Apatity (median 1.9 microg/l), Tromso (median 1.2 microg/l), and Sor-Varanger (median 0.6 microg/l). Regardless of geographical location, the Russian study groups all had a higher urinary-nickel average than those in Norway (p<0.001). With the exception of Nikel, neither the Russian nor the Norwegian urinary-nickel levels were associated with residence location near a Russian nickel refinery. We concluded that industrial nickel pollution alone could not explain the observed discrepancy between Norway and Russia; we also discuss other possible nickel exposure sources that may account for the high urinary levels found in Russia.     

Cadmium exposure pathways in the Czech urban population

The article describes the exposure pathways of cadmium in the Czech urban population. The data on Cd concentrations originated from the Environmental Health Monitoring System, which has been realized in 30 cities since 1994. The data on cadmium content in particular exposure pathways - diet, drinking water, ambient air and soil -were processed for the period 1994-2003. The estimate of the daily dietary intake for an average adult population amounted to 11-19 microg/d, i.e. 0.17-0.30 microg/kg bw/d, which represents 17%-30% of the PTWI (provisional tolerable weekly intake). The contribution from drinking water to the oral exposure is low; on average 0.5 microg/d. Potential exposure to airborne Cd was estimated at about 0.02 microg/d. The additional Cd intake from urban soil ingestion probable in small children was found to be insignificant based on Cd concentrations in the soil of kindergarten playgrounds. Biomonitoring outputs characterize the recent and life-long cadmium burden of the Czech population from general environment In 1994-2003, the median blood Cd levels ranged in the interval 0.9-0.4 microg/l blood, in smokers being more than double that in non-smokers. Blood Cd levels detected indicate slightly decreasing trend as well as urine Cd levels (range of median values 0.44-0.28 microg/g creatinine). Since 1996 the levels in children have been found in more than 50% cases below the detection limit of the methods used. The estimated total cadmium intake in the Czech urban population does not signalize any increased risk of health impairment considering non-carcinogenic effects.     

A study of carboxyhaemoglobin levels of cigarette and sheesha smokers in Saudi Arabia.

A single carboxyhaemoglobin (COHb) estimation of late evening blood sample among non-smokers, cigarette smokers, and sheesha smokers was evaluated among Saudis. The COHb level in smokers of 15 to 40 cigarettes a day ranged between 0.7 and 10.3 with a mean value of 6.1 +/- 2.58 COHb. Values among sheesha smokers ranged between 6.5 and 13.9 with a mean value of 8.8 +/- 1.83, significantly higher than those of cigarette smokers (P less than 0.001) for a given degree of exposure to tobacco smoke.     

Assessment of cadmium and lead released from cigarette smoke]

Cigarette smoke, which contains many harmful compounds, affects not only the smoker's health but also indoor air quality. To evaluate indoor air contamination by cadmium (Cd) and lead (Pb), we measured Cd and Pb contained in the mainstream and sidestream smoke exhaled by experimental smoking of Japanese cigarettes and also determined urinary and blood Cd and Pb levels in smokers and non-smokers and air Cd and Pb levels in smoky environments. 1. One cigarette of each of 7 Japanese brands contained about 1 microgram each of Cd and Pb, of which about 50 ng each was released to the mainstream and 250 ng of Cd and 50 ng of Pb to the sidestream by smoking. 2. The blood Cd level in the smokers was significantly higher than that in the non-smokers. The urinary Cd level in the smokers was slightly higher than that in the non-smokers. The blood Cd level was related to the number of cigarettes smoked daily. Blood and urinary Pb levels did not differ between the smokers and non-smokers, but the blood Pb level was also related to the number of cigarettes smoked daily. 3. The air Cd levels in smoky places such as the smoking car of the special express train, an office, and a pachinko parlor were markedly higher than that in outdoor air. The air Cd concentration was well correlated with the environmental tobacco smoke concentration. On the other hand, the air Pb level was slightly higher in the above smoky places than outdoors. The mean air Pb concentration was not correlated with the environmental tobacco smoke concentration but was higher at higher environmental tobacco smoke concentration in each place.     

Urinary monohydroxylated phenanthrenes and hydroxypyrene – the effects of smoking habits and changes induced by smoking on monooxygenase-mediated metabolism

Objectives: Internal polycyclic aromatic hydrocarbon (PAH) exposure is usually studied by determining 1-hydroxypyrene in urine. In many studies, increased urinary levels of 1-hydroxypyrene have been found in smokers compared with non-smokers. The disadvantage of this procedure, however, is that it is based on only one substance. Therefore, in our study, urine specimens from smokers and non-smokers were tested for four monohydroxylated phenanthrenes in addition to 1-hydroxypyrene. Subjects and methods: Spot urine samples from 288 non-smokers and 100 smokers were analysed for 1-, 2-, 3- and 4-hydroxyphenanthrene and 1-hydroxypyrene by a very sensitive high performance liquid chromatography (HPLC) method with fluorescence detection. The detection limit of the method is 5 ng metabolite/l urine. The data were calculated on a creatinine basis (ng/g creatinine). Results: Highly significant differences and dose-response relationships with regard to cigarettes smoked per day were found for 2-, 3- and 4-hydroxyphenanthrene and 1-hydroxypyrene, but not for 1-hydroxyphenanthrene. When the ratio of the sum of hydroxyphenanthrenes to 1-hydroxypyrene, and the ratio of 1- and 2-/3- and 4-hydroxyphenanthrene were taken into consideration, significant negative dose-response relationships to the numbers of cigarettes smoked per day, were found. Conclusion: 1-Hydroxypyrene as well as 2-, 3- and 4-monohydroxylated phenanthrenes in urine may be used as parameters to detect PAH exposure from cigarette smoking. Moreover, 3,4-oxidation of phenanthrenes was found to be enhanced in smokers, with a significant dose-response relationship. This phenomenon is thought to be caused by an induction of the CYP 1A2 (or CYP 3A4) monooxygenase system in smokers. Therefore, it may be recommended that monohydroxylated phenanthrenes be analysed in order to assess the balance between the PAH-metabolising cytochrome isoforms, and the activity or induction of cytochrome P450 isoforms, respectively. Received: 12 May 2000 / Accepted: 1 November 2000     

Detection of exposure to mutagenic compounds in low-tar and medium-tar cigarette smokers

A volunteer study was carried out on groups smoking low-tar (5.4 mg/cig.) and mediumtar (16.3 mg/cig.) cigarettes and on non-smokers. The number of cigarettes smoked was recorded daily throughout a 51-day study period, and the effects of smoking were measured in the beginning and after 3-week terms of smoking medium-tar or low-tar cigarettes. The parameters measured were blood carboxyhemoglobin concentration, thioethers excreted into the urine, mutagenic activity in the urine, and the frequency of sister-chromatid exchanges in blood lymphoyctes. For all four parameters, the differences between the smokers and the non-smokers were significant. However, within the study design no differences could be detected between low-tar or medium-tar cigarette smoking in the biological-monitoring tests used.     

Prevalence of cardiovascular risk factors of the smokers and non-smokers in the city of Debrecen, Hungary

The aim of our study was to compare the major cardiovascular disease (CVD) risk factors of smokers and non-smokers. Risk screening of CVD was estimated by a questionnaire, via interview. Random samples of 20 000 inhabitants of Debrecen, Hungary, aged 30-65 y, took part in the study. 19 922 questionnaires were considered appropriate for further evaluation. 32.2% of the participants (n=6410) were smokers, whose data were compared to those of the 68.8% of non-smokers (n=13 512). There were more male smokers than female (39.3% vs 27.7%), (P<0.001). 36.5% of males and 58.9% of females had not previously smoked regularly (P<0.001). 24.2% of males and only 13.3% of females were able to stop smoking (P<0.001). 8.7% of the participants smoked more than 20 cigarettes per day (14.8% of males, 5.0% of females), (P<0.001). Smokers were younger, with a mean age of 43.4 y vs 47.1 y for non-smokers (P<0.01). The ex-smokers and non-smokers had a higher body mass index than light, moderate and heavy smokers (26. 75+/-4.1 kg/m2 and 26.09+/-4.3 kg/m2 vs 24.87+/-3.9 kg/m2 and 24. 89+/-4.2 kg/m2 and 25.32+/-4.3 kg/m2, respectively), (P<0.001). The results of the last measured blood pressures did not differ between the two groups. 94.8% of smokers and 93.6% of non-smokers did not perform any regular leisure time exercises (P<0.01). 39.8% of smokers regularly ate fatty food, in comparison to 28.0% of non-smokers (P<0.001). 30.6% of smokers vs 28.6% of non-smokers were factory workers while 69.4% of smokers vs 71.4% of non-smokers did sedentary jobs (P<0.001). 2.3% of smokers vs 0.9% of non-smokers admitted regular consumption of alcohol (P<0.001). Amongst the parents and brothers/sisters of smokers the prevalence of heart attack was higher 19.7% vs 18.7%, than for those of non-smokers (P<0. 05). We observed an accumulation of cardiovascular risk factors in the case of smokers, which indicates the higher susceptibility of smokers to CVD.     

Mercury concentrations in urine,scalp hair,and saliva in children from Germany

Mercury levels measured in urine, hair, and saliva of 245 German children (8-10 years old) are reported. Mercury concentrations in urine ranged between <0.1 and 5.3 microg/l [geometric mean (GM) 0.26 microg/l or 0.25 microg/g creatinine; median for both, 0.22 in microg/l and microg/g, respectively]. Using multiple linear regression analysis, two predictors have been found accounting for 25.3% of the variance of mercury levels in urine: the number of teeth with amalgam fillings (23.2%) and the number of defective amalgam fillings (2.1%). The mercury content in hair ranged from <0.06 to 1.7 microg/g (GM 0.18 microg/g; median 0.18 microg/g). The frequency of fish consumption, the smoking habits of the parents, and the age of the children accounted for 20.4% of the variance of mercury levels in hair. The correlation between the hair mercury content and urine mercury concentration was low (r=0.297). Mercury levels in saliva ranged between <0.32 and 4.5 microg/l (median 0.16 microg/l). The mercury concentration in saliva was below the limit of quantification of 0.32 microg/l in more than 70% of the samples. Mercury analysis in urine is suitable to estimate mercury exposure due to amalgam fillings, whereas hair mercury better reflects mercury intake by fish consumption. Up to now, saliva does not seem to be a suitable tool to monitor the mercury burden, at least not at low exposure levels.     

Secondhand exposure to aerosol from electronic cigarettes: pilot study of assessment of tobacco-specific nitrosamine (NNAL) in urine

ObjectiveTo assess the levels of a tobacco-specific nitrosamine (NNAL) in non-smokers passively exposed to the second-hand aerosol (SHA) emitted from users of electronic cigarettes (e-cigarettes).MethodWe conducted an observational study involving 55 non-smoking volunteers divided into three groups: 25 living at home with conventional smokers, 6 living with e-cigarette users, and 24 in control homes (smoke-free homes). We obtained urine samples from all volunteers to determine NNAL.ResultsWe detected NNAL in the urine of volunteers exposed to e-cigarettes (median:0.55 pg/mL; interquartile range: 0.26-2.94 pg/mL). The percentage of urine samples with quantifiable NNAL differed significantly among the three groups of homes: 29.2%, 66.7% and 76.0%, respectively (p = 0.004).ConclusionsWe found NNAL nitrosamine in urine samples from people exposed to SHA from e-cigarettes. However, these results could be confirmed with more studies with larger sample sizes.     

Cotinine excretion (tobacco smoke biomarker) of smokers and non-smokers: comparison of GC/MS and RIA results

With a validated GC/MS method, the tobacco smoke biomarker cotinine has been estimated in urine for 148 non-smokers (male; 43±13 years; median 5.0 μg/g creatinine; 95^th percentile 104 μg/g) and 96 smokers (male; 39±12 years; 1002 μg/g; 2993 μg/g). For a subgroup of 50 persons, the GC/MS results were compared with those by a commercially available radio immunoassay. Both methods identified the same persons as non-smokers and smokers, respectively, and were closely related. For smokers, the relationship was distinctly closer than for the non-smokers (r=0.90, p<0.001, n=14 vs. r=0.41, p<0.02, n=36). The RIA values were 2.4times (smokers) and 2.9times (non-smokers) higher than the GC/MS results. This was probably caused by the cross reactivity of the RIA antibodies against other urinary nicotine metabolites, e.g. trans-3′-hydroxycotinine, and has to be taken into account to correctly compare results of studies obtained with different analytical techniques and for choosing cut-off points to discriminate between active smokers and non-smokers or between non-smokers with higher or lower exposure to environmental tobacco smoke.     

Determination of cadmium and lead in urine of some Nigerian subjects

Forty-one urine samples of smokers and non-smokers from Ile-Ife, Nigeria were analyzed for normal cadmium and lead levels after acid digestion. Results of the preliminary study show that concentrations of cadmium obtained were generally low compared with lead. The mean urinary levels from non-smokers ranged from 0.05 - 0.02 to 0.16 - 0.01 wg ml-1 and from 0.02 - 0.03 to 0.88 - 0.04 wg ml-1 for cadmium and lead respectively, whilst, for smokers, urinary levels varied between 0.07 - 0.01 and 0.23 - 0.02 wg ml-1 and between 0.28 - 0.03 and 1.02 - 0.02 wg ml-1 were obtained for cadmium and lead, respectively. Cd levels in urine of smokers and non-smokers are higher than the recommended normal level of 0.0085 wg ml-1, while levels of Pb are above the 0.08-0.15 wg ml-1 exposure range. Results of spiking experiments with urine gave high percentage recoveries for both elements (Cd, 87.9 - 0.40%) and (Pb, 90.40 - 0.12%). Blank determination was done for background correction.     

Mercapturic acids as metabolites of alkylating substances in urine samples of German inhabitants

Hydroxyalkyl mercapturic acids (HAMA) are the main urinary metabolites of several alkylating substances that possess a carcinogenic potential, like acrolein, 1,3-butadiene, ethylene oxide, propylene oxide and glycidol. These alkylating substances are used extensively in industrial processes, but they do also occur environmentally, e.g. in tobacco smoke. The aim of this study was the determination of six HAMA, as biomarkers of exposure, in human urine of smokers and non-smokers. We applied a sensitive analytical method, using hydrophilic interaction liquid chromatography with tandem mass spectrometry (HILIC-MS/MS) for the determination of 2-hydroxyethyl mercapturic acid (HEMA, biomarker for ethylene oxide), 2-hydroxypropyl mercapturic acid (2-HPMA, biomarker for propylene oxide), 3-hydroxypropyl mercapturic acid (3-HPMA, biomarker for acrolein), 2,3-dihydroxypropyl mercapturic acid (DHPMA, biomarker for glycidol) as well as 3,4-dihydroxybutyl mercapturic acid and 3-monohydroxybutenyl mercapturic acids (DHBMA and MHBMA, biomarkers for 1,3-butadiene). Background concentrations of four HAMA were detected in each urine sample we analyzed. The mercapturic acids HEMA and MHBMA were detected in 55% and 10% of the samples, respectively. In the urine of non-smokers (n = 54) we observed median levels of 206, 1.6, 12.1, 146, 159, and <5.0 μg/g creatinine for DHPMA, HEMA, 2-HPMA, 3-HPMA, DHBMA and MHBMA, respectively. Among smokers (n = 40) median levels of DHPMA, HEMA, 2-HPMA, 3-HPMA, DHBMA and MHBMA were determined to be 217, 4.9, 46.2, 884, 211 and <5.0 μg/g creatinine, respectively. The excretion rate of the biomarkers HEMA, 2-HPMA and 3-HPMA was distinctly higher in smokers than in non-smokers. Furthermore, our study revealed a comparatively high background level of DHPMA in urine of smokers and non-smokers whose origin is still unknown. The presented data may contribute to the evaluation of reference values for urinary HAMA levels in the general population.