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Biomedical subjects

G Maranelli

Publications and source records attributed to G Maranelli.

At least 19 recordsLinked to original sources
PubMed1997

Reference values of urinary chromium in Italy.

OBJECTIVES: The paper describes the results of a polycentric study for the assessment of reference values of urinary chromium (U-Cr) in the Italian population. METHOD: A total of 890 subjects (58.3% males and 41.7% females) were selected on the basis of standardized criteria in eight different areas of Italy. Urinary chromium was determined on morning spot samples collected using standardized procedures. The U-Cr was determined independently by three laboratories using an Electrothermic atomization-Atomic Absorption Spectrometry (ETA-AAS) method with a detection limit of 0.05 microgram/l, adopting-for the statistical analysis-the median value of the results of the three laboratories. The between-laboratories within-subjects standard deviation was 0.049 microgram/l. Due to the high proportion (approx, 28%) of undetectable chromium levels, the geometric mean (GM) and geometric standard deviation (GSD) were estimated using a procedure of linear interpolation. The analysis of the effects of some variables (sex, age, center, residence, smoking and drinking habits) on the U-Cr values, was also performed, by multiple regression analysis after logarithmic transformation, using GM and SD. RESULTS: The reference value of U-Cr was of 0.08 microgram/l as an estimated GM, whereas the expected distribution ranged from not detectable (nd) (95% CI = nd-0.06) to 0.24 microgram/l (95th percentile; 95% CI = 0.20-0.31). Among the variables studied, only geographical area and sex significantly influenced the U-Cr levels. In subjects selected in the provinces of Bari and Venice values of U-Cr were significantly lower than those determined in subjects residing in other areas. CONCLUSIONS: From our investigation the reference values for U-Cr were lower than those obtained in previous investigations. In addition it confirms a further reduction in U-Cr levels following the previous decline reported in the 1970s and 1980s. In over 20 years U-Cr values in the general population dropped from values greater than 1 microgram/l to values between 0.5 and 0.2 microgram/l. The reasons of this progressive decline cannot be attributed in our opinion to a reduced intake of the metal, but mainly to the improvement in analytical instrumentation and methods. A further decrease may be ascribed to a more accurate definition of the reference groups and to a better control of pre-analytical factors. Considering that the reference values for U-Cr are much lower than those determined some decades ago, toxicological studies in order to verify the significance of biological limit values currently suggested for chromium seem to be necessary.

Adult↗
PubMed1994

Blood acetone concentration in "normal people" and in exposed workers 16 h after the end of the workshift.

Acetone levels were measured by gas chromatography mass spectrometry (GC-MS) in environmental and alveolar air, blood and urine of 89 non-occupationally exposed subjects and in three groups of workers exposed to acetone or isopropanol. Acetone was detected in all samples from non-exposed subjects, with mean values of 840 micrograms/l in blood (Cb), 842 micrograms/l in urine (Cu), 715 mg/l in alveolar air (Ca) and 154 ng/l in environmental air (Ci). The ninety-fifty percentiles were 2069 micrograms/l in Cb, 2206 micrograms/l in Cu and 1675 ng/l in Ca. The blood/air partition coefficient of acetone was 597. Correlations were found in Cb, Cu and Ca. In specimens sampled at the end of the workshift from subjects occupationally exposed to acetone, a correlation was found in the blood, urine, alveolar and environmental air concentrations. The blood/air partition coefficient of acetone was 146. On average, the blood acetone levels of workers were 56 times higher than the environmental exposure level, and the concentration of acetone in alveolar air was 27% more than that found in inspiratory air. The half-life for acetone in blood was 5.8 h in the interval of 16 h between the end of the workshift and the morning after. The morning after a workshift with a mean acetone exposure of 336 micrograms/l, blood and urinary levels were 3.5 mg/l and 13 mg/l, respectively, which were still higher than those found in "normal" subjects. It can be concluded that endogenous production of acetone and environmental exposure to acetone or isopropanol do not affect the reliability of biological monitoring of exposed workers, even 16 h after low exposure.

Acetone↗
PubMed1994

Non-occupational lead exposure and hypertension in northern Italy.

BACKGROUND: Previous research has addressed the issue that low-level blood lead concentration could be associated with an increased risk of hypertension. METHODS: This paper examines the cross-sectional association between blood lead and hypertension in 630 adult males not employed in activities characterized by specific exposure to lead and living in two Northern Italian cities (Verona and Brescia). The participants, aged 26-69 years, constituted a random sample of the patients in the practice of a general practitioner (Verona) and of regular blood donors (Brescia). Logistic regression analysis was used to evaluate the effects of selected variables (blood lead, blood cadmium, zinc erythroprotoporphyrin, haemoglobin, whole blood viscosity, age, body mass index, smoking habits and alcohol consumption) on the probability of being hypertensive. RESULTS: The blood lead concentration (range: 4.3-46.9 micrograms/dl; median: 14.8 micrograms/dl) was very similar in the two samples, whereas the prevalence of hypertension was significantly higher in the Verona sample than in the Brescia sample (20.4% versus 8.3%). Hypertensive subjects showed significantly higher blood lead levels than normotensive ones. In a preliminary (univariate) analysis blood lead levels, body mass index (BMI) and age were each significantly related to the prevalence of hypertension. After adjusting for age and/or BMI, statistical significance of the relationship between blood lead and hypertension was lost.CONCLUSIONS. The present study showed that blood lead is weakly related to hypertension in non-occupationally exposed men. The statistical significance of this association disappeared when age and BMI were used to make adjustments.

Adult↗
PubMed1993

Blood concentrations of carbon disulphide in dithiocarbamate exposure and in the general population.

Blood carbon disulphide (CS2), both free and total, was determined by gas chromatography-mass spectrometry in 112 "normal" subjects and in 20 subjects employed in a dithiocarbamate factory, comprising ten blue-collar workers involved in dithiocarbamate production and ten white-collar office staff. The ten production workers were examined over two workshifts, the first at the beginning of the week (Monday) and the second after an intervening period of at least 1 day. Three blood samples were taken for each shift studied, one prior to starting work, one at the end of the shift and the third 16 h after the end of the shift (on the following morning). The mean CS2 blood levels measured in the 112 normal subjects was 663 ng/l for the free fraction and 3178 ng/l for the total. In 16 blood samples taken from the ten dithiocarbamate factory office workers, the mean free and total CS2 blood levels were 846 and 4140 ng/l, respectively, i.e. not significantly different from those observed in the normal subjects. At the end of the first 8-h shift, the ten dithiocarbamate factory production workers had free and total CS2 values of 1070 and 8471 ng/l, respectively, which were significantly higher than those observed prior to starting work (240 and 4738 ng/l). All the total CS2 levels measured in the shop-floor workers, with the sole exception of the values recorded prior to the start of the Monday shift (4738 ng/l), ranged from 7047 to 8471 ng/l and were significantly higher than those measured in the white-collar staff (4140 ng/l).

Adult↗
PubMed1993

Reference values for blood toluene in the occupationally nonexposed general population.

Blood toluene was measured by gas chromatography--mass spectrometry in 232 occupationally nonexposed subjects, consisting of 126 rural and 106 urban workers, and 37 chemical workers. Mean blood toluene was significantly lower in rural (698 ng/l) and urban workers (984 ng/l) than in chemical workers (2789 ng/l). Blood toluene was not significantly different between the rural and urban workers or among the urban workers with different jobs. Smokers had significantly higher levels (median 606 ng/l) than nonsmokers (median 424 ng/l). Subjects who had smoked at least one cigarette in the last 2 h before blood sampling had significantly higher blood toluene (median 1170 ng/l) than those who had not smoked during this time (median 693 ng/l), for whom the level was not significantly different from that in nonsmokers. Blood toluene in the total population was less than 2863 ng/l in 95% cases.

Adult↗
PubMed1993

Blood styrene concentrations in a "normal" population and in exposed workers 16 hours after the end of the workshift.

Blood styrene was measured by a gas chromatography-mass spectrometry method in 81 "normal people" and in 76 workers exposed to styrene. In the normal subjects, styrene was also tested in alveolar and environmental air. Styrene was found in nearly all (95%) blood samples. Average styrene levels in the normal subjects were 221 ng/l in blood (Cb), 3 ng/l in alveolar air (Ca) and 6 ng/l in environmental air (Ci). Styrene levels did not differ significantly between smokers and nonsmokers, 95% of values being below 512 ng/l in Cb, 7 ng/l in Ca and 15 ng/l in Ci. In workers with an average exposure to styrene of 204 micrograms/l, at the end of the workshift, mean blood styrene concentration was 1211 micrograms/l. In blood samples collected at the end of the Thursday shift, styrene levels were significantly higher (1590 micrograms/l) than those found at the end of the Monday shift (1068 micrograms/l). A similar difference was found in samples taken the morning after exposure (60 and 119 micrograms/l, respectively). Significant correlations between blood and environmental styrene were found both at the end of the shift and the morning after exposure (r = 0.61 and 0.41, respectively). In workers occupationally exposed to styrene, 16 h after the end of the workshift, blood styrene (94 micrograms/l) was significantly higher than that found in the normal subjects (0.22 microgram/l). The half-life of blood styrene was 3.9 h.

Adult↗
PubMed1992

Tentative reference values for some elements in broncho-alveolar lavage fluid.

The concentrations of Fe, Mn, Pb and Cr have been determined in broncho-alveolar lavage (BAL) fluid of 25 subjects without occupational or abnormal environmental exposure to metals, using the AAS method. The numerous factors which can interfere with the results in pre-analytical and in analytical phases are stressed. Metals concentrations in BAL are expressed in micrograms/l. They were not correlated with the volume of fluid recovered, the total cells, alveolar macrophages and erythrocytes. The results were not modified by stratification considering age and sex. Iron concentrations were higher than others, probably due to higher environmental exposure and partly to its essential role in humans. The diagnostic significance of element determination in BAL fluid and the relationship with exposure and lung load is discussed.

Bronchoalveolar Lavage Fluid↗
PubMed1992

Is hypertension a confounding factor in the assessment of blood lead reference values?

In order to evaluate whether hypertension can be considered as a confounding factor in the setting up of reference values for blood lead, we examined the results of a cross sectional study which evaluated the relationship between lead in blood and hypertension in a sample of 254 males and 271 females of a general population not occupationally exposed to lead. The statistical analysis and in particular the multiple logistic regression showed that, even if some well-known confounding factors such as age, sex, overweight, smoking and alcohol are taken into account, blood lead levels are well correlated with hypertension. The results suggest that even modest lead absorption is able to influence the probability of being hypertensive. The relationship between blood lead and hypertension and their relationship with the main confounding factors involved in the determination of reference values of metals in blood are discussed.

Adult↗
PubMed1992

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).

Adult↗
PubMed1992

Blood concentration of carbon disulphide in "normal" subjects and in alcoholic subjects treated with disulfiram.

Assay of free and acid labile carbon disulphide (free and total CS2 respectively) in human blood was performed by gas chromatography/spectrometry. The method used a large dynamic head space volume and a "cryogenic trap". Blood CS2 concentration was measured in 42 subjects not occupationally exposed to CS2 (group A) and in 11 alcoholic subjects (group B) treated with disulfiram. Free CS2 concentration showed a mean value of 261 ng/l in the 42 subjects in group A and 9482 ng/l in eight subjects of group B. Total CS2 concentration was 897 ng/l and 40,084 ng/l in groups A and B respectively. Differences between the groups were highly significant for concentrations of both free and total CS2. Total CS2 concentration was about four times as high as free CS2 concentration in both groups. A significant correlation was found between free and total CS2 concentration both in group A and in group B. In the alcoholic subjects (group B), blood concentrations of both free and total CS2 were related to time of sampling after treatment with disulfiram.

Alcoholism↗
PubMed1991

Ubiquitous pollution by n-hexane and reference biological levels in the general population.

n-Hexane levels were determined by gas chromatography and mass spectrometry in environmental air and in the alveolar air, blood and urine of a group of subjects aged on average of 38 years who had not been occupationally exposed to this hydrocarbon. n-Hexane was found in all environmental air samples examined (n = 49), with the mean concentration being 104 ng/l (limit values, 1-279 ng/l). It was also found in all 49 samples of alveolar air, with the mean concentration being 50 ng/l (variation limit, 1-304 ng/l). In 64 samples of urine, n-hexane was found in only 50 samples, with the mean concentration being 1,417 ng/l (limit values, 34-8,820 ng/l). In 77 of the 90 blood samples taken, a mean concentration of 608 ng/l was detected (variation limit, 15-7,684 ng/l). Particularly the haematic and urinary concentration showed significant differences among the nine groups of individuals classified according to their work activity. The lowest levels were found in the blood and urine of farmers: 270 and 298 ng/l, respectively. The highest values were found for chemical workers (1,377 and 411 ng/l), respectively printers (585 and 2,691 ng/l respectively), and traffic wardens (740 and 8,820 ng/l, respectively). In all, 95% of the determinations of n-hexane yielded values of less than 255 ng/l in environmental samples, less than 105 ng/l in alveolar air, less than 1,475 ng/l in blood and less than 5,875 ng/l in urine. A comparison of these data revealed a significant correlation between environmental levels and alveolar (r/s = 0.769; P less than 0.00001), haematic (r/s = 0.624; P less than 0.0002), and urinary (r/s = 0.597; P less than 0.0005) values for n-hexane.

Adult↗
PubMed1990

Blood lead and blood pressure: a cross sectional study in a general population group.

In a sample of general population not occupationally exposed to lead (254 males and 271 females), a cross sectional study has been carried out to evaluate the relationship between lead in blood (PbB), blood pressure and hypertension. The data were analyzed by the common statistical significance tests (Student t test, variance analysis) and by logistic regression and showed that, even taking into account the well-known confounding factors (such as age, overweight, heredity, smoking, alcohol) PbB and blood pressure are significantly correlated. In light of these results and according to the more recent literature, it is proposed to consider PbB as a synthetical indicator of major cardiovascular risk rather than a single risk factor.

Adult↗
PubMed1989

Benzene in the blood and breath of normal people and occupationally exposed workers.

Benzene was measured in blood and alveolar air of 168 men, aged 20-58 years, subdivided into four groups: blood donors, hospital staff, chemical workers occupationally exposed to benzene, and chemical workers not occupationally exposed to benzene. The group of exposed workers was employed in work places with a mean environmental exposure to benzene of 1.62 mg/M3 (8 hr TWA). Non-exposed workers were employed elsewhere in the same plant, with an environmental exposure to benzene lower than 0.1 mg/M3. Blood and alveolar air samples were collected in the morning, before the start of the work shift for the chemical workers. The group of exposed workers was found to be significantly different from the other three groups, both for blood and alveolar benzene concentrations. The mean blood benzene concentration was 789 ng/l in the exposed workers, 307 ng/l in the non-exposed workers, 332 ng/l in the hospital staff, and 196 ng/l in the blood donors. Apart from the exposed workers, blood benzene concentration was significantly higher in smokers than in non-smokers. The mean alveolar benzene concentration was 92 ng/l in the exposed workers, 42 ng/l in the non-exposed workers, 22 ng/l in the hospital staff, and 11 ng/l in the blood donors. Alveolar benzene concentration was significantly higher in smokers than in non-smokers in the groups of the hospital staff and non-exposed workers, but not in the blood donors and exposed workers. In the three groups without occupational exposure considered altogether, the alveolar benzene concentration correlated significantly with environmental benzene concentration measured at the moment of the individual examinations, both in the smokers (r = .636; p less than .001) and non-smokers (r = .628; p less than .001). In the same three groups and in the exposed workers, alveolar benzene concentration showed a significant correlation with the blood benzene concentration.

Adult↗
PubMed1989

Breath and blood levels of benzene, toluene, cumene and styrene in non-occupational exposure.

Benzene, toluene, cumene and styrene were measured in the breath and blood of two groups of individuals. The first group included individuals belonging to a hospital staff, the second group included chemical workers who were not exposed to the abovementioned chemicals. The chemical workers were examined in plant infirmaries on the morning before the start of the workshift, and the hospital staff in the hospital infirmaries. One environmental air sample was taken in the infirmaries for each individual at the moment of the biological samplings. The environmental concentrations of benzene and styrene were significantly higher in the infirmaries of the chemical plant than in the infirmaries of the hospital. On the other hand, the environmental concentrations of toluene and cumene were not significantly different in the plant infirmaries and in the hospital infirmaries. In the hospital staff the alveolar concentrations of benzene, toluene and styrene were significantly lower than those in the chemical workers. In the hospital staff the blood concentrations of benzene, toluene and styrene were not significantly different from those in the chemical workers. Only the blood cumene concentration was significantly higher in the chemical workers. In hospital staff, smokers showed alveolar and blood concentrations of benzene and toluene that were significantly higher than those measured in the non smoker hospital staff. With reference to chemical workers, only alveolar benzene concentration was significantly higher in smokers than in non smokers.(ABSTRACT TRUNCATED AT 250 WORDS)

Benzene↗
PubMed1988

Urinary thallium: critical problems, reference values and preliminary results of an investigation in workers with suspected industrial exposure.

Using a sensitive ETA ASS method, urinary thallium (Tl-U) has been measured in a group of non-exposed individuals and in two groups of workers with suspected industrial exposure. In non-exposed subjects (72 healthy males aged 41 +/- 11 years) the Tl-U mean value was 0.22 mu/l (range 0.05-0.61). Significantly higher values were found in two groups of workers (30 and 21 subjects) employed in two cement factories and two cast iron foundries (mean Tl-U value: 0.38 and 0.33 mu/l, respectively; range 0.06-1.2). Thallium has been determined in coal, raw materials and, in one factory, also in environmental samples, but no detectable levels were found. The analytical problems connected to urinary thallium determination and the preliminary results of biological monitoring in non-exposed individuals and in workers are discussed.

Environmental Exposure↗
PubMed1988

Urinary chromium levels in subjects living in two north Italy regions.

The concentration of total urinary chromium (Cr-U) in two different groups of healthy occupationally non-exposed subjects living in the Italian regions of Lombardia and Veneto has been determined using an ETA-AAS direct method. The age, sex, residence and smoking habits were correlated with CrU excretion. The mean CrU value found in subjects living in Lombardia (n = 310, males 170 and females 140) was 0.59 + 0.26 microgram/l (range 0.08 - 2.10); in Veneto subjects (n = 238, males 187 and females 51) the mean value was 0.52 +/- 0.31 microgram/l (range 0.05 - 1.90). A significative difference between male and female values and a decrease of CrU levels with age increasing have been evidenced in both groups. Smoking habits seem to influence metal urinary levels while, on the other hand, no influence of living sites was observed. Some analytical problems of ETA-AAS Cr determination systems are discussed and "normal" CrU values measured in this study are compared with data reported in the literature.

Adult↗
PubMed1987

[Occupational contact dermatitis: analysis of clinical case reports, 1972-1985].

The hospital records of 105 subjects with professional dermatitis, admitted at the Institute of Occupational Health of Verona between 1972 and 1985, were reviewed. Work sectors, chemicals, sites of dermatitis, latency and age of onset were evaluated. Contact allergic dermatitis were 80% while irritative ones were 10%. Metal-, construction- and tannery workers were more frequently involved. The most common causes were salts of heavy metals. The authors discuss results and remark the need of standardization in diagnostic procedures.

Adult↗