Occupational exposure to n-hexane in Italy--analysis of a registry of biological monitoring.

OBJECTIVE: This study assesses 2,5-hexanedione (2,5-HD) in the urine of subjects exposed to n-hexane solvent between 1991 and 1998, from details obtained from the Registry of Biological Monitoring (BM) at the Florence Local Health Unit, and its development over time. METHODS: The Registry contains 15,925 samples from 6,650 subjects occupationally exposed to n-hexane, especially in leather (9,099 samples; 3,607 subjects) and shoe (3,865 samples; 1,938 subjects) production. RESULTS: Over the time span studied there was a total reduction of 31.9% in urinary 2,5-HD level. The yearly decrease over the entire period was 5.4%. Dividing the 8 years into three periods: before the introduction of the new legislation for health protection in the workplace (1991-1993), during its transition (1994-1996) and after its complete enforcement (1997-1998), respectively, we observed a marked decrease in the last period. Women and young people (under 30 years) experienced significantly higher absorption levels (respectively, 7.1% and 24.4%). CONCLUSION: The data suggest that monitoring was more frequent in subjects with higher starting values, and the greatest decrease was reported in this group. Reduction may be due to less n-hexane in the products used, better structural conditions in the factories, and the effectiveness of inspections carried out by the authority for hygiene and safety in the workplace. The results confirm the usefulness of the reporting of risk levels of exposure to industrial toxicants by routine biological monitoring.

[Blood lead levels in a non-professionally-exposed population from six Tuscan provinces]. / Livelli ematici di piombo in popolazioni non professionalmente esposte residenti in sei provincie toscane.

We report the results obtained in 1992 concerning the determination of blood lead levels (PbB) in 1321 subjects of the general population living in ten villages/towns of the Florence district characterised by the presence of artistic ceramic factories. We reported also the PbB values found in 2330 adults, 280 children, 39 pregnant women and their correspondent umbilical cords, who were examined during the second biological monitoring campaign against the risk of lead intoxication according to the DPR 496/82. Median PbB values were 92.5 micrograms/l (range 15-520 micrograms/l) for males and 62.5 micrograms/l (range 11-343 micrograms/l) for females. The lower PbB median values were found in the district of Livorno (76.25 micrograms/l and 48.25 micrograms/l in males and females, respectively) and Arezzo (80.5 micrograms/l and 52 micrograms/l in males and females, respectively). In comparison with the results obtained for the general Italian population during the previous biological monitoring campaign carried out in 1985-86 we observed PbB median values about 40% lower for both males and females and PbB median values about 55% lower for children. A significant statistic correlation (r = 0.53) was found between PbB of pregnant women and their umbilical cords.

[20 years of biological monitoring (1976-1995) of occupational lead exposure in various Tuscan provinces]. / Venti anni di sorveglianza biologica (1976-1995) dell'esposizione professionale a piombo in alcune provincie toscane.

We report the results of 24,475 blood lead determinations (PbB) performed by the Occupational Toxicology Laboratory of Florence between 1976 and 1995. Biological monitoring was carried out in 383 factories localized in the districts of Florence, Prato, Pistoia, Lucca and Pisa. The most represented production fields were colouring ceramic factories, artistic ceramics, transfer-pictures for ceramics, glass factories, typographies, glass decoration factories, chemical factories. In twenty years, the median values of PbB decreased from 48 to 17 micrograms/100 ml in males and from 40 to 8 micrograms/100 ml in females. The 95 degrees centile ranged from 84 to 46 micrograms/100 ml for males and from 63 to 42 micrograms/100 ml for females. In the 1988-95 period, we observed an increase of both the 95 degrees centile and the maximal values because of the inclusion of data from workers employed in factories where the "decorazione a scavo" technique, which is characterized by elevated environmental lead concentrations, was used. In the period 1991-93, the ranges of PbB observed in glass decoration factories were 13-160 micrograms/100 ml for males and 4-80 micrograms/100 ml for females, respectively.

Determination of urinary 2,5-hexanedione in the general Italian population.

OBJECTIVE: Determination of the urinary levels of 2.5-hexanedione (2,5-HD) was performed in subjects belonging to the Italian general population to define the reference value for this metabolite. MATERIALS AND METHODS: Urine samples were collected from 123 healthy Italian subjects who had not been occupationally exposed to n-hexane or methyl-n-butyl ketone (60 men and 63 women; 53 living in urban areas and 70 living in rural areas; 36 smokers and 87 nonsmokers; 65 aged above 35 years and 58 aged below 35 years). The determinations were performed by a gas chromatography method using a flame ionization detector (FID). A quality-control step was realized by analysis of 78 of these samples by high-performance liquid chromatography (HPLC) with UV detection. RESULTS AND DISCUSSION: The distribution of 2,5-HD concentration was log-normal and the corresponding centiles at the 95% confidence interval were as follows: the 50th centile, 0.270 mg/l for men and 0.191 mg/l for women; the 75th centile, 0.352 and 0.330 mg/l, respectively, for men and women; and the 95th centile, 0.762 and 0.582 mg/l, respectively, for men and women. The reference value, calculated as the upper unilateral 95% tolerance interval at 95% of confidence, was 0.795 mg/l for men and 0.627 for women.

Skin contamination and low airborne nickel exposure of electroplaters.

The present study was performed to evaluate the role of hand and facial contamination in the absorption of soluble nickel compounds in 41 male subjects employed in electroplating operations in 25 small factories in the province of Florence (Italy). Personal exposure to airborne nickel ranged from 0.10 to 42 micrograms/m3; the median (range) urine, hands and face nickel levels were 4.2 (0.7-50) micrograms/l, 39 (1.9-547) micrograms, 9.0 (1.0-86) micrograms, respectively. Face nickel values explained the bulk of the variance in urine nickel levels (42%). In stepwise multiple regression analysis all other variables were not significant. The log-linear model can be expressed as: log (urine-Ni) = 0.295 + 0.593 log (face-Ni). Our results suggest that skin contamination, especially facial skin, plays an important role in nickel absorption in exposed workers.

[Occupational exposure and individual factors influencing urinary elimination of hippuric acid]. / Esposizione professionale e fattori individuali che condizionano l'eliminazione urinaria di acido ippurico.

The influence of not occupational factors (smoking, alcohol, coffee, drugs, sport, sex, age and body weight) on hippuric acid excretion was analyzed in two groups of healthy male subjects. A group was constituted of 710 painters occupied in wood and coach workings and the other one of 109 not occupational. The 5 degrees, 50 degrees, 95 degrees percentiles of the two distribution were 208, 605, 1784 and 153, 538, 1700 mg/g creatinine respectively. The analysis of variance undertaken on exposed subjects showed that there was a significative difference between urinary hippuric acid levels of subjects consuming alcohol and the not ones. Multiple regression analysis on hippuric acid excretion values distribution in not exposed group showed that only the variable "coffee consumption" resulted statistically significative (Ln hippuric acid = 5.0287 + 0.8062; R2 = 01221). Coffee consumption increase excretion rate (mg/hour) of hippuric acid likely an exposure to a toluene air concentration of 50 mg/m3. The authors suggest an action of caffeine on endogenous amount of benzoic acid.

[Quality control in a system for the biological surveillance of exposure to n-hexane]. / Verifica di qualità in un sistema di sorveglianza biologica dell'esposizione a n-esano.

The paper reports the results of a quality assurance programme for routine biological monitoring of n-hexane exposure via measurement of its urinary metabolite 2.5-hexanedione. The programme involved a number of local occupational health services and was coordinated by the industrial toxicology laboratory in Florence. The analytical results show good agreement (68.6%, i.e., 46/67) between high urinary levels of 2.5-hexanedione (equal to or higher than an action level of 3.2 mg/l) and a relatively poor environmental situation at the workplace as reported by the local occupational health services. The fall in the number of 2.5-hexanedione values equal to or higher than the action level in the course of the study period (1990-1991) could be a result of the prevention measures taken. To confirm this hypothesis, 69 enterprises with at least 3 determinations in both 1990 and 1991 were selected. A 58% decrease in the mean 2.5-hexanedione value between 1990 and 1992 was observed in the group of enterprises (24) with at least one sentinel health event in 1990 (a value equal to or higher than 3.2 mg/l). In the group of enterprises with no sentinel health event in 1990, the mean 2.5-hexanedione values were practically unchanged. The authors stress the need for further studies to test the hypotheses based on the data obtained in this study.