Ignazio Drago

Indoor formaldehyde and acetaldehyde levels in the province of Bari, South Italy, and estimated health risk

Indoor and outdoor formaldehyde and acetaldehyde levels were assessed to characterize pollution in dwellings in the city and the Province of Bari, also taking into account seasonal variability, and to investigate health effects of aldehyde exposure on the general population. In 2007, passive environmental monitoring was performed, for 24 hours, in the kitchen of 59 dwellings, as well as outdoors for 27 of them. A questionnaire probing personal and home characteristics was administered to all 182 subjects habitually resident in the homes. During the period January-June 2008, formaldehyde and acetaldehyde levels were monitored monthly in 20 of the investigated dwellings inhabited only by non smokers. Indoor formaldehyde and acetaldehyde concentrations were significantly higher (16.0 +/- 8.0 and 10.7 +/- 8.8 microg m(-3)) than outdoor concentrations (4.4 +/- 1.7 and 3.4 +/- 2.0 microg m(-3)), showing a correlation between indoor levels of the two aldehydes (r = 0.41; p = 0.001). In dwellings inhabited only by non smokers, formaldehyde concentrations were higher in the presence of furniture bought new or restored less than one year before (p = 0.03). Formaldehyde and acetaldehyde levels were significantly higher in winter months than in spring-summer months (F = 2.86, p = 0.02; F = 5.39, p < 0.001) and seemed to be influenced by the time that kitchen windows were kept open. As regards the effects on human health, a low prevalence of allergic disease and no association between any irritant or allergic complaints and indoor levels of the two aldehydes was observed. In conclusion, the results showed low indoor and outdoor concentrations of formaldehyde and acetaldehyde, not generally posing a risk for human health.

Significance of urinary arsenic speciation in assessment of seafood ingestion as the main source of organic and inorganic arsenic in a population resident near a coastal area

In order to characterize the different sources of exposure to arsenic (As), urinary excretion of total As, the sum of inorganic As+MMA+DMA determined by the hydride generation-atomic absorption spectrophotometry technique, and the species As3, As5, monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine were determined in 49 workers at a steel foundry, with presumed occupational exposure to As, and 50 subjects from the general population, all males. No evidence of occupational exposure to As resulted from environmental monitoring performed in the foundry, although the analysis of minerals used as raw materials showed the presence of As, particularly in fossils and fine ores. The urinary concentrations of As3, MMA, DMA, the sum of inorganic As+MMA+DMA and total As were not different in the two groups, while arsenobetaine appeared significantly higher in the controls than in the workers. The different species of urinary As were all significantly correlated. Urinary excretion of As3 was associated with the consumption of mineral water and with residence in an industrial zone, while MMA, DMA, arsenobetaine, the sum of inorganic As+MMA+DMA and total As urinary excretion were associated with the consumption of crustaceans and/or shellfish 3 days or less before urine collection. Multiple regression analysis confirmed these results. In conclusion, in populations with a high consumption of seafood, living in areas characterized by coastal/marine As pollution, only speciation of As can identify a prevalent role of environmental sources, like the consumption of seafood contaminated by As, in determining urinary As excretion, and exclude an occupational origin of the exposure.

Biomarkers of internal dose for the assessment of environmental exposure to benzene

The urinary excretion of t,t-muconic acid (t,t-MA), S-phenylmercapturic acid (SPMA) and urinary benzene and the influence of a smoking habit and of exposure to urban traffic on the urinary excretion of these biomarkers were investigated in 137 male adults from the general population. All subjects were not occupationally exposed to benzene and resident in two cities in Puglia (Southern-Italy). Environmental exposure to benzene was measured using passive personal samplers. The biomarkers t,t-MA, SPMA and urinary benzene were determined in urine samples collected from each subject at the end of the environmental sampling. The percentage of cases above the limit of detection was higher for SPMA and urinary benzene in smokers than in non-smokers, and for airborne benzene and urinary benzene in subjects exposed to urban traffic. Airborne benzene was correlated with the time spent in urban traffic during the environmental sampling. Among the biomarkers, urinary benzene was found to be correlated with airborne benzene only in non-smokers, and with the time spent in urban traffic, both in smokers and non-smokers considered together, and in non-smokers only. Finally, multiple regression analysis showed that the urinary excretion of all the biomarkers was dependent on the number of cigarettes smoked per day and, for urinary benzene, also on the time spent in urban traffic. In conclusion, urinary benzene seems to be a more valid biomarker than t,t-MA and SPMA to assess environmental exposure to extremely low concentrations of benzene. Cigarette smoking prevailed over traffic exhaust fumes in determining the internal dose of benzene.

Evaluation of chromosome aberration and micronucleus frequencies in blood lymphocytes of workers exposed to low concentrations of benzene.

The frequency of chromosome aberrations (CA) and micronuclei (MN) was investigated in the peripheral lymphocytes of workers occupationally exposed to low or very low concentrations of benzene. The study included 43 exposed workers (all males), namely 19 fuel-tanker drivers and 24 filling-station attendants, and 31 male subjects with no occupational exposure to the toxicant (controls). Benzene exposure was verified by means of environmental monitoring with passive personal samplers (Radiello(®)), and through biological monitoring, i.e. by measurement of urinary trans,trans-muconic acid, S-phenylmercapturic acid and benzene. The frequency of CA and MN in peripheral lymphocytes was determined according to standard procedures. Exposure to benzene was found to be significantly higher for fuel-tanker drivers (median 246.6 μg/m(3)) than for filling-station attendants (median 19.9 μg/m(3)). Both groups had significantly higher exposure than controls (median 4.3 μg/m(3)). No increased frequency of CA and MN was observed in either fuel-tanker drivers or filling-station attendants compared with controls. In all subjects examined as a single group, the frequency of MN was significantly dependent on age. Only in the fuel-tanker drivers was the frequency of MN found to depend not only on age, but also on exposure to benzene. In conclusion, the frequency of MN, but not of CA, could be influenced by exposure to benzene concentrations of up to one order of magnitude lower than the threshold limit value (time-weighted average).

The influence of diet on intra and inter-individual variability of urinary excretion of arsenic species in Italian healthy individuals.

To study the effect of eating foods with a high arsenic (As) content on the intra and inter-individual variability of urinary concentrations of the As species, daily urine samples were collected for 10 consecutive days from 12 healthy male subjects. A daily food diary was kept throughout the study period. Personal exposure to airborne As was measured once during the study. As(3), As(5), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA) and arsenobetaine were determined in all urine samples by inductive coupled plasma mass spectrometry, and the sum of As(3)+As(5)+MMA+DMA (iAs) by hydride generation-atomic absorption spectrophotometry. Exposure to airborne As was below the limit of detection in all samplings. As(3) was found in only 19.2% and As(5) in only 3.3% of the urine samples, whereas high urinary concentrations of arsenobetaine were observed. With the exception of arsenobetaine, expressed as a percentage, a significant inter-individual variability was observed for all species of As, for iAs and for the MMA/DMA ratio (p<0.001). Instead, the intra-individual variability was significant only for the MMA/DMA ratio (p<0.001). Among foods with a high As content, only a heavy consumption of seafood was shown to influence inter-individual variability of DMA%, arsenobetaine expressed as μg g(-1) creatinine and iAs. In conclusion, even in populations with a high intake of organic As through foods, the finding of a significant inter-individual but no significant intra-individual variability of urinary species confirms the usefulness of urinary As speciation for biological monitoring of exposure to As.

DNA damage and repair capacity in workers exposed to low concentrations of benzene.

DNA damage and cellular repair capacity were studied in 18 male fuel tanker drivers and 13 male filling‐station attendants exposed to low and very low concentrations of benzene, respectively, and compared to 20 males with no occupational exposure (controls). Exposure to airborne benzene was measured using passive personal samplers, and internal doses were assayed through the biomarkers t,t‐muconic acid, S‐phenylmercapturic acid and urinary benzene. DNA damage was evaluated using tail intensity (TI) determined by the comet assay in peripheral lymphocytes. Urinary 7‐hydro‐8‐oxo‐2’‐deoxyguanosine (8‐oxodG) was measured as a biomarker of oxidative damage. DNA repair kinetics were assessed using the comet assay in lymphocytes sampled 20 and 60 min post H2O2 exposure. Benzene exposure differed significantly between the drivers (median 246.3 µg/m3), attendants (median 13.8 µg/m3), and controls (median 4.1 µg/m3). There were no differences in TI and 8‐oxodG among the three groups, or between smokers and non‐smokers. DNA repair kinetics were similar among the drivers, attendants and controls, although the comet assay on H2O2‐damaged lymphocytes after 60 min revealed significantly lower levels of TI only in drivers. The DNA repair process in smokers was similar to that observed in drivers. In conclusion, this study found no relationship between low levels of benzene exposure and DNA damage, although there was evidence that exposure interferes with DNA repair kinetics. The biological impact of this finding on the onset of genotoxic effects in exposed workers has still to be ascertained. Environ. Mol. Mutagen. 57:151–158, 2016.

Immune effects of polychlorinated biphenyls, smoking and alcohol.

Polychlorinated biphenyls (PCB) have been shown to exert some immune effects. Here we analysed their effects also on immune parameters not previously studied such as TCR α-β, TCR γ-δ and regulatory T cells (Treg), taking into account the specific and cumulative interference of smoking and alcohol. The study subjects consisted of 26 male workers in a steelworks factory, employed in the electrical maintenance sector, with previous exposure to a mixture of PCB (exposed subjects), and 30 male workers with no occupational exposure to PCB (controls). All subjects were given a questionnaire and peripheral venous blood samples were taken to determine serum PCB (33 congeners), total cholesterol and triglycerides, leukocytes, total lymphocytes and the T lymphocyte subpopulations (TCR α-β, TCRγ-δ, CD4+ and Treg lymphocytes). PCB, even though at a very low concentration, were significantly higher in exposed subjects than controls, and were significantly correlated with age. Monocytes% and CD4+ were significantly reduced in the exposed subjects as compared to the controls. The serum concentration of PCB positively correlated with TCR α-β, and negatively with TCRγ-δ. Treg lymphocytes showed a positive dependence on tobacco smoking, while the monocytes% and CD4+ showed a negative and positive dependence, respectively, on alcohol intake. Our results seem to show some effects of slight exposure to PCB in particular reducing the relative concentration of TCRγ-δ. This effect can favour indirectly the increase in Treg induced by smoking, the anti-inflammatory or proinflammatory/fibrogenetic/angiogenetic effect of which, exerted by produced cytokines, particularly TGF-β, deserves further clarification.

Assessment of Environmental Exposure to Benzene: Traditional and New Biomarkers of Internal Dose

In view of the widespread ubiquity of benzene in the environment and of its carcinogenic effects on man, this toxicant poses a public health problem that has prompt nations to undertake active measures to contain environmental concentrations below the limit judged to be an acceptable risk threshold for the general population (World Health Organization [WHO], 2000). In the occupational field, until the 1950s benzene was the solvent most commonly employed in some industrial processes, and especially in rubber, printing and shoemaking industries, because of its chemico-physical properties and low cost. This caused exposure of these workers to high benzene concentrations that induced toxic effects and acute non lymphocytic leukemia (Agency for Toxic Substances and Disease Registry [ATSDR], 2007; WHO, 1993). Due to these adverse effects, its use in industrial processes was then abandoned, replacing benzene firstly by hexane, but this proved to provoke peripheral neuropathies, and then by less toxic solvents such as heptane. In Italy the use of benzene as a solvent is banned by Law 245/1963, although traces below 2% are permitted in solvents of a different chemical nature (Italian Parliament, 1963). Benzene is still used as a raw material or intermediate product in the chemical industry, mainly to synthesize ethylbenzene, cumene and cyclohexane, and to a limited extent as a

Biological monitoring of exposure to low concentrations of benzene in workers at a metallurgical coke production plant: new insights into S-phenylmercapturic acid and urinary benzene

Abstract Context: Urinary S-phenylmercapturic acid (SPMA) and benzene (U-Ben) are usually measured at the end of the work shift (ES), although their kinetic of elimination is not clearly known. Objective: To investigate SPMA and U-Ben elimination 16 h after the ES, in 93 coke production workers exposed to low benzene concentrations. Materials and methods: Airborne benzene (A-Ben) was measured by passive samplings, while SPMA, U-Ben, methyl-tert-butyl ether (U-MTBE), cotinine (U-Cot) and creatinine were determined on urine samples collected at ES and before the beginning of the next work shift (next BS). Results: Median A-Ben concentrations were 17.2 µg/m3 in the personal and 34.7 µg/m3 in the stationary samplings. SPMA was always detectable, whereas U-Ben was below the limit of quantification in 26.7% of the ES and 35.6% of the next BS samples, and U-MTBE in more than the 80.0% of the samples. At both the sampling times, SPMA and U-Ben showed a positive dependence on personal A-Ben, as well as on creatinine and U-Cot values. Discussion and conclusion: SPMA and U-Ben at the next BS were dependent on the exposure to low benzene concentrations suffered in the previous work shift, prompting a reconsideration of the urine sampling time recommended by the American Conference Governmental Industrial Hygienists (ACGIH).

Risk due to exposure to metallic elements in a birdshot factory

ABSTRACT The contribution of biological and environmental monitoring to the risk assessment of occupational exposure to lead (Pb), arsenic (As), and antimony (Sb) was studied in 18 workers at a birdshot factory (Exposed) and in 18 control workers (Controls) by the determination of both airborne Pb (PbA) and airborne As (AsA) only in the exposed workers and blood Pb (PbB), erythrocytic zinc protoporphyrin (ZPP), urinary Sb (SbU), and the urinary As species in exposed workers and controls. PbA (12–42 μg/m3) and AsA (1–4 μg/m3) were strongly correlated (r = .95). PbB, ZPP, and the sum of As3+As5+MMA were significantly higher in the exposed workers. As3 was higher than the limit of detection in 14 exposed workers and 1 control, As5 only in 1 exposed worker, SbU in all the exposed workers and in 4 controls. Monitoring for more metallic elements reveals a wider spectrum of exposures than can be achieved by lead surveillance alone and is preferable for characterizing occupational risk wherever possible.