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E Clonfero

Publications and source records attributed to E Clonfero.

68 records · Page 4Linked to original sources

[Dosimetry of DNA and protein adducts in occupational health].

Genotoxic carcinogenic compounds react chemically with DNA and proteins to form covalent adducts which, in the case of DNA adducts, are strongly believed to be the first step in cancer process (biologically effective dose). The paper reviews the main studies on the dosimetry of adducts in the biological monitoring of occupational exposure to mutagens and carcinogens. Dosimetry of DNA adducts has been used to assess exposure to polycyclic aromatic hydrocarbons in environments such as foundries, coke ovens and the aluminium industry. In many cases, adduct levels higher than those of control populations were found in exposed workers. Only one study reported increased levels of DNA adducts in workers exposed to styrene. Dosimetry of hemoglobin adducts has been used to identify occupational exposure to ethylene oxide, styrene, BaP and arylamines. The results obtained in the last few years confirm the usefulness of dosimetry of DNA and protein adducts in assessing occupational exposure to genotoxic carcinogens occurring in working environments, even at very low exposure levels, but the methods in question require high standardization and validation if systematic errors in measurement are to be avoided. In the coming years, dosimetry of adducts, together with evaluation of individual genetic sensitivity to mutagens and carcinogens, will be one of the new frontiers in research on the prevention of occupational cancer. Current research already makes use of sophisticated analytical techniques such as mass spectrometry, and both specificity and sensitivity in the determination of adducts have been considerably improved. In the future, therefore, dosimetry of adducts may also be applied to industrial health practices.

Air Pollutants, Occupational↗

[Reference values in biological monitoring of occupational exposure to mutagens and carcinogens].

This work reports values of biological markers indicating mutagenic/carcinogenic risk in professionally non-exposed populations. The main confounding factors for most of these biomarkers are tobacco smoke, diet and air pollution. With the sole exception of compounds specifically present in work environments, in which determination in biological fluids of unchanged substances or their metabolites has high sensitivity and specificity (e.g., some aromatic amines), other biomarkers (urinary mutagenicity, DNA adducts and cytogenetic analyses), in order to be used properly as reference values, require ad hoc study of suitable control groups paired for the main confounding factors. Analytical determination of some protein adducts appears to be promising, due to its sensitivity and specificity.

Air Pollutants↗

[Criteria and methods for the study of occupational exposure to antineoplastic agents].

Risk assessment for occupational exposure to antiblastic chemotherapeutic drugs (ACD) is carried out by means of environmental and biological monitoring. These practices are not widespread and furthermore their results are frequently difficult to interpret. This paper discusses some of the most important aspects of risk assessment for ACD and in particular for their exposure evaluation. The following guidelines are proposed: a) working rooms, working procedures, type and quantity of drugs, and preventive measures must be checked using a standardized scheme for collecting data: an example of a check list experimented in some Italian hospitals is presented; b) cyclophosphamide, 5-fluorouracil, and Pt coordination compounds have been identified as tracers of drug mixtures usually administered, and their determination is recommended both in environmental and biological samples; c) for a correct evaluation of exposure, ACD should be determined firstly on the contaminated surfaces or on work clothes and secondly in urine of workers; the measurement of ACD in air must be limited to well documented conditions of high exposure and the urinary mutagenicity tests should be avoided; d) the biological monitoring practices should be enhanced, in particular the determination of ACD adducts to proteins and nucleic acids as promising indicators of effective dose.

Antineoplastic Agents↗

[Urban air pollutant exposure among traffic policemen].

Exposure to dusts and benzene was studied in 65 traffic policemen. Samples of total dusts showed that mean personal exposure was 0.44 (SD = 0.30) mg/m3, with peaks of about 2 mg/m3. Exposure to 1-nitropyrene (1-NP), the main compound occurring in emissions from diesel engines, which was estimated from concentrations in dusts collected with high-flow samplers, was 0.28 (SD = 0.19) ng/m3 (range: 0.06-1.24 ng/m3). The mean concentration of benzene in the breathing zone was 41 (SD = 20) micrograms/m3, although a level of 100 micrograms/m3 was slightly exceeded in one subject. In urine samples collected before and after workshifts, two biological indicators of exposure to benzene were measured, urinary benzene and urinary trans, trans-muconic acid (MA). The mean values of urinary benzene before and after workshift were similar (98, SD = 81 and 83, SD = 55 ng/l; n = 63; Wilcoxon's T-test = not significant), while a moderate increase in the metabolite was observed (MA = 0.08, SD = 0.11; 0.11, SD = 0.09 mg/g creatinine, in pre- and post-shift samples respectively; Wilcoxon's T-test, z = 3.00; p < 0.01). The levels of exposure to dusts and 1-NP deriving from diesel engine emissions were comparable to those of other occupational groups with this type of risk (garage mechanics, workers operating diesel engine machinery, etc.). Traffic police exposure to benzene was similar to that of the whole population of Padova (40 micrograms/m3, mean annual 24-hour value). However, the values of urinary MA, like those reported by other authors for non-smoker controls, increased after the workshift, indicating low occupational exposure to this pollutant. It should be noted that traffic police exposure to benzene is much lower than that of other occupational categories, e.g., fuel pump distributors.

Air Pollutants↗

[Genotoxicity of urban air particulate matter].

This paper reviews the genetic toxicology of urban air particulate. Dusts present in the urban environment are composed of a special type of soot, currently mainly emitted by motor vehicles. This soot contains variable quantities of adsorbed highly active genotoxic compounds (polycyclic aromatic hydrocarbons and their nitro derivatives, i.e., nitroarenes). Nitroarenes are among the compounds with the highest genotoxic activity according to the Ames test (genetic point mutation on bacteria), and are particularly abundant in ultrafine particulate matter (< 1.1 microns) emitted by diesel engines, mainly trucks. Diesel emissions have been considered as probable carcinogenic agents for man by the International Agency for Research on Cancer (IARC). Highly mutagenic activity is present in the air of all the cities in the world, and there is increasing concern about possible carcinogenic effects on the general population as a result of exposure to urban particulate matter. Early epidemiological studies on city-dwellers exposed to heavy pollution indicate an excess of lung tumours. Lastly, there is a possible carcinogenic risk for occupationally exposed workers, such as traffic police and those working for city road cleaning services, etc., who are constantly obliged by their jobs to be exposed to polluted city air at work.

Air Pollutants↗

[The toxicology and prevention of the risks of occupational exposure to aromatic polycyclic hydrocarbons. I. Guide lines for the prevention of the risks of occupational exposure to aromatic polycyclic hydrocarbons. Società Italiana Valori di Riferimento and Cattedra di Medicina del Lavoro, Università di Brescia].

These guidelines mainly deal with prevention of carcinogenic effects following occupational exposure to polycyclic aromatic hydrocarbons (PAH). After some toxicological remarks, the guidelines define a possible method to demonstrate and evaluate occupational exposure to PAH. In particular, it is illustrated the strategy of environmental monitoring and indicated which PAH should be measured, with suggestion about the most appropriate analytical techniques. As regards biological monitoring, the 1-OH-pyreneseems to be currently the most useful indicator since it reflects the recent and global exposure to PAH. The guidelines also give elements to interpret monitoring data, taking into account environmental and biological reference and limit values suggested by some authors, Associations, or current regulations. The most important health effects are carcinogenic and excess risks have been described mainly for lung, bladder and skin cancer in some PAH exposed workers. The studies on cytogenetic effects showed contradictory results. On the basis of such information and current regulations, the guidelines show how to perform health surveillance in preventive and periodical examinations and how to proceed for the information and formation of exposed workers. It is not advisable, on the basis of the current scientific data, to screen asymptomatic PAH exposed workers for early diagnosis of lung or bladder cancer, nor it is opportune the use of tumor markers for health surveillance nor is genetic screening applicable for individual susceptibility evaluation outside research programs.

Carcinogens↗

[The toxicology and prevention of the risks of occupational exposure to aromatic polycyclic hydrocarbons. II. Toxicology. Exposure assessment. Environmental and biological monitoring].

The evaluation of exposure to polycyclic aromatic hydrocarbons (PAH) should firstly comply with current regulations (D.Lgs. 626/94), that is, identify the compounds and exposed subjects, quantify exposure, adopt preventive measures and health and epidemiological surveillance. Environmental monitoring should take into account the technological cycle and the tasks with higher PAH exposure risk, and the main sources of emissions. In the case of skin contamination, it should be considered the measure of skin PAH by means of sampling or removal techniques; moreover, the determination of urinary hydroxypyrene (1-HP) should be performed. It is mandatory to analyse (Benz[a]) anthracene; Benzo[b]fluroanthene; Benzo[j]fluoranthene; Benzo[k]fluoranthene; Benzo[a]pyrene; Dibenzo[a,h]anthracene, i.e. the PAH marked with the R45-R49 phrase. When 1-HP determination is planned, Pyrene should be added. Biological monitoring has been addressed mainly to hydroxylated metabolites of pyrene and among these 1-HP, the main metabolite of pyrene, although non occupational factors, such as tobacco smoking and consumption of smoked foods are potentially confounding. Urinary mutagenicity tests which are heavily influenced by non occupational factors such as tobacco smoking and diet are not advisable. The determination of DNA and protein adducts is a promising test for evaluation of metabolic active dose but at the moment it is not suitable for routine use in occupational medicine. In order to interpret environmental and biological data, it will be useful to consider appropriate reference values ("limit" "guide", "operative", "maximum admissible") such as 0.1 mg/m3 for total PAH extracted with benzene, 5 micrograms/m3 for the mixture of 15 PAH listed by US NTP, the limits varying from 0.1 to 5 micrograms/m3 for Benzo[a]pyrene, and 2.7-4.4 micrograms/g creat, for 1-HP.

Carcinogens↗