The role of hepatitis B vaccine challenge dose in patients with underlying health conditions.

We have evaluated the immunological response to Hepatitis B virus (HBV) booster vaccine dose in 129 adults with underlying diseases in comparison with 694 subjects at occupational risk of infection, who have previously completed the primary series and resulted with anti-HBs <10 mIU/mL. After booster dose, 60.5% of the patients with underlying diseases and 14.8% of the subjects at occupational risk resulted seronegative. By comparing two groups, rate of subjects with anamnestic response was higher in at occupational risk group respect to that at risk for medical conditions (OR: 5.99 [95%IC, 3.81-9.41], p < .001). This difference was associated to gender (males/females: OR: 0.619 [95%IC, 0.421-0.910], p = .015) and age (better response for younger people, p = .011).

Utility of serological screening for measles, mumps and rubella in immunocompromised patients.

Marchi et al. in their article (Measles in pregnancy: a threat for Italian women? Hum Vaccin Immunother. 2019 Jun 20:1-3) observed that 96.9% of pregnant women were positive for anti-measles IgG (with a higher risk of contracting measles in those aged 19-29 years) emphasizing the importance of serological screening before pregnancy. We evaluated seroprotection/seropositivity rates to Measles, Mumps and Rubella in 324 adults with an acquired immune-deficiency needing an immunization program. We found that younger patients (20-29 years) had a seroprevalence below 85%. Overall, a relevant proportion (21.6%, 54/250) of patients was susceptible to at least one infection needing immunization. Our results confirm the usefulness of proper strategies for identifying individuals susceptible to vaccine-preventable infections and protecting them through vaccination.

[SENTIERI Project: rationale and objectives]. / Razionale e obiettivi del Progetto SENTIERI.

SENTIERI Project (Mortality study of residents in Italian polluted sites) studied mortality of residents in the sites of national interest for environmental remediation (Italian polluted sites--IPSs). IPSs are in proximity of either active or dismissed industrial areas, near dumping sites of industrial and hazardous waste or incinerators. SENTIERI Project described and evaluated the mortality of the populations residing in IPSs and it specifically focused on causes of death for which environmental exposure is suspected or ascertained to play an etiologic role. The epidemiological evidence of the causal association was classified a priori into one of these three categories: Sufficient (S), Limited (L) and Inadequate (I). The study results will allow the priorities setting in remediation intervention, so as to prevent adverse health effects from environmental exposure. At the time of 2001 Census, about 10%of Italian population resided in the 44 IPSs included in SENTIERI; the mortality analysis was carried out for the years 1995-2002 for 63 causes of death. The study results for the 44 IPSs are here commented and read on the basis the a priori evaluation of the epidemiological evidence in terms of strength of the causal association, and taking into account the limits of a geographic study design and its implied complexities. The procedures and results of the evidence evaluation have been presented in a 2010 Supplement of Epidemiology & Prevention devoted to SENTIERI.

[Global burden of mortality in Italian polluted sites]. / Valutazioni globali del carico di mortalità nei siti di interesse nazionale per le bonifiche.

SENTIERI Project has assessed the overall mortality profile in all the IPSs combined, and performed IPS-specific analyses. The epidemiological evidence of the causal association between cause of death and exposure was classified into one of these three categories: Sufficient (S), Limited (L) and Inadequate (I). The procedures and results of the evidence evaluation have been presented in a 2010 Supplement of Epidemiology & Prevention devoted to SENTIERI. Mortality for causes of death with a priori Sufficient or Limited evidence of association with the environmental exposure exceeds the expected figures, with a SMR of 115.8 for men (90%CI 114.4-117.2; 2 439 extra deaths) and 114.4 for women (90% CI 112.4-116.5; 1 069 extra deaths). These excesses are also observed when analysis is extended to all the causes of death (i.e. with no restriction to the ones with a priori Sufficient or Limited evidence): for a total of 403 692 deaths (men and women combined), an excess of 9 969 deaths is observed, with an average of around 1 200 extra deaths per year. Most of these excesses are observed in IPSs located in Southern and Central Italy. The distribution of the causes of deaths shows that the excesses are not evenly distributed: cancer mortality accounts for 30%of all deaths, but is 43.2%of the excess deaths (4 309 cases of 9 969). Conversely, the percentage of excesses in non cancer causes, 19%, is lower than their share of total mortality (42%). Consistently with previous studies, the results suggest that the health status of populations living in the IPSs is worse than what regional averages show. Compared to previous studies, the analysis of the causes selected in SENTIERI, on the basis of a priori Sufficient or Limited evidence of association with the environmental exposures, provides additional information on their role, though some limitations, due to methodology and data used, should be considered.

[SENTIERI Project: discussion and conclusions]. / Progetto SENTIERI: discussione e conclusioni.

SENTIERI Project is the first comprehensive study of the health impact of residence in Italian polluted sites (IPSs). The present Chapter examines the main validity aspects of the present mortality investigation and the evaluation of causality of the observed associations; in addition, some recommendations for public health intervention and research priorities in epidemiological studies on environment and health are given. Exposure ascertainment is a key aspect when an ecological study design is adopted in environmental epidemiology, therefore any exposure potentially affecting the population at study should be described in detail. This is here discussed. SENTIERI is an ecological study, based on a priori hypotheses, in which each IPS's types of exposure were described with specific attention to human exposure. Though, when commenting the results, the problem of concurrent air pollution exposure and/or industrial activities implying occupational risk, if present in the IPSs, was taken into account. Socioeconomic status is a determinant of health and disease, therefore in SENTIERI the Standardized Mortality Ratios were computed both crude and adjusted for an ad hoc deprivation index. About 60% versus an expected 40% of IPSs residents are in the two most deprived quintiles of the index. This hints to a possible problem of environmental justice that should be taken into account when planning remediation intervention. The mortality results here presented are a first step in the epidemiological IPSs' characterization, and some developments have been made or planned. Firstly, a mortality analysis was performed combining mortality data in IPSs presenting similar pollution, i.e. asbestos, or industrial hazardous wastes or dumping sites; secondly, the mortality analysis will be extended beyond 2002, namely the year when ICD X started to be in use in Italy. In addition, disease prevalence will be investigated using hospital discharge records; cancer incidence and congenital anomalies incidence will be studied in IPSs in which a Cancer Register or a Congenital Anomalies Register are active. The above described activities will lead to a more valid estimate of the disease burden of IPSs residents, and allow to identify priorities of remediation activities. The method adopted in SENTIERI, specifically the ecological design and the use of mortality data at municipal level, in general does not grant the evaluation of the causal association between environmental exposure and adverse health effects. However, it allows etiological observations that make unacceptable the delay of remediation intervention.

[Mortality results in SENTIERI Project]. / Risultati dell'analisi della mortalità nel Progetto SENTIERI.

SENTIERI Project (Mortality study of residents in Italian polluted sites) studies mortality of residents in 44 sites of national interest for environmental remediation (Italian polluted sites, IPS). The epidemiological evidence of the causal association between causes of death and exposures was a priori classified into one of these three categories: Sufficient (S), Limited (L) and Inadequate (I). In these sites various environmental exposures are present. Asbestos (or asbestiform fibres as in Biancavilla) has been the motivation for defining six sites as IPSs (Balangero, Emarese, Casale Monferrato, Broni, Bari-Fibronit, Biancavilla). In five of these, increases in malignant neoplasm or pleura mortality are detected; in four of them, results are consistent in both genders. In six other sites (Pitelli, Massa Carrara, Aree del Litorale Vesuviano, Tito, "Aree industriali della Val Basento", Priolo), where other sources of environmental pollution in addition to asbestos are reported, mortality from malignant neoplasm of pleura is increased in both genders in Pitelli, Massa Carrara, Priolo, "Litorale vesuviano". In the time span 1995-2002, a total of 416 extra cases of malignant neoplasm of pleura are detected in the twelve asbestos-polluted sites. Asbestos and pleural neoplasm represent an unique case. Unlike mesothelioma, most causes of death analyzed in SENTIERI have multifactorial etiology; furthermore, in most IPSs multiple sources of different pollutants are present, sometimes concurrently with air pollution from urban areas: in these cases, drawing conclusions on the association between environmental exposures and specific health outcomes might be complicated. Notwithstanding these difficulties, in a number of cases an etiological role could be attributed to some environmental exposures. The attribution could be possible on the basis of increases observed in both genders and in different age classes, and the exclusion of a major role of occupational exposures was thus allowed. For example, a role of emissions from refineries and petrochemical plants was hypothesized for the observed increases in mortality from lung cancer and respiratory diseases in Gela and Porto Torres; a role of emissions from metal industries was suggested to explain increased mortality from respiratory diseases in Taranto and in Sulcis-Iglesiente-Guspinese. An etiological role of air pollution in the raise in congenital anomalies and perinatal disorders was suggested in Falconara Marittima, Massa-Carrara, Milazzo and Porto Torres. A causal role of heavy metals, PAH's and halogenated compounds was suspected for mortality from renal failure in Massa Carrara, Piombino, Orbetello, "Basso bacino del fiume Chienti" and Sulcis-Iglesiente-Guspinese. In Trento-Nord, Grado and Marano, and "Basso bacino del fiume Chienti" increases in neurological diseases, for which an etiological role of lead, mercury and organohalogenated solvents is possible, were reported. The increase for non-Hodgkin lymphomas in Brescia was associated with the widespread PCB pollution. Mortality for causes of death with a priori Sufficient or Limited evidence of association with the environmental exposure exceeds the expected figures, with a SMR of 115.8% for men (90% IC 114.4-117.2; 2 439 extra deaths) and 114.4% for women (90% CI 112.4-116.5; 1 069 extra deaths). These excesses are also observed when analysis is extended to all the causes of death (i.e. with no restriction to the ones with a priori Sufficient or Limited evidence): for a total of 403 692 deaths (both men and women), an excess of 9 969 deaths is observed, with an average of about 1 200 extra deaths per year. Most of these excesses are observed in IPSs located in Southern and Central Italy. The procedures and results of the evidence evaluation are presented in a 2010 Supplement of Epidemiology & Prevention devoted to SENTIERI.

[Scientific collaboration between Istituto Superiore di Sanità and Italian Association of Cancer Registries for the study of cancer incidence in Italian polluted sites]. / Collaborazione scientifica ISS-AIRTUM per lo studio dell'incidenza dei tumori nei siti di interesse nazionale per le bonifiche.

The collaborative study between Istituto superiore di sanità and Associazione italiana registri tumori (ISS-AIRTUM) aims at investigating cancer incidence in polluted sites for adults and for children (0-14 years) and adolescents (15-19 years) to comment the study results in the light of a set of a priori hypotheses. On the whole, 141 out of 298 municipalities included in SENTIERI Project are served by a Cancer Register participating to the AIRTUM network. For a description of SENTIERI, refer to the 2010 Supplement of Epidemiology & Prevention devoted to SENTIERI Project. The time window of the study is the period 1996-2005. The number of expected cases in each polluted site will be estimated by applying incidence rates of the national pool of cancer registries and of the pool of the geographic macroarea in which each site is located: Northern, Central, Southern Italy and Islands. Cancer incidence in children and adolescents is one of the main priorities of international public health institutions, because of the need to protect childhood health from involuntary exposure to environmental risk factors. Standardized incidence ratios (SIRs) will be computed using expected figures derived from the national pool of cancer registries.

Determinants of mobile phone output power in a multinational study: implications for exposure assessment.

OBJECTIVES: The output power of a mobile phone is directly related to its radiofrequency (RF) electromagnetic field strength, and may theoretically vary substantially in different networks and phone use circumstances due to power control technologies. To improve indices of RF exposure for epidemiological studies, we assessed determinants of mobile phone output power in a multinational study. METHODS: More than 500 volunteers in 12 countries used Global System for Mobile communications software-modified phones (GSM SMPs) for approximately 1 month each. The SMPs recorded date, time, and duration of each call, and the frequency band and output power at fixed sampling intervals throughout each call. Questionnaires provided information on the typical circumstances of an individual's phone use. Linear regression models were used to analyse the influence of possible explanatory variables on the average output power and the percentage call time at maximum power for each call. RESULTS: Measurements of over 60,000 phone calls showed that the average output power was approximately 50% of the maximum, and that output power varied by a factor of up to 2 to 3 between study centres and network operators. Maximum power was used during a considerable proportion of call time (39% on average). Output power decreased with increasing call duration, but showed little variation in relation to reported frequency of use while in a moving vehicle or inside buildings. Higher output powers for rural compared with urban use of the SMP were observed principally in Sweden where the study covered very sparsely populated areas. CONCLUSIONS: Average power levels are substantially higher than the minimum levels theoretically achievable in GSM networks. Exposure indices could be improved by accounting for average power levels of different telecommunications systems. There appears to be little value in gathering information on circumstances of phone use other than use in very sparsely populated regions.

The role of CSA in the response to oxidative DNA damage in human cells.

Cockayne syndrome (CS) is a rare genetic disease characterized by severe growth, mental retardation and pronounced cachexia. CS is most frequently due to mutations in either of two genes, CSB and CSA. Evidence for a role of CSB protein in the repair of oxidative DNA damage has been provided recently. Here, we show that CSA is also involved in the response to oxidative stress. CS-A human primary fibroblasts and keratinocytes showed hypersensitivity to potassium bromate, a specific inducer of oxidative damage. This was associated with inefficient repair of oxidatively induced DNA lesions, namely 8-hydroxyguanine (8-OH-Gua) and (5'S)-8,5'-cyclo 2'-deoxyadenosine. Expression of the wild-type CSA in the CS-A cell line CS3BE significantly decreased the steady-state level of 8-OH-Gua and increased its repair rate following oxidant treatment. CS-A cell extracts showed normal 8-OH-Gua cleavage activity in an in vitro assay, whereas CS-B cell extracts were confirmed to be defective. Our data provide the first in vivo evidence that CSA protein contributes to prevent accumulation of various oxidized DNA bases and underline specific functions of CSB not shared with CSA. These findings support the hypothesis that defective repair of oxidative DNA damage is involved in the clinical features of CS patients.

Validation of short term recall of mobile phone use for the Interphone study.

AIM: To validate short term recall of mobile phone use within Interphone, an international collaborative case control study of tumours of the brain, acoustic nerve, and salivary glands related to mobile telephone use. METHODS: Mobile phone use of 672 volunteers in 11 countries was recorded by operators or through the use of software modified phones, and compared to use recalled six months later using the Interphone study questionnaire. Agreement between recalled and actual phone use was analysed using both categorical and continuous measures of number and duration of phone calls. RESULTS: Correlations between recalled and actual phone use were moderate to high (ranging from 0.5 to 0.8 across countries) and of the same order for number and duration of calls. The kappa statistic demonstrated fair to moderate agreement for both number and duration of calls (weighted kappa ranging from 0.20 to 0.60 across countries). On average, subjects underestimated the number of calls per month (geometric mean ratio of recalled to actual = 0.92, 95% CI 0.85 to 0.99), whereas duration of calls was overestimated (geometric mean ratio = 1.42, 95% CI 1.29 to 1.56). The ratio of recalled to actual use increased with level of use, showing underestimation in light users and overestimation in heavy users. There was substantial heterogeneity in this ratio between countries. Inter-individual variation was also large, and increased with level of use. CONCLUSIONS: Volunteer subjects recalled their recent phone use with moderate systematic error and substantial random error. This large random error can be expected to reduce the power of the Interphone study to detect an increase in risk of brain, acoustic nerve, and parotid gland tumours with increasing mobile phone use, if one exists.

Cancer risk associated with residential proximity to industrial sites: a review.

In this study, the authors sought to review available epidemiologic studies of cancer risk and its association with residence in a neighborhood characterized by industrial sites and to discuss options for future study design. The authors attempted to identify all case-control studies published from January 1980 through July 1997 in which investigators examined exposure resulting from residential proximity to an industrial site neighborhood relative to an increased risk of lung, urinary tract, and lymphohematopoietic malignancies. During these years, some authors reported significant associations between lung cancer risk and residential proximity to (a) smelters, (b) complex industrial areas, and (c) other localized emission sources. There was some evidence that leukemia and lymphomas occurred in the neighborhoods that contained industrial sites.

Risk factors for basal cell carcinoma in a Mediterranean population: role of recreational sun exposure early in life.

OBJECTIVE: To investigate the role of pigmentary traits, different patterns of sun exposure, artificial sources of UV radiation, and lifestyle-related factors on the risk of basal cell carcinoma (BCC) in a Mediterranean population from central-southern Italy. DESIGN: Hospital-based case-control study. SETTING: A referral dermatological hospital in Rome, Italy. PATIENTS: A convenience sample of 166 case patients with histologically confirmed BCC and 158 cancer-free control subjects with minor dermatological conditions observed between March 1995 and June 1997. RESULTS: In the multivariate analysis, the mean number of weeks per year spent at the beach before the age of 20 years was significantly associated with BCC. A dose-response trend was found for subjects who had spent 3 to 4 (odds ratio, 1.8; 95% confidence interval, 0.8-4.4), 5 to 8 (odds ratio, 3.7; 95% confidence interval, 1.5-9.0), or more than 8 (odds ratio, 4.5; 95% confidence interval, 1.9-10.5) weeks per year at the beach (P =.01 for trend). There was a significant association with the presence of actinic keratoses or solar lentigines, whereas no effect was found for skin type, history of sunburns, exposure to nonsolar UV radiation, and lifestyle-related habits such as cigarette smoking, alcohol consumption, and coffee drinking. Subjects reporting a family history of skin cancer had an extremely increased risk of BCC. CONCLUSION: The definite association with recreational sun exposure during childhood and adolescence and the strong relation with family history of skin cancer suggest that genetic predisposition and peculiar exposure patterns to UV radiation are key independent risk factors for the development of BCC in a southern European population.

Smoking habits in multiple system atrophy and progressive supranuclear palsy. European Study Group on Atypical Parkinsonisms.

OBJECTIVE: To evaluate smoking habits in patients with multiple system atrophy (MSA) and progressive supranuclear palsy (PSP) in a multicenter case-control study to determine whether these two forms of atypical parkinsonism share the inverse association with smoking previously found in PD. BACKGROUND: No epidemiologic studies have been performed on smoking habits in MSA. A previous investigation in PSP revealed no differences in smoking habits between patients and hospital control subjects. METHODS: Seventy-six MSA patients, 55 PSP patients, 140 PD patients, and 134 healthy control subjects were enrolled consecutively at seven neurologic clinics from January 1, 1994, to July 31, 1998. Detailed information on smoking habits was obtained using a structured questionnaire. RESULTS: The comparison between frequencies of never-smokers versus ever-smokers (ex-smokers/current smokers; adjusted odds ratio [ORadj], 0.56; 95% CI, 0.29 to 1.06) and a dose-response analysis for never-smokers, moderate smokers (ORadj, 0.64; 95% CI, 0.31 to 1.32), and heavy smokers (ORadj, 0.47; 95% CI, 0.21 to 1.05) suggest that MSA patients smoke less than population control subjects. By contrast, the comparison of frequencies of never-smokers versus ever-smokers (ORadj, 0.91; 95% CI, 0.42 to 1.98) and a dose-response analysis for never-smokers, moderate smokers (ORadj, 0.68; 95% CI, 0.27 to 1.69), and heavy smokers (ORadj, 1.24; CI 95%, 0.51 to 3.06) revealed no differences in smoking habits between PSP patients and population control subjects. CONCLUSIONS: The fact that the inverse association with smoking found previously in PD is shared by multiple system atrophy but not by progressive supranuclear palsy lends epidemiologic support to the notion that different smoking habits are associated with different groups of neurodegenerative disease.

Factors that influence the DNA repair capacity of normal and skin cancer-affected individuals.

DNA repair capacity (DRC) was studied in 49 patients affected by basal cell carcinoma (BCC) and 68 cancer-free controls belonging to a larger case-control population enrolled for studying BCC risk factors. DRC was measured in the subjects' peripheral blood lymphocytes by using a host-cell reactivation assay that measures cellular activation of a reporter gene irradiated with UV light. A statistically significant age-related decline in DRC was observed in the controls from 20 to 70 years of age but not in the BCC cases. When the DRC values of the BCC patients and controls were compared by age, young BCC cases (age, < or =40 year) repaired less than the controls, although the difference was not statistically significant. Conversely, older BCC patients (age, >40 years) presented an enhanced repair capacity (P < 0.001) as compared with their controls. The search for possible factors associated with the high repair rate of elderly BCC cases revealed that both target cell physiology and life-style habits may affect host DNA repair. Smoking was the variable that explained most of the increase in DRC among older patients. The understanding of how these factors affect host DRC will be relevant for a correct use of this biomarker.

Asbestos-related lung cancer mortality in Piedmont, Italy.

This study investigates the association between pleural neoplasm mortality, a possible proxy for asbestos exposure, and lung cancer mortality among males resident in Piedmont (northwestern Italy). Pleural neoplasm mortality was estimated in the 1,209 municipalities of the region for the period 1980-1992, applying Bayesian methods. The association with lung cancer mortality for municipalities was studied using Poisson regression. Urban/rural indicators and altitude were also included in the analysis. A positive, statistically significant association was found between pleural neoplasm and lung cancer mortality (beta = 0.025, P < 0.001); lung cancer risk was associated also with urban status (vs. rural, beta = 0.223, P < 0.001) and altitude (P = 0.01). The proportion of lung cancer deaths attributable to living in municipalities with increased pleural neoplasm mortality was 3.9% (95% confidence interval, 2.1-5.7%). The observed association and the presence of a dose-response relationship at the municipality level underscore the dangers of asbestos for human health.

Methodological issues in biomonitoring of low level exposure to benzene.

Data from a pilot study on unmetabolized benzene and trans,trans muconic acid (t,t-MA) excretion in filling station attendants and unexposed controls were used to afford methodological issues in the biomonitoring of low benzene exposures (around 0.1 ppm). Urinary concentrations of benzene and t,t-MA were measured by dynamic head-space capillary GC/FID and HPLC, respectively. The accuracy of the HPLC determination of t,t-MA was assessed in terms of inter- and intra-method reliability. The adequacy of urinary t,t-MA and benzene as biological markers of low benzene exposure was evaluated by analysing the relationship between personal exposure to benzene and biomarker excretion. Filling station attendants excreted significantly higher amounts of benzene, but not of t,t-MA, than controls. Adjusting for occupational benzene exposure, smokers excreted significantly higher amounts of t,t-MA, but not of unmetabolized benzene, than nonsmokers. A comparative analysis of the present and previously published biomonitoring surveys showed a good inter-study agreement regarding the amount of t,t-MA and unmetabolized benzene excreted (about 0.1-0.2 mg/l and 1-2 micrograms/l, respectively) per unit of exposure (0.1 ppm). For each biomarker, based on the distribution of parameters observed in the pilot study, we calculated the minimum sample size required to estimate the population mean with given confidence and precision.

Bladder cancer: a selected review of the epidemiological literature.

The present contribution reviews the epidemiological literature on the risk factors for bladder cancer in humans, pointing to the new leads from the available knowledge and to suggestions on prevention and research needs. Smoking accounts for about 50% of bladder cancer cases in western countries, occupational exposures are second in importance in bladder cancer development. Exposure to aromatic amines in dyestuff manufacture, in the rubber and textile industry, occupations entailing exposure to paints and solvents, leather dust, inks, some metals, PAH, combustion products and diesel exhausts have been identified as risk factors from epidemiological studies. Other investigations have detected increased risk for bladder cancer in association with dietary factors, specifically fats and cholesterol, and with contamination of drinking water by chlorination by-products.

Genetic effects of petroleum fuels: cytogenetic monitoring of gasoline station attendants.

Workers in the petroleum distribution trades experience relatively high-level exposures to fuel vapours whose consequences have not been fully elucidated. In this study, the possible relationship between occupational exposure to petroleum fuels and cytogenetic damages in peripheral lymphocytes was investigated. Twenty-three male, non-smoking workers from the area of Rome were enrolled in the study, together with age-paired controls with no occupational exposure to fuels. Peripheral lymphocyte cultures were set up for the analysis of structural chromosome aberrations (CAs), sister chromatid exchanges (SCEs) and micronuclei (MN) in cytokinesis-blocked lymphocytes. Frequencies of CAs, SCEs and MN were compared between exposed and control groups, and evaluated in relation to blood lead level (as an indicator of engine exhausts exposure) for the whole group under study, and to yearly averaged exposure to benzene (8-h time weighted averages, as determined by repeated personal sampling) for fillingstation attendants only. Both CAs and SCEs were slightly increased in station attendants: 1.97 versus 1.46 aberrations per 100 cells, and 4.73 +/- 0.15 versus 4.48 +/- 0.11 SCEs/cell in exposed and control individuals, respectively. The difference between cumulative CA rates in the exposed and control populations was of borderline statistical significance (p = 0.066). However, when the exposed population was dichotomized for benzene exposure, a significant (p = 0.018) correlation of CAs with benzene exposure was found. The analysis of SCE data highlighted a significant increase of cells with more than 6 exchanges (HFCs), corresponding to the 75 degrees percentile of the overall distribution, in fillingstation attendants (relative risk (RR) = 1.3, 95% CI = 1.1-1.5) in comparison with controls. In the pooled population, the frequency of HFCs showed a statistically significant upward trend at increasing blood lead levels (chi 2 for trend = 27.8, p < 0.0001). A complex relationship between SCEs and benzene exposure was observed, with an increased frequency of HFCs in the medium exposure intensity class (RR = 1.5, 95% CI = 1.2-1.7), and no difference for exposure to higher benzene levels (RR = 1.0, 95% CI = 0.9-1.2), compared to reference subjects. Finally, the analysis of MN in both phytohemagglutinin- and pokeweed-stimulated cell cultures did not show significant excess of MN in binucleated lymphocytes of exposed workers with respect to the age-paired controls.

[Exposure to benzene and genotoxic effects among filling station attendants]. / Esposizione a benzene ed effetti genotossici tra gli addetti all'erogazione di carburanti.

Exposure to gasoline vapors is classified by the International Agency for Research on Cancer as possibly carcinogenic to humans, mainly on the basis of the established carcinogenicity of some component chemicals such as benzene. The mechanism of benzene toxicity, particularly its leukemogenic effects, is far from being fully understood. Different studies, aimed at evaluating the risk associated with exposure to benzene through fuels and coordinated by the Istituto Superiore di Sanità, are in progress in Italy. In an environmental monitoring survey on a sample of 111 service stations, conducted in Rome (Italy) in 1992, average yearly personal exposure to benzene, toluene and xylenes were estimated. Chemical determination of benzene and methylbenzene was carried out by GL-gas chromatography. From a sample of 27 service stations 34 fuel samples were collected, and their benzene content was measured by hr-gas chromatography. Subgroups of the filling station attendants undergoing the exposure assessment study, were included in biological monitoring surveys of early indicators of genotoxicity. In particular, 65 subjects were enrolled in a study aimed at evaluating the urinary concentrations of 8-hydroxydeoxyguanosine (8-OHdG), a biological marker of oxidative DNA damage, and 23 filling station attendants were selected for a survey of the frequencies of sister chromatid exchanges (SCE) and micronuclei (MN) in peripheral T lymphocytes. In the exposure assessment survey levels of 0.53, 0.71 e 0.32 mg/m3 in the average yearly personal exposure to benzene, toluene and xylenes, respectively, were estimated (individual means based on 6.5 repeated samples per employee). The daily quantities of super premium gasoline sold proved to be associated with the average yearly personal exposure to benzene, and current smokers showed a significantly lower exposure intensity compared with non-smokers. Among the latter, an increase of 0.11 ln mg/m3 in benzene exposure per unit increase (100 l) in gasoline sold (p < 0.001) was estimated by a multiple regression analysis with some personal characteristics of the subjects included in the model as potentially predictive variables (R2 = 0.17, p (F) < 0.05). Among smokers, however, only the age and the length of employment were able to predict the intensity of benzene exposure. On a sample of 27 filling station attendants, furthermore, the relationship between personal exposure to benzene and benzene fuel content was evaluated and an increase of 0.01 mg/m3 in the personal benzene exposure per unit increase (100 g) in the absolute quantity of benzene in the fuel sold was estimated (p < 0.0001, R2 = 0.50).(ABSTRACT TRUNCATED AT 400 WORDS)

Exposure to benzene and urinary concentrations of 8-hydroxydeoxyguanosine, a biological marker of oxidative damage to DNA.

OBJECTIVES: Benzene is an established animal and human carcinogen. The mechanism of benzene toxicity, particularly its leukaemogenic effect, is not fully understood. The modified base 8-hydroxy-deoxyguanosine (8-OHdG) is a sensitive marker of the DNA damage due to hydroxyl radical attack at the C8 of guanine. This damage, if left unrepaired, has been proposed to contribute to mutagenicity and cancer promotion. We conducted this biomonitoring study with the aim of evaluating the association between excretion of 8-OHdG and level of exposure to benzene and other aromatic compounds among occupationally exposed people. METHODS: A random sample of 65 filling station attendants from Rome, Italy was studied for personal exposure to benzene, toluene, and xylenes, and excretion of 8-OHdG. Information about age, length of employment, smoking habits, and diagnostic exposure to x rays was collected by questionnaire. An average yearly level of exposure to benzene and methylbenzenes was calculated for each filling station attendant on the basis of about seven repeated personal samples collected during one year. A spot sample of 20 ml of urine was collected from each worker. Concentrations of 8-OHdG were determined by high performance liquid chromatography (HPLC) with coupled columns. RESULTS: A mean (SD) concentration of 1.36 (0.49) mumol of 8-OHdG/mol of creatinine was measured. A significant correlation was found between urinary 8-OHdG and exposure to benzene (r = 0.34). In a multiple regression analysis relating the concentration of urinary 8-OHdG with the age, length of employment, smoking, diagnostic exposure to x rays and personal exposure to benzene, an increase of 0.15 mumol/mol creatinine in urinary 8-OHdG/unit increase in the natural logarithm of the average yearly benzene concentration was estimated. CONCLUSION: This study shows a dose-response effect between personal exposure to benzene and urinary 8-OHdG concentration; further studies are needed to clarify the biological significance of 8-OHdG as a marker of cancer risk.