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.

Optimising beached litter monitoring protocols through aerial imagery.

The monitoring of beached litter along the coast is an onerous obligation enshrined within a number of legislative frameworks (e.g. the MSFD) and which requires substantial human resources in the field. Through this study, we have optimised the protocol for the monitoring of the same litter along coastal stretches within an MPA in the Maltese Islands through aerial drones, with the aim of generating density maps for the beached litter, of assisting in the identification of the same litter and of mainstreaming this type of methodology within national and regional monitoring programmes for marine litter. Concurrent and concomitant in situ monitoring of beached litter enabled us to ground truth the aerial imagery results. Results were finally discussed within the context of current and future MSFD monitoring obligations, with considerations made on possible future policy implications.

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.

Synthesis and antimicrobial activity of pyranobenzoquinones related to the pyranonaphthoquinone antibiotics.

The synthesis and antimicrobial activity of isochromane-type analogs of the pyranonaphthoquinone antibiotics are reported. Isochromane derivatives with (17a, b) and without (22a, b) a C-4 hydroxyl moiety and their corresponding quinones (19a and 23), were prepared. Both quinones exhibited antimicrobial activity against Staphylococcus aureus, Bacillus atrophaeus and Streptococcus agalactiae, while the related isochromanes were inactive. The results suggest that the quinone moiety is important for biological activity while the C-4 hydroxyl may not be essential.

Exposure assessment in a historical cohort of filling station attendants.

A historical cohort of service station attendants is underway. It is aimed at evaluating possible excess cancer risk in relation to exposure intensity. In this paper we discuss the feasibility of a retrospective exposure assessment by evaluating the association between indicators of workload and the exposure intensity to some aromatic hydrocarbons measured in a sample of current employees. Available for the analysis were 703 personal samples from 111 filling station workers. Measured concentrations of benzene, toluene and xylenes (8-hour time weighted averages) averaged 0.55 mg/m3, 0.71 mg/m3 and 0.32 mg/m3, respectively. The number of vehicles filled, the daily sales of super premium gasoline and motorbike fuel, and the winter season were all significant predictors of the log concentration of benzene in simple regression analyses. The size of the station acted as an effect modifier. While no single variable was able to predict the benzene level in large stations, for small stations an increase of 0.0579 and of 0.0418 in the log benzene concentration per unit increase in super premium gasoline (100 I) and in motorbike fuel (10 I) dispensed, was estimated. The overall variance explained by the multivariate model, however, was only 12.3%. Therefore, a clear categorization of groups with homogeneous and significantly different exposure levels is not achievable. From the point of view of exposure assessment, workers in small stations with higher sales of super premium gasoline tend to have higher exposure levels. This group should be examined in detail when the final results of the cohort study are available.

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.

Mortality of filling station attendants.

OBJECTIVES: Gasoline contains established human carcinogens, such as benzene. The health impact of exposure to this fuel, however, has not been fully elucidated. We report on the mortality of a cohort of 2665 filling station managers from the Latium region (Italy). METHODS: This is the first workplace-based cohort of gas station attendants. However, only self-employed individuals were available for study (about 50% of the whole work force). The follow-up period extended from 1981 through 1992. The mortality experience of the cohort was compared with that of the regional population. RESULTS: The overall analysis for standardized mortality ratios (SMR) showed a significantly decreased mortality from all causes, mainly due to a deficit of cardiovascular diseases and malignant neoplasms. Nonsignificantly increased risks for esophageal cancer [SMR 241, 90% confidence interval (90% CI) 82-551], brain cancer (SMR 195, 90% CI 77-401) and non-Hodgkin's lymphoma (SMR 173, 90% CI 47-448) were found for the men; mortality due to lung cancer and leukemia was lower than expected, and no kidney cancer death was recorded. Among the attendants of small stations (characterized by a small number of employees and high sales of gasoline per full-time employee), the SMR values for esophageal cancer (for men SMR 351, 90% CI 120-803) and brain cancer (for men and women SMR 266, 90% CI 105-559) showed increased values. CONCLUSIONS: Filling station attendants are exposed to gasoline vapors and seem at risk of cancer of various sites. Due to the power limitations of this study, however, a precise estimate of the risk for many causes of death was not achievable. Further cohort studies of greater size are warranted.

Rome women's screening study: knowledge, attitudes and practices of women regarding screening for breast and cervical cancer.

A survey on knowledge, attitudes, and practice regarding breast and cervical cancer screening was conducted in Rome on a sample of women aged 18-64 years. Of the 793 interviewees, 31.9% had undergone at least one breast imaging examination; examinations were more frequent in women over 35 and in those familiar with breast self-examination and female pathophysiology. Seventy percent of the women had had at least one Pap smear. Women were classified as Pap smear underusers (26.0%), appropriate users (28.8%), and overusers (45.2%) as compared to standard screening recommendations, according to their age and their lifetime number of smears. Age over 35 was associated with both underuse and overuse. Such inappropriate screening patterns could be related in part to the fact that the women reported that their physicians recommendations for Pap smear frequency were once a year or more in 62%, and once every two or three years in only 2%.

Cancer incidence and mortality among flight personnel: a meta-analysis.

BACKGROUND: Increased cancer risk among flight personnel have previously been noted, including breast cancer among flight attendants and acute myeloid leukemia among pilots. HYPOTHESIS: Exposure to cosmic radiation and other physical or chemical agents may pose health risks for flight personnel. METHODS: We performed an exhaustive search for published and unpublished cohort studies of flight personnel from 1986-98. We combined relative risks (RR) for selected causes from four mortality and/or incidence studies of pilots and two incidence studies of flight attendants, using standard meta-analytic methods. Heterogeneity among the combined studies was explored and adjustments were made for possible confounding by socioeconomic status (SES), where indicated, using correction factors from published studies. RESULTS: SES-adjusted combined RRs were elevated (>1.2) among male pilots for mortality from melanoma 11.97 (95%, CI: 1.02-3.82)] and brain cancer [1.49 (0.89-2.20)], and for cancer incidence of the prostate [1.65 (1.19-2.29)] and the brain [1.74 (0.87-3.30)]. Among female flight attendants, increases were seen for incidence of all cancers [1.29 (0.98-1.70)], melanoma [11.54 (0.83-2.87)], and breast cancer [1.35 (1.00-1.83)]. CONCLUSIONS: Flight personnel appear to be at increased risk for several types of cancer. Both occupational exposures and well-established non-occupational risk factors may contribute to this increased risk. To better control for confounding factors and to identify exposures potentially amenable to preventive measures, future studies should compare risks within cohorts by flight routes, work history, and exposure to cosmic and UV radiation, electromagnetic fields, and chemical substances.

[Infantile leukemia and exposure to 50/60 Hz magnetic fields: review of epidemiologic evidence in 2000]. / Leucemia infantile ed esposizione a campi magnetici a 50/60 Hz: una rassegna delle evidenze epidemiologiche al 2000.

We review the epidemiological evidence on childhood leukemia and residential exposure to 50/60 Hz magnetic fields. The possibility of carcinogenic effects of power frequency magnetic fields (ELF-EMF), at levels below units of micro tesla (microT), was first raised in 1979 by a case-control study on childhood cancer carried out in Denver, USA. In that study, excess risks of total cancer and leukemia were observed among children living in homes with "high or very high current configuration", as categorised on the basis of proximity to electric lines and transformers. Many other epidemiological studies have been published since then, characterised by improved--although still not optimal--methods of exposure assessment. At the end of 2000, the epidemiological evidence to support the association between exposure to extremely-low-frequency magnetic fields and the risk of childhood leukemia is less consistent than what was observed in the mid 90s. At the same time, a growing body of experimental evidence has accumulated against both a direct and a promoting carcinogenic effect of ELF-EMF. Such "negative" experimental evidence hampers a causal interpretation of the "positive" epidemiological studies.

[Air pollution from traffic and the risk of tumors]. / Inquinamento atmosferico da traffico e rischio di tumori.

This paper describes the epidemiological evidence on lung cancer and childhood leukemia in relation to traffic-related air pollution, with particular reference to diesel exhausts, polycyclic aromatic hydrocarbons (PAH) and benzene. Recent epidemiological studies strengthen the hypothesis of an increased lung cancer risk related to residential exposure to air pollution and to occupational exposure to diesel exhausts. The evidence on the carcinogenicity of several PAH mixtures comes from occupational studies, while the risk incurred by the general population is difficult to estimate. A few papers suggest that traffic-related air pollution may be associated with an increased risk of childhood leukemia. The observed relative risks are small but the exposure is widespread. Therefore, the overall impact of exposure to current levels of urban air pollution may be substantial.

[Surveillance systems in occupational environmental health: documentation notes]. / I sistemi di sorveglianza della patologia da ambiente di lavoro: note di documentazione.

The surveillance of occupationally related disease is a research topic in many countries. A working group on the information system within the Italian Association for Occupational Health has recently proposed to reorganize the national surveillance system. In Epidemiologia e Prevenzione a series of contributions relevant to this issue will be published. This paper reviews the on-going research in our country and abroad (United States, United Kingdom, Scandinavian Countries and Canada).

[Open questions in the interpretation of daily time-series studies on air pollution and health. Part I: estimate of exposure]. / Problemi interpretativi delle analisi di serie temporali su inquinamento atmosferico e salute. Parte I: le stime di esposizione.

This paper is a commentary to the MISA study (Meta-analysis of the Italian studies on short-term effects of air pollution). The interpretation of the relationships observed in the time-series analyses is not straightforward. I will review a number of open questions: the exposure estimates; the meaning of the daily mortality and hospitalisation rates, in terms of impact on life expectancy, incidence of specific diseases, exacerbation of pre-existing chronic diseases; the pattern of the estimated dose-response curves; the role of possible effect modifiers; the hypotheses about the underlying mechanisms. These interpretative problems often present overlapping aspects. Some of the pending answers are relevant for policy making. For editorial reasons this review is divided into two parts. This first paper focuses on the exposure estimates. The second part, to be published in the next issue of this journal, will deal with the meaning of the outcome variable, the shape of the dose-response curves, possible effect modifiers and underlying mechanisms.

[Interpretation problems in the analysis of temporal series of air pollution and health. Part II: significance of outcome variables, relations forms, effect modifiers, and mechanisms of action]. / Problemi interpretativi delle analisi di serie temporali su inquinamento atmosferico e salute. Parte II: Significato delle variabili di outcome, forma delle relazioni, modificatori d'effetto e meccanismi d'azione.

This paper is a commentary to the MISA study (Meta-analysis of Italian studies on short-term effects of air pollution). The interpretation of the relationships observed in the time-series analyses is not straightforward. I will review a number of open questions: the exposure estimates; the meaning of the daily mortality and hospitalisation rates, in terms of impact on life expectancy, incidence of specific diseases, exacerbation of preexisting chronic diseases; the pattern of the estimated dose-response curves; the role of possible effect modifiers; the hypotheses about the underlying mechanisms. These interpretative problems often present overlapping aspects. Some of the pending answers are relevant for policy making. For editorial reasons this review is divided in two parts. A first paper, focusing on the exposure estimates, has been published on the previous issue of this journal. This second part deals with the meaning of the outcome variable, the shape of the dose-response curves, possible effect modifiers and underlying mechanisms.

[Carcinogenic risk of automobile exhaust: a review]. / Rassegna sul rischio cancerogeno negli esposti a gas di scarico di veicoli a motore.

The increasing number of motor vehicles is associated with diffuse exposure to their exhausts, formed by mixtures of hundreds of chemical compounds. Some of these compounds cause chronic irritation of the respiratory mucosa, while others are carcinogenic in experimental animals, particularly polycyclic aromatic hydrocarbons and nitroarenes. This review aims to describe epidemiologic evidences of carcinogenicity of engine exhausts. The study of the effects in humans of the exposure at issue is impaired by several difficulties: widespread exposure of a large part of the population, with low levels of exposure; aspecific effects, shared with other exposures; concurrent exposures acting on the same targets, particularly the respiratory mucosa (smoking, occupational exposures); difficulties in the quantitation of exposure to exhaust. We review the epidemiologic studies concerning occupational exposures published up to June, 1988. Overall, excess risks for lung and bladder cancers and for hematolymphopoietic malignancies have been reported, particularly in people exposed to diesel exhaust. Excesses are modest, and their interpretation is often impaired by lacking or inadequate consideration of the effects of potential confounders. The review considers, for each study, enrollment procedures, information on exposure, and inclusion of potential confounders. In addition, aspects concerning internal coherence, such as a dose-response relationship, are considered. Particularly relevant are two studies on USA railroad workers, showing a relative risk of 1.4 among those exposed to diesel exhaust. The authors used, in the estimation of exposure, actual measurement of dose in recent years for some jobs and workplaces. Levels of exposure to respirable dusts were around 82-330 micrograms/m3, after allowing for cigarette smoking. According to the International Agency for Research on Cancer, these is limited evidence of carcinogenicity in humans of diesel exhaust, and inadequate evidence for gasoline exhaust.

[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)

[Synthesis of the epidemiological evidence concerning childhood leukemia in relation to exposure to 50 Hz. electric and magnetic fields]. / Sintesi delle evidenze epidemiologiche sulla leucemia infantile in relazione all'esposizione a campi elettrici e magnetici a 50 Hz.

A review of epidemiologic evidence concerning the association between childhood leukaemia and exposure to 50 Hz electric and magnetic fields is presented, with special reference to fourteen studies published between 1979 and 1997 that utilised different systems of exposure assessment. While spot measurements of indoor magnetic fields were not associated with childhood leukaemia, combined relative risks from studies using 24 hour measurements range from 1.3 to 1.6 with lower confidence limits > or = 1.0. Thus, epidemiologic studies support an association between exposure to 50 Hz magnetic fields and childhood leukaemia. However, the causal nature of the association does not appear conclusively demonstrated because of limitations in study design and lack of a plausible biologic mechanism. In this framework, it seems justified to recommend the adoption of preventive measures aimed at reducing exposure to magnetic fields in dwellings, particularly in those featuring relatively high exposure levels.

[Economic and occupational activities at an increased risk of mortality for lung tumors in Turin (1981-89) and in Italy (1981-82)]. / Attività economiche e professioni ad elevato rischio di mortalità per tumore polmonare a Torino (1981-89) e in Italia (1981-82).

In the framework of occupational disease surveillance program, based on integration of current information systems, the first Italian occupational mortality study was carried out. This paper reports on excess lung cancer risk by industry and occupation. The study population consists of subjects included in the Italian Cross-Sectional Study (STI) and in the Turin Longitudinal Study (SLT), both of which are surveys based on record-linkage procedures between census records and death certificates. The STI is a six-month follow-up of Italian residents at the 1981 census. The SLT is a prospective study of Turin residents at the 1981 census, followed for mortality up to 1989. Only persons aged 18-64 years at entry, and economically active, were eligible for the occupational mortality analysis (i.e. 15,734 deceased individuals out of 13 million subjects in the STI, and 435,608 individuals, among whom 10,789 deaths occurred, in the SLT). Information about job and economic activity recorded at census consisted of the Italian standard 1981 industry and occupation codes. Lung cancer relative risks by category of industry and job were estimated as mortality odds ratios (MOR) in the STI, and as observed to expected death ratios (SMR) in the SLT. Only excess risks based on > or = 3 observed cases and with p < 0.1, were included in the present report. Lung cancer mortality was increased in different industries and jobs. The excess risks found in the mechanic and transport industries are of particular interest in a public health perspective, due to the high number of Italian workers employed in these sectors. From an etiologic point of view, however, careful attention should be paid to the excess lung cancer risks among workers in the wood manufacturing industry, in meat preparation, and in nursing occupations, where detailed analytical studies of exposure profile and cancer risk are warranted.

[Exposure to benzene of service station employees and composition of benzene]. / Esposizione a benzene tra gli addetti alle stazioni di rifornimento e composizione della benzina.

The International Agency for Research on Cancer (IARC) classifies gasoline vapours and exhaust fumes from gasoline fueled automobiles as potential human carcinogens. Data on the chemical composition of gasoline marketed in Italy and especially on the concentration of benzene, are rather poor. Within the framework of an investigation aimed at assessing the mean annual level of exposure to aromatic hydrocarbons among gasoline pump attendants, made on a sample of attendants in Rome between December 1991 and November 1992, samples of gasoline were also collected so as to determine the benzene content of the gasoline over the investigation period, assess the variability of benzene concentration in the various gasolines and according to the season of the year, and take account of gasoline composition in analysing the factors determining individual exposure levels of pump attendants. Benzene exposure was measured via gas chromatography of air samples obtained with personal pumps in the breathing zone. The mean benzene exposure level (8 h TWA) of the 27 subjects under study was 1.73 mg/m3 (SD = 5.53). The benzene concentration in the samples of gasoline, which were collected on the same day as personal exposure monitoring was performed, was measured by means of high resolution gas chromatography (hr-GC). Mean benzene levels of 25.03 g/l (SD = 3.47), equivalent to 2.86% by volume, were measured in 24 samples of alkylated gasoline, and mean levels of 23.18 g/l (SD = 3.93), equivalent to 2.65% v/v, were measured in 10 samples of lead-free gasoline. Statistically significant associations were found between individual exposure to benzene and the quantity of gasoline pumped (r = 0.69) and the quantity of benzene present in the gasoline sold on the day monitoring was performed (r = 0.70). Using regression analysis, the estimated increase in the level of personal benzene exposure was 0.01 mg/m3 for every increase of 100 g in the benzene content of the total amount of gasoline sold. This estimation could be used to quantify the expected reduction in benzene exposure levels in service station attendants following a reduction in the benzene content of gasoline.

[Mortality among lead-zinc miners in Val Seriana]. / Studio di mortalità dei minatori di piombo-zinco della Val Seriana.

The mortality experience of 1392 lead-zinc-silver miners (Gorno, Northern Italy) employed in the period 1/1/1950-31/12/1980 and followed-up to 31/12/1986 was examined. Two separate estimates of the radon exposure level are available: 0.60 and 0.36 working levels respectively. The silica exposure level was not assessed. Vital status was ascertained for 95.6% of the cohort members and their mortality was compared with expected deaths based on national rates. Significant excess mortality from esophageal cancer, stomach cancer, lung cancer, respiratory tuberculosis, respiratory diseases and deaths from external causes was found among underground miners. Surface workers show significantly increased mortality from liver and bile ducts cancer, hepatic cirrhosis, respiratory tuberculosis and respiratory diseases. Based on the 16.4 excess lung cancer cases among underground miners and their cumulative radon exposure, an attributable risk estimate ranging from 9.78 and 16.31 cases per million person-years and WLM (Working Level Month) was calculated.