Dietary Supplementation of Myo-Inositol, Cocoa Polyphenols, and Soy Isoflavones Improves Vasomotor Symptoms and Metabolic Profile in Menopausal Women with Metabolic Syndrome: A Retrospective Clinical Study

Background and Objectives: Hormonal changes physiologically occurring in menopausal women may increase the risk of developing metabolic and vasomotor disturbances, which contribute to increase the risk of developing other concomitant pathologies, such as metabolic syndrome (MetS). Materials and Methods: Retrospective data from 200 menopausal women with MetS and vasomotor symptoms taking one sachet per day of the dietary supplement INOFOLIC® NRT (Farmares srl, Rome, Italy) were collected. Each sachet consisted of myo-Inositol (2000 mg), cocoa polyphenols (30 mg), and soy isoflavones (80 mg, of which 50 mg is genistin). Patients recorded their symptoms through a medical questionnaire at the beginning of the administration (T0) and after 6 months (T1). Results: We observed an improvement in both the frequency and the severity of hot flushes: increased percentage of 2-3 hot flushes (28 at T0 vs. 65% at T1, p value < 0.001) and decreased percentage of 4-9 hot flushes (54% at T0 vs. 18% at T1, p value < 0.001). Moreover, symptoms of depression improved after supplementation (87% at T0 vs. 56% at T1 of patients reported moderate depression symptoms, p value < 0.001). Regarding metabolic profile, women improved body mass index and waist circumference with a reduction in the percentage of overweight and obesity women (88% at T0 vs. 51% at T1, p value = 0.01; 14% at T0 vs. 9% at T1, p value = 0.04). In addition, the number of women suffering from non-insulin dependent diabetes reduced (26% at T0 vs. 16% at T1, p value = 0.04). Conclusions: These data corroborate previously observed beneficial effects of the oral administration of myo-Inositol, cocoa polyphenols, and soy isoflavones against menopausal symptoms in the study population. Considering the promising results of the present study, further prospective controlled clinical trials are needed to deeply understand and support the efficacy of these natural compounds for the management of menopausal symptoms.

MicroRNA Expression in Endometrial Cancer: Current Knowledge and Therapeutic Implications

Background and Objectives: An extracellular vesicle is part of a class of submicron particles derived from cells, mediating cellular crosstalk through microRNA (miRNA). MiRNA is a group of RNA molecules, each of which consists of 15-22 nucleotides and post-transcriptionally modulates gene expression. The complementary mRNAs-onto which the miRNAs hybridize-are involved in processes such as implantation, tumor suppression, proliferation, angiogenesis, and metastasis that define the entire tumor microenvironment. The endometrial biopsy is a standard technique used to recognize cellular atypia, but other non-invasive markers may reduce patient discomfort during the use of invasive methods. The present study aims to examine the distribution and the regulation of the differentially expressed miRNAs (DEMs) and EV-derived substances in women with endometrial cancer. Materials and Methods: We systematically searched the PubMed, EMBASE, Scopus, Cochrane Library, and ScienceDirect databases in April 2023, adopted the string "Endometrial Neoplasms AND Exosomes", and followed the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. We selected all the studies that included patients with endometrial cancer and that described the regulation of miRNA molecules in that context. The differences in molecule expression between patients and controls were evaluated as significant when the proteins had a fold change of ±1.5. Results: Seventeen records fulfilled the inclusion criteria: a total of 371 patients and 273 controls were analyzed. The upregulated molecules that had the widest delta between endometrial cancer patients and controls-relative expression ≥ 1 > 3 log2(ratio)-were miR-20b-5p, miR-204-5p, miR-15a-5p, and miR-320a. In particular, miR-20b-5p and miR-204-5p were extracted from both serum and endometrial specimens, whereas miR-15a-5p was only isolated from plasma, and miR-320a was only extracted from the endometrial specimens. In parallel, the most downregulated miRNA in the endometrial cancer patients compared to the healthy subjects was miR-320a, which was found in the endometrial specimens. Conclusions: Although their epigenetic regulation remains unknown, these upregulated molecules derived from EVs are feasible markers for the early detection of endometrial cancer. The modulation of these miRNA molecules should be assessed during different treatments or if recurrence develops in response to a targeted treatment modality.

The Role of Adjuvant Therapy for the Treatment of Micrometastases in Endometrial Cancer: A Systematic Review and Meta-Analysis

Endometrial cancer is the most incident gynecological cancer. Lymph node dissemination is one of the most important factors for the patient's prognosis. Pelvic lymph nodes are the primary site of extra-uterine dissemination in endometrial cancer (EC), setting the 5-year survival to 44-52%. It is standard practice for radiation therapy (RT) and/or chemotherapy (CTX) to be given as adjuvant treatments to prevent the progression of micrometastases. Also, administration of EC patients with RT and/or CTX regimens before surgery may decrease micrometastases, hence the need for lymphadenectomy. The primary aim of the systematic review and meta-analysis is to assess whether adjuvant RT and/or CTX improve oncological outcomes through the management of micrometastases and nodal recurrence. We performed systematic research using the string "Endometrial Neoplasms" [Mesh] AND "Lymphatic Metastasis/therapy" [Mesh]. The methods for this study were specified a priori based on the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Outcomes were 5-year overall survival, progression-free survival, recurrence rate, and complications rate. We assessed the quality of studies using the Newcastle-Ottawa Scale (NOS). A total of 1682 patients with stage I-to-IV EC were included. Adjuvant treatment protocols involved external-beam RT, brachytherapy, and CTX either alone or in combination. The no-treatment group showed a non-statistically significant higher recurrence risk than any adjuvant treatment group (OR 1.39 [95% CI 0.68-2.85] p = 0.36). The no-treatment group documented a non-statistically significant higher risk of death than those who underwent any adjuvant treatment (RR 1.47 [95% CI 0.44-4.89] p = 0.53; I2 = 55% p = 0.000001). Despite the fact that early-stage EC may show micrometastases, adjuvant treatment is not significantly associated with better survival outcomes, and the combination of EBRT and CTX is the most valid option in the early stages.

Meigs Syndrome and Elevated CA-125: Case Report and Literature Review of an Unusual Presentation Mimicking Ovarian Cancer

Background and Objectives: Meigs syndrome is represented by a benign adnexal tumor, ascites, and hydrothorax. Even though the ovarian mass is often characterized by a fibroma-like origin, cancer antigen-125 (CA-125) serum levels could be elevated as in the development of ovarian cancer. Here, we present the case of a patient with Meigs syndrome and increased CA-125. Materials and Methods: We performed systematic research for articles including similar cases in PubMed, EMBASE, and Scopus in February 2023, adopting the string of idioms: "Meigs syndrome AND Cancer antigen 125", and following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results: Eligible records were 25. Hydrothorax was right-sided in 10 cases over 25; left-sided in two patients over 25. Concerning ascites, two patients showed more than 6 L of ascitic fluid, whereas three patients had 6 L or less. CA-125 elevation ranged from 149 IU/mL to 3803 IU/mL. Adnexal mass histotypes were: struma ovarii (12 cases), thecomas (two cases), fibrothecomas (five cases), fibromas (five cases), and one sclerosing stromal tumor (SST). Conclusions: In postmenopausal women with elevated CA-125 serum levels and an adnexal mass suspicious for malignancy at ultrasound (US), ascites and pleural effusion, surgery, and histopathological examination are necessary. MS is a diagnostic option, with an excellent prognosis after exeresis of the mass.

The Efficiency of Sclerotherapy for the Management of Endometrioma: A Systematic Review and Meta-Analysis of Clinical and Fertility Outcomes

Background and Objectives: The most common sites of implantation of endometriotic tissue are the ovaries. Endometriomas are present in most cases of endometriosis (up to 45%). Although laparoscopic cystectomy is the standard of care in endometrioma, new strategies have been set up to minimize iatrogenic injuries to ovarian tissue. Sclerotherapy consists of injecting alcohol into the endometrioma to denature the amino acidic components of its pseudocapsule. The aim of this systematic review and meta-analysis is to compare clinical and pregnancy outcomes in surgery and sclerotherapy. Materials and Methods: Following the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we systematically searched PubMed, EMBASE, Scopus, Google Scholar, Clinical-trials.gov, and the Cochrane Central Register of Controlled Trials databases in January 2023, adopting the string "Endometriosis and sclerotherapy". We made no limitations on the country and year of publication. We included the studies containing Success Rate (SR), Recurrence Rate (RR), Pregnancy Rate (PR) before and after the procedure. We used comparative studies for meta-analysis. Results: A total of 29 studies fulfilled inclusion criteria, 7 retrospective observational studies and 22 prospective studies. Eight comparative studies were enrolled in meta-analysis. Patients were analyzed concerning the number of recurrences and pregnancies in surgery, and compared with sclerotherapy. Four studies showed SR > 80.0%, and only two had SR < 80.0%, of which one consisted of tetracycline instillation. Only 1 study had 100% PR, the other 14 reported PR > 30.0%, whereas six had PR < 30.0%, of which one showed 0.0% PR with ethanol injection at two-thirds of the cyst fluid volume. Meta-analysis highlighted a non-significant lower incidence of recurrence in the surgery group compared to the sclerotherapy group (p = 0.87). In parallel, the surgery group showed a non-significant better PR than the sclerotherapy group (p = 0.08). Conclusions: Despite sclerotherapy having a minor incidence of postoperative complications compared to surgery, the latter is associated with a lower RR and better PR. However, those data assert the importance of a targeted therapy according to preoperative conditions and reproductive potential.

Minimally Invasive Staging of Early-Stage Epithelial Ovarian Cancer versus Open Surgery in Terms of Feasibility and Safety: A Systematic Review and Meta-Analysis

Epithelial ovarian cancer is women's fourth most common oncological cause of death. One of the main prognostic factors in ovarian cancer is the tumor stage. For instance, surgical staging of the disease is focal when choosing the best therapeutic option for each case. Although open surgery is the prevalent approach for staging and treating ovarian cancer, the use of minimally invasive surgery (MIS) has found recent application in staging or restaging cases of early disease. Our work compares oncological outcomes after MIS staging for FIGO I epithelial ovarian cancer with the laparotomic approach. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations, we systematically searched the Pub Med and Scopus databases in February 2023. No temporal nor geographical limitation was made. We included the articles containing data about Disease-Free Survival (DFS) and Overall Survival (OS), Recurrence Rates (RR), and Upstaging Rates (UpR). We used comparative studies for the meta-analysis. After the database search and article selection, 19 works matched the inclusion criteria for the systematic review. Eleven of these were comparative studies between MIS and Open Surgical Staging (OSS) approaches for ovarian cancer staging and were included in the meta-analysis. The meta-analysis did not show a statistically significant difference between the MIS and the OSS group concerning DFS, OS, and RR. Only Upstaging Rate ≥ FIGO Stage II was statistically significative higher in the OSS group. Likewise, MIS is confirmed to be an approach with a lower profile of surgical complications. In conclusion, our study did not show one approach to be safer than the other. However, the lack of dedicated studies limits the evidence of our study. For instance, we recommend adequately selecting the specimen, minimizing the risk of spillage, and optimizing surgical staging.

Radiotherapy and Chemotherapy Features in the Treatment for Locoregional Recurrence of Endometrial Cancer: A Systematic Review

Radiation therapy (RT) is the standard of care in patients with locoregional or isolated vaginal recurrence who never underwent irradiation. It is often associated with brachytherapy (BT), whereas chemotherapy (CT) is a rare treatment option. We systematically searched the PubMed and Scopus databases in February 2023. We included patients with relapsed endometrial cancer, describing the treatment of locoregional recurrence, and reporting at least one outcome of interest-disease-free survival (DFS), overall survival (OS), recurrence rate (RR), site of recurrence, and major complications. A total of 15 studies fulfilled the inclusion criteria. Overall, 11 evaluated RT only, 3 evaluated CT, and 1 analyzed oncological outcomes after administration with a combination of CT and RT. In total, 4.5-year OS ranged from 16% to 96%, and DFS ranged from 36.3% to 100% at 4.5 years. RR ranged from 3.7% to 98.2% during a median follow-up of 51.5 months. Overall, RT showed a 4.5-year DFS from 40% to 100%. CT revealed 36.3% DFS at 4.5 years. RT showed a 4.5-year OS ranging from 16% to 96%, whereas CT revealed a 27.7% OS rate. It would be appropriate to test multi-modality regimens to evaluate outcomes and toxicity. EBRT and BT are the most employed options to treat vaginal recurrences.

Liquid Biopsy in Endometriosis: A Systematic Review

Despite laparoscopy being a standardized option to diagnose pelvic endometriotic implants, non-invasive biomarkers are necessary to avoid the discomfort of invasive procedures. Recent evidence suggests a potential role of microRNAs (miRNAs) as feasible biomarkers for the early diagnosis of endometriosis. Following the recommendations in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement, we systematically searched PubMed, EMBASE, Scopus, Cochrane Library, and Science Direct in January 2023. We provided no restriction on the country and year of publication, and considered English published articles. We selected studies including patients with endometriosis and describing miRNA regulation in the context of endometriosis. Overall, 45 studies fulfilled the inclusion criteria, and 2045 patients with endometriosis and 1587 controls were screened. Patients were analyzed concerning miRNAs expression and sources, stage of disease, and symptoms, and compared to controls. Among DEMs, the ones with the widest delta between endometriosis patients and controls-Relative Expression ≥ 4 Log2(ratio)-were miR-145, miR-191, miR-195, miR-21-5p, miR-106b-5p, miR-195-5p, miR-451a, miR-200c, miR-20a-5p, and miR-15a-5p. Although the epigenetic regulation is partially unclear, miRNAs are valid biomarkers to diagnose endometriotic lesions in symptomatic and non-symptomatic women. MiRNAs modulation should be clarified, especially during therapies or relapse, to plan targeted management protocols.

Oncological outcomes in fertility-sparing treatment in stage IA-G2 endometrial cancer

Background

The gold standard treatment for early-stage endometrial cancer (EC) is hysterectomy with bilateral salpingo-oophorectomy (BSO) with lymphadenectomy. In selected patients desiring pregnancy, fertility-sparing treatment (FST) can be adopted. Our review aims to collect the most incisive studies about the possibility of conservative management for patients with grade 2, stage IA EC. Different approaches can be considered beyond demolition surgery, such as local treatment with levonorgestrel-releasing intra-uterine device (LNG-IUD) plus systemic therapy with progestins.

Study design

Our systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. PubMed, EMBASE, and Scopus databases were consulted, and five studies were chosen based on the following criteria: patients with a histological diagnosis of EC stage IA G2 in reproductive age desiring pregnancy and at least one oncological outcome evaluated. Search imputes were “endometrial cancer” AND “fertility sparing” AND “oncologic outcomes” AND “G2 or stage IA”.

Results

A total of 103 patients were included and treated with a combination of LNG-IUD plus megestrol acetate (MA) or medroxyprogesterone acetate (MPA), gonadotrophin-releasing hormone (GnRH) plus MPA/MA, hysteroscopic resectoscope (HR), and dilation and curettage (D&C). There is evidence of 70% to 85% complete response after second-round therapy prolongation to 12 months.

Conclusions

Conservative measures must be considered temporary to allow pregnancy and subsequently perform specific counseling to adopt surgery. Fertility-sparing management is not the current standard of care for young women with EC. It can be employed for patients with early-stage diseases motivated to maintain reproductive function. Indeed, the results are encouraging, but the sample size must be increased.

Incidence of gestational diabetes mellitus before and after the Covid-19 lockdown: A retrospective cohort study

AIM

To evaluate whether the first Covid-19 lockdown for Italian citizens (March to July 2021) might have altered the incidence of gestational diabetes mellitus (GDM).

METHODS

A retrospective single-center study in a tertiary referral center. Primary outcome was the incidence of GDM among pregnant women. GDM incidence, from June 11, 2019 to December 4, 2020, was compared by dividing the study time as follows: from the beginning of the study to before Covid-19 lockdown (from June 11, 2019, to March 9, 2020) and lockdown period (from March 10, 2020, to December 4, 2020). GDM was diagnosed with a 75-g, 2-h oral glucose tolerance test (OGTT) at 24-28 gestational weeks.

RESULTS

Concerning 1295 women, GDM incidence increased during the lockdown period (9.3% vs. 3.4%, p < 0.001). Higher pregnancy weight gain with an increased body mass index (BMI) at the delivery was reported during the lockdown (31.3 vs. 28.4 kg/m2 , p = 0.02 and mean weight gain of 9.3 vs. 6.6 kg, p = 0.007). There was no difference in other comorbidity incidence and OGTT values between the two groups.

CONCLUSIONS

Pregnant women during the Covid-19 lockdown might have experienced higher BMI and pregnancy weight gain with increased GDM diagnoses. This may be related to physical limitations and emotional distress experienced during the lockdown. However, evidence is limited due to restricted study duration and random variations of outcomes across time. More studies are needed to understand the dietary patterns and the physical activity changes during the Covid-19 lockdown and its impact on fetal outcomes.

The gut-brain axis in irritable bowel syndrome and inflammatory bowel disease

Research increasingly demonstrates the bidirectional communication between gut microbiota and the brain, enhancing the role of gut microbiota modulation in the treatment of central nervous system (CNS) disorders. The first five years of life are extremely important as it affects the development of gut microbiota, immune system and, consequently, the onset of psychometric alterations, particularly in genetically predisposed individuals. In this review, we focus on the link between specific microbial genera, gastrointestinal (GI) disorders, anxiety and depression and on the effects of different therapeutic strategies for mood disorders on gut microbiota.

[SENTIERI Project: discussion and conclusions]

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.

[Global burden of mortality in Italian polluted sites]

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.

[Mortality results in SENTIERI Project]

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.

[SENTIERI Project: rationale and objectives]

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.

[Scientific collaboration between Istituto Superiore di Sanità and Italian Association of Cancer Registries for the study of cancer incidence in Italian polluted sites]

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.

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.

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.

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.

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.

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.

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]

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.

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.

[Exposure to benzene of service station employees and composition of benzene]

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.

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.