Introduction: The health profile of military veterans deployed in foreign operative theatres was assessed by several international studies because of potential exposure to depleted uranium and other pollutants. Here we reported results of 15-year epidemiological surveillance assessing long-term health effects in a cohort of Italian soldiers deployed in Iraq in 2004-2005 and participating in a biomonitoring campaign to identify potential genotoxic exposure to environmental xenobiotics before and after deployment (n = 981, SIGNUM cohort). Methods: We evaluated mortality and hospitalization risks of the SIGNUM cohort retrospectively until 2016 and 2018 respectively. A wide cohort of military personnel never deployed abroad (n = 114,260) and the general Italian population were used as control populations in risk assessment. Causes of death and diagnoses of hospitalization were derived through deterministic record linkage with official national databases of mortality and hospital discharge. Standardized Mortality Ratio (SMR) and Standardized Hospitalization Ratio (SHR) were computed adjusting according to sex, age, area of birth, and calendar year. Differential pre-post deployment in xenobiotics concentrations and early effect biomarkers (oxidative DNA alterations and micronuclei) measured in blood serum were analysed in relation to cancer hospitalization. Results: Mortality risk due to pathologies was more than halved compared to the general population (SMR = 0.41, 95% CI 0.11-1.05) and not significantly different compared to soldiers never deployed abroad (SMR = 0.69, 95% CI 0.19-1.68). Similarly overall hospitalization risk due to pathologies was decreased with respect to the general population (SHR = 0.86, 95% CI 0.80-0.92) and comparable to the control military group (SHR = 0.99, 95% CI: 0.93-1.06). For haematological cancers a decreased hospitalization risk compared to the Italian general population was observed (SHR = 0.38, 95% CI 0-0.92). No statistically significant differences emerged in the patterns of biomarkers in association with cancer hospitalization. Conclusion: The study confirms the so called 'healthy warrior' effect for the SIGNUM veterans and showed no correlation between cancer occurrence and biomonitoring markers measured on field.

Scientific background: Environmental sampling of SARS-CoV-2 is a fundamental tool for evaluating the effectiveness of non-specific prophylaxis measures in counteracting virus spread. The purpose of our work was to evaluate the effectiveness of the different sampling methods in the hospital setting to assess their correlation with the structural, functional, and operational situation of the monitored departments and to define the dynamics of the spread of the virus in indoor environments.Methods: The monitoring (air bubbling sampling, surface wipe test) was carried out at the San Martino Polyclinic Hospital (Genoa, Italy) in the period since April 2020 to June 2021. The presence of viral RNA in the collected samples was evaluated by qPCR. The infection capacity of the samples collected was also evaluated by an in vitro challenge test on cells sensitive to SARS-CoV-2 infection.Results: The percentage of positivity with respect to the number of tests performed (sensitivity) were air bubbler 50%, wipe test 17%, and challenge test 11%. Only 20% of the samples tested positive in the wipe test and 43% of the samples tested positive in the bubbler sampling were also positive in the challenge test. All the positivity obtained was detected at a distance of less than 2 m and height of less than 1.5 from COVID-19 patients.Conclusions: Environmental contamination from SARS-CoV-2 detected at the San Martino Polyclinic Hospital is found lower than similar assessments performed in other hospitals both in Italy and abroad. Our study predicted that environmental monitoring of SARS-CoV-2 must be carried out in an integrated way by not using a single sampling method, as each individual test has a different biological significance and performance. However, the virus detected by wipe test only is often a degraded viral fragment and not an intact infecting virion.

Background Primary open angle glaucoma (POAG) is a progressive optic nerve degeneration, leading to irreversible visual damage. Alterations of the aqueous humor (AH), the biological fluid filling both the anterior and the posterior chambers of the eye, play a pathogenic role in POAG. AH protein composition is altered during glaucoma progression. Nestin protein was found to be differentially expressed in the AH of glaucomatous patients compared to unaffected matched controls. Methods: Nestin was analyzed by an open quartz crystal microbalance (QCM) in the AH of 21 glaucomatous patients compared to nine unaffected controls. The surface of the electrode used in the QCM was coated with an analyte-specific recognition layer. Results: Positive nestin values were recorded in the AH collected from POAG patients; negative values of nestin detection were obtained by analyzing the AH collected from non-POAG glaucomatous patients and unaffected controls. Conclusion: The present study proposes and validates a new clinically applicable approach to analyze biological markers in AH for POAG diagnosis.

The olfactory nuisance, due to the emissions of active molecules, is mainly associated with unproperly managed waste disposal and animal farming. Volatile compounds e.g., aromatics, organic and inorganic sulfide compounds, as well as nitrogen and halogenated compounds are the major contributor to odor pollution generated by waste management plants; the most important source of atmospheric ammonia is produced by livestock farming. Although an odorous compound may represent a nuisance rather than a health risk, long-term exposure to a mixture of volatile compounds may represent a risk for different diseases, including asthma, atopic dermatitis, and neurologic damage. Workers and communities living close to odor-producing facilities result directly exposed to irritant air pollutants through inhalation and for this reason the cumulative health risk assessment is recommended. Health effects are related to the concentration and exposure duration to the odorants, as well as to their irritant potency and/or biotransformation in hazardous metabolites. The health effects of a single chemical are well known, while the interactions between molecules with different functional groups have still to be extensively studied. Odor emissions are often due to airborne pollutants at levels below the established toxicity thresholds. The relationship between odor and toxicity does not always occurs but depends on the specific kind of pollutant involved. Indeed, some toxic agents does not induce odor nuisance while untoxic agents do. Accordingly, the relationship between toxicity and odor nuisance should be always analyzed in detail evaluating on the characteristics of the airborne mixture and the type of the source involved.

Extracellular vesicles (EVs) are released from cells and enter into body fluids thereby providing a toxicological mechanism of cell-cell communication. The present study aimed at assessing (a) the presence of EVs in mouse body fluids under physiological conditions, (b) the effect of exposure of mice to cigarette smoke for 8 weeks, and (c) modulation of smoke-related alterations by the nonsteroidal anti-inflammatory drug celecoxib, a selective cyclooxygenase-2 inhibitor. To this purpose, ICR (CD-1) mice were either unexposed or exposed to cigarette smoke, either treated or untreated with oral celecoxib. EVs, isolated from bronchoalveolar lavage fluid (BALF), blood serum, and urines, were analyzed by nanoparticle tracking analysis and flow cytometry. EVs baseline concentrations in BALF were remarkably high. Larger EVs were detected in urines. Smoking increased EVs concentrations but only in BALF. Celecoxib remarkably increased EVs concentrations in the blood serum of both male and female smoking mice. The concentration of EVs positive for EpCAM, a mediator of cell-cell adhesion in epithelia playing a role in tumorigenesis, was much higher in urines than in BALF, and celecoxib significantly decreased their concentration. Thus, the effects of smoke on EVs concentrations were well detectable in the extracellular environment of the respiratory tract, where they could behave as delivery carriers to target cells. Celecoxib exerted both protective mechanisms in the urinary tract and adverse systemic effects of likely hepatotoxic origin in smoke-exposed mice. Detection of EVs in body fluids may provide an early diagnostic tool and an end-point exploitable for preventive medicine strategies.

Identification of specific molecular changes (fingerprints) is important to identify cancer etiology. Exploitable biomarkers are related to DNA, epigenetics, and proteins. DNA adducts are the turning point between environmental exposures and biological damage. DNA mutational fingerprints are induced by carcinogens in tumor suppressor and oncogenes. In an epigenetic domain, methylation changes occurs in specific genes for arsenic, benzene, chromium, and cigarette smoke. Alteration of specific microRNA has been reported for environmental carcinogens. Benzo(a)pyrene, cadmium, coal, and wood dust hits specific heat-shock proteins and metalloproteases. The multiple analysis of these biomarkers provides information on the carcinogenic mechanisms activated by exposure to environmental carcinogens.

Atherosclerosis is associated with DNA damage in both circulating and vessel-wall cells and DNA adducts derived from exposure to environmental mutagens are abundant in atherosclerotic vessels. Environmental chemical carcinogens identified as risk factor for atherosclerosis include polycyclic aromatic hydrocarbons (benzo(a)pyrene, dimethylbenz(a)anthracene, beta-naphthoflavone, pyrene, 3-methylcolanthrene), arsenic, cadmium, 1,3-butadiene, cigarette smoke. Accordingly, polymorphisms of genes encoding for phase I/II metabolic reaction and DNA repair are risk factor for cardiovascular diseases, although their role is negligible as compared to other risk factors. The pathogenic relevance of mutation-related molecular damage in atherosclerosis has been demonstrated in experimental animal models involving the exposure to chemical mutagens. The relevance of mutation-related events in worsening atherosclerosis prognosis has been demonstrated in human clinical studies mainly as referred to mitochondrial DNA damage. Atherosclerosis is characterized by the occurrence of high level of oxidative damage in blood vessel resulting from both endogenous and exogenous sources. Mitochondrial damage is a main endogenous source of oxidative stress whose accumulation causes activation of intrinsic apoptosis through BIRC2 inhibition and cell loss contributing to plaque development and instability. Environmental physical mutagens, including ionizing radiation, are a risk factor for atherosclerosis even at the low exposure dose occurring in case of occupational exposure or the high exposure doses occurring during radiotherapy. Conversely, the role of exciting UV radiation in atherosclerosis is still uncertain. This review summarizes the experimental and clinical evidence supporting the pathogenic role of mutation-related pathway in atherosclerosis examining the underlying molecular mechanisms.

The first evidence that microRNA expression is early altered by exposure to environmental chemical carcinogens in still healthy organisms was obtained for cigarette smoke. To date, the cumulative experimental data indicate that similar effects are caused by a variety of environmental carcinogens, including polycyclic aromatic hydrocarbons, nitropyrenes, endocrine disruptors, airborne mixtures, carcinogens in food and water, and carcinogenic drugs. Accordingly, the alteration of miRNA expression is a general mechanism that plays an important pathogenic role in linking exposure to environmental toxic agents with their pathological consequences, mainly including cancer development. This review summarizes the existing experimental evidence concerning the effects of chemical carcinogens on the microRNA machinery. For each carcinogen, the specific microRNA alteration signature, as detected in experimental studies, is reported. These data are useful for applying microRNA alterations as early biomarkers of biological effects in healthy organisms exposed to environmental carcinogens. However, microRNA alteration results in carcinogenesis only if accompanied by other molecular damages. As an example, microRNAs altered by chemical carcinogens often inhibits the expression of mutated oncogenes. The long-term exposure to chemical carcinogens causes irreversible suppression of microRNA expression thus allowing the transduction into proteins of mutated oncogenes. This review also analyzes the existing knowledge regarding the mechanisms by which environmental carcinogens alter microRNA expression. The underlying molecular mechanism involves p53-microRNA interconnection, microRNA adduct formation, and alterations of Dicer function. On the whole, reported findings provide evidence that microRNA analysis is a molecular toxicology tool that can elucidate the pathogenic mechanisms activated by environmental carcinogens.

Biphosphonate (BPN) are widely used in clinics to treat metastatic cancer and osteoporosis thus representing a problem not only for patients but also for workers involved in their preparation and administration. A similar exposure occurred years ago in match-making workers undergoing bone alterations similar to those consequent to BPN exposure. Osteonecrosis of the jaw (ONJ) is a main adverse effect related to BPN administration, which is performed in millions of patients worldwide for osteoporosis and cancer therapy, thus representing an emerging problem in public health. In susceptible patients, BPN induce severe, progressive, and irreversible degeneration of facial bones, resulting in avascular ONJ often triggered by dental surgery. BPN induced ONJ occurs in subjects depending on lifestyle factors of both environmental and endogenous origins. Exogenous risk factors include cigarette smoke, alcohol consumption, bacterial infections, and cyclosporine therapy. Endogenous risk factors include systemic diseases such as diabetes or hypertension and adverse polymorphisms of genes involved in metabolism (CYPs, MTHFR), thrombosis (Factor V, Prothrombin), and detoxification (MDR). Available molecular findings provide evidence that ONJ is related to risk-factors associated with environmental mutagenesis and gene-environment interactions. This issues may be useful to identify susceptible subjects by molecular analyses in order to prevent ONJ occurrence.

T lymphocytes play a major role in counteracting cancer occurrence and development. Immune therapies against cancer are focused on eliciting a cytotoxic T cell response. This anticancer activity is related to a variety of mechanisms including the activation of cytokines and proapoptotic mediators. Interferon α is an established inhibitor of cancer cell growth. A clinical situation involving the coexistence of high interferon α levels and lymphocyte activation is the Aicardi-Goutières syndrome, a progressive encephalopathy arising usually during the first year of life characterized by intracranial basal ganglia calcifications, leukodystrophy and microcephaly. Aicardi-Goutières syndrome 1 mutation silences the TREX1 gene, a major endogenous nuclease. The in vitro study presented herein evaluates the efficacy of the TREX1 mutation in potentiating the anticancer properties of T cells. A TREX1-mutated lymphocyte cell line was derived from an Aicardi-Goutières syndrome patient and co-cultured with neuroblastoma cells and vascular endothelial cells in the presence of interferon α. TREX1-mutated lymphocytes exerted marked inhibitory action on neuroblastoma cell growth. Cathepsin D was recognized by qPCR as the main mediator produced by TREX1-mutated lymphocytes involved in the inhibition of neuroblastoma cell growth. These effects were enhanced in the presence of interferon α. Similar inhibitory effects in cell growth were exerted by TREX1-mutated lymphocytes towards vascular endothelial cell angiogenesis as evaluated on Matrigel. The results obtained provide evidence that mutations of the TREX1 gene increase the capability of T-lymphocytes to inhibit growth of neoplastic neuronal cells and related angiogenesis.

Molecular mechanisms relating interferon-alpha (IFN-alpha) to brain damage have recently been identified in a microarray analysis of cerebrospinal fluid lymphocytes from patients with Aicardi-Goutières Syndrome (AGS). These findings demonstrate that the inhibition of angiogenesis and the activation of neurotoxic lymphocytes are the major pathogenic mechanisms involved in the brain damage consequent to elevated interferon-alpha levels. Our previous study demonstrated that cathepsin D, a lysosomal aspartyl endopeptidase, is the primary mediator of the neurotoxicity exerted by AGS lymphocytes. Cathepsin D is a potent pro-apoptotic, neurotoxic, and demyelinating protease if it is not properly inhibited by the activities of leukocystatins. In central nervous system white matter, demyelination results from cathepsin over-expression when not balanced by the expression of its inhibitors. In the present study, we used RNA interference to inhibit cathepsin D expression in AGS lymphocytes with the aim of decreasing the neurotoxicity of these cells. Peripheral blood lymphocytes collected from an AGS patient were immortalized and co-cultured with astrocytes in the presence of interferon alpha with or without cathepsin D RNA interference probes. Cathepsin D expression was measured by qPCR, and neurotoxicity was evaluated by microscopy. RNA interference inhibited cathepsin D over-production by 2.6-fold (P<0.01) in AGS lymphocytes cultured in the presence of interferon alpha. AGS lymphocytes treated using RNA interference exhibited a decreased ability to induce neurotoxicity in astrocytes. Such neurotoxicity results in the inhibition of astrocyte growth and the inhibition of the ability of astrocytes to construct web-like aggregates. These results suggest a new strategy for repairing AGS lymphocytes in vitro by inhibiting their ability to induce astrocyte damage and leukodystrophy.

Intracellular RNAses are involved in various functions, including microRNA maturation and turnover. Mutations occurring in genes encoding RNAses cause Aicardi–Goutiéres syndrome (AGS). AGS mutations silence RNAse activity, thus inducing accumulation of endogenous RNAs, mainly consisting of short RNAs and microRNAs. Overload of intracellular RNA triggers Toll like receptor-dependent interferon-alpha production in the brain, which in turn activates neurotoxic lymphocytes and inhibits angiogenesis thus inducing the typical clinical phenotype of AGS. However, these pathogenic mechanisms are attenuated after three years of age by the endogenous production of DNAJP58IPK and Cystatin F, which arrest AGS progression. Because RNAses are involved in microRNA turnover, we evaluated the expression of 957 microRNAs in lymphocytes from AGS patients and control patients. Our results indicate that microRNA overload occurs in AGS patients. This upregulation inhibits microRNA turnover impeding the synthesis of the novel microRNAs required for the differentiation and myelination of the brain during the initial period of postnatal life. These pathogenic mechanisms result in AGS, a neurological syndrome characterized by irritability, mild hyperpyrexia, pyramidal and extrapyramidal signs, and spastic-dystonic tetraplegia. Typical cerebrospinal fluid alterations include lymphocytosis and elevated interferon-alpha levels. Brain imaging demonstrates cerebral calcifications, white matter abnormalities, and progressive cerebral atrophy.Thus, evidence exists that mutations silencing intracellular RNases affect microRNA turnover resulting in the severe clinical consequences in the brain characterizing the clinical feature of AGS.

Chronic-degenerative dentistry diseases, including periodontal diseases and oral osteonecrosis, are widespread in human populations and represent a significant problem for public health. These diseases result from pathogenic mechanisms created by the interaction between environmental genotoxic risk-factors and genetic assets conferring individual susceptibility. Osteonecrosis occurs in subjects undergoing exposure to high doses of DNA-damaging agents for chemo- and radiotherapy of neoplastic diseases. In susceptible patients, ionizing radiation and biphosphonate-chemotherapy induce severe, progressive, and irreversible degeneration of facial bones, resulting in avascular necrosis of the jaw. This may also occur in patients receiving biphosphonate for osteoporosis therapy. Periodontal diseases include chronic, aggressive, and necrotizing periodontitis, often resulting in severe alteration of periodontal tissues and tooth loss. Cigarette smoking and chronic inflammation caused by specific bacteria are the main risk factors for periodontitis. Oxidative damage plays a fundamental pathogenic role, as established by detection of mitochondrial DNA damage in the gingival tissue of patients with periodontitis. Endogenous risk factors in dental diseases include polymorphisms for metabolic enzymes such as glutathione transferases M1 and T1, N-acetyl transferase 2, and CYP 1A1. Other genetic polymorphisms that confer susceptibility to dentistry diseases affect genes encoding metalloproteases (involved in periodontal tissue remodeling and degradation), cytokines (involved in inflammation), prothrombin, and DNA repair activities. These findings provide evidence that dentistry diseases are related to risk factors associated with environmental mutagenesis. This issue warrants future investigations aimed at improving oral health and preventing oral degenerative diseases using molecular and experimental approaches currently utilized in mutagenicity studies.

Aicardi-Goutieres syndrome (AGS) is a rare encephalopathy, arising during the first year of life, characterized by cerebral atrophy, leukodystrophy, basal ganglia calcification, raised interferon (IFN)-alpha in the CSF, CSF lymphocytosis, and negative serologic findings for infections.1,2 Identification of AGS pathogenesis may provide insights into the neurodegenerative mechanism resulting from exposure of the developing human brain to IFN-alpha. The aim of this study is to provide an insight into global gene expression of CSF cells in AGS using microarray technology. ### Methods. CSF aliquots have been collected from patients with AGS and controls for diagnostic purposes. The study was approved by the Ethical Committee of the IRCSS Mondino, University of Pavia, Italy. Patients with AGS (n = 20), 12 boys and 8 girls (age 4.5 ± 4.4 years), have been identified by the presence of an appropriate clinical picture in presence of CSF lymphocytosis (>5 cells/mm3), IFN-alpha in CSF >2 IU/mL, in absence of any infections.3 Controls, 11 boys and 9 girls, matched to patients with AGS by gender, age (age 4.4 ± 4.3 years), and number (n = 20), devoid of any alteration in the CSF, included 13 subjects with congenital hydrocephalus, 3 with endocranial tumor, 2 with myelo-meningocele with hydrocephalus, 1 with choroid plexus papilloma, and 1 with upper sella turcica cyst. Lymphocyte was the main cell type detected (>80%) in the CSF of all recruited subjects, the cell …

Urinary mutagenicity was evaluated in relation to environmental mutagen exposure (i.e., diet, indoor/outdoor activities, residential area etc.) on the day prior to sample collection, and also considering factors that contribute to the variability of Salmonella mutagenicity assay results. Overnight urine samples from 283 healthy non-smoking residents of northeast Italy (46% males, 20-62 years) were analyzed for mutagenicity on sensitive Salmonella typhimurium strain YG1024 with S9 mix employing the preincubation version of the plate incorporation assay (i.e., the Salmonella reverse mutation test). Urinary mutagenicity varied between 0.02 and 9.84 rev/ equiv. ml, and 7% of samples were positive (i.e., sample elicited a two-fold increase in revertants). There was an evident increase in mutagenicity in subjects with increased intake of mutagen-rich meals (n = 80) (P < 0.01 and positive urine 13% vs. 5%, P = 0.025). Indoor-exposed subjects (n = 65) also showed a higher percentage of positive urine (14% vs. 5%, P = 0.015). In particular, those subjects exposed to cooking fumes the previous evening (n = 28) revealed higher urinary mutagenicity (P = 0.035, positive urine 25% vs. 5%, P < 0.001) than non-indoor exposed. The sources of variability of the mutagenicity assay, mainly the histidine content of the urine concentrate (z = 4.06, P < 0.0001), and to a lesser extent bacterial inoculum size (z = 2.33, P = 0.019), also significantly influenced urinary mutagenicity values. In a linear multiple regression analysis, their effects were still significant (i.e., histidine content P = 0.026 and inoculum size P = 0.021), but the effects of diet, indoor exposure, and other environmental exposures (i.e., traffic and heating system exhausts, residential area) were not. It is concluded that the previous day's exposure to mutagen-rich meals and cooking fumes may influence the presence of mutagenic activity in the overnight urine of non-smoking subjects. This mutagenic activity, which remains in contact with bladder mucosa for several hours, could be considered risk factors for colorectal adenoma and possibly other cancers (i.e., bladder) in non-smokers. Accurate control of histidine content and bacterial inoculum size is strongly recommended when investigating the mutagenic activity of urine from non-smokers.

The functional significance of genetic polymorphisms on tobacco smoke-induced CYP1A2 activity was examined. The influence of three polymorphisms of the cytochrome P450 1A2 gene (CYP1A2) (-3860 G -> A (allele *1C), -2467 T -> delT (allele *1D), -163 C -> A (allele *1F)), located in the 5'-noncoding promoter region of the gene, on CYP1A2 activity (measured as caffeine metabolic ratio, CMR), was studied in Caucasian current smokers (n = 95). Tobacco smoke intake was calculated from the number of cigarettes/day. Also, studied was the influence of these CYP1A2 genotypes on smoking-associated urinary mutagenicity, detected in Salmonella typhimurium strain YG1024 with S9 mix, considering the urinary excretion of nicotine plus its metabolites as an internal indicator of tobacco smoke exposure.Smokers with at least one of the variant alleles CYP1A2 -3860A and -2467 delT showed a significantly increased CYP1A2 CMR (-3860 G/A versus G/G, p < 0.05; -2467 delT/delT versus T/delT and T/T, p < 0.01). Multiple regression analysis showed that the increase in CYP1A2 CMR (In values) was again significantly related to the presence of CYP1A2 variants -2467delT and also to variant -163A (p < 0.05), but moderately to -3860A (p = 0.084). No influence of the number of cigarettes smoked per day by each subject was found. Heavy smokers ( n = 48, with urinary nicotine plus its metabolites >= 0.69 mg/mmol creatinine) with variant allele -2467delT or -163A had significantly increased urinary mutagenicity (p < 0.01 and < 0.05).CYP1A2 genetic polymorphisms are shown to influence the CYP1A2 phenotype in smokers, -2467 T -> delT having the main effect. This information is of interest for future studies assessing the possible role of tobacco smoke inducible CYP1A2 genotypes as individual susceptibility factors in exposure to carcinogens. (c) 2005 Published by Elsevier B.V.

[Anti-B[a]PDE-DNA formation in lymphomonocytes of humans environmentally exposed to polycyclic aromatic hydrocarbons] We are currently evaluating anti-benzo[a]pyrenediolepoxide-(B[a]PDE)-DNA adduct levels in lymphomonocytes of humans exposed to polycyclic aromatic hydrocarbons (PAHs) to validate this indicator of biologically effective dose in a surrogate tissue. The study protocol (October 2002-June 2005) implies: (a) a signed informed consent by each participant; (b) recruitment of 600 Padua municipal workers during visits at our outpatient clinic; (c) administration of a questionnaire regarding non occupational sources of PAH (B[a]P) exposure; (d) collection of blood (15 ml) and urine (200 ml) samples. Anti-B[a]PDE-DNA adduct levels in lymphomonocytes are detected by HPLC-fluorescence analysis. To date, 438 subjects have been examined (age range 20-62 years; 52% males). We found that: (i) anti-B[a]PDE-DNA adduct levels are significantly lower than those we previously found in coke-oven workers (N=95) occupationally exposed to high levels of PAHs (1.51 +/- 2.68 versus 4.07 +/- 3.78 anti-B[a]PDE-adduct/10(8) nucleotides, p < 0.001; 37% versus 97% positive subjects with > or =1 adduct/10(8) nucleotides; p < 0.001); (ii) smokers (23%) have significantly higher adduct levels than non smokers (p < 0.001); iii) non smokers who consume PAH-rich meals > or =52 times/year (142 subjects, 42%) have significantly increased adduct levels than those <52 times/year (p < 0.01). Dietary and smoking habits did not influence the occupationally-induced adduct levels in coke-oven workers. This is the first study that examines anti-B[a]PDE-DNA adduct levels in a large cohort showing that anti-B[a]PDE-DNA adducts can be detected in humans environmentally exposed to low doses of PAH (B[a]P and are modulated by smoke and dietary habits.

It is important to identify the potential genetic-susceptible factors that are able to modulate individual responses to exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs). In the present study we evaluated the influence of four polymorphisms of nucleotide excision repair (NER) genes [xeroderma pigmentosum-C (XPC)-PAT +/-, xeroderma pigmentosum-A (XPA) 5' non-coding region-A23G, XPD-exon 23 A35931C Lys751Gln, xeroderma pigmentosum-D (XPD)-exon 10 G23591A Asp312Asn] and that of glutathione S-transferase mu1 (GSTM1-active or -null) on benzo[a]pyrene diol epoxide (B[a]PDE)-DNA adduct levels from the lympho-monocyte fraction (LMF) of highly PAH benzo[a]pyrene (B[a]P)-exposed Polish coke oven workers (n = 67, 67% current smokers) with individual urinary post-shift excretion of 1-pyrenol exceeding the proposed biological exposure index (BEI) (2.28 micromol/mol creatinine). The bulky (+/-)-r-7,t-8-dihydroxy-t-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene (anti-B[a]PDE)-DNA adduct levels were detected by high-performance liquid chromatography (HPLC)/fluorescence analysis and genotypes by polymerase chain reaction. We found that workers with the low DNA repair capacity of XPC-PAT+/+ and XPA-A23A genotypes had significantly increased anti-B[a]PDE-DNA adduct levels (Mann-Whitney U-test, z = 2.24, P = 0.02 and z = 2.65, P = 0.01). Moreover, DNA adducts were also raised in workers without GSTM1 activity (GSTM1-null genotype) (Mann-Whitney U-test, z = 2.25, P = 0.0246). Workers with unfavourable XPC-PAT+/+ and XPA-A23A NER genotypes, alone (approximately 65% of workers) or combined with GSTM1-null genotype (approximately 75% of workers) were in the tertile with the highest adduct level, i.e. >4.11 adducts/10(8) nt (chi2 = 5.85, P = 0.0156 and chi2 = 5.40, P = 0.01). The increase in anti-B[a]PDE-DNA adduct levels (ln values) was significantly related in a multiple linear regression analysis to PAH exposure (i.e. urinary post-shift excretion of 1-pyrenol) (t = 2.61, P = 0.0115), lack of GSTM1 activity (t = 2.41, P = 0.0192) and to low DNA repair capacity of the XPC-PAT+/+ genotype (t = 2.34, P = 0.0226). The influence of the XPA-A23A genotype was not evident in this statistical analysis, and no associations with XPD polymorphisms, dietary habits or tobacco smoking were found. The modulation of anti-B[a]PDE-DNA adducts in the LMF by GSTM1-null and some low-activity NER genotypes may be considered as a potential genetic susceptibility factor capable of modulating individual responses to PAH (B[a]P) genotoxic exposure and the consequent risk of cancer in coke oven workers.