Occupational exposure to asbestos and risk of kidney cancer: an updated meta-analysis.

Limited information is available on carcinogenicity of asbestos on non-respiratory organs. We aimed at conducted an updated systematic review and meta-analysis of cohort studies on occupational exposure to asbestos and risk of kidney cancer. We searched through three databases, PubMed, Embase and Scopus for article published after 2000, and after eliminating duplicates and non-relevant studies, we identified 13 studies. We combined their results with those of 31 non-overlapping studies included in a previous review up to 2000. We conducted a meta-analysis based on random-effects models. The pooled relative risk of kidney cancer for asbestos exposure was 0.94 (95% confidence interval, 0.84-1.04), with no differences according to type of asbestos fiber, geographic region, period of exposure, or estimated quality of the study. Our results showed a lack of association between occupational asbestos exposure and risk of kidney cancer.

The role of the occupational physician in controlling gastric cancer attributable to Helicobacter pylori infection: A review.

This review aimed to describe the potential role of occupational physician in the implementation of a screening program for Helicobacter pylori (Hp) infection for gastric cancer prevention. We reviewed the epidemiological background of gastric cancer and its association with Hp, exploring the hypothesis of a "test-and-treat" protocol among working population. Clinical trials and model-based studies were collected to provided empirical evidence of the feasibility of eradication on large scale. In particular, previous studies conducted in occupational settings were discussed. Hp prevalence ranges between about 20 and 90%, with higher rates in Asia and Latin America and lower rates in Europe and North America. Large-scale trials on screening and treatment of infection have been conducted especially in East Asia, lacking elsewhere. Only few studies investigated Hp prevalence among workers. The benefit of eradication at occupational level has not yet been adequately studied. The design of a workplace-based Hp screening program appears to be innovative and could contribute to controlling gastric cancer. The benefit would involve not only high-risk subjects, but also their families, since the route of transmission is principally within the household. An occupational setting for a Hp screening would have positive consequences in terms of individual and public health.

Temporal Patterns of Exposure to Asbestos and Risk of Asbestosis: An Analysis of a Cohort of Asbestos Textile Workers.

OBJECTIVE: The aim of the study was to assess the risk of asbestosis death based on the temporal pattern of exposure to asbestos. METHODS: We followed up a cohort of asbestos textile workers, employed in 1946 to 1984, until November 2013. We measured the duration of the employment, the time since last employment (TSLE), the age, and the year of first employment. Hazard ratios (HR) were estimated through multivariable Cox regression models. RESULTS: We observed 51 asbestosis deaths among 1823 workers. The HR of asbestosis death increased with exposure duration (HR 2.4 for ≥15 years compared with <5 years, P trend = 0.014) and declined with TSLE (HR 0.3 for ≥25 compared with <5 years, P = 0.004). The risk of asbestosis mortality strongly declined for exposure starting after 1968. CONCLUSIONS: The risk of asbestosis death strongly declines in the decades after cessation of the exposure.

Updated mortality study of a cohort of asbestos textile workers.

Limited information is available on risk of peritoneal mesothelioma after asbestos exposure, and in general on the risk of cancer after cessation of asbestos exposure. We updated to 2013 the follow-up of a cohort of 1083 female and 894 male textile workers with heavy asbestos exposure (up to 100 fb/mL), often for short periods. A total of 1019 deaths were observed, corresponding to a standardized mortality ratio (SMR) of 1.68 (95% confidence interval [CI]: 1.57-1.78). SMRs were 29.1 (95% CI: 21.5-38.6) for peritoneal cancer, 2.96 (95% CI: 2.50-3.49) for lung cancer, 33.7 (95% CI: 25.7-43.4) for pleural cancer, and 3.03 (95% CI: 1.69-4.99) for ovarian cancer. For pleural and peritoneal cancer, there was no consistent pattern of risk in relation to time since last exposure, whereas for lung cancer there was an indication of a decline in risk after 25 years since last exposure. The findings of this unique cohort provide novel data for peritoneal cancer, indicating that - as for pleural cancer - the excess risk does not decline up to several decades after cessation of exposure.

Radiation-induced mesothelioma among long-term solid cancer survivors: a longitudinal analysis of SEER database.

We investigated the association between external beam radiotherapy (EBRT) and pleural and peritoneal mesothelioma among long-term (>5 years) solid cancer survivors. We analyzed data from the US Surveillance, Epidemiology, and End Results (SEER) program (1973-2012). We fitted survival models adjusted by age, gender, race, year, surgery, and relative risk of primary mesothelioma in the county of residence (proxy for individual asbestos exposure). We estimated hazard ratios [HR] with reference to nonirradiated patients. We distinguished between scattered and direct irradiation to study the dose-response. We observed 301 mesotheliomas (265 pleural; 32 peritoneal; 4 others) among 935,637 patients. EBRT increased the risk of mesothelioma (any site; HR 1.34, 95% CI 1.04-1.77). We observed an increased risk of pleural mesothelioma (HR for EBRT 1.34, 95% CI 1.01-1.77), but we did not find signs of a dose-response relationship (HR for scattered irradiation 1.38; HR for direct irradiation 1.23). On the opposite, only direct peritoneal irradiation was associated with peritoneal mesothelioma (HR 2.20, 95% CI 0.99-4.88), particularly for latencies ≥10 years (HR 3.28, 95% CI 1.14-9.43). A competing risks analysis revealed that the clinical impact of radiation-induced mesothelioma was limited by the high frequency of competing events. The cumulative incidence function of mesothelioma after 40 years of observation was very low (nonirradiated patients 0.00032, irradiated patients 0.00055).EBRT might be a determinant of mesothelioma. Longer latency periods are associated with higher risks, while the dose-response seems nonlinear. The clinical impact of mesothelioma after EBRT for primary solid cancers is limited.

DNA damage and repair capacity in workers exposed to low concentrations of benzene.

DNA damage and cellular repair capacity were studied in 18 male fuel tanker drivers and 13 male filling-station attendants exposed to low and very low concentrations of benzene, respectively, and compared to 20 males with no occupational exposure (controls). Exposure to airborne benzene was measured using passive personal samplers, and internal doses were assayed through the biomarkers t,t-muconic acid, S-phenylmercapturic acid and urinary benzene. DNA damage was evaluated using tail intensity (TI) determined by the comet assay in peripheral lymphocytes. Urinary 7-hydro-8-oxo-2'-deoxyguanosine (8-oxodG) was measured as a biomarker of oxidative damage. DNA repair kinetics were assessed using the comet assay in lymphocytes sampled 20 and 60 min post H2O2 exposure. Benzene exposure differed significantly between the drivers (median 246.3 µg/m(3)), attendants (median 13.8 µg/m(3)), and controls (median 4.1 µg/m(3)). There were no differences in TI and 8-oxodG among the three groups, or between smokers and non-smokers. DNA repair kinetics were similar among the drivers, attendants and controls, although the comet assay on H2 O2 -damaged lymphocytes after 60 min revealed significantly lower levels of TI only in drivers. The DNA repair process in smokers was similar to that observed in drivers. In conclusion, this study found no relationship between low levels of benzene exposure and DNA damage, although there was evidence that exposure interferes with DNA repair kinetics. The biological impact of this finding on the onset of genotoxic effects in exposed workers has still to be ascertained.

Incidence rates of surgically treated rhegmatogenous retinal detachment among manual workers, non-manual workers and housewives in Tuscany, Italy.

PURPOSE: Candidate risk factors for idiopathic rhegmatogenous retinal detachment (RRD) include heavy manual handling (requiring Valsalva's maneuver). We assessed incidence rates of surgically treated idiopathic RRD among manual workers, non-manual workers and housewives resident in Tuscany, Italy. METHODS: We retrieved all hospital discharge records bearing a principal diagnosis corresponding to RRD coupled with retinal surgery for any resident of Tuscany during 1997-2009. After elimination of repeated admissions and patients with coexistent, associated conditions (including recent trauma), subjects aged 25-59 years were classified as manual workers, non-manual workers or housewives. Population data were extracted from the 2001 census. RESULTS: We identified 1,946 eligible cases (1,142 men). Among men, manual workers experienced a 1.8-fold higher age-standardized rate per 100,000 person-years than non-manual workers [17.4 (95 % confidence interval (CI) 16.1-18.7) vs. 9.8 (95 % CI 8.8-10.8)]. Age-standardized rates among women were 1.9-fold higher for manual workers [11.1 (95 % CI 9.8-12.3)] and 1.7-fold higher for housewives [9.5 (95 % CI 8.3-10.8)] than in non-manual workers [5.7 (95 % CI 4.8-6.6)]. CONCLUSIONS: This large population-based study suggests that manual workers are affected by idiopathic RRD requiring surgical treatment more often than non-manual workers. The higher rates of surgically treated RRD experienced by manual workers are in accord with the hypothesis that heavy manual handling may have a causal role.

[Occupational risks in grocery stores]. / Rischi da lavoro nella grande distribuzione.

AIM: This work provides an overview of the spectrum of possible occupational risk factors in the retail grocery store/supermarket workplace. METHOD: Literature on this theme, obtained consulting PubMed database and Google Scholar, was checked. We also exjlore results from the National bInstitute for Occupational Safety and Health (NIOSH) and the Occupational Safety and Health Administration (OSHA). RESULTs: Contacts with objects, use of dangerous equipment (cutter, food slicer) and falls to the same level (slips, trips and falls) are the mainly described workplace hazards. Exposure to chemical (flour dust, components of detergents or disinfectants, volatile organic compounds and contact with nickel) and physical agents (cold exposure, nonionizing radiation and whole bpdy vibration) are reported by many authors. Relations between biomechanical and ergonomic risk factors and musculoskeletal disorders represent the main subjects of study. Few studies are found about biological agents (particularly among butchers). Data regarding psychosocial risks factors in this setting are still limited. CONCLUSIONS: Musculoskeletal disorders continue to be the most recurrent health problem between the grocery store workers (particularly low back pain and carpal tunnel syndrome among cashiers). Many technical documents and international Srecommendations are present to prevent these kinds of disorders. Psychosocial risk factors and risk of workplace violence should deserve further investigation.

PubMed search strings for the study of agricultural workers' diseases.

BACKGROUND: Several optimized search strategies have been developed in Medicine, and more recently in Occupational Medicine. The aim of this study was to identify efficient PubMed search strategies to retrieve articles regarding putative occupational determinants of agricultural workers' diseases. METHODS: We selected the Medical Subjects Heading (MeSH) term agricultural workers' diseases and six MeSH terms describing farm work (agriculture, agrochemicals NOT pesticides, animal husbandry, pesticides, rural health, rural population) alongside 61 other promising terms. We estimated proportions of articles containing potentially pertinent information regarding occupational etiology to formulate two search strategies (one "more specific," one "more sensitive"). We applied these strategies to retrieve information on the possible occupational etiology among agricultural workers of kidney cancer, knee osteoarthritis, and multiple sclerosis. We evaluated the number of needed to read (NNR) abstracts to identify one potentially pertinent article in the context of these pathologies. RESULTS: The "more specific" search string was based on the combination of terms that yielded the highest proportion (40%) of potentially pertinent abstracts. The "more sensitive" string was based on use of broader search fields and additional coverage provided by other search terms under study. Using the "more specific" string, the NNR to find one potentially pertinent article were: 1.1 for kidney cancer; 1.4 for knee osteoarthritis; 1.2 for multiple sclerosis. Using the sensitive strategy, the NNR were 1.4, 3.6, and 6.3, respectively. CONCLUSION: The proposed strings could help health care professionals explore putative occupational etiology for agricultural workers' diseases (even if not generally thought to be work related).

Sarcoidosis in a dental surgeon: a case report.

INTRODUCTION: Although the causes of sarcoidosis are still unknown, past and current studies have provided evidence that this disease may be associated with occupational exposure to specific environmental agents. We describe a case of sarcoidosis in a dental surgeon with long exposure to inorganic dusts. To the best of our knowledge, this is the first report of this kind in the literature. CASE PRESENTATION: At the beginning of 2000, a 52-year-old Caucasian man, who worked as a dental surgeon, presented with shortness of breath during exercise, cough and retrosternal pain. After diagnosis of sarcoidosis, a scanning electronic microscopy with X-ray microanalysis of biopsy specimens was used in order to determine whether the disease could be traced to an occupational environmental agent. Results showed the presence of inorganic dust particles within sarcoidotic granulomas, and demonstrated that the material detected was identical to that found in a powder used by our patient for several years. CONCLUSIONS: Although these results cannot be considered as definitive proof, they do however provide strong evidence that this disease may be associated with material used by dental surgeons.

Search strings for the study of putative occupational determinants of disease.

OBJECTIVE: To identify efficient PubMed search strategies to retrieve articles regarding putative occupational determinants of conditions not generally considered to be work related. METHODS: Based on MeSH definitions and expert knowledge, we selected as candidate search terms the four MeSH terms describing 'occupational disease', 'occupational exposure', 'occupational health' and 'occupational medicine' (DEHM) alongside 22 other promising terms. We first explored overlaps between the candidate terms in PubMed. Using random samples of abstracts retrieved by each term, we estimated the proportions of articles containing potentially pertinent information regarding occupational aetiology in order to formulate two search strategies (one more 'specific', one more 'sensitive'). We applied these strategies to retrieve information on the possible occupational aetiology of meningioma, pancreatitis and atrial fibrillation. RESULTS: Only 20.3% of abstracts were retrieved by more than one DEHM term. The more 'specific' search string was based on the combination of terms that yielded the highest proportion (40%) of potentially pertinent abstracts. The more 'sensitive' string was based on the use of broader search fields and additional coverage provided by other search terms under study. Using the specific string, the numbers of abstracts needed to read to find one potentially pertinent article were 1.2 for meningioma, 1.9 for pancreatitis and 1.8 for atrial fibrillation. Using the sensitive strategy, the numbers needed to read were 4.4 for meningioma, 8.9 for pancreatitis and 10.5 for atrial fibrillation. CONCLUSIONS: The proposed strings could help health care professionals explore putative occupational aetiology for diseases that are not generally thought to be work related.

Risk factors for operated carpal tunnel syndrome: a multicenter population-based case-control study.

BACKGROUND: Carpal tunnel syndrome (CTS) is a socially and economically relevant disease caused by compression or entrapment of the median nerve within the carpal tunnel. This population-based case-control study aims to investigate occupational/non-occupational risk factors for surgically treated CTS. METHODS: Cases (n = 220) aged 18-65 years were randomly drawn from 13 administrative databases of citizens who were surgically treated with carpal tunnel release during 2001. Controls (n = 356) were randomly sampled from National Health Service registry records and were frequency matched by age-gender-specific CTS hospitalization rates. RESULTS: At multivariate analysis, risk factors were blue-collar/housewife status, BMI > or = 30 kg/m2, sibling history of CTS and coexistence of trigger finger. Being relatively tall (cut-offs based on tertiles: women > or =165 cm; men > or =175 cm) was associated with lower risk. Blue-collar work was a moderate/strong risk factor in both sexes. Raised risks were apparent for combinations of biomechanical risk factors that included frequent repetitivity and sustained force. CONCLUSION: This study strongly underlines the relevance of biomechanical exposures in both non-industrial and industrial work as risk factors for surgically treated CTS.

Physical exertion (lifting) and retinal detachment among people with myopia.

BACKGROUND: People with myopia (near sightedness) are at increased risk for retinal detachment. We explored other factors that may be associated with retinal detachment within this high-risk group. METHODS: We conducted a case-control study comprising 61 cases with retinal detachment and myopia and 99 hospital controls who also had myopia. Cases were recruited from a general hospital, and controls from ophthalmologic clinics. Participants compiled a questionnaire including details of past and current occupational lifting tasks to explore Valsalva maneuver as a possible risk factor. We devised a cumulative lifting index to distinguish light and heavy lifting. RESULTS: After adjusting for potential confounders, we found strong associations of retinal detachment with eye surgery, eye or head trauma, severe myopia (all known risk factors), and heavy lifting (vs. no lifting, odds ratio = 4.4 [95% confidence interval = 1.5-13]) and high body mass index (>or=25.5 kg/m, 6.8 [1.6-29]). CONCLUSIONS: Heavy occupational lifting and being overweight may be important risk factors for retinal detachment among people with myopia. The role of these risk factors in the etiology of retinal detachment deserves to be explored in more general populations.

Incidence rates of in-hospital carpal tunnel syndrome in the general population and possible associations with marital status.

BACKGROUND: Carpal tunnel syndrome (CTS) is a socially relevant condition associated with biomechanical risk factors. We evaluated age-sex-specific incidence rates of in-hospital cases of CTS in central/northern Italy and explored relations with marital status. METHODS: Seven regions were considered (overall population, 14.9 million) over 3-6-year periods between 1997 and 2002 (when out-of-hospital CTS surgery was extremely rare). Incidence rates of in-hospital cases of CTS were estimated based on 1) codified demographic, diagnostic and intervention data in obligatory discharge records from all Italian public/private hospitals, archived (according to residence) on regional databases; 2) demographic general population data for each region. We compared (using the chiscore test) age-sex-specific rates between married, unmarried, divorced and widowed subsets of the general population. We calculated standardized incidence ratios (SIRs) for married/unmarried men and women. RESULTS: Age-standardized incidence rates (per 100,000 person-years) of in-hospital cases of CTS were 166 in women and 44 in men (106 overall). Married subjects of both sexes showed higher age-specific rates with respect to unmarried men/women. SIRs were calculated comparing married vs unmarried rates of both sexes: 1.59 (95% confidence interval [95% CI], 1.57-1.60) in women, and 1.42 (95% CI, 1.40-1.45) in men. As compared with married women/men, widows/widowers both showed 2-3-fold higher incidence peaks during the fourth decade of life (beyond 50 years of age, widowed subjects showed similar trends to unmarried counterparts). CONCLUSION: This large population-based study illustrates distinct age-related trends in men and women, and also raises the question whether marital status could be associated with CTS in the general population.

Grand rounds: could occupational exposure to n-hexane and other solvents precipitate visual failure in leber hereditary optic neuropathy?

CONTEXT: Leber hereditary optic neuropathy (LHON) is a maternally inherited loss of central vision related to pathogenic mutations in the mitochondrial genome, which are a necessary but not sufficient condition to develop the disease. Investigation of precipitating environmental/occupational (and additional genetic) factors could be relevant for prevention. CASE PRESENTATION: After a 6-month period of occupational exposure to n-hexane and other organic solvents, a 27-year-old man (a moderate smoker) developed an optic neuropathy. The patient had a full ophthalmologic and neurologic investigation, including standardized cycloergometer test for serum lactic acid levels and a skeletal muscle biopsy. His exposure history was also detailed, and he underwent genetic testing for LHON mitochondrial DNA mutations. The patient suffered a sequential optic neuropathy with the hallmarks of LHON and tested positive for the homoplasmic 11778G--> A/ND4 mutation. Routine laboratory monitoring revealed increased concentrations of urinary 2.5 hexandione (n-hexane metabolite) and hippuric acid (toluene metabolite) in the period immediately preceding the visual loss. DISCUSSION: In a subject carrying an LHON mutation, the strict temporal sequence of prolonged appreciable occupational exposure followed by sudden onset of visual loss must raise a suspicion of causality (with a possible further interaction with tobacco smoke). RELEVANCE: In this article, we add to the candidate occupational/environmental triggers of LHON and highlight the need for appropriate case-control (and laboratory) studies to validate the causal effect of mixed toxic exposures.

Simultaneous determination of low levels of methotrexate and cyclophosphamide in human urine by micro liquid chromatography/electrospray ionization tandem mass spectrometry.

The aim of this study was to develop and validate a novel solid-phase extraction (SPE) liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the simultaneous determination of two antineoplastic drugs, cyclophosphamide (CP) and methotrexate (MTX), in human urine using trophosphamide as internal standard. The method showed good precision and accuracy (mean RSD 2.8% and 0.9%; bias 2.7% and 2.4% for MTX and CP, respectively). The lower limits of detection obtained, 0.2 microg/L(urine) for MTX and 0.04 microg/L(urine) for CP, were lower than the best previously reported values. The use of a 96-well SPE plate for matrix purification ensures a high throughput (50 samples/day), allowing the routine biological monitoring of CP and MTX as measures of occupational exposure at very low levels.

Spectrum of chromosomal aberrations in peripheral lymphocytes of hospital workers occupationally exposed to low doses of ionizing radiation.

Chromosome aberrations frequency was estimated in peripheral lymphocytes from hospital workers occupationally exposed to low levels of ionizing radiation and controls. Chromosome aberrations yield was analyzed by considering the effects of dose equivalent of ionizing radiation over time, and of confounding factors, such as age, gender and smoking status. Frequencies of aberrant cells and chromosome breaks were higher in exposed workers than in controls (P = 0.007, and P = 0.001, respectively). Seven dicentric aberrations were detected in the exposed group and only three in controls, but the mean frequencies were not significantly different. The dose equivalent to whole body of ionizing radiation (Hwb) did appear to influence the spectrum of chromosomal aberrations when the exposed workers were subdivided by a cut off at 50 mSv. The frequencies of chromosome breaks in both subgroups of workers were significantly higher than in controls (< or =50 mSv, P = 0.041; >50 mSv, P = 0.018). On the other hand, the frequency of chromatid breaks observed in workers with Hwb >50 mSv was significantly higher than in controls (P = 0.015) or workers with Hwb < or =50 mSv (P = 0.046). Regarding the influence of confounding factors on genetic damage, smoking status and female gender seem to influence the increase in chromosome aberration frequencies in the study population. Overall, these results suggested that chromosome breaks might provide a good marker for assessing genetic damage in populations exposed to low levels of ionizing radiation.

Lack of association between occupational radiation exposure and thyroid nodules in healthcare personnel.

OBJECTIVES: To investigate whether healthcare workers routinely exposed to low-level ionizing radiation have a higher prevalence of thyroid nodularity. METHODS: Presence of thyroid nodularity, as assessed by 10-MHz neck ultrasonography, was compared with accumulated radiation doses of 579 exposed university hospital workers (M:F 350:229) obliged to wear a personal dosimeter. RESULTS: Nodules were detected in 141/579 (24.3%) subjects. Mean accumulated dose was not different among subjects with and without nodules (14.19+/-28.00 mSv vs 17.71+/-32.89 mSv; P=0.12). Duration of occupational exposure (<10 years vs 10-19 years vs >or=20 years) did not affect prevalence of nodularity. At multivariate analysis, only female gender and age were significant risk factors. CONCLUSIONS: Mildly exposed health workers do not appear to incur any excess risk of thyroid nodularity.

Lack of correlation between environmental or biological indicators of benzene exposure at parts per billion levels and micronuclei induction.

Despite growing concern for possible carcinogenic effects associated with environmental benzene exposure in the general population, few studies exist at parts per billion (ppb) levels. We investigated the existence of a relationship between airborne/biological measurements of benzene exposure (i.e., personal/area sampling and unmodified urinary benzene/trans,trans-muconic acid; t,t-MA) and micronuclei induction (cytochalasin B technique) among exposed chemical laboratory workers (n=47) and traffic wardens (n=15). Although urinary t,t-MA (106.9+/-123.17 microg/L(urine)) correlated (R(2)=0.37) with urinary benzene (0.66+/-0.99 microg/L(urine)), neither biological measurement correlated with environmental benzene exposure (14.04+/-9.71 microg/m(3); 4.39+/-3.03ppb), suggesting that, at ppb level (1ppb=3.2 microg/m(3)), airborne benzene constitutes a fraction of the total intake. Traffic wardens and laboratory workers had comparable numbers of micronuclei (4.70+/-2.63 versus 5.76+/-3.11; n.s.), similar to levels recorded in the general population. With univariate/multivariate analysis, no association was found between micronuclei induction and air/urinary benzene exposure variables. Notably, among the personal characteristics examined (including age, gender, smoking, drinking, etc.), high body mass index correlated with micronuclei induction while, among females, use of hormonal medication was associated with less micronuclei. Thus the present study provides no evidence that ppb levels of environmental benzene exposure appreciably affect micronuclei incidence (against the background of other relevant factors). However, this should not be taken as an argument against efforts aiming to reduce environmental benzene pollution.