Post-occupational health surveillance of asbestos workers.

BACKGROUND: Italian law requires an extensive health surveillance of workers after cessation of their employment status in the case of occupational exposure to carcinogens, including asbestos. Nonetheless, Italian law does not specify the timeframe of these clinical checks, nor who has financial and organizational responsibility for this surveillance. A literature search confirmed a lack of consensus around the objectives and methods to follow up workers with past occupational exposure to asbestos. OBJECTIVES: To develop an updated evidence-based methodology for an appropriate health surveillance programme. METHODS: We present an overview of the field experience developed by the Veneto Region from 2000 to 2011, and new studies that could contribute to establishing a national policy for the medical surveillance of workers with past asbestos exposure. RESULTS: There were three specific topics: (1) definition of a reliable method to identify asbestos workers (through multiple sources and procedures that meet current confidentiality regulations); (2) detection of asbestos fibres in biological media (to support the etiological diagnosis of asbestos-related diseases); (3) creation of a national protocol of health surveillance (through the assessment of policies developed by other Regions in this field, and recruiting from these regions a cohort of past-exposed workers: the epidemiological study should offer relevant suggestions for specific surveillance approaches, based on either estimated cumulative asbestos exposure or detection of x-ray patterns of pleural plaques and/or asbestosis). CONCLUSIONS: These studies will support the Regions in setting up health care policies directed at workers with past asbestos exposure.

[Feasibility of a screening programme for lung cancer among workers previously heavily exposed to asbestos]. / Valutazione di un programma per la diagnosi precoce di cancro polmonare negli ex esposti ad asbesto.

BACKGROUND: We evaluated the feasibility and costs of a screening programme with spiral CT for the early diagnosis of lung cancer among workers previously heavily exposed to asbestos. METHODS: We invited 2000 workers, 1165 (58%) of whom accepted. Women and individuals with incomplete information were excluded; 1119 subjects (mean age, 57 years) entered the main analysis. Subjects with non-calcified lung nodules and/or dubious pleural plagues (No=338) entered a post-screening diagnostic protocol based on radiological follow-up. RESULTS: Twenty-five biopsies were performed (13 pulmonary, 9 pleural, 3 combined) revealed 5 cases of lung cancer (including 1 in stage IA). The positive predictive value of the screening test was low (31%) despite its known high sensitivity (100%) and specificity (99%). Incidence of lung cancer was similar to that registered among male residents of the Veneto Region aged 55 to 59 years. The cost of the programme was Euro 1,000 per screened subject and Euro 245,000 per diagnosis (total cost, Euro 1,181,310). The total radiation dose administered to healthy subjects was about 1,100 mSv (220 mSv per lung cancer diagnosis). CONCLUSIONS: This screening programme was ineffective due to the low participation rate, the small number of diagnoses, low predictive value, and high costs.

Exposure to hydrogen peroxide and eye and nose symptoms among workers in a beverage processing plant.

OBJECTIVES: Two cross-sectional studies were undertaken on workers in a beverage processing plant to investigate the association between low H(2)O(2) exposure and symptoms of irritation (2005 study) and to investigate the effect of wearing respiratory protection (2006 study). METHODS: The study comprised 69 workers exposed to H(2)O(2) in sterile chambers and 65 unexposed controls. The exposure was assessed from measurements and work task information from employment records. The severity of work-related symptoms was evaluated using questionnaires. Data were analyzed by the Student's t-test, multiple linear regression and analysis of variance for repeated measures of symptoms. RESULTS: Symptoms of eye, nose and throat irritation were significantly (P < 0.001) more severe among exposed workers compared to controls. Exposure values were occasionally above American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value-time-weighted average (TLV-TWA) in the sterile chambers. The relationship between the severity of symptoms and the number of entrances in the chambers was significant (P < 0.0001) in 2005 but not in 2006, when respirators were used during work in the sterile chamber. No differences were found between exposed who entered a sterile chamber in 2005 but not in 2006 and exposed who entered a sterile chamber both in 2005 and 2006. This suggests that respirators provided an efficient protection and that the irritative effects of exposure to H(2)O(2) in 2005 did not disappear after 1 year. CONCLUSIONS: The source of risk was exposure in the sterile chamber, even though the time of exposure was generally only approximately 30 min. To ensure complete worker protection, there is a need for a short-term exposure limit for H(2)O(2) in addition to the existing ACGIH TLV-TWA value.

How to prevent immunological reactions in leprosy patients and interrupt transmission of Mycobacterium leprae to healthy subjects: two hypotheses.

The basis of World Health Organization strategy for leprosy elimination is that the only source and reservoir for infection are patients with the disease. It was assumed that multi drug therapy (MDT) would reduce transmission of Mycobacterium leprae, but there is no convincing evidence for this. Furthermore, even if MDT has been proved to be extremely effective against the infectious disease, a noticeable proportion of leprosy patients can suffer from immunologic hypersensitivity reactions which are now the most significant issue in the managements of the disease. In endemic areas it was found that: M. leprae survives outside human body; healthy individuals harbor M. leprae bacilli in nasal cavity and shed micro-organisms in environment; there is widespread subclinical transmission of M. leprae with transient infection of the nose resulting in the development of a mucosal immune response. This disparate clinical, epidemiologic, and microbiologic evidence leads to the first hypothesis: that antigenic load in local tissues, sufficient to trigger the immune response, comes from external supply of M. leprae organisms. The hypothiocyanite anion (OSCN-) is generated in vivo by the reaction of thiocyanate with hydrogen peroxide catalyzed by lactoperoxidase. OSCN- is an antimicrobial oxidizing agent that prevents growth of bacteria, fungi, and viruses. OSNC- exists in lower airway secretions and lung has never been reported to be affected by leprosy. There is a sufficient concentration of OSCN- in the saliva, and accordingly mouth is rarely affected by leprosy. By contrast, the concentration of this compound is low or nil in nasal and lacrimal secretions and leprosy very often affects nose and eyes. The second hypothesis is that OSCN- may also protect from leprosy. Recently a method of OSCN- production, not involving enzymatic steps or use of toxic heavy-metal salts, has been patented. Studies on the susceptibility of M. leprae to hypothiocyanite could be carried out and, in case of positive results, the substance might be used in order to sterilize the nasal cavity of healthy carriers and prevent transmission of M. leprae to healthy subjects and to leprosy patients in whom it may trigger an immune response.

[Working and health conditions and preventive measures in a random sample of 5000 workers in the Veneto Region examined by telephone interview]. / Condizioni di lavoro e di salute e attività di prevenzione in un campione di 5000 lavoratori del veneto esaminati con questionario mediante intervista telefonica.

BACKGROUND: A survey was carried out in 2000 by the European Foundation for the Improvement of Living and Working Conditions in a random sample of workers from 15 countries of the European Union in order to obtain information on occupational exposure, health problems and preventive measures taken at the workplaces. OBJECTIVES: To obtain similar information in workers in the Veneto Region and compare the results with those of the third European Survey on Working Conditions (ESWC). The results of the survey on Veneto Region workers were further analyzed, investigating the distribution by risk factors in each work sector, and the association between risk factors and reported health problems. METHODS: The ESWC questionnaire was adapted to the requirements of a telephone interview and a sample of 5000 workers (size based on the budget) between 15 and 64 years of age was randomly extracted from the regional list of telephone subscribers. The questionnaire was administered by trained interviewers. No statistical tests were used in the comparison between ESWC and Veneto Region results due to the lack of a priori hypotheses. Odds ratio (OR) was calculated in estimating the association between risk factors and symptoms; and p-value for OR trend across the increasing level of exposure was also obtained. RESULTS: Workers reported to be exposed for more than a quarter of their work time to: vibrations (20%), noise (19%), dusts, fumes vapours, chemicals (18%), repetitive hand/arm movements (50%), tiring/painful positions (46%); working at very high speed or tight deadlines (60%). 54.4% of the subjects reported working with computers. Taking as a reference the third ESWC in 2000, among Veneto Region workers in 2005 exposure was lower as regards physical, chemical and ergonomic risk factors, and similar as regards working at very high speed. The more frequently reported work-related health problems were: stress (26.9%), backache (17.8%), overall fatigue (11.9%), muscular pains in upper limbs (6.8%), headache (6.1%), sight problems (5.4%), anxiety (5.5%), muscular pain in lower limbs (4.3%), irritability (4.0%), hearing problems (2.3%). Except for stress, all symptoms/health problems were two-three times more frequently reported in the ESWC than in the Veneto Region survey where, conversely, the number of persons with at least one new sick- leave spell was higher. Lastly, there was no difference as regards preventive measures taken at the workplace: information on risks (78.2%), wearing personal protective equipment (28.7%), training paid by employer (28.7%). Among the Veneto Region workers, the most often reported risk factors were exposure to physical and chemical risk factors in industry/agriculture, and shift-work and working at very high speed in the services. The most commonly adopted preventive measures were information on risks and wearing of personal protective equipment in industry, and training in services. Moreover, among the Veneto Region workers, a significant exposure-dependent increase was reported for respiratory problems, allergies, dermatitis, hearing loss, accidents, back pain, pain in the upper and lower limbs, and headache. The risk of stress, anxiety, sleeping problems, stomach pain and headache increased when skills were not adequate to cope with job demand. In contrast, the perception of improved health conditions increased with increasing skill discretion, decision authority, social support (which are dimensions of control of job demand), but not with information on risk, training, or use of personal protective equipment. CONCLUSIONS: Data from the present survey provide useful insights on working and health conditions of workers in the Veneto Region, revealing problems that were subsequently investigated using other sources of information, as reported in the studies published elsewhere in this volume.

[Comparison of four measurements of sickness absence in workers in the Veneto Region: interpretation and applicability. Data from Italian National Social Security Institute, 1997-2002]. / Quattro misure di assenze dal lavoro per malattia nei lavoratori del veneto, dati INPS 1997-2002: interpretazione dei risultati e applicabilità.

BACKGROUND: In 2005, 52% of workers in the Veneto Region reported one or more sick leave spells in the previous 12 months, compared with 16% reported in the European Survey on Working Condition in 2000 (ESWC), although health conditions were better in the Veneto Region than in the ESWC. OBJECTIVES: Since the above findings were based on answers to a questionnaire, we used an objective source of information in order to further investigate the problem. METHODS: The source of data consisted of the sick leave records of workers in the Veneto Region, 1997-2002, which were obtained from the Italian National Social Security Institute (INPS). Four measurements were used: (1) frequency = number of sick-leave spells during the study period/number of insured persons at risk for sickness absence during the study period; (2) cumulative incidence = number of persons with at least one new sick-leave spell during the study period/number of insured persons at risk for sickness absence during the study period; (3) sick-leave rate = number of sick-leave days during the study period/number of insured persons at risk for sickness absence during the study period; (4) duration of absence = number of sick-leave days in new sick leave spells during the study period/number of new sick-leave spells during the study period. Cumulative incidence could only be analyzed by statistical methods (binomial regression). RESULTS: The first three measurements gave overlapping results. The values were highest in industry, lowest in agriculture, and intermediate in crafts and services; they were highest in middle-aged subjects and lowest in younger and older individuals; the time trend increased up to 1999 and then decreased slowly. Cumulative incidence was 52.0%, 38.0%, 36.4% and 22.9%, in industry, services, crafts, and agriculture, respectively, and 42.8% in the total population. The results of binomial regression confirmed the above pattern, as well as an excess in women, in white collar workers, and in various occupational categories which, however, were probably not due to occupational exposures since in each occupational category the risk was always higher in industry than in crafts. By contrast, the sick-leave rate was higher in crafts and agriculture and lower in services and industry; it increased exponentially with age and did not show real differences between males and females. CONCLUSIONS: The choice of measurements influences the results; duration of absence could be used to detect areas of suspected work-related diseases, while cumulative incidence might be more helpful to detect areas of suspected absenteeism/presenteeism.

[Occupational injuries and sickness absence: association with job demand, decision latitude, and life style in 2174 workers in the Veneto Region]. / Infortuni sul lavoro e assenze dal lavoro per malattia: associazioni con carico lavorativo, autonomia decisionale e stili di vita in 2174 lavoratori del veneto.

BACKGROUND: Stress was the most frequent (26,9%) health problem reported in a survey on the perception of working and health conditions in 5000 workers in the Veneto Region. OBJECTIVES: The aim of the study was to investigate in the Veneto Region the association between occupational stress and events occurred in the previous 12 months: occupational accidents, or sickness absence for 10 or more consecutive days. METHODS: Perceived occupational stress is correlated, according to Karasek's model, to high job demand (JD) and low decision latitude (DL). Using Karasek's questionnaire (to which questions on smoking and alcohol consumption were added), we examined 2174 subjects working in 30 companies with between 10 and 500 employees, who belonged to the occupational categories of industry and services that are more prevalent in the Veneto Region. The questionnaire was administered by the occupational physician during health surveillance. The subjects were classified on the basis of current exposure to psychosocial factors or, for subjects reporting an event, their exposure at that time. We identified the tertiles of JD and DL; data were submitted to the analysis of multiple logistic regression, estimating odds ratio (OR) and 95% confidence interval (CI). The population attributable risk (PAR) was calculated using the formula (pc (OR-1)/OR), where pc is the fraction of exposed cases. RESULTS: An elevated risk of occupational accidents was found in subjects with regular consumption of alcohol (OR = 2.0; IC = 1.2-3.5), in smokers smoking 10-20 (2.3; 1.3-3.8) or >20 cigarettes/day (3.8; 1.8-7.9), in the highest tertile of JD (2.29; 1.35-3.89) and in the lowest tertile of DL (1.6; 1.0-2.6). PAR was 37.6% for occupational factors (high JD and low DL), 44.5%for non-occupational factors (cigarette smoking and alcohol consumption), and 82.1% overall. The risk of sickness absence increased in subjects smoking 10-20 cigarettes (1.63 = 1.1-2.40), in the highest tertile of JD (1.5; 1.0-2.2) and in the lowest tertile of DL (1.6; 1.1-2.2). PAR was 26.1% for occupational factors (high JD and low DL), 7.6% for non-occupational factors (smoking), and 30.4% overall. While the risk of sick absence increased mainly with the reduction of DL, the risk of occupational accidents increased with increasing JD and, to a lesser extent, with decreasing DL. The current approach to accident prevention is based only on technical and administrative aspects, in spite of the fact that 80% of accidents are not attributable to malfunctioning of machinery. Injury prevention should address technical, personal and psychosocial risk factors together as a whole.

[Association between causes of lNPS compensated disability and occupational category (Veneto Region, 1994-2002): a surveillance method for occupational diseases?]. / Associazione tra causa di invalidita pensionabile INPS e comparto lavorativo (Veneto, 1994-2002): un metodo di sorveglianza delle malattie professionali?

BACKGROUND: According to Italian law, workers are insured against disability through the National Social Security Institute (INPS), whose records contain information on diseases causing disability and occupational histories. OBJECTIVES: Using the INPS data, our objective was to identify any excess risk of disabling diseases in relation to the occupational categories. METHODS: Insurance covers all private sector employees, a small proportion of public sector employees, agricultural labourers, domestic workers, self-employed workers (craftsmen, commercial dealers,farmers), and few other occupational categories. For each insured worker, a database was created containing registry data, occupational history and, for compensated workers, the disease code, for each year from 1994 to 2002. A cohort study design was adopted, in which references were self-employed workers (with mixed exposure) to whom different categories of employees in agriculture, industry, crafts, and services were compared. Data were analyzed by means of Poisson regression, estimating the Incidence Rate Ratio (IRR) and confidence interval (CI) at 99.99%, instead of 95%, in order to set the threshold of error for the entire study at 0.05. RESULTS: In the construction industry there were significantly high risks of disability in both industry and crafts for tumours (industry: IRR = 2.07; IC = 1. 67-2.57; crafts: 2.57; 1.89-3.18), circulatory disorders (industry: IRR = 2.24; IC = 1.65-3.04; crafts.: 3.06; 2.16-4.32), and bone and joint diseases (industry. IRR = 5.0; IC = 3.15-7.94; crafts: 6.58; 5.04-8.59). CONCLUSIONS: The advantage of this approach is to recruit a large number of subjects at limited cost. The procedure here proposed is a mainly exploratory approach aimed at establishing new study hypotheses: disability, in fact, is acknowledged by INPS when its cause is not occupational according to the current literature.

[Safety and health in workers employed in industry. Data from Industrial Accidents Compensation Board (INAIL) and National Social Security Institute (INPS), Veneto Region, 1994-2002]. / Sicurezza e salute dei lavoratori dell'Industria attraverso i dati INAIL e INPS, Veneto, 1994-2002.

BACKGROUND: A decreasing time trend for occupational injuries and sickness absence would be the effect of the new legislation (D.Lgs. 626/94 and successive laws) on prevention in occupational settings. Conversely, the reduction of INPS disability would reflect a health improvement due to non-occupational causes. OBJECTIVES: The aim of the study was to investigate the efficacy of the new legislation among employees in industry (where the law was mainly applied), via the time trend of three standardized rates in the Veneto Region. METHODS: The numerator for the rate of occupational accidents (cases occurring in industry workers in the Veneto Region, broken down for sex, age and calendar years) was supplied by INAIL. The denominator for the above rate, as well as numerators and denominators for disability and sickness absence were supplied by INPS. Data were available from 1994 to 2002 for accidents and disability, and from 1997 to 2002 for sickness absence. In every year from 1994 to 2002, the rates were standardized for age and sex with the direct method, using an internal "standard" population. The time trend of year-specific standardized rates was analyzed by Joinpoint regression software. RESULTS: Among industrial workers in the Veneto Region, occupational accidents increased by 0.4% yearly, while disability decreased by 2.56% from 1994 to 2002. Sick absence increased up to 1999, then decreased. CONCLUSIONS: This epidemiological pattern is difficult to explain. The increase in accidents could be due to the increase of non-European Union workers and/or to the fact that accidents on the way to or from work were recognized as occupational accidents by INAIL starting from 2000. Both these phenomena could have contributed to increase the rate that was otherwise diminishing. On the other hand, this same situation could be due to insufficient efficacy of the legislation (D.Lgs. 626/94 and successive laws) for preventing occupational accidents and diseases.

[A procedure for estimating the rate of occupational accidents in non-European-Union workers with irregular immigrant status]. / Una procedura per la stima del tasso di infortunio nei lavoratori extracomunitari irregolari.

BACKGROUND: Statistics on occupational accidents provided by the Italian Institute for Occupational Diseases and Accidents (INAIL, Italian acronym) include only events that occurred in workers with regular employment status. OBJECTIVES: The aim of the study was to establish a procedure in order to estimate the rate of occupational accidents in non-European-Union (non-EU) workers with irregular employment status and/or irregular immigrant status. METHODS: The sources of data were the clinical records of the Emergency Department of San Bonifacio Hospital, and the population data of District 4 of Local Health Authority 20 of Verona, which was considered the catchment area of this hospital. RESULTS: Among 419 cases of accidents occurred in the numerator of the rate. The denominator of the rate was estimated by calculating: (1) the subjects of working age resident in District 4 (= 83714); (2) the total number of non-EU workers, assuming that the percentage was similar to that in San Bonifacio Municipality (= 0.115); the number of irregular non-EU workers, assuming that the percentage was similar to that in north-eastern Italy (= 0.103). Non-EU workers with irregular employment status and/or irregular immigrant status should, according to these calculations, be 992 (= 83714 x 0.115 x 0.103). The rate--147.2 (= 146/992) occupational accidents per 1000 irregular non-EU workers--is more than twice as high as that calculated in 2004 in Italy in regular non-EU workers (approximately 65 accidents per 1000). The difference can be explained by the fact that irregular workers find employment mainly in agriculture, building and the metallurgic industry, which have a high frequency of accidents, and are more willing to accept risky work and longer work shifts. CONCLUSIONS: On the assumption that the rate of occupational accidents in the 500,000 irregular workers living in Italy in 2004 was 147.2 per 1000 (as in the catchment area of the San Bonifacio Hospital), the number of accidents would be 73,600, against the 116,000 that occurred among regular non-EU workers in 2004 according to INAIL. Official INAIL statistics on occupational accidents therefore show a considerable underestimation.