Age Characteristics of Mesothelioma Incidence in the General Population of the Province of Padova, 1965–1976

Twenty-four incidental cases of mesothelioma, diagnosed in the province of Padova during the period 1965–1976, were analyzed according to age characteristics. The results show that the incidence rate increases in the general population under study at the same rate as in other populations occupationally and non-occupationally exposed to carcinogenic fibers according to the time since first exposure. This finding suggests a similar neoplastic process independent of age, in different environmental situations.

Occupational exposure to electromagnetic fields in physiotherapy departments

To assess occupational exposure to electromagnetic fields, 11 microwave (MW), 4 short-wave diathermy and 15 magneto therapy devices were analysed in eight physiotherapy departments. Measurements taken at consoles and environmental mapping showed values above European Directive 2004/40/EC and ACGIH exposure limits at approximately 50 cm from MW applicators (2.45 GHz) and above the Directive magnetic field limit near the diathermy unit (27.12 MHz). Levels in front of MW therapy applicators decreased rapidly with distance and reduction in power; this may not always occur in work environments where nearby metal structures (chairs, couches, etc.) may reflect or perturb electromagnetic fields. Large differences in stray field intensities were found for various MW applicators. Measurements of power density strength around MW electrodes confirmed radiation fields between 30 degrees and 150 degrees , with a peak at 90 degrees , in front of the cylindrical applicator and maximum values between 30 degrees and 150 degrees over the whole range of 180 degrees for the rectangular parabolic applicator. Our results reveal that although most areas show substantially low levels of occupational exposure to electromagnetic fields in physiotherapy units, certain cases of over-occupational exposure limits do exist.

Protection of third parties in current legislation and preventive practice

The problem of safety and the management of risks to third parties, which may be caused by a change in the mental or physical health of an employee, is one which affects a number of different areas (infectious diseases, psychiatric illnesses, conditions of drug and alcohol abuse, etc.). Italian legislation deals with the issue of fitness for work through a variety of laws, decrees and regulations which, because many of them were issued in different historical circumstances, are not always mutually harmonized. The growing complexity of the workplace makes the role of the Occupational Physician more complex, and to this person the law assigns the exclusive task of monitoring the health of employees in the cases covered by the current regulations. In our opinion, the Occupational Physician, to the best of his knowledge and conscience, having taken into consideration all the aforementioned factors, must take each case on its merits, in the most responsible manner possible, weighing up the complexity and delicacy of the aspects discussed earlier, and decide to deliver a verdict of fitness and/or to break or not to break the obligation of confidentiality, tending, in our view, to favour the need to safeguard collective health, or that of third parties, should there be a conflict of interest.

[Interactions between solvents and noise: state of the art]

There are several environmental and occupational scenes where a co-exposure of noise and solvents occurs, therefore between a neurotoxic and a ototoxic agent. Epidemiological and experimental studies with simultaneous exposure to noise and solvents like toluene, styrene and carbon disulfide have been analysed. These studies investigate possible ototoxic effects through audiometry, auditory brainstem response, potential recall and reflex decay test. The current available data show that with high exposure levels, that are responsible for tissue damage by themselves, the interaction between noise and solvents could occur. The present knowledge can not permit a conclusion for low exposure levels.

[Occupational chronic obstructive pulmonary disease: Italian law (decree no. 336/1994) and epidemiological evidence]

BACKGROUND

In Italy, occupational diseases are required by law to be listed (however, any occupational diseases not included in the list may be compensated if workers demonstrate causation in court). The list is periodically updated in order to incorporate new findings from medical research. Decree no. 336/94 uses a less inclusive term (chronic obstructive bronchitis) than that used in the earlier decree, no. 482/75 (chronic obstructive pulmonary disease, COPD). Moreover, it includes fewer occupations that involve a risk of developing COPD.

OBJECTIVES

In order to find an epidemiological basis that might justify the above changes to Italian law, risk of COPD was investigated in relation to occupation and time, using a case-referent design.

METHODS

The same definition for COPD (clinical history of >2 years with shortness of breath and/or winter phlegm and an FEV1 less than 80% of the predicted value, only minimally reversible with bronchodilators and without marked change during the hospital observation period) was used in two case-referent studies. The first study was carried out from 1972 to 1980 (202 cases of COPD and 202 referents matched for age and sex) and the second from 1990 to 1997 (131 cases of COPD and 298 referents, every fourth eligible patient in each calendar year of observation). In both studies cases and referents were classified into 16 occupational categories, and office workers were the reference. All subjects were selected from male patients admitted to the Occupational Health Clinic in Padua. Smoking-adjusted (Mantel-Haenszel analysis, first study), or age-smoking-adjusted (logistic regression analysis, second study) Odds Ratio (OR) and 95% confidence interval (CI) for COPD were estimated in each occupational category and in two main groups: workers employed in occupations at either high or low risk for COPD. The latter OR and the fraction of exposed cases (pc) were used to estimate the population attributable risk (PAR) through: pc(OR-1)/OR.

RESULTS

Significantly high risks for COPD in miners and chemical workers were observed in the first period, but not in the second time window. On the other hand, an increased time trend for OR estimates was found in welders, wood carpenters, construction and foundry workers. Among farmers, painters, cotton textile and refractory brick workers, the OR for COPD was significantly above unity in both time periods. PAR was 37% in the first and 52% in the second study.

CONCLUSIONS

The restrictive definition of occupational COPD, which was introduced by Decree no. 336/94, contrasts with the epidemiological evidence showing that the risk of occupational COPD has increased over time: up to 50% of COPD cases referred to an occupational medicine physician might have an occupational origin.

[Musculoskeletal diseases among a group of geriatric residence workers]

A total of 274 workers of a geriatric residence underwent physical and anamnestic examination in order to ascertain the existence of diseases associated with occupational risks of manual handling of patients. Data on musculo-skeletal disorder of the spine and of the upper limbs were collected. The correlation between manual handling of patients and musculo-skeletal disorder in this worker population is consistent with those already reported in the literature. Data was compared with prevalence estimates of musculo-skeletal disorder in worker population not exposed. This comparison showed significant increase of scapulo-humeral periarthritis in female over 35 years of age. In conclusion, this duty is a specific risk for the upper limbs; therefore more risk evaluation studies are needed. Also, a check for these types of disorders should be included in all duty specific medical exam protocols.

Ascertaining the risk of chronic obstructive pulmonary disease in relation to occupation using a case-control design

BACKGROUND

Recent community surveys have reported a risk of chronic obstructive pulmonary disease (COPD) in occupations involving exposure to organic dust and gas/vapour. Aims Our aim was to confirm these results using a case-control design on 131 COPD cases (FEV(1) < 80% of predicted value, minimally reversible with bronchodilators) and 298 controls, selected from registers for patients admitted to our Institute of Occupational Medicine.

METHODS

Surrogates of past exposure were occupation, exposure assigned by a job-exposure matrix, and years spent in a given occupation. The odds ratio (OR) and 95% confidence interval (CI) for COPD were calculated using logistic regression models with office workers as the reference.

RESULTS

Age-smoking-adjusted ORs (and CIs) were: 15.1 (3.2-71.6) in farmers; 7.2 (1.3-41.1) in cotton workers; 6.4 (1.6-25.5) in welders; 4.7 (1.3-16.4) in painters; 12.1 (1.3-108) in foundry workers; 6.50 (1.14-37.0) in refractory brick workers; and 3.1 (1.0-9.5) in construction workers. In farmers, cotton workers, welders and painters, the adjusted ORs significantly increased (by 6-9%) for each extra year of work, while in other occupations any such increase was of borderline significance. Adjusted ORs were 3.80 (1.21-12.0), 5.83 (1.82-18.6) and 8.86 (2.29-34.3) in workers exposed to high levels of mineral dust, gas/vapour/fume and biological dust, respectively. Consistent risk estimates were obtained for farmers, textile workers, painters and welders.

CONCLUSIONS

Our findings confirm previous epidemiological evidence and are supported by recent observations that cigarette smoke, cotton and organic farm dust contain the same powerful pro-inflammatory agents, and that organic dust and irritant gas induce bronchitis by triggering the same effector molecules as cigarette smoke.

[Diseases in hospital workers]

Occupational diseases and labour accidents in health care workers (Azienda Ospedaliera di Padova) were evaluated from 1990 to 2000; the information collected is compared with the same data of Regione Veneto and INAIL. 262 occupational diseases were found; nurses are more affected than other health care workers. In both reports (Azienda Ospedaliera di Padova and Osservatorio epidemiologico della Regione Veneto) half of the occupational diseases and injuries are represented by allergic disease. Low back pain is also equally represented in Azienda Ospedaliera and in Osservatorio epidemiologico results (5.3% and 6.6% respectively). Among the labour accidents reported to INAIL from 1994 to 2000, 25% of them were represented by falls and slips, 23% by car accidents, 17% were caused by tools, 17% by movement of goods and persons, 8% by contact with splinters, liquids, dusts, 5% by assaults and 5% by contact with blood or body fluid. The latter result is widely underestimated in the INAIL report, because these events usually produce a temporary inability of less than 3 days; in fact, they represent more than half of the labour accidents treated at the Azienda Ospedaliera di Padova. Medical surveillance (in exposure to aldehydes, anaesthetic gases, chemioterapic drugs) has shown many other occupational health problems that often need specific structural intervention (restructuration and restoration of workplaces in health care environments), and work organization changes.

[Occupational exposure to electromagnetic fields in physiotherapy departments]

An assessment of the electromagnetic fields emitted from short and ultrashort wave diathermy sources and from magneto therapy operating at a frequency of 50 Hz was made to evaluate the occupational exposure to the operators. Operators were exposed to electromagnetic fields which rarely exceed the recommended limits of International Commission on Non-Ionizing Radiation Protection (ICNIRP) and American Conference of Governmental Industrial Hygienists (ACGIH). Only a measurement of electromagnetic fields near short wave diathermy equipment operating at a frequency of 27.12 MHz exposed operators to levels above those recommended by ICNIRP at a distance of 1 metre. Magnetic fields of magneto therapy exceeded residential exposition of 1 microtesla, at a distance of 4 metres.

Susceptibility of healthcare workers to measles, mumps rubella and varicella

Susceptible healthcare workers are at risk of acquiring and transmitting measles, mumps, rubella and varicella to or from patients. We tested 333 employees at Padova University Hospital, for specific IgG. Of the workers tested, 98.2% were positive for measles, 85.9% for mumps, 97.6% for rubella and 97.9% for varicella. Eventhough participants born before 1957 were not all positive, they had a higher prevalence of immunity. We suggest serological screening in high-risk areas (paediatrics, oncology, radiotherapy, infectious diseases, maternity and the laboratory) and vaccination of susceptible employees.

[Organization of health and safety activities in health care centers]

The paper proposes a model for health and safety organization in health care units and hospitals which takes account of the risk assessment procedures required by law and the quality assessment of the measures thus taken. A redefinition is given of the role of Medical Director and of the functions, aims and standards on which health and safety service and the services of an authorized occupational health physicians must be based.

[Risk during manual movement of loads]

The estimation of risk from manual movement of loads in health care workers was carried out in 8 hospitals of Veneto Region, North-eastern Italy. 49 medical wards, 53 surgical wards, 23 surgery departments and 21 emergency and diagnostic services were examined. Operationally, a check-list was used to analyze the organization of the work (staff, duties, typology of patients to mobilize) and the work environment. Results show that 61% of the medical wards and 75% of the surgical wards have a higher risk. In particular, the medical wards of geriatrics and neurology, the wards of neurosurgery, heart surgery, orthopedics, the big burns center and geriatric surgery resulted in greater risk. Similarly, 70% of the emergency and diagnostic services and all surgical areas were estimated to be at risk. Given this reality, it has been determined that there are inadequacies in both organizational and structural aspects. In all the examined situations, the risk related to the relationship non self-sufficient patients/nurse was greater when mechanical help was lacking. In 70% of the cases the nursing staff transported patients with the bed. Concerning structural inadequacies, insufficient space was verified in over 50% of the examined wards. Preventive measures should be taken on the two aspects considered, variation of the work organization and the reclamation of work environment. But above all, the need for mechanical help should be emphasized, in order to reduce to a minimum the manual load thus preventing the onset of low-back pain in the nursing staff.

[Health surveillance: scope, tools, efficacy, prospects]

According to experts of the European Commission, NIOSH and OSHA, health surveillance's goal is the both health protection and occupational diseases prevention (including injury and uneasiness). This goal is pursued by assigning workers according to his or her working capacity without any health prejudice. Currently available instruments to protect workers' health include: (i) medical surveillance before employment, (ii) medical surveillance before placement in a job involving exposure to toxics, (iii) medical surveillance at periodic intervals during employment, (iv) medical surveillance at termination of employment. Studies carried out on the efficacy of medical surveillance show the capacity both of identifying health problem and of being perceived as a benefit for workers. An appropriate application of medical surveillance should take into account points as efficacy, guidelines, costs and benefits, and effectiveness. This entails the need to carry out research aiming (i) to make the importance of currently used preventive instruments explicit and (ii) to study new approaches to be applied in occupational health care.

[Analysis of a preventive health service]

This paper reports the experience and organization of an Occupational Health Service for health-care workers, in order to improve the effectiveness of the unit. The Authors describe the activities of the unit, its organization, and evaluate the amount of working time spent in the different activities.

[Reduction of the lung cancer risk among dairy ranchers: dose response relationship with the traditional indicators of professional exposure]

An epidemiological study of mortality was carried out in the Province of Padua in a cohort of family farmers. The subjects, identified from the SCAU files, were enrolled in the cohort if informations were available on complete registry data, date of beginning and of termination of farm work, size of farm, and number of dairy cattle. The 2,415 farmers selected were followed-up for mortality through the registry offices of their Communes of residence. The cause of death was obtained for the 541 decedents. The standardised mortality ratio (SMR) was the ratio between observed and expected mortality, calculated on the basis of the mortality rates in the regional general population. The lung cancer SMR was 0.54 (0.36-0.79; observed = 27) among the 1641 dairy farmers, and 0.78 (0.46-1.25; observed = 17) among the 774 arable farmers. Among dairy farmers, moreover, lung cancer SMRs showed a significant trend across the quartiles of length of work, number of cattle, area of farm, age at beginning farm work, and age at work termination. Dairy farmers are known to be exposed to higher airborne endotoxin concentrations, and it is reasonable to assume that this cumulative exposure further increases with years of work, number of cattle, and area of farm. Microbial endotoxin might have protected dairy farmers against lung cancer through a host factor, the Tumor Necrosis Factor, produced by alveolar macrophages.

Repeated case-control studies as a method of surveillance for asthma in occupations

Our aim was to establish whether the case-control design may be applied in surveillance for occupational asthma. In a region with intensive manufacturing industries, we carried out one case-control study from 1974 to 1978 and another from 1989 to 1993; 325 and 387 pairs of cases of asthma and of age- and sex-matched control subjects, respectively, were selected. Current risks were found to be higher than past estimates for painters, farmers, millers/bakers, textile, wood/ furniture, and chemical workers. High risks for asthma have recently appeared in leather, polyurethane plastics, hospital and food industry workers, welders, and shoemakers. It is concluded that the case-control approach may be used to describe variations in asthma risk by occupational categories and time. A method to measure the efficiency of the diagnostic process for occupational asthma is also proposed.

[Mortality by tumors and other causes in dairy cattle and other agricultural workers in Veneto]

The study was conducted to verify a reduction in mortality from tumors in dairy farm workers, exposed to endotoxins, which increase in the host a cytotoxic antitumoral. From the SCAU files of the Province of Padova, we selected 2.415 subjects with informations on: date of hire, date of work termination, number of dairy cattle, area of the farm. The vital status was ascertained through the Communes of residence, and for the 541 decedents the cause of death was established. The standardized mortality ratio (SMR) was calculated on the basis of age-sex-cause-calendar period specific mortality rates in the Veneto. In the 1.641 dairy farm workers, SMRs were significantly low for total tumors (= 81) and lung tumors (= 66), and significantly high for brain tumors (= 283). In other 774 farmers, no significant SMRs were observed. The data will be further processed to verify a dose-response relationship with the occupational risk indicators. Smoking habits will be collected.

[Carcinogenic risk of extremely-low-frequency electromagnetic fields: state of the art]

This paper summarizes the published literature and current problems relating to possible cancerogenic effects of occupational and residential exposure to ELF electromagnetic fields at levels slightly above ambient background. There are several suggestions that such an exposure may increase the risk of cancer, but these studies failed to provide conclusive indications. The present state of uncertainty led to a variety of recommendations and statements being made concerning restrictions to the exposure of people to ELF electromagnetic fields. Attempts to detect direct chromosomal damage from ELF electromagnetic fields have proven negative, while results on cancer promotion have been controversial. On the basis of several epidemiological studies on occupational exposure, an increased risk of leukemia, brain cancer and male breast cancer is apparent; the literature on residential exposure provides some evidence of an effect on childhood cancer, especially leukemia; however, when interpreting these results some major methodological concerns should be kept in mind. In conclusion, the public concern and potential public health impact of this environmental agent argue strongly for addressing further research in order to identify mechanisms of action on biological systems, to define the proper assessment of exposure and to obtain good epidemiological evidence.

[Biotransformation in occupational medicine: the role of hepatic cytochrome P-450 in the mechanism of action and the biological monitoring of occupational toxic compounds]

Biotransformation is an important step in the investigation of occupational toxic chemicals. This is because the knowledge of the metabolic pathways and the enzymes involved in the activation and/or detoxication of xenobiotics may help in understanding the mechanism of toxicity and to rationalize the biological monitoring of exposed subjects. The largest enzymatic system involved in the biotransformation of industrial chemicals is cytochrome P-450, a family of haemoproteins capable of metabolizing a vast number of lipophilic, structurally different compounds. The study of the various metabolic reactions of this peculiar group of enzymes has greatly contributed to a) the clarification of the mode of action of several classes of occupational toxic and/or carcinogenic compounds, such as aromatic amines, polycyclic aromatic hydrocarbons, halogenated alkanes, benzene compounds and others, and b) the improvement of risk assessment in the biological monitoring of the exposed subjects, by allowing the toxicological significance (activation/detoxication) of single metabolites to be better understood.

[The occupational risks in a company producing aluminum alloy wheels]

An environmental hygiene study was carried out in a factory making aluminium alloy wheels via pressure moulding. Physical risk factors (noise and microclimate) and chemical risk factors (respirable dust, mineral oils, solvents, fluorides, formaldehyde, CO) were assessed. Analysis of the data showed that physical risk factors were prevalent, whereas chemical pollution was insignificant due to technical improvements made by the management in the course of several redesigns of the plants.

[Mutagens and carcinogens in city air]

Many urban air pollutants are recognized to be mutagenic and carcinogenic agents. Combustion processes, which generate gaseous and particulate complex mixtures, are responsible for the major part of urban air pollution. Emissions from automotive sources are estimated to be nowadays the main cause of mutagenic/carcinogenic risk for people living in urban areas of industrialized countries. Increasing vehicle traffic also contributes to the presence in urban air of valuable concentrations of asbestos fibers and benzene, both well-known potent carcinogens.

[The AMES test in environmental and occupational medicine]

The authors review the use of the gene mutation test on Salmonella typhimurium, better known as the Ames test, in environmental and occupational health. This test, which was originally intended as a predictive test of the carcinogenicity of chemical substances, has been widely applied in in vitro screening of complex mixtures of substances present in the environment and in the biological monitoring of high risk populations. Data are reported on the main environmental exposures that were positive with the Ames test and it is stressed how this biological assay has contributed to the identification of new classes of genotoxic compounds (nitropyrenes, mutagen X). The Ames test performed on extracts of human urine was used to study exposure to carcinogenic substances in the working environment. Many occupational exposures can cause an increase in mutagenic activity in the exposed subjects (cytostatic drugs, rubber manufacture, polycyclic aromatic hydrocarbons). It is recommended to restrict the use of the urinary mutagenesis test to group studies and carefully check confounding factors (e.g., smoking and diet).

[Urinary excretion of mutagens and cisplatin among the nursing staff at a medical oncology department exposed to cytostatic drugs]

Exposure to cytostatic drugs was assessed in a group of 9 nurses employed in a hospital cancer therapy department by measuring the post-shift levels of urinary mutagens and cis-platinum. A slight but significant increase in urinary mutagenic activity compared to 11 controls was observed in the non-smokers: the mean values of mutagenic activity on the Ta100 strain in the presence of both microsomal and deconjugating enzymes were 4418 +/- 1186 and 2468 +/- 1681 respectively. Conversely, the urinary platinum concentration was below the detection limit of the analytical method (10 micrograms/l) in all samples. The increased urinary mutagenic activity in the exposed group can probably be attributed to the absorption of cyclophosphamide either during preparation and administration of the drug, or due to accidental contact with contaminated biological fluids, in view of the fact that the level of mutagens in urine samples from cyclophosphamide-treated patients is extremely high (up to 319,478 revertants/g creatinine in the case we examined).

[Kinds of home accidents]

A survey on hospitalization due to domestic accidents conducted in Padua in three public hospitals shows that between 1979 and 1988 there were 12.251 cases. Women in particular seemed to be affected by the phenomenon (7.926 cases, 64.7% of total) especially if aged 45 years or over (6.382 hospitalizations). Home injuries among females are the second cause of hospitalization due to trauma and represent the leading cause of accidental deaths (355 cases during the period of the survey). Lethality of this kind of injury progressively increases starting from the ages 30-44, and reaches 7.1% in older people (60 years or over). The causes of these accidents have been analyzed in 197 cases of fatal domestic accidents during the five years 1984 to 1988 and in 277 cases of non fatal accidents that involved subjects between the ages of 15 and 59 during the years 1986. In both situations the most frequent cause was falling (132 fatal, 159 non fatal cases); this finding shows the importance of a primary prevention programme based on the improvement of domestic structures and more care in furniture planning. The second place both among fatal and non fatal injuries belongs to burns (21 fatal and 17 non fatal). These frequently arise from incorrect behavior and emphasize in this way the necessity of improving sanitary education. A great number of home accidents (33 hospitalizations), can be attributed to bad working instruments or absence of security devices. This all shows the necessity of specific security regulations regarding installations and utensils of domestic use.

[Environment and the immune system]

A large number of xenobiotics (i. e. chemicals, drugs and biologicals) may adversely affect the immune system in consequence of different mechanisms: 1) the capacity of a large variety of xenobiotics to cause an allergic sensitization and different types of allergic sequelae (e.g. bronchial asthma, rhinitis, hypersensitivity pneumonitis, contact dermatitis); 2) the adjuvant effect, potentiating the IgE mediated immuno-response against ubiquitous allergens (e.g. pollens); 3) the direct or indirect action on the immune system, at doses that did not cause overt toxicity. This effect is studied by a new discipline, called Immunotoxicology; 4) the indirect action on the target organ, which facilitate the onset of respiratory symptoms in previously asymptomatic subjects. The widespread distributions of xenobiotics in the environment suggests that our current knowledge of their adverse health effects may represent only the tip of the iceberg and that exposure to such immunotoxic agents may play a greater role than heretofore suspected in disease causation. The exposure to immunotoxic agents in the workplace might represent and additional risk to HIV positive individuals.

Mortality of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy

After reports appeared from other countries indicating an excess risk of lung cancer among silicotics, a cohort of workers compensated for silicosis during the period 1959-1963 in the Veneto region of Italy was constructed and followed for mortality through 1984. The results of the study showed a large mortality excess for infectious diseases (180 observed versus 9.5 expected), due to silicotuberculosis, and for diseases of the respiratory system (270 observed versus 33.5 expected) due to silicosis. An elevated standardized mortality ratio of 239 (70 observed versus 29.3 expected) from lung cancer was also detected. An increasing pattern was observed with time since first exposure, while the relationship with employment category and duration of exposure was less clear-cut. The lung cancer excess was also strongly associated with cigarette smoking, there being a dose-response relationship with daily cigarette consumption. The study confirms the results from other epidemiologic studies on silicotics which show this pathological condition to be associated with increased lung cancer mortality.

Study of immunological parameters in farmer's lung

A cross-sectional epidemiological study was carried out on 2932 farmers (response rate 92%) living in Northern Italy. A questionnaire on respiratory symptoms was supplied, chest X-ray taken and simple spirometry tests made. Thirty-nine subjects reported attacks of breathlessness associated with fever after exposure to mouldy hay; thirty-six had a clinical history of farmer's lung and X-ray and/or respiratory function changes indicative of chronic farmer's lung; 113 were classified as having bronchial asthma. These 118 subjects and a random sample of 131 non-symptomatic subjects were examined by intracutaneous skin tests and double diffusion precipitation tests with antigens associated with farmer's lung. All sera positive by precipitation were examined by immunoelectrophoresis, counterimmunoelectrophoresis, and C1q binding test, and Bovine conglutinin test in solid phase for the detection of circulating immunocomplexes. 27.8% cases of chronic farmer's lung, 4.4% of cases of bronchial asthma and 2.3% of non-symptomatic subjects showed precipitating antibodies against farmer's lung antigens. Of the precipitin-positive subjects, the majority had precipitating antibodies against Micropolyspora faeni. No differences in immunoelectrophoregrams in number and pattern of precipitation arcs for M. faeni were found between chronic farmer's lung and bronchial asthma subjects. Circulating immune complexes were present in 50% of chronic farmer's lung patients, 40% of those with bronchial asthma and 33.3% of non-symptomatic subjects. Three farmer's lung subjects (9.3%) showed immediate skin-test reactions to rural environmental allergens.

Epidemiological study of pneumoconiosis in the Italian poly(vinyl chloride) industry

Among 1216 workers employed in a poly(vinyl chloride) production factory, 20 cases of pneumoconiosis were found. None of these workers had had previous exposure to organic or inorganic dusts; 731 had been exposed to PVC dust (employed in drying, sacking and blending of polymer) and 485 had been exposed to monomer alone. Chest x-ray films were read by two independent physicians utilizing the ILO/UC Pneumoconiosis Classification, 1971. X-ray abnormalities were characterized by limited profusion, irregular type and low gravidity; in a small percentage of cases these were associated with slight restrictive respiratory function impairments. All 20 workers with PVC-induced pneumoconiosis had been exposed to high PVC dust pollution for at least five years. Mild nonspecific alterations (profusion of 0/1 class) were found both in the group exposed to PVC dust and in the group exposed to VCM alone. Such changes (observed in 388 cases, 31.9% of the whole population), are related mainly to age and smoking habits, and the role of exposure is minor.

Descriptive Epidemiology of Hodgkin's Disease in the Province of Padova, 1970-1974

The age-standardized incidence rates of Hodgkin's disease in the province of Padova during the period 1970-1974 were 4.33/105 per year for males and 3.70/105 per year for females. These rates are higher (particularly for females) than in other European countries and close to those reported for North America. A bimodal distribution by age is present in the province as a whole. These findings, with the limitations due to the small population and diagnostic difficulties taken into account, are discussed with a view to further investigation.

Descriptive Epidemiology of Non-Hodgkin's Lymphoma in the Province of Padova, 1970-1974

The age-standardized incidence rates of non-Hodgkin's lymphoma in the province of Padova during the period 1970-1974 were 3.19/105/year for males and 1.60/105/year for females. These rates are similar to those found in other industrialized countries and slightly higher than in the province of Torino. An increasing trend with age is described, beginning in the age group 35-44, while low rates were found in younger ages in both sexes. No relevant' pattern was shown in the geographical distribution of cases, and no observed/expected ratio was significant in any of the administrative districts considered. The influence of environmental factors and the limitations due to uncertain diagnostic criteria and the small size of the population considered are discussed.

Polyvinyl chloride pneumoconiosis: epidemiological study of exposed workers

Among 1216 workers who were employed in a polyvinyl chloride production factory and who had had no previous dust exposure elsewhere, 20 cases of pneumoconiosis were found. Chest x-ray abnormalities were characterized by limited profusion, irregular type and low gravity. All 20 workers had been exposed to high PVC dust levels. The chest x-ray changes were observed after a minimum exposure of five years and, in a small percentage of cases, were associated with slight restrictive respiratory function impairments. Moreover, in the whole group of workers 388 cases (31.9%) were found with non-specific x-ray abnormalities mainly related to age and smoking.

[Clinical and statistical study on the allergy of type 1 to mycetes (author's transl)]

From 1963 to 1977 the authors have examined 5700 patients; 11.5% of those positive to intradermal test were sensitive to Mold spores. 78 individuals showed allergic sensitivity exclusively to Mold spores; 89% were affected by bronchial asthma. Symptom onset was observed more frequently in subjects 30 to 50 years old. The authors intend to stress the important role played by the allergy to Mold spores in determining type 1 immunologic reactions.

[Chronic broncopneumopathy and pneumoconiosis in workers employed in phosphoric acid production (author's transl)]

Thirty-five subjects employed in a phosphoric acid producing plant were studied by the authors. The investigation included: history, according to the C.E.C.A. questionnaire for chronic bronchitis and emphysema; physical examination, chest X-ray spirometry and lung diffusing capacity for carbon monoxide by the steady state method (DLCOSS). High prevalence of chronic bronchitis (45.7%), obstructive spirometric impairment (37.1%), and decreased values of DlcoSS (31.4%) were detected. Two subjects were found to be affected with p 1/0 and 7 with p 0/1 pneumoconiosis. Such findings were significantly related to the lenght of working activity as well as to dust and gaseous fluoride (hydrofluoric acid, hexafluorosilicic acid and silicon tetrafluoride) exposure.

[Epidemiologic evaluation of isocyanate immediate irritative action: 'one day effect' control (author's transl)]

Nineteen MDI exposed workers showed ventilatory changes, after eight hour exposure, mainly involving upper respiratory airways; the changes reversed following a bronchodilator aerosol. An incomplete recovery of VC was found in some subjects; therefore, the possibility of changes in the lung elastic recoil forces was hypothesized. No statistically significant differences were found as to occupation and smoking habit, which suggests that even low MDI concentrations could be enough to give rise to acute effects. The greater impairment found in subjects who were already affected by morning time emphasizes the necessity that such subjects were not employed in their specific work.