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The prevalence of farmer's lung was studied in five districts of the French Doubs province (Rougemont, Clerval, Levier, Montbenoît, Mouthe) on the basis of a medical and occupational questionnaire and serological studies for precipitins. Of the 1763 active farmers (response rate 69%) who participated in the study, 270 were suspected of having farmer's lung and divided, on the basis of clinical and serological criteria, into probable and possible farmer's lung groups. This subgroup of 270 patients was examined in more detail with physical examination, chest radiographs, and pulmonary function tests. Probable farmer's lung was diagnosed in 77 cases (53 men and 24 women, mean age 51.7 years), a prevalence of 43.7/1000. Possible farmer's lung was present in a further 193 subjects. Fever was the most specific symptom. In the group with probable farmer's lung the frequency of crepitations, restrictive ventilatory defect, and radiological interstitial abnormalities was 21.5%, 9.5%, and 9.2% at the time of the study. Farmer's lung was more common in the middle tablelands than in the plain or mountain areas (p less than 0.01). The difference in prevalence of farmer's lung between the Mouthe mountain and Levier middle tableland districts (25.2/1000 and 60.8/1000) raises the possibility that cold may protect against the disease. Farmer's lung was more frequent in men and in the age group 51-55 years. Among possible occupational factors, only regular work connected with feeding animals was associated with a significant risk (odds ratio 2.55 with a 95% confidence interval of 1.09-5.93). The frequency of chronic bronchitis in the population studied was 14.8%. There was a close link between farmer's lung and chronic bronchitis, 50.6% of patients with probable farmer's lung having it but only 8.6% of patients without farmer's lung (p less than 0.001). In patients with probable farmer's lung chronic bronchitis was independent of smoking and age. There were fewer smokers in the probable farmer's lung than in the non-farmer's lung group (p less than 0.05).

Farmer's lung is a cause of disability to agricultural workers in Devon and there is no evidence that the incidence is falling. A survey of known cases was made to assess the degree of disability in relation to the clinical history, the presence of farmer's lung precipitins, tests of lung function, and radiographic changes. Information was obtained about 200 patients diagnosed between 1939 and 1971. A survey of 148 of these patients showed that the disease was most commonly diagnosed in men aged 40 to 50 years and the most important symptom at diagnosis was dyspnoea related to occupational exposure to hay or grain. The onset was often insidious and only 67 patients (45%) were diagnosed during the first year of the disorder. Disability was severe in about one-third of the cases. The degree of disability did not seem to be related to the serological changes recorded either at diagnosis or at the time of our survey. Disability was commonly associated with restriction and reduced gas transfer factor and with airways obstruction in more severe cases. Many individuals reporting significant disability had only slightly abnormal ventilatory function tests at rest. Radiographic changes were found at survey in about one-third of the subjects reporting disability. Many farmers had not used an efficient mask. Treatment is unsatisfactory but steroid therapy is effective in acute episodes.

In a survey of the farming population of Orkney, Ayrshire, and East Lothian the prevalence of farmer's lung was estimated at 86 per 1,000 in both Orkney and Ayrshire and 23 per 1,000 in East Lothian. If cases with a negative farmer's lung hay (F.L.H.) precipitin test are excluded these figures are reduced to 43, 36, and nil respectively, but those for Orkney and Ayrshire are still about 20 times higher than any figure previously reported for the prevalence of farmer's lung in Britain.

Regional variations in prevalence are probably related both to climatic conditions and to differences in agricultural methods, the latter often being dictated by economic circumstances. Nevertheless the prevalence of farmer's lung could be reduced considerably by the energetic application of preventive measures, backed by financial incentives. The most important of these are efficient drying of hay and cereals before storage, more extensive use of silage, better ventilation of farm buildings, and the introduction of mechanical feeding systems. Individual farmworkers could be taught how to recognize the early symptoms of the disease and encouraged to wear respirators when handling mouldy fodder.

Surveys were carried out on random samples of the farming population in Devon and Wales in order to estimate the prevalence of respiratory symptoms and of positive precipitin reactions to thermophilic fungi. Bronchitis, as defined, was common among the Welsh hill farmers, and the proportion of positive serological tests was higher in both the areas surveyed in Wales as compared with Devon. All three surveys confirmed a previous finding that the proportion of positive precipitin tests was higher among non-smokers than smokers. Although the numbers were small there was some indication that measurement of peak expiratory flow showed different relationships with age in non-smokers according to the presence or absence of positive precipitin tests. The difficulty of determining prevalence rates for farmer's lung is discussed, but the results suggest a rate not dissimilar to those found in two areas of Scotland which were more than 20 times higher than any figure previously reported in Britain.

Boyd, G. and Parratt, D. (1974).Thorax, 29, 417-420. Improved diagnosis of farmer's lung using the fluorescent antibody technique. In the west of Scotland 20 of 40 farmers surveyed had symptoms of farmer's lung. Ten of this group (50%) gave positive precipitin reactions to Micropolyspora faeni. The fluorescent antibody test was positive in all those with symptoms and also in one who had no clinical evidence of farmer's lung. There was a close relationship between evidence of sensitization to M. faeni in the serum, demonstrated by the fluorescent antibody test, and the presence of symptoms compatible with farmer's lung. This test may detect the disease in milder form than is possible by conventional precipitin tests and this study confirms the value of this more sensitive technique as a screening procedure.

Morgan, D. C., Smyth, J. T., Lister, R. W., and Pethybridge, R. J. (1973).British Journal of Industrial Medicine,30, 259-265. Chest symptoms and farmer's lung: a community survey. Farmer's lung is one of the commonest causes of extrinsic allergic alveolitis, but there have been few studies of representative samples of farmers. A survey was carried out in Devon among 91 farmers and their families in order to estimate the prevalence of respiratory symptoms and of positive precipitin reactions to thermophilic fungi. Answers to a questionnaire about respiratory symptoms and smoking habits revealed among the men a prevalence of symptoms comparable with that found in other surveys of agricultural populations in the United Kingdom but with a lower proportion of smokers. A positive answer to a question about attacks of breathlessness associated with fever or shivering appeared to differentiate people suffering from farmer's lung. Twenty-three per cent of the population had precipitins to Micropolyspora faeni and two of these individuals also had precipitins to other fungi. There were statistically significant differences in the proportions of positive precipitin tests found in smokers, ex-smokers, and non-smokers. Six known cases of farmer's lung were included in the sample and all had positive precipitins.

Ninety four dairy farmers were investigated by chest radiography, pulmonary function tests, and bronchoalveolar lavage. They were divided into five groups--1: 11 subjects with acute farmer's lung; 2: 25 subjects with previously diagnosed farmer's lung who had stayed on their farm; 3: 15 farmers with previously diagnosed farmer's lung who had left the farm; 4: 23 precipitin positive symptomless farmers; 5: 20 precipitin negative symptomless farmers. The study evaluated the relationships between radiographic changes measured with a scoring system derived from the International Labour Office (ILO) classification, the results of pulmonary function tests, and bronchoalveolar lavage fluid. Thirty eight subjects had radiographic evidence of interstitial pulmonary infiltrates. Group 1 had the highest percentage of lymphocytes recovered by bronchoalveolar lavage (mean 66.3 (SD 19.2]. For all subjects carbon monoxide transfer factor (TLCO) and total lung capacity were negatively correlated with radiographic changes (r = -0.45 and -0.30; p less than 0.001 and less than 0.01 respectively). TLCO was also negatively correlated with radiographic change in group 2 (r = -0.59, p less than 0.005). The percentage of lavage lymphocytes was correlated with radiographic changes for all subjects (r = 0.36, p less than 0.001), but this correlation was not seen within groups. This study shows good correlation between radiographic abnormalities, pulmonary function changes and the cellular composition of bronchoalveolar lavage fluid.

A serological analysis of the extracellular antigens of Micropolyspora faeni by immunodiffusion with a combination of sera revealed 29 individual antigens. A survey was made of the incidence of precipitins to the antigens in sera from patients with clinical farmer's lung disease (FLD) and other respiratory diseases. Precipitating antibody was found in 75% of farmer's lung cases and in 20% of other cases who had been exposed to the same environment. More precipitin reactions were seen in sera from severe forms of FLD than from milder forms. The distribution of precipitins to individual antigens was not significantly affected by severity of disease.

Most of the patients with precipitins to M. faeni, but without the symptoms of FLD, were suffering from mild or moderate symptoms of other respiratory diseases with a history of chronic onset of symptoms. The distribution of precipitins to individual antigens in this group was similar to that in clinical FLD patients but the incidence was considerably lower.

The significance of these results is discussed.

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A group of 92 farmers had clinical evaluation, pulmonary function tests, and bronchoalveolar lavage (BAL). There were 12 patients with acute farmers' lung disease (FLD) (group 1) and 37 farmers who had had acute FLD, of whom 22 were still on their farm (group 2) and 15 had ceased contact (group 3); others were normal dairy farmers, 23 serology positive to Micropolyspora faeni (group 4), 20 serology negative (group 5), and 42 normal controls (group 6). Of the 134 subjects, 59 had an increase in alveolar lymphocytes (greater than 22% lymphocytes in BAL) (12 in group 1, 19 in group 2, six in group 3, 14 in group 4, five in group 5, and three in group 6). Within each group there was no correlation between BAL lymphocytes (% and absolute number) and most pulmonary function tests. It is concluded that although an increase in BAL lymphocytes is always seen in acute FLD it may also be seen in the absence of clinically evident disease and that BAL lymphocytosis does not correlate with physiological changes in FLD.

Immunodiffusion, immunoosmophoresis, and precipitin inhibition tests were carried out on various categories of sera with extracts of Micropolyspora faeni (Thermopolyspora polyspora), Aspergillus fumigatus, and Thermoactinomyces vulgaris. The sera were from clinical cases of farmer's lung, from symptomless farm workers, from expectant mothers, from tuberculous and from asthmatic patients, and from patients with miscellaneous lung disorders. The clinical cases of farmer's lung became divisible into two groups by serological tests for antibody to a particular soluble antigenic component of M. faeni. The suggestion is made that one of these two groups of cases may be aetiologically unrelated to M. faeni. One of six sera tested in this group reacted strongly with an extract of T. vulgaris. Antibodies to certain components of some extracts of M. faeni and of A. fumigatus were found in a high proportion of normal sera. Possible reasons for this finding have been given.

The immunological response of cattle exposed to moldy hay was examined by agar gel diffusion with standard farmer's lung hay antigens. A high incidence of precipitins against Micropolyspora faeni (60%) and moldy hay antigen (80%) was detected in exposed but apparently healthy cattle from a region with a high incidence of bovine farmer's lung. In comparison, in the plains, a low incidence area, we found only 1 animal of 164 harboring precipitins against M. faeni. We further observed that many animals from exposed populations lost their precipitins during pasturing and regained them during winter housing. Thirty-nine clinical cases of bovine farmer's lung (“Urner Pneumonie”) were investigated serologically. Only 49% of these animals showed precipitins against M. faeni and 54% showed precipitins against moldy hay antigen. We discuss in this paper the probable causes of this apparent lack of immunological response.

Background: A protective effect of endotoxin exposure on atopy and asthma in farmers' children has been postulated. Studies of adult farmers have shown conflicting results but often lack exposure data. The prevalence of asthma in farmers with different exposure levels to microbial agents and irritant gases was compared.

Methods: Atopy was defined as a positive response to multiple radioallergosorbent tests (RAST) with a panel of 10 common respiratory allergens, and asthma was ascertained by a questionnaire using a stratified sample (n = 2169) of a farming population from south-eastern Norway. Exposure of farmers to total dust, fungal spores, bacteria, endotoxins, and ammonia was assessed by exposure measurements.

Results: The prevalence of asthma was 3.7% for physician diagnosed asthma and 2.7% for current asthma. The prevalence of atopy was 14%, but most asthmatic subjects were non-atopic (80%). Compared with farmers without livestock, (1) asthma was significantly higher in cattle farmers (ORadj 1.8, 95% CI 1.1 to 2.8) and pig farmers (ORadj 1.6, 95% CI 1.0 to 2.5), (2) non-atopic asthma was significantly higher in pig farmers (ORadj 2.0, 95% CI 1.2 to 3.3) and in farmers with two or more types of livestock (ORadj 1.9, 95% CI 1.1 to 3.3), and (3) atopic asthma was less common in farmers with two or more types of livestock (ORadj 0.32, 95% CI 0.11 to 0.97). Exposure to endotoxins, fungal spores, and ammonia was positively associated with non-atopic asthma and negatively associated with atopic asthma. No associations were found with atopy.

Conclusions: Exposure to endotoxins and fungal spores appears to have a protective effect on atopic asthma but may induce non-atopic asthma in farmers.

Less than one per cent of serum samples taken from 257 fish farmers in 1981 had agglutinating antibodies to strains of Leptospira interrogans of serogroup Icterohaemorrhagiae at a titre of 30 or greater. Compared with the results from other serological surveys, this agglutinating antibody prevalence suggests that fish farming does not have a high occupational risk for leptospirosis. Between 1961 and 1981 the incidence in fish farmers was about 33 per 100000 person years at risk. During the same period the incidence in the general adult male population was 0.137 per 100000 person years at risk, so that fish farming had a moderately increased risk of Icterohaemorrhagiae serogroup infection (relative risk = 243). No one particular risk factor within fish farming could be reliably identified and therefore recommendations to reduce the risk can only be general.

In assessing patients suffering from farmer's lung, the acute stage must be distinguished from the chronic stage of the disease. The conspicuous radiographic signs in the acute farmer's lung episode and the often dramatic clearing make an important contribution to the diagnosis. The radiographic changes in chronic farmer's lung are not specific and cover a wide range of appearances. Even minor nodular changes are significant. Farmer's lung, acute and chronic, is not a disease predominantly characterized by a defect in gas exchange. During the acute illness the reduction in diffusing capacity is often accompanied by a decrease in lung volumes; the pulmonary function profile of the chronic stage is variable. In only a relatively small proportion of chronic farmer's lung patients does a defect in gas exchange predominate, and in some it may be manifest only during exercise. Airway obstruction is a feature of chronic farmer's lung. In chronic farmer's lung patients discrepancies between the severity of complaints and results of pulmonary function tests are not infrequent. In some patients with considerable disability conventional pulmonary function studies may demonstrate little or no impairment of the functions measured. In patients suffering from an acute farmer's lung episode, serological tests should be positive, possibly in high titre. In the chronic stage of the disease the chance of finding positive serology in a patient diminishes with the length of time elapsed since the last acute episode. The period of serological transition appears to be the third year.

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A total of 888 randomly selected dairy farmers participated in an epidemiological study to evaluate the prevalence of precipitins to farmer's lung antigens, and the socioeconomic factors associated with their presence. Precipitins were present in 75 farmers (8.4%) (65 to Micropolyspora faeni, seven to Aspergillus spp, two to both Aspergillus and Micropolyspora faeni, and one to Aspergillus and Thermoactinomyces vulgaris). The titres ranged from a dilution of 1/32 to a concentration of X 2 (Ouchterlony's double diffusion method). In the study population there were 544 who had never smoked, 146 ex-smokers, and 198 smokers. Sixty nine precipitin positive subjects were either never smokers or ex-smokers; only six were smokers. The negative relationship between cigarette smoking and precipitins was highly significant (p = 0.004). Factors positively associated with positive precipitin reactions were: size of farm, time spent in the barn, and the presence of a family member previously diagnosed as having farmer's lung disease. Interestingly, positive precipitin reactions were not associated with any of the following: use of silos, hay conditioners, or hay dryers; the presence or quantity of mouldy hay; or the presence of respiratory symptoms. It is concluded that precipitin analysis is not useful as a screening method for farmer's lung, though it can be of diagnostic value in acute farmer's lung disease.

In France and Finland, farmer's lung disease (FLD), a hypersensitivity pneumonitis common in agricultural areas, is mainly caused by Eurotium species. The presence of antibodies in patients' serum is an important criterion for diagnosis. Our study aimed to improve the serological diagnosis of FLD by using common fungal particles that pollute the farm environment as antigens. Fungal particles of the Eurotium species were observed in handled hay. A strain of Eurotium amstelodami was grown in vitro using selected culture media; and antigen extracts from sexual (ascospores), asexual (conidia), and vegetative (hyphae) forms were made. Antigens were tested by enzyme-linked immunosorbent assay (ELISA), which was used to test for immunoglobulin G antibodies from the sera of 17 FLD patients, 40 healthy exposed farmers, and 20 nonexposed controls. The antigens were compared by receiver operating characteristic analysis, and a threshold was then established. The ascospores contained in asci enclosed within cleistothecia were present in 38% of the hay blades observed; conidial heads of aspergillus were less prevalent. The same protocol was followed to make the three antigen extracts. A comparison of the results for FLD patients and exposed controls showed the area under the curve to be 0.850 for the ascospore antigen, 0.731 for the conidia, and 0.690 for the hyphae. The cutoffs that we determined, with the standard deviation for measures being taken into account, showed 67% for sensitivity and 92% for specificity with the ascospore antigen. In conclusion, the serological diagnosis of FLD by ELISA was improved by the adjunction of ascospore antigen.

Consumers who had purchased farm products from both quarantined and nonquarantined farms were examined during the cross-sectional clinical survey of 1,029 Michigan residents. Since PBB had inadvertently contaminated cattle and other farm animals, ingestion of meat, milk, eggs and other farm products was thought to have possibly resulted in significant PBB body burdens in some consumers. Findings were considered in comparison with those made among farm residents. Prevalence of symptoms in consumers of farm products from quarantined farms (CQ) was similar to that found in farmers on quarantined farms (FQ); the prevalence was lower in consumers of products from nonquarantined farms (CNQ). Liver function abnormalities were found with similar prevalence in dairy farmers and consumers. Distribution, mean and median values of PBB serum levels in consumers were found to be similar to those of dairy farmers. These results indicate that significant body burdens of PBB had been accumulated by some consumers of farm products in Michigan and that prevalence of symptoms and liver function abnormalities resembled those found among dairy farm residents.

The aim was to test the hypothesis that atopy increases the occurrence of chronic bronchitis. Relations between atopy, smoking, and chronic bronchitis were studied in farmers. The data were from two successive postal surveys and a skin prick tested subsample. The cross-sectional study consisted of 9017 farmers. Those 6899 farmers who did not have chronic bronchitis at the beginning and who continued farming were followed for three years. A sample of 150 farmers was skin-tested with 36 allergens. The prevalence of chronic bronchitis (rate per 1000), standardised for age and sex, was 41 in non-atopic non-smokers, 101 in atopic non-smokers, 106 in non-atopic smokers, and 257 in atopic smokers (effect of atopy: p less than 0.001; effect of smoking: p less than 0.001). The standardised incidence rates of chronic bronchitis (per 1000 farming years) were 14, 34, 36, and 50, respectively (atopy: p less than 0.001; smoking p less than 0.001). The relative risk of chronic bronchitis, calculated from the incidence data adjusting for the effects of age, sex, smoking or atopy by logistic regression analysis was 2.2 for atopy (95% confidence interval 1.8-2.7) and 2.3 for smoking (1.8-2.9). Only 20 farmers had chronic bronchitis in the skin-tested subjects; the results were consistent with the findings in the surveys but did not reach statistical significance for atopy. In conclusion, atopy and smoking have independent and additive effects on the occurrence of chronic bronchitis at least in dusty farming work.

A study was performed to compare respiratory symptoms and lung function measurements in a sample of male farmers and farmworkers in different regions of England and Wales with the results obtained in a similar number of control men working in industries in the same areas. A total of 428 farmers and farmworkers drawn from 146 farms were studied. The prevalence of symptoms of chronic bronchitis assessed by the Medical Research Council questionnaire did not differ between farmers and controls. Farmers were older, taller, and heavier than controls; were less likely to smoke; and had significantly higher forced vital capacity (FVC). When each of these factors was taken into account, together with social class and geographical region, in a multiple linear regression analysis farmers were found to have significantly lower forced expiratory volume in one second (FEV1) and forced mid expiratory flow rate (FEF25-75). Among the farmers, those doing dairy farming and silage work were the only groups on their own to have significantly reduced lung function. The results of this survey suggest the need for further exploration of the mechanism of an effect of farming occupations on lung function.

The prevalence of chronic bronchitis and of clinical farmer's lung was studied in 30 districts of the French Doubs province in relation to individual (age, sex, smoking) and geographical (altitude) factors. 5703 exclusively dairy farmers (response rate 83%) participated in the study by answering a medical questionnaire. Prevalences of chronic bronchitis and clinical farmer's lung were 9.3% and 1.4% respectively. A logistic regression model was used to evaluate risk factors for chronic bronchitis and clinical farmer's lung. A risk of chronic bronchitis was associated with male sex (p < 10(-4)), age (p < 10(-4)), smoker category (p < 10(-4)), and altitude (p < 10(-4)). A risk of clinical farmer's lung was associated with non-smokers (p < 0.05), and linearly with altitude (p < 10(-4)). Also there was a strong positive relation between chronic bronchitis and clinical farmer's lung (odds ratio 19.5 (95% confidence interval 12.1-31.4) after adjustment for confounding variables. The main finding of this study is the highly significant increase of prevalence of the diseases in relation to altitude.

Respiratory disease is a well known health hazard for farmers, but the long-term prognosis is less well known. This is a 12-year follow-up of an investigation of Swedish farmers, most of them dairy farmers. A questionnaire was mailed to all 418 farmers who were alive of the farmers originally participating in 1982. They were invited to an interview, spirometry, and blood sampling. Ninety-one per cent (380) of the farmers, 321 men and 59 women, responded to the questionnaire. The mean age was 56 years for the men and 55 years for the women. Of the group, 10% were smokers, 25% ex-smokers, and 65% had never smoked. The population estimate for asthma in the farmers was 8.9% in 1994 compared to 2% in 1982, and to 5.4%–6.6% in the general population in the region in 1982. Of the asthmatic subjects, one-third had positive RAST tests (radioallergosorbent tests). Almost 90% of the new onset asthma cases since 1982 had non-IgE-mediated asthma. Most of the IgE-mediated asthmatics had had symptoms for many years, while 70% of the non-IgE-mediated asthmatic farmers had no or only wheezing with colds 1982. Two new cases of hypersensitivity pneumonitis were identified, and 7.3% had experienced inhalation fever during the last 12 years. In general, individuals with asthma and chronic bronchitis who had left farming were in better health in 1994 as compared to 1982. In conclusion, farmers have an enhanced risk to develop asthma increasing with age. Asthma in farmers is often non-IgE-mediated.

Three purified cell-wall glycoprotein antigens, a, b and c, sensitive to sodium periodate and resistant to pronase, were extracted from mycelium of Micropolyspora faeni with aqueous phenol or trichloracetic acid. Pronase-sensitive, sodium periodate-resistant protein antigens were extracted from mycelium with aqueous phenol. Immunoelectrophoresis was a critical method of assessing purity of preparation.

Antibodies to glycoprotein antigens only occurred in clinically defined cases of farmer's lung disease, whereas antibodies to protein antigens also occurred in symptomless farmers. Precipitins to a occurred in all cases of farmer's lung disease, and this antigen was isolated and purified.

Fractionation of pooled sera from cases of farmer's lung disease showed that precipitins were IgG globulins, whereas latex-agglutinating antibodies were IgG, IgA and especially IgM globulins. It is suggested that farmer's lung may involve a cytotoxic type II reaction, in which glycoproteins adsorbed to tissue cells react with IgG, IgA and IgM immunoglobulins in the presence of complement, causing cellular damage.

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Four hundred and forty five of 888 dairy farmers studied in an epidemiological survey four years previously were restudied to determine change in precipitins and in clinical features. Subjects answered the same questionnaire, which was filled in by the same nurse in the same winter months, and had blood withdrawn for precipitin analysis (double diffusion technique). Of the 445 subjects retested, 48 (10.8%) had been precipitin positive at the first study; of these, 34 remained positive four years later and 14 had reverted to negative. Twenty eight subjects previously negative for precipitins had become positive, so that 62 subjects in all were precipitin positive when restudied (13.9%). Of the 445 farmers, 369 were precipitin negative at both studies. The prevalence of symptoms, including cough, sputum production, wheezing, dyspnoea, and fever and chills, was similar for subjects who were consistently negative for precipitins and consistently positive and for those who changed from one to the other. Only one subject developed farmer's lung; he had precipitins in both studies. This study shows a fluctuation in the precipitin state of dairy farmers, suggesting that more farmers have precipitins at least once in their lifetime than are identified by screening at a single point in time. Relatively few develop farmer's lung or other respiratory symptoms. The presence of precipitins in a symptomless farmer appears to have no clinical importance.

Aims: To estimate the prevalence of neurotic symptoms in a sample of British farmers, to investigate whether farming characteristics are associated with psychiatric morbidity, and to test the hypothesis that British farmers have a higher prevalence of depression and thoughts of life not worth living than the British household population.

Methods: A total of 425 farmers from Hereford, Norwich, and Preston completed the Revised Clinical Interview Schedule (CIS-R) by computer between March and July 1999. The comparison cohort consisted of 9830 private householders aged 16–64 from the Office of Population Censuses and Surveys National Psychiatric Morbidity Surveys of Great Britain carried out in 1993 in which the CIS-R was administered. All analyses used the commands developed specifically for survey data available in Stata version 6.0.

Results: Taking a threshold of an overall score of 12 or more on the CIS-R, only 6% of farmers reported clinically relevant psychiatric morbidity. Psychiatric morbidity was not significantly associated with farm type or size in this study. Farmers reported a lower prevalence of psychiatric morbidity than the general population but were more likely to report thinking that life is not worth living, particularly after the low prevalence of psychiatric morbidity had been taken into account (odds ratio 2.56, 95% CI 1.39 to 4.69). When restricting the comparison to only rural or semirural householders, this increased risk was even more pronounced (odds ratio 3.26, 95% CI 1.51 to 7.02).

Conclusions: The relation between depression and suicidal ideation seems to be quite different among farmers and the general population and warrants further investigation. We have shown it is possible to measure mental health systematically in a sample of British farmers. This study should be repeated in the aftermath of the foot and mouth crisis.

Cancer risk for farmers in Denmark and Italy was studied by linking occupational census data with incidence of cancer in Denmark and with cancer mortality in Italy. Farmers in the two countries had a consistent risk reduction for cancer of the lung, bladder, small intestine, colon, rectum, and prostate. No excess of stomach cancer was found among farmers in the two countries, which is in agreement with the most recent data from other surveys. The risk of oesophageal cancer was reduced among the Danish and increased among the Italian male farmers. This can probably be explained by differences in alcohol consumption between the Danish and Italian farmers compared with the general population. The risk of brain cancer was significantly reduced among Italian farmers. There was a significant risk reduction for Hodgkin's disease and no excess for non-Hodgkin's lymphoma in Denmark, whereas in Italy a statistically significant excess risk was found for the first and a slight excess risk for the second of these diseases. The per capita consumption of phenoxy-herbicides between 1950 and 1970 was lower in Italy than in Denmark but treatments were performed mainly by professional applicators in Denmark and by the farmers themselves in Italy. Risk of leukaemia among Italian female farmers was increased. In Denmark, this increase was limited to women who were themselves owners of a farm. Specific occupations in agriculture showing a high risk for cancers of the lymphopoietic system in Denmark mostly entailed contact with animals.