Respiratory symptoms of obstructive lung disease in European crop farmers

Physician Notified Work-Related Diseases Among Farmers in Norway: Data from 2007 - 2016

Introduction: This study provided a profile of work-related diseases in the farming sector notified by physicians to the Norwegian Labor Inspection Authority's (NLIA) Registry for Work-Related Diseases (RAS) over a 10-year period.Methods: Data for the occupational code "farmers" were extracted from RAS for the period 2007-2016. We performed a descriptive analysis to obtain frequency, percentage, and incidence distribution of the data. We also explored the relationship of the notified diagnosis with gender, age, occupational exposures and the type of reporting physicians.Results: Four hundred and sixty-nine cases of work-related diseases among farmers were notified in the period 2007-2016. Eighty-seven percent of the reported cases were males. The incidence of work-related diseases for the entire study period was computed to be 114/100 000 workers. The incidence and number of cases notified were highest among males and for the age group 55-74 years. Noise was the most frequently reported occupational exposure accounted for 291 cases. Hearing loss constituted for 62% of the notified cases, followed by respiratory diseases that accounted for 20% of the cases. Forty-eight cases of skin diseases, while only a few cases of musculoskeletal (n = 7) and mental disorders (n = 1) were notified. There was a strong association (λ = 0.51) between occupational exposure and notified diagnosis, and a moderate association (λ = 0.32) between type of reporting physician and the notified diagnosis.Conclusion: This profile of the physician notified work-related diseases among farmers in Norway yielded a suppressed estimate of the actual incidence of cases. The biased distribution of nature and number of work-related diseases amongst farmers is primarily attributed to the significant undercount of cases. Physician underreporting of cases to the NLIA coupled with lack of Occupational Health Services coverage of workers in the farming sector contributes to this undercount of cases.

The association of self-reported respiratory system diseases with farming activity among farmers of greenhouse vegetables

Objectives

Several studies have investigated the link between agricultural activities of open-field farmers and the prevalence of respiratory diseases, but the relationship with greenhouse vegetable farmers remains unclear.

Methods

A total of 1,366 participants from four villages in China provided information about their agricultural activities and symptoms of diagnosed respiratory system diseases. The Poisson regression model and zero-inflated Poisson regression model were used to assess the association between diseases, symptoms, and agricultural activities.

Results

The prevalence of respiratory diseases was 3.59%, and the rates of four main symptoms (cough, tachypnea, chest distress, and hemoptysis) were 17.21%, 8.56%, 10.25%, and 1.61%, respectively. Mix spray of pesticides associated with cough, tachypnea and chest distress, 1.740-, 3.385- and 2.882-fold likelihood were found than hand spray, and the significant association were detected in empty, general information, life-style information adjusted models.

Conclusions

The relationship between agricultural activities and respiratory diseases is unclear. However, use of the mix spray method of pesticide application may increase the risk of cough, tachypnea, and chest distress.

Association between greenhouse working exposure and bronchial asthma: A pilot, cross-sectional survey of 5,420 greenhouse farmers from northeast China

Long-term exposure to greenhouse environments exposes greenhouse workers to inhalation of antigens that can cause respiratory diseases. This study was conducted to investigate the prevalence and potential risk factors for bronchial asthma among the Chinese greenhouse workers based on questionnaire and spirometry data. This was an observational cross-sectional study, performed via stratified-cluster-random sampling. It was conducted in Liaoning Province from the northeast of People's Republic of China, using a population-based sample of 5,880 workers at 835 plastic film greenhouses. All subjects were interviewed using a standardized questionnaire and underwent pulmonary function tests. Multiple logistic regression analysis was conducted to assess associations between self-reported factors of greenhouse worker exposure and bronchial asthma and to identify potential risk factors for this disease. A total of 5,420 questionnaires were completed. The overall prevalence of asthma in greenhouse workers was 19.2% (1040/5420). Multiple logistic regression analysis revealed that the use of multiple pesticides (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.03-1.49), bad odors in the greenhouse (OR = 1.26, 95% CI = 1.07-1.49), and report of the onset of cough when entering the greenhouse (OR = 1.25, 95% CI = 1.09-1.44) were associated with the development of asthma. In contrast, a higher body mass index (BMI >18.5 kg/m^2, OR = 0.93, 95% CI = 0.90-0.95), planting flowers (OR = 0.92, 95% CI = 0.87-0.98), open sidewall to outside (natural ventilation) for at least 30 min per event (OR = 0.82, 95% CI = 0.69-0.96), living in greenhouse (OR = 0.85, 95% CI = 0.73-0.99), and experiencing cough before 14 years old (OR = 0.61, 95% CI = 0.43-0.84) were protective factors to the presentation of asthma among greenhouse workers. Our results suggest that asthma is a major public health problem among Chinese greenhouse workers and more attention should be devoted to preventive measures and management of this disease.

High prevalence of obstructive lung disease in non-smoking farmers: The Irish farmers lung health study

BACKGROUND

Mortality rates within the Irish farming community are increasing, whilst that of the general population falls. The aim of this cross-sectional study was to determine the prevalence of respiratory disease amongst Irish farmers.

METHODS

All study participants were farming volunteers attending an agricultural exhibition. Data collected by questionnaire included baseline demographics, respiratory history, presence of respiratory symptoms and occupational exposures. Spirometry was performed on all participants.

RESULTS

Data from 372 farmers was analysed. The majority were male (76%) with median age of 55 years. 61% were never smokers. 13% were previously diagnosed with airway disease (Chronic Obstructive Pulmonary Disease(COPD)/Asthma/Inhaler use) with 14% reporting hayfever/allergies. Almost two-thirds reported one or more chronic respiratory symptom. Forty-four (12%) had obstructive spirometry using fixed FEV1/FVC < 0.70 criterion and 29 (7.8%) using FEV1/FVC < 5% lower limit of normal. The majority, two-thirds, were never smokers. Amongst never smokers with obstruction (13%), there was a significantly higher proportion with a prior diagnosis of airway disease and hayfever/allergies. There was no significant association between specific occupational exposures and obstruction.

CONCLUSION

The majority of Irish farmers are never smokers. They have a high prevalence of respiratory symptoms. 13% of never smokers have airflow obstruction (FEV1/FVC < 0.70). The presence of airflow obstruction is significantly associated with self-reported allergy history and prior airway disease. Further studies are needed to identify the workplace factors accounting for these findings.

Respiratory Symptoms among Crop Farmers Exposed to Agricultural Pesticide in Three Rural Communities in South Western Nigeria: A Preliminary Study

Background:

The improper use of pesticide is associated with respiratory morbidity in many developing countries.

Aim:

The purpose of this study was to determine the prevalence of respiratory symptoms and its association with the use of agricultural pesticide among crop farmers in three rural communities in Ekiti State, South Western Nigeria.

Subjects and Methods:

This was a cross-sectional study conducted in Ijero local government in Ekiti State, Nigeria from June 2009 to August 2009. Pre-tested structured questionnaire was administered by trained interviewers to obtain clinical information and exposure to pesticide and this was followed by peak expiratory flow rate (PEFR) measurement using wright peak flow meter. The data were analyzed using SPSS version 15 (SPSS Corp., Chicago, IL, USA).

Results:

A total of 228 farmers participated in the study and 8.3% (19/228)of the farmers reported a lifetime exposure to pesticides. Recurrent breathlessness (odds ratio [OR] = 4.28; 95% confidence interval [CI]: 1.65-10.86), chronic cough (OR = 2.96; 95% CI: 1.21-7.23), chronic sputum (OR = 2.64; 95% CI: 1.12-6.24) and nasal symptoms (OR = 2.96; 95% CI: 1.21-7.25) were independently associated with pesticide exposure. Mean PEFR was lower in farmers using pesticide (323 [217] L/min) when compared with those not using pesticide (467 [189] L/min) P < 0.01. All the 228 (100.0%) respondents in this study were aware of the adverse effect of pesticide and only 2 (10.5%) of those exposed used a respiratory protective device. Previous pesticide education was not significantly associated with lower occurrence of respiratory symptoms.

Conclusion:

The use of pesticide among crop farmers is associated with increased respiratory symptoms and airflow limitations. Our results support the need for continuing pesticide education and promotion of safe practices among the farmers as the majority of them do not use protective devices.

Respiratory disease in United States farmers

OBJECTIVES

Farmers may be at increased risk for adverse respiratory outcomes compared with the general population due to their regular exposures to dusts, animals and chemicals. However, early life farm exposures to microbial agents may result in reduced risk. Understanding respiratory disease risk among farmers and identifying differences between farmers and other populations may lead to better understanding of the contribution of environmental exposures to respiratory disease risk in the general population.

METHODS

We compared the prevalence of self-reported respiratory outcomes in 43548 participants from the Agricultural Health Study (AHS), a prospective cohort of farmers and their spouses from Iowa and North Carolina, with data from adult participants in the National Health and Nutrition Examination Survey (NHANES) over the same period (2005-2010).

RESULTS

AHS participants had lower prevalences of respiratory diseases (asthma, adult-onset asthma, chronic bronchitis and emphysema), but higher prevalences of current respiratory symptoms (wheeze, cough and phlegm) even after controlling for smoking, body mass index and population characteristics. The overall prevalence of asthma in the AHS (7.2%, 95% CI 6.9 to 7.4) was 52% of that in NHANES (13.8%, 95% CI 13.3 to 14.3), although the prevalence of adult-onset asthma among men did not differ (3.6% for AHS, 3.7% for NHANES). Conversely, many respiratory symptoms were more common in the AHS than NHANES, particularly among men.

CONCLUSIONS

These findings suggest that farmers and their spouses have lower risk for adult-onset respiratory diseases compared with the general population, and potentially higher respiratory irritation as evidenced by increased respiratory symptoms.

Agricultural exposure and asthma risk in the AGRICAN French cohort

Epidemiological studies have reported an increased risk of respiratory diseases in agricultural population, but a protective "farm-effect" has also been reported for asthma. In the AGRICAN cohort, self-reported doctor-diagnosed asthma was analyzed according to allergy, in relation with history of life-time exposure to 13 crops and 5 livestock, pesticide exposure and early life on a farm, taking into account sex, age, education and body mass index. Among the 1246 asthmatics (8.0%), 505 were allergic (3.3%) and 719 non-allergic (4.6%). In multivariate analysis, a significant excess was observed, only for allergic asthma, in vine-growing (OR=1.43, p=0.002), fruit-growing (OR=1.58, p=0.001), greenhouses (OR=1.66, p=0.02), grasslands (OR=1.35, p=0.009), beets (OR=1.52, p=0.003) and horses (OR=1.35, p=0.04). Pesticide use and history of pesticide poisoning were significantly associated with allergic asthma in grassland, vineyards and fruit-growing and with non-allergic asthma in beets. Living on a farm in the first year of life tended to be protective for childhood allergic asthma in farms with livestock (OR=0.72, p=0.07) but deleterious in farms with vineyards, fruit or vegetables (OR=1.44, p=0.07). In AGRICAN, an increased risk of allergic asthma was observed with crop exposure, pesticide use and early life on a farm, especially in vine-growing, grassland, beets, fruit and vegetable-growing.

Agricultural exposures and chronic bronchitis: findings from the AGRICAN (AGRIculture and CANcer) cohort

PURPOSE

Livestock farming has been recognized as a risk factor for chronic bronchitis (CB). The role of crop farming, however, has been less studied. We sought to assess the role of a large range of farming activities on the risk of CB in the French agricultural cohort AGRICAN (AGRIculture and CANcer).

METHODS

Data on respiratory health and farming activities were collected by questionnaire from 2005 to 2007. Associations between farming activities and self-reported doctor's diagnosis of CB were estimated by a logistic regression adjusted for confounders.

RESULTS

CB was reported by 1207 farmers (8.4%). Two farming activities were associated with CB: cattle raising (odds ratio [OR] 1.24, 95% confidence interval 1.03-1.48), and potato production (OR 1.33, 95% confidence interval 1.13-1.57). Associations were more pronounced in small-scale cattle raising and in large-scale potato production, in particular among the longest exposed workers (≥20 years). Pesticide poisoning and exposure to pesticides in potato farmers were significantly associated with CB risk (OR 1.64 and OR 1.63, respectively).

CONCLUSIONS

This analysis suggests that other agricultural settings not previously reported, such as potato production, may be a risk factor for CB. The nature and circumstances of exposure to hazardous agents need to be further explored.

Asthma increase among farmers: a 12-year follow-up

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.

An official American Thoracic Society public policy statement: Novel risk factors and the global burden of chronic obstructive pulmonary disease

RATIONALE

Although cigarette smoking is the most important cause of chronic obstructive pulmonary disease (COPD), a substantial proportion of COPD cases cannot be explained by smoking alone.

OBJECTIVES

To evaluate the risk factors for COPD besides personal cigarette smoking.

METHODS

We constituted an ad hoc subcommittee of the American Thoracic Society Environmental and Occupational Health Assembly. An international group of members was invited, based on their scientific expertise in a specific risk factor for COPD. For each risk factor area, the committee reviewed the literature, summarized the evidence, and developed conclusions about the likelihood of it causing COPD. All conclusions were based on unanimous consensus.

MEASUREMENTS AND MAIN RESULTS

The population-attributable fraction for smoking as a cause of COPD ranged from 9.7 to 97.9%, but was less than 80% in most studies, indicating a substantial burden of disease attributable to nonsmoking risk factors. On the basis of our review, we concluded that specific genetic syndromes and occupational exposures were causally related to the development of COPD. Traffic and other outdoor pollution, secondhand smoke, biomass smoke, and dietary factors are associated with COPD, but sufficient criteria for causation were not met. Chronic asthma and tuberculosis are associated with irreversible loss of lung function, but there remains uncertainty about whether there are important phenotypic differences compared with COPD as it is typically encountered in clinical settings.

CONCLUSIONS

In public health terms, a substantive burden of COPD is attributable to risk factors other than smoking. To prevent COPD-related disability and mortality, efforts must focus on prevention and cessation of exposure to smoking and these other, less well-recognized risk factors.

Lung function and respiratory symptoms in male Palestinian farmers

In a cross-sectional study of 250 farmers aged 22 to 77 years, of whom 36.4% are smokers, the authors aimed at describing lung function and respiratory symptoms and to estimate associations with exposures to pesticides and dust. Lung function was measured using a spirometer. Respiratory symptoms and exposure levels were self-reported based on a modified standardized questionnaire. Mean forced vital capacity (FVC) was 4.20 L (SD = 0.93 L), 95.51% of predicted as compared to European standards. Mean forced expiratory volume in one second (FEV(1)) was 3.28 L (SD = 0.80 L), 91.05% of predicted. The authors found high symptom prevalences: 14.0% for chronic cough; 26.4% for wheeze; and 55.2% for breathlessness. There was no clear association between exposure to pesticides or dust and lung function or between such exposures and respiratory symptoms. However, a significant association was found between smoking and respiratory symptoms such as chronic cough, cough with phlegm, and wheezes. The lack of farm exposure associations could be due to improvement in farmers' awareness to pesticides hazards as well as regulations of pesticide import, or because of inherent problems with the experimental design. Farmers who kept animals and poultry seem to have less respiratory symptoms and better lung function.

99th Dahlem conference on infection, inflammation and chronic inflammatory disorders: farm lifestyles and the hygiene hypothesis

About 15 years have gone by since Strachan first proposed the idea that infections and unhygienic contact may confer protection from the development of allergic illnesses. The so-called 'hygiene hypothesis' has since undergone numerous modifications in the field of epidemiology, clinical science and immunology. Three main areas of research have been brought forward: to explore the role of overt viral and bacterial infections for the inception of allergic diseases; to investigate the significance of environmental exposure to microbial compounds on the development of allergies; and to study the effect of both exposures on underlying innate and adaptive immune responses. A concept unifying these various aspects has not been found, but various pieces of a complex interplay between immune responses of the host, characteristics of the invading microorganism, the level and variety of the environmental exposure and the interactions between an exposed subject's genetic background and the environmental exposures becomes apparent. A natural experiment relating to the hygiene hypothesis is the recurrent observation of a protective effect of growing up on a farm for asthma and allergies. This has been shown in a large number of epidemiological studies across the world among children and adults. The timing and duration of exposure are likely to play a critical role. The largest reduction in risk has been demonstrated for those exposed prenatally and continuously thereafter until adulthood. The protective factors in these farming environments have not been unravelled completely. Findings from various studies suggest that the contact with farm animals, at least in childhood, confers protection. Also the consumption of unprocessed cow's milk directly from the farm has been shown to protect from childhood asthma and allergies. Increased levels of microbial substances may, at least in part, contribute to the 'farm effect'. However, only few studies have measured microbial exposures in these environments and the results obtained so far suggest that the underlying protective microbial exposure(s) have not been identified, but a number of studies using metagenomic approaches are currently under way. The mechanisms by which such environmental exposures confer protection from respiratory allergies are also not well understood. There is good evidence for the involvement of innate immune responses, but translation into protective mechanisms for asthma and allergies is lacking. Furthermore, a number of gene x environment interactions have been observed.

Assessment of the total inflammatory potential of bioaerosols by using a granulocyte assay

Occupational health symptoms related to bioaerosol exposure have been observed in a variety of working environments. Bioaerosols contain microorganisms and microbial components. The aim of this study was to estimate the total inflammatory potential (TIP) of bioaerosols using an in vitro assay based on granulocyte-like cells. A total of 129 bioaerosol samples were collected in the breathing zone of workers during their daily working routine at 22 biofuel plants. The samples were analyzed by traditional assays for dust, endotoxin, fungal spores, (1-->3)-beta-d-glucan, total number of bacteria, the enzyme N-acetyl-beta-d-glucosaminidase (NAGase; primarily originating from fungi), Aspergillus fumigatus, and mesophilic and thermophilic actinomycetes; the samples were also assayed for TIP. In a multilinear regression four factors were significant for the TIP values obtained: endotoxin (P < 0.0001), fungal spores (P < 0.0001), (1-->3)-beta-d-glucan (P = 0.0005), and mesophilic actinomycetes (P = 0.0063). Using this model to estimate TIP values on the basis of microbial composition, the correlation to the measured values was r = 0.91. When TIP values obtained in the granulocyte assay were related to the primary working area, we found that bioaerosol samples from personnel working in straw storage facilities showed high TIP values ( approximately 50 times the TIP of unstimulated controls). In contrast, bioaerosol samples from personnel with work functions in offices or laboratories showed low TIP values ( approximately 5 times the TIP of the unstimulated control). This indicates, as expected, that these areas were less contaminated. In conclusion, the granulocyte assay reacts to multiple contaminants in the environmental samples and can be used to obtain a measurement of TIP. Therefore, potential occupational health effects related to inflammation of the airways in a working environment can be estimated using this assay.

Occupational risk factors for rhinitis in greenhouse flower and ornamental plant growers

BACKGROUND

The purpose of this study was to assess the relationships between rhinitis, exposure to workplace air contaminants, and occupational characteristics in greenhouse flower and ornamental plant (OP) growers.

METHODS

A random sample of growers cultivating such crops and participating in the European Farmers' Study was selected for a cross-sectional assessment of (1) rhinitis in the last year, (2) sensitization to workplace allergens, and (3) occupation characteristics. Associations between variables were assessed through univariate and multivariate analyses.

RESULTS

Thirty-nine greenhouse flower and OP growers participated in the study (mean, 48.6; SD, 10.2 years; 35 men). Rhinitis was reported by 12 (31%) of them and was significantly related to sensitization to workplace allergens (odds ratio [OR], 13.20; 95% confidence interval [CI], 2.59-67.23) and pesticide application by hand pump (OR, 12.50; 95% CI, 2.00-78.05). After adjustment for these variables rhinitis emerged as significantly related to number of hours worked inside the greenhouse per day (OR, 1.85; 95% CI, 1.05-3.23).

CONCLUSION

Rhinitis is often reported by greenhouse flower and OP growers and is related to sensitization to workplace allergens and pesticide application by hand pump. The disease shows a dose-response relationship with the number of hours spent inside the greenhouse per day, a finding supporting a causal link with greenhouse exposure.

Living on a farm: impact on asthma induction and clinical course

Exposure to a farming environment protects individuals from respiratory allergy. The timing and duration of exposure seem to play critical roles. The largest reduction in risk of developing respiratory allergies is seen among those who are exposed prenatally and continuously thereafter. Contact with farm animals, at least in childhood, likely confers protection; other factors have not been completely identified. Also, the consumption of milk directly from the farm during childhood has been shown to be beneficial with respect to childhood asthma and allergies. Increased levels of microbial substances may contribute to the protective effects. The mechanisms by which such environmental exposures confer protection from respiratory allergies are not well understood. A number of gene-by-environment interactions have been observed with polymorphisms in genes of innate immunity receptors and exposure to farming environments. Increased levels of microbial exposures recognized by innate immune responses may affect adaptive immune responses resulting in decreased levels of atopic sensitization and asthma.

Reduced risk of atopic sensitization among farmers: the Humboldt study

BACKGROUND

It needs to be clarified whether farming is associated with a reduced risk of atopy or allergic condition. There is a lack of consistent evidence for prevalences of atopy, respiratory allergy and asthma in adult farmers.

METHODS

A cross-sectional study of adults (n = 2,081) was conducted in the town of Humboldt, Sask. Allergy skin prick tests were conducted to determine atopic sensitization. Respiratory allergy and physician-diagnosed asthma were based on self-reporting. Logistic regression was used to assess the associations of atopy, respiratory allergy and asthma with farming practices, adjusting for other important variables.

RESULTS

Of 2,081 participants, 27.8% were farmers. Reduced risks of atopic sensitization, respiratory allergy and asthma were observed among farmers compared to non-farmers. After adjustment for sex and age, which are major confounders, the odds ratio for atopic sensitization was 0.79 (95% confidence interval: 0.65, 0.97) for farmers versus non-farmers. Asthma showed a similar trend; however, there was no statistically significant difference in either respiratory allergy or asthma rates observed between farmers and non-farmers.

CONCLUSIONS

The prevalence of atopy was lower in adult farmers than in non-farmers.

Hay fever and asthma symptoms in conventional and organic farmers in The Netherlands

BACKGROUND

Farming has been associated with respiratory symptoms and with protection against atopy. To date, effects of organic farming on respiratory health have not been studied.

AIMS

To (1) compare hay fever and asthma-like symptoms in organic and conventional farmers and (2) assess associations between current and childhood farm exposures and respiratory health effects by conducting a survey.

METHODS

Questionnaire data from 1205 conventional and 593 organic farmers were evaluated. Associations between health effects and farm exposures were assessed by logistic regression analyses.

RESULTS

Organic farmers reported less wheezing with shortness of breath and slightly more hay fever than conventional farmers. However, organic farming was not an independent determinant of hay fever when adjusted for farming practices and potential confounders. Livestock farmers who grew up on a farm had a threefold lower prevalence of hay fever than crop farmers without a farm childhood (odds ratio (OR) 0.3, 95% confidence interval (CI) 0.1 to 0.5). Both crop farmers who grew up on a farm and livestock farmers who did not grow up on a farm had a reduced prevalence, although less pronounced and not statistically significant. Use of disinfectants containing quaternary ammonium compounds was positively related to hay fever (OR 2.1, 95% CI 1 to 4.4). No effects of farming practices were found for asthma.

CONCLUSIONS

Our study adds to the evidence that a farm childhood in combination with current livestock farming protects against allergic disorders. This effect was found for both organic and conventional farmers.

Agricultural dust exposure and respiratory symptoms among California farm operators

OBJECTIVE

To study whether dust exposure in California agriculture is a risk factor for respiratory symptoms.

METHODS

A population-based survey of 1947 California farmers collected respiratory symptoms, occupational and personal exposures. Associations between dust and respiratory symptoms were assessed by logistic regression models.

RESULTS

The prevalence of persistent wheeze was 8.6%, chronic bronchitis 3.8%, chronic cough 4.2%, and asthma 7.8%. Persistent wheeze was independently associated with dust in a dose-response fashion odds ratio, 1.2 (95% confidence interval[CI]=0.8-2.0) and 1.8 (95% CI=1.1-3.2) for low and high time in dust. A borderline significant association between chronic bronchitis and dust exposure was found. Asthma was associated with keeping livestock, but not with dust exposure.

CONCLUSIONS

Occupational dust exposure among California farmers, only one third of whom tended animals, was independently associated with chronic respiratory symptoms.

Cough: occupational and environmental considerations: ACCP evidence-based clinical practice guidelines

OBJECTIVES

This section of the guideline aims to review the role of occupational and environmental factors in causing and contributing to cough. It also aims to indicate when such causes should be considered in a clinical setting, and a general approach to assessment and management.

METHODS

A review was performed of published data between 1985 and 2004 using PubMed. The search terms used included "air pollution," "sick building syndrome," "occupational asthma," "occupational lung disease," "hypersensitivity pneumonitis" (HP), "cigarette smoke," and "asthma." Selected articles were chosen when meeting the objectives, but the extent of articles available and the limited space for this section does not permit a fully comprehensive review of all of these areas, for which the reader is referred to other sections of this clinical practice guideline, the published literature, textbooks of occupational lung disease, or more specific review articles.

RESULTS/CONCLUSIONS

Almost any patient presenting with cough may have an occupational or environmental cause of or contribution to their cough. The importance of this is that recognition and intervention may result in full or partial improvement of the cough, may limit the need for medication/symptomatic treatment, and may improve the long-term prognosis. Nonoccupational environmental contributing factors for upper and lower airway causes of cough include indoor irritant and allergenic agents such as cigarette smoke, cooking fumes, animals, dust mites, fungi, and cockroaches. Causes of HP indoors include birds and fungal antigens. Outdoor pollutants and allergens also contribute to upper and lower airway causes of cough. Occupational exposures can cause hypersensitivity responses leading to rhinitis and upper airway cough syndrome, previously referred to as postnasal drip syndrome, as well as asthma, HP, chronic beryllium disease, and hard metal disease, as well as irritant or toxic responses. The diagnosis is only reached by initially considering possible occupational and environmental factors, and by obtaining an appropriate medical history to determine relevant exposures, followed by objective investigations. This may require referral to a center of expertise.

Pesticides and respiratory symptoms among farmers

OBJECTIVE

Despite the intensive use of pesticides in agriculture there are few studies assessing the risk of respiratory conditions from this exposure. The study aimed at quantifying the prevalence of respiratory symptoms among farmers and evaluating its relationship with occupational use of pesticides and the prevalence of respiratory symptoms.

METHODS

A cross-sectional study was conducted among 1,379 farmers from two municipalities of Southern Brazil in 1996. Frequency and type of chemical exposure and pesticide poisoning were recorded for both sexes. All subjects aged 15 years or older with at least 15 weekly hours of agricultural activity were interviewed. An adapted questionnaire developed by the American Thoracic Society was used for the assessment of respiratory symptoms. Multivariate logistic regression analysis was carried out.

RESULTS

More than half (55%) of interviewees were male. The prevalence of asthma symptoms was 12% and chronic respiratory disease symptoms was 22%. Higher odds ratios for both asthma (OR=1.51; 95% CI: 1.07-2.14) and chronic respiratory disease (OR=1.34; 95% CI 1.00-1.81) symptoms were found in women. Logistic regression analysis identified associations between many forms of exposure to pesticides and increased respiratory symptoms. Occurrence of pesticide poisoning was associated with higher prevalence of asthma symptoms (OR=1.54; 95% CI: 1.04-2.58) and chronic respiratory disease symptoms (OR=1.57; 95% CI: 1.08-2.28).

CONCLUSIONS

In spite of causality limitations, the study results provide evidence that farming exposure to pesticides is associated with higher prevalence of respiratory symptoms, especially when the exposure is above two days per month.

Another explanation for the low allergy rate in the rural Alpine foothills

A low allergy rate in coal and wood heated homes has been described in the small villages in the Alpine foothills and subsequently found to be associated with the farming environment. This was interpreted within the framework of the hygiene hypothesis but there are also alternative explanations. Lower air pollution could be one reason, which is, however, unlikely since the differences between the Bavarian countryside and the Munich municipal area were only weak. There could be genetic differences between the urban and rural population by previous isolation or by self-selection. The potential drop-out of allergy genes, however, will also not explain the absent increase of allergies in two generations. More likely, other lifestyle factors are important. Dietary habits are different in farmers and a less frequent vitamin D supplementation of newborns (otherwise expected to be allergy promoting) has been shown recently. The underlying cause for the "non-allergic farm child" remains speculative until the transfer of any farm-associated factor is leading to a similar risk reduction in the general population.

Allergic rhinitis, asthma, and atopy among grape farmers in a rural population in Crete, Greece

STUDY OBJECTIVE

To measure the prevalence of allergic rhinitis, atopy, and asthma among grape farmers, and to compare the respiratory and atopic status in grape farmers with those of nonexposed control subjects.

DESIGN

Cross-sectional study.

SETTING

Malevisi region in northern Crete, Greece.

SUBJECTS AND METHODS

One hundred twenty grape farmers and 100 control subjects living in the Malevisi region were examined. The protocol comprised a questionnaire, skin prick tests for 16 common allergens, measurement of specific IgE antibodies against 8 allergens, and spirometry before and after bronchodilation.

RESULTS

Grape farmers were found to have an excess of respiratory symptoms. The comparison with the control group, after adjusting for age, sex, and smoking status, showed that the differences were statistically significant for rhinorrhea (odds ratio [OR], 2.7; 95% confidence interval [CI], 1.5 to 5.1; p < 0.001), sneezing (OR, 2.2; 95% CI, 1.2 to 4.0; p < 0.01), and nasal itching (OR, 1.9; 95% CI, 1.0 to 3.6; p < 0.05), but were nonsignificant for asthma-related symptoms. In the multiple logistic regression model, grape farmers were found to have increased work-related symptoms, such as sneezing (OR, 2.9; 95% CI, 1.3 to 6.6; p < 01), rhinorrhea (OR, 2.9; 95% CI, 1.3 to 6.6; p < 0.01), cough (OR, 3.7; 95% CI, 1.2 to 11.4; p < 0.05), and dyspnea (OR, 3.8; 95% CI, 1.1 to 1.3; p < 0.05). The prevalence of allergic rhinitis was 40.8% in grape farmers and 26% in control subjects (OR, 2.0; 95% CI, 1.1 to 3.5; p < 0.02). Increased but statistically nonsignificant values of asthma prevalence were found in grape farmers (6.7%) compared with the control group (2.0%). The prevalence of atopy was 64.2% in grape farmers and 38.0% in the control group (OR, 2.2; 95% CI, 1.2 to 3.5; p < 0.01). Mean FEV1 was significantly lower in grape farmers than in control subjects (p < 0.05), after adjusting for age, sex, and smoking status. Bronchial obstruction was reversible in 23 grape farmers (19.2%) and in 6 control subjects (6%; p < 0.01).

CONCLUSIONS

The study mainly demonstrated the high prevalence of allergic rhinitis and work-related respiratory symptoms in grape farmers compared to control subjects. It also suggested that grape farming is possibly associated with increased allergic sensitization to specific pollens, low baseline FEV1, and increased bronchial hyper-responsiveness. Further studies are needed to determine the potential risk factors for these disorders among the farming population.

Chronic obstructive pulmonary disease in never-smoking animal farmers working inside confinement buildings

BACKGROUND

In animal farming, respiratory disease has been associated with indoor air contaminants and an excess in FEV1 decline. Our aim was to determine the characteristics and risk factors for chronic obstructive pulmonary disease (COPD) in never-smoking European farmers working inside animal confinement buildings.

METHODS

A sample of participants in the European Farmers' Study was selected for a cross-sectional study assessing lung function and air contaminants. Dose-response relationships were assessed using logistic regression models.

RESULTS

COPD was found in 18 of 105 farmers (45.1 SD 11.7 years) (17.1%); 8 cases (7.6%) with moderate and 3 cases (2.9%) with severe disease. Dust and endotoxin showed a dose-response relationship with COPD, with the highest prevalence of COPD in subjects with high dust (low=7.9%/high=31.6%) and endotoxin exposure (low=10.5%/high=20.0%). This association was statistically significant for dust in the multivariate analysis (OR 6.60, 95% CI 1.10-39.54).

CONCLUSION

COPD in never-smoking animal farmers working inside confinement buildings is related to indoor dust exposure and may become severe.

Occupational asthma in greenhouse workers

PURPOSE OF REVIEW

A prevalence of asthma over 5% has been reported in flower farmers,and work inside greenhouses has emerged as an additional risk factor. Workplace determinants behind this high prevalence has been examined, and a prevalence of sensitization to workplace allergens over 30% has been reported being pollens, moulds, and Tetranychus urticae allergens the main sensitizers. Bronchial challenge tests in the workplace have demonstrated occupational asthma in more than 20% of the sensitized greenhouse growers.

RECENT FINDINGS

Air contamination inside greenhouses is mainly related to moulds, and is facilitated by the high indoor temperature and humidity. Cladosporium, Penicillium, Aspergillus, and Alternaria and a wide range of flower pollens are able to sensitize the greenhouse worker and cause occupational asthma. Tetranychus urticae have allergens shared with other mites, but the low prevalence of cross-sensitization between them confirm that Tetranychus urticae contains species-specific allergens that may cause respiratory symptoms. Additionally, working inside greenhouses has been related to an increase in the prevalence of chronic bronchitis in nonsmokers.

SUMMARY

The cultivation of greenhouse crops may cause occupational asthma through sensitization to workplace pollens, moulds, and Tetranychus urticae allergens. In greenhouse flower growers, skin testing identifies sensitization to these allergens in one third of the growers, and more than one fifth of the sensitized workers will develop occupational asthma. Greenhouse work has also been related to chronic bronchitis in nonsmokers, suggesting a causal effect of greenhouse air contaminants on this disease as well.

Work-related asthma-like symptoms among florists

OBJECTIVES

In this study, we evaluated the prevalence of work-related asthma-like symptoms and possible risk factors among florists in Turkey.

METHODS

We collected questionnaire data from 128 florists, and investigated occupational history and respiratory, ocular, dermal, and nasal symptoms. We evaluated pulmonary function tests with spirometry and atopy by using the skin-prick test. Possible risk factors were analyzed by age-adjusted, smoking-adjusted, and gender-adjusted logistic regression models comparing symptomatic and asymptomatic individuals.

RESULTS

The prevalence of work-related asthma-like symptoms was 14.1% (18 patients). We observed excess risk with a high work intensity (odds ratio [OR], 7.3; 95% confidence interval [CI], 1.1 to 51.8) and long work duration (OR, 5.1; 95% CI, 1.2 to 21.6). Florists with work-related asthma-like symptoms were 5.9 times more likely (95% CI, 1.4 to 24.3) to have a positive skin test response to a flower mix allergen. We also observed an excess risk for work-related asthma-like symptoms among those with allergic rhinitis (OR, 13.2; 95% CI, 3.1 to 56.4) and conjunctivitis (OR, 8.4; 95% CI, 2.4 to 29.2).

CONCLUSION

The most prominent risk factors in florists were work intensity, work duration, and specific atopy.

Agricultural lung disease

Agricultural work is associated with high rates of injury, disability, and illness. Agricultural workers are at increased risk for a variety of illnesses including respiratory disorders, dermatologic conditions, and cancer. The recognition of ODTS led to increased understanding of acute illness in farmers and grain workers. Previously, many cases of acute illness were probably erroneously called farmer's lung. The same agents that are responsible for ODTS are responsible for the high prevalence of bronchitis in certain agricultural workers. The recent description of the innate immune system is very exciting because it will lead to increased understanding of the pathogenesis of organic dust induced disorders.

Indoor women jobs and pulmonary risks in rural areas of Isfahan, Iran, 2000

The prevalence rate of chronic airway's diseases in women and associated risk factors in developing countries are not well clarified. We evaluated the role of indoor duties in the prevalence of asthma, chronic bronchitis, and related symptoms among females in Isfahan suburbs. In three randomly selected villages, 561 responder females (response rate=95.25%) were evaluated through medical interview and physical examinations. Symptoms, signs, occupational and smoking histories, indoor and farming duties, possible outdoor jobs, housing and farming conditions were assessed. The observed respiratory morbidities were: current asthma (11.2%), history of asthma (1.3%), using asthma medications in life (15.2%), chronic bronchitis (3.4%), exercise-induced dyspnea and/or cough (16.2%), and frequent night coughs and/or dyspnea (15.3%). Age, childhood pulmonary infection, bread baking, carpet weaving and using biomass fuels were significant risk factors for all the pulmonary morbidities (P<0.05 to <0.001). Poultry feeding, using kerosene and gas fuels, were less strong risk factors for asthma and chronic bronchitis, respectively Only seven women were current or ex-smokers. Indoor respirable particulate matters were two to four folds more concentrated than outdoors. Women doing indoor jobs in Iran are potential risk factors for development of chronic obstructive pulmonary disease.

Occupational asthma in greenhouse flower and ornamental plant growers

The objective of this study was to determine the prevalence of occupational asthma and sensitization to workplace allergens in greenhouse flower and/or ornamental plant growers. A random sample of 40 growers who cultivated such crops and had participated in the European Farmers' Study was selected for a cross-sectional study that included (1) greenhouse characteristics and air contaminants (dust, endotoxin, and microorganisms), (2) respiratory symptoms, (3) occupational asthma diagnosed by bronchial provocation challenge, and (4) sensitization to workplace flowers or molds. Associations among respiratory symptoms, sensitization, greenhouse characteristics, and air contaminants were analyzed by logistic regression modeling. Thirty-nine growers agreed to participate (response rate, 97.5%). Bronchial provocation challenge confirmed occupational asthma in three workers (7.7%), all of them sensitized to workplace flowers or molds. No cases of occupational asthma were found among nonsensitized growers. Poor ventilation proved to be a marginal risk factor for wheezing (air velocity: odds ratio, 0.11; 95% confidence interval, 0.01-1.04). Sensitization to flowers or molds was found in 13 of 38 growers (34.2%) but was not related to greenhouse characteristics. We conclude that one-fourth of greenhouse flower and/or ornamental plant growers sensitized to workplace flowers or molds have occupational asthma, a disease that is suffered by 8% of the growers who cultivate these crops.

Respiratory symptoms in European animal farmers

Farmers are known to be at high risk for the development of occupational airway disease. The aim of this European study was to determine which airway symptoms predominate in different types of animal farmers (cattle, pigs, poultry, sheep) and to compare the prevalence of symptoms to the general population. A total of 6,156 randomly selected animal farmers in Denmark, Germany (Schleswig-Holstein, Niedersachsen), Switzerland, and Spain completed a questionnaire on respiratory symptoms and farming characteristics in 1995-1997. The prevalence of general respiratory symptoms was compared to the results of the European Community Respiratory Health Survey (ECRHS) obtained in the same regions. Pig farmers were at highest risk for the development of work-related symptoms. A significant dose-response relationship between daily hours worked inside animal houses and symptoms was established for pig and poultry farmers. Additionally, self-reported nasal allergies (odds ratio (95% confidence interval): 3.92 (3.26-4.71)) and nasal irritation during work (3.98 (3.35-4.73)) were shown to be associated with the development of chronic phlegm. The prevalence of wheezing, shortness of breath, asthma and nasal allergies was signficantly lower among all farmers in the age group 20-44 yrs than among the general population. However, the prevalence of usually bringing up phlegm in winter among farmers was significantly higher than in the general population (9.4 (8.3-10.5%) versus 7.5 (6.5-8.5%)). Individual factors have been shown to be related to the prevalence of chronic phlegm among farmers. Additionally, this study could support the hypothesis that farming could be negatively related to allergic diseases.