Exposure to grain dust and changes in lung function

Utah Regional Differences in Respirator Use and Fit Testing among Pesticide Applicators

The purpose of this study was to determine regional differences within Utah in response to piloting a mobile respirator training and fit assessment program for pesticide applicators. The objectives were to describe worker perceptions of respirator use and training experiences. Pilot trainings were offered in two southern counties and two northern counties of Utah. A total of 141 individuals completed the post-training questionnaire regarding use and fit testing experience with respirators as well as perceptions of the benefits to protecting respiratory health. The majority of respondents were male (95.7%, f = 112). The proportion of participants in the southern counties who had respirator training experience (61.0%, f = 25) was not significantly higher (2 = 3.763, df = 1, p = 0.05) than the proportion of participants in the northern counties (43.0%, f = 43). Three-fourths (73.5%, f = 72) of participants in the northern counties agreed that they expect to wear a respirator in dusty conditions, while two-thirds (61.0%, f = 25) of participants in the southern counties agreed that they expect to wear a respirator in dusty conditions. The results indicated that more training should be done to improve perceptions and beliefs about using respirators. A high priority for this population will be identification of comfortable respirator options as well as communicating the importance of proper fit testing.

Respiratory disorders are not more common in farmers. Results from a study on Icelandic animal farmers

RATIONALE

The current prevalence of respiratory disorders and symptoms in Icelandic farmers is unknown, but a high prevalence of respiratory symptoms has been reported in the past. Modern farming practices have been implemented in Iceland in the past decade and the processing of hay has changed markedly leading to less organic dust exposure.

OBJECTIVE

The aim was to estimate the prevalence of respiratory disorders and symptoms in a nationwide study of Icelandic farmers.

METHODS

We conducted a questionnaire-based study of all Icelandic farmers with a comparison group randomly selected from the national citizen registry of Iceland. The questionnaire included items regarding respiratory symptoms and disorders.

RESULTS

Out of 2042 farmers invited to participate, 1107 responded (54%), as did 689 of 1500 controls (46%). Farmers were slightly older and more likely to be male (87% vs. 47%). Smoking rates were significantly lower among farmers than among controls. The prevalence of asthma was not significantly different between the two groups, with a lifetime prevalence of 9.4% (n=104) among farmers compared to 10.2% (n=70) among controls. Medication use for asthma was not significantly different. The prevalence of self-reported, physician-diagnosed chronic bronchitis and emphysema likewise did not significantly differ between the groups, but self-reported hay fever was significantly more prevalent among farmers.

CONCLUSION

The prevalence of respiratory disorders and symptoms among Icelandic farmers is currently similar to non-farmers. This may suggest that modernization of the agricultural environment has had a positive effect on workers' health.

Exposure to varying concentration of fungal spores in grain storage godowns and its effect on the respiratory function status among the workers

Grain storage depot workers suffer from different respiratory problems after getting the exposure to storage grain dust. Which is a mixture of pesticides, fungi, silica, bacteria, spores, storage mites, animal hairs, pollens etc. The present study was undertaken to evaluate the fungal spore concentration in summer and winter season as well as the pulmonary function status of the workers; studies are limited in our country. In summer and winter seasons, air sampling was done to measure the airborne fungal spore concentration inside the godowns by Rotorod sampler, UK. Aspergilla, Alternaria, Drechslera, Epicoccum, Nigrospora, Periconia were very much common and found higher in winter compared to summer. The respiratory functional status was assessed in two groups of workers of the same storage grain depot (total n=316) in summer (n=136) and in winter (n=180). List of the workers was collected from the authority and randomly selected every alternate worker and divide them for the studies in summer and winter seasons. Slow Vital Capacity (SVC), Forced Vital Capacity (FVC), and Peak Expiratory Flow Rate (PEFR) were recorded and Forced Expiratory Volume in one second (FEV1), FEV1% and different flow rates were calculated. The Immunoglobulin- E (IgE) level in the blood serum was assessed on post shift pulmonary function tests (PFT) decreased workers. The age, height and weight of the same categories of workers of both studies are highly comparable. Mean PFT values in summer found higher than winter. A gradual decrement of values were found as age was increased but not with duration of exposure. Post-shift PFT was carried in 21.8% (69) workers of which 46.4% (32) workers showed the decrement of values. The serum IgE level of the post-shift PFT decreased subjects was found more than 250 IU/ml in 53.1% (17) workers. Restrictive, obstructive and combined types of respiratory impairments were noticed among the workers. Presence of different spores in varying concentration in the working atmosphere may be responsible for the post shift decrement of PFT, allergic symptoms, high IgE level and respiratory impairments among the workers.

Recommendations for reducing the effect of grain dust on the lungs. Canadian Thoracic Society Standards Committee

OBJECTIVE

To assess the appropriateness of the current Canadian standards for exposure to grain dust in the workplace.

OPTIONS

The current permissible exposure limit of 10 mg of total grain dust per cubic metre of air (expressed as mg/m3) as an 8-hour time-weighted average exposure, or a lower permissible exposure limit.

OUTCOMES

Acute symptoms of grain-dust exposure, such as cough, phlegm production, wheezing and dyspnea, similar chronic symptoms, and spirometric deficits revealing obstructive or restrictive disease.

EVIDENCE

Articles published from 1924 to December 1993 were identified from Index Medicus and the bibliographies of pertinent articles. Subsequent articles published from 1994 (when the recommendations were approved by the Canadian Thoracic Society Standards Committee) to June 1996 were retrieved through a search of MEDLINE, and modification of the recommendations was not found to be necessary. Studies of interest were those that linked measurements of total grain dust levels to the development of acute and chronic respiratory symptoms and changes in lung function in exposed workers. Papers on the effects of grain dust on workers in feed mills were not included because other nutrients such as animal products may have been added to the grain. Unpublished reports (e.g., to Labour Canada) were included as sources of information.

VALUES

A high value was placed on minimizing the biological harm that grain dust has on the lungs of grain workers.

BENEFITS, HARMS AND COSTS

A permissible exposure limit of 5 mg/m3 would control the short-term effects of exposure to grain dust on workers. Evidence is insufficient to determine what level is needed to prevent long-term effects. The economic implications of implementing a lower permissible exposure limit have not been evaluated.

RECOMMENDATIONS

The current Canadian standards for grain-dust exposure should be reviewed by Labour Canada and the grain industry. A permissible exposure level of 5 mg/m3 is recommended to control short-term effects. Further measurements that link the levels of exposure to respiratory health effects in workers across Canada should be collected to establish an exposure-response relation and possible regional differences in the effects of grain dust.

VALIDATION

There has been no external review of these recommendations. However, the American Conference of Governmental Industrial Hygienists has recommended an 8-hour average exposure limit of 4 mg/m3 for wheat, oats and barley.

Comparison of dust related respiratory effects in Dutch and Canadian grain handling industries: a pooled analysis

OBJECTIVES

Four previously conducted epidemiological studies in more than 1200 grain workers were used to compare exposure-response relations between exposure to grain dust and respiratory health.

METHODS

The studies included Dutch workers from an animal feed mill and a transfer grain elevator and Canadian workers from a terminal grain elevator and the docks. Relations between forced expiratory volume in one second (FEV1) and exposure were analysed with multiple regression analysis corrected for smoking, age, and height. Exposure variables examined included cumulative and current dust exposure and the numbers of years a subject was employed in the industry. Sampling efficiencies of the Dutch and Canadian measurement techniques were compared in a pilot study. Results of this study were used to correct slopes of exposure-response relations for differences in dust fractions sampled by Dutch and Canadian personal dust samplers.

RESULTS

Negative exposure-response relations were shown for regressions of FEV1 on cumulative and current exposure and years employed. Slopes of the exposure-response relations differed by a factor of three to five between industries, apart from results for cumulative exposure. Here the variation in slopes differed by a factor of 100, from -1 to -0.009 ml/mg.y/m3. The variation in slopes between industries reduced to between twofold to fivefold when the Dutch transfer elevator workers were not considered. There was evidence that the small exposure-response slope found for this group is caused by misclassification of exposure and a strong healthy worker effect. Alternative, but less likely explanations for the variation in slopes were differences in exposure concentrations, composition of grain dust, exposure characteristics, and measurement techniques.

CONCLUSION

In conclusion, this study showed moderately similar negative exposure-response relations for four different populations from different countries, despite differences in methods of exposure assessment and exposure estimation.

Epidemiology of health and safety risks in agriculture and related industries. Practical applications for rural physicians

Epidemiologic studies document that work in the agricultural sector is associated with many occupational health hazards. Exposure to organic dusts and airborne microorganisms and their toxins may lead to respiratory disorders. The burden of exposure-related chronic bronchitis, asthma, hypersensitivity pneumonitis, organic-dust toxic syndrome, and chronic airflow limitation can be diminished by appropriate preventive measures. The contribution of exposures to agricultural chemicals to cancers and neurodegenerative disorders is being investigated. Some studies document that farmers and those in related industries are at higher risk for the development of cancer of the stomach, soft tissue sarcoma, non-Hodgkin's lymphoma, and multiple myeloma. Chronic encephalopathy and Parkinson's and Alzheimer's diseases are being studied in relation to agricultural chemicals. The possible carcinogenicity and neurotoxicity of pesticides emphasize the need to promote the safe use of chemicals. Another area for health promotion programs is disabling injuries and traumatic deaths. Farm accidents are important because of their frequent occurrence among young people and disturbing fatality rates. Other health issues of concern in these industries include skin diseases, hearing loss, and stress.