Now Available for Public Comment: Notice of Proposed Rulemaking (NPRM) for FDAAA 801 and NIH Draft Reporting Policy for NIH-Funded Trials

Epidemiology and Pulmonary Response To Organic Dust Exposure

This study has been completed.
Sponsor:
Information provided by:
National Heart, Lung, and Blood Institute (NHLBI)
ClinicalTrials.gov Identifier:
NCT00005288
First received: May 25, 2000
Last updated: June 23, 2005
Last verified: April 2001
  Purpose

To characterize the nature of pulmonary responses to organic dust exposures in order to gain insight into patterns of respiratory disease in agricultural workers.


Condition
Lung Diseases, Obstructive
Chronic Obstructive Pulmonary Disease

Study Type: Observational
Study Design: Observational Model: Natural History

Further study details as provided by National Heart, Lung, and Blood Institute (NHLBI):

Study Start Date: December 1986
Estimated Study Completion Date: November 1991
Detailed Description:

BACKGROUND:

In 1986 when the study began, agriculture was one of the largest employers in the United States, comprising nearly 12 million people. Farm workers were hospitalized more frequently than other occupational groups and were found to have the highest number of restricted activity days due to injury and illness. Much of this was due to frequent and disabling farm related accidents which made agriculture the most hazardous occupation in the United States. Agricultural workers were also found to have high rates of respiratory disability, compared with other industrial sectors, based on Social Security disability records.

The common denominator for respiratory disorders among agricultural workers was exposure to organic dust which was recognized to be a complex mixture of vegetable particles and fragments, microorganisms and their products, insects and insect fragments, feed additives including fish meal and antibiotics, and avian and rodent proteins. While the vegetable dust itself was by far the most important exposure, individual circumstances of growing, storage and subsequent use of the product from which the organic dust arose, influenced specific exposures. In certain situations, like animal confinement housing, irritant gases including ammonia and hydrogen sulfide co-existed with an organic dust to further vary respiratory exposure.

Workers exposed in Iowa swine production units were known to be significantly exposed to grain dust, endotoxin, animal danders and other proteins, ammonia and hydrogen sulfide gas, and a variety of microorganisms including fungi and thermophilic actinomycetes. Cross-sectional epidemiological surveys had documented a high prevalence of respiratory symptoms including chronic cough, phlegm and wheezing, but also prominent constitutional symptoms including fever, myalgias and malaise. This study was one of several projects supported by a Specialized Center of Research in Occupational and Immunologic Lung Disease.

Funding represents approximately 35 percent of the dollars of the Specialized Center of Research in Occupational and Immunologic Lung Disease (P50HL37121) used to support epidemiologic studies.

DESIGN NARRATIVE:

A nested case-control study was carried out on a previously studied cohort. Members of the cohort were resurveyed in the first year of the study. All participants received a routine physical examination, chest x-ray, electrocardiogram if over 40 years of age, routine laboratory tests, methacholine challenge, intradermal skin testing, and bronchoalveolar lavage. Cases for the swine confinement farmer cohort were selected if they had FEF50 of 60 percent or less of predicted for age, sex, height, and race. Three referents for each case were randomly selected from all swine confinement farmers not selected as cases, non-confinement farmers, and blue collar workers. Measurements were repeated in the fourth year, finishing in the fifth year of the study. The study determined: the extent to which epidemiological studies underestimated pulmonary responses and impairments among agricultural workers; the environmental risk factors significantly related to cases; whether atopy and heightened airway reactivity were significantly associated risk factors. The subproject was not renewed in 1992.

  Eligibility

Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   No
Criteria

No eligibility criteria

  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

No Contacts or Locations Provided
  More Information

Publications:
Merchant JA: Agricultural Respiratory Disease, In: Seminars in Respiratory Medicine - Vol. 7, Number 3. Thieme Inc, pp 211-224, New York, 1986
Merchant JA: Silicosis Issues - Past, Present, Future. Published in Book: Silica, Silicosis, and Cancer: Controversy in Occupational Medicine, 1986, Goldsmith DF, Winn DM, Shy CM (Eds), Praeger Special Studies, Praeger Scientific, pp 87-90, New York, 1986
Merchant JA: Contribution to Report The Health Consequences of Smoking: Cancer and Chronic Lung Disease in the Workplace: A Report of the Surgeon General. U.S. Department of Health and Human Services, Public Health Service, Office on Smoking and Health, U.S. Government Printing Service, Washington, D.C., 1986
Merchant JA, Boehlecke BA, Taylor G (EDs): Occupational Respiratory Diseases, U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, U.S. Government Printing Office, Washington, D.C., 1986
Dement JM, Merchant JA: Chapter III. C: Asbestosis, in Occupational Respiratory Diseases, U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, U.S. Government Printing Office, Washington, D.C., 1986
Merchant JA: Chapter VI. Byssinosis, in Occupational Respiratory Diseases, U.S. Department of Health and Human Services, Public Health Services, Centers for Disease Control, National Institute for Occupational Safety and Health, U.S. Government Printing Office, Washington, D.C., 1986
Merchant JA, Hodous T, Taylor G, Reger R: Chapter III. D: Coal Workers Pneumoconiosis, in Occupational Respiratory Diseases, U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control, National Institute for Occupational Safety and Health, U.S. Government Printing Office, Washington, D.C., 1986
Merchant JA, Donham KJ: Health Risks from Animal Confinement Units. Proceedings of the International Symposium on Health and Safety in Agriculture. Saskatoon, Canada. In press, 1987
Leistikow BN, Donham KJ, Merchant JA: Health Hazards of Poultry Production: Proceedings of the International Symposium on Health and Safety in Agriculture, Saskatoon, Canada. In press, 1987
Merchant JA: Occupational Parenchymal Lung Disease. Kelley: Textbook of Internal Medicine. In press, 1988
Merchant JA, Donham KJ, Popendorf WJ, Burmeister LF, Lassise DG, Lee NF, Weinrich AJ: Acute Responses Among Swine Confinement Workers. Proceedings of Agricultural, Occupational, and Environmental Health: Health Policy Strategies for the Future. Iowa City, Iowa. In press 1988

ClinicalTrials.gov Identifier: NCT00005288     History of Changes
Other Study ID Numbers: 2009
Study First Received: May 25, 2000
Last Updated: June 23, 2005
Health Authority: United States: Federal Government

Additional relevant MeSH terms:
Lung Diseases
Lung Diseases, Obstructive
Pulmonary Disease, Chronic Obstructive
Respiratory Tract Diseases

ClinicalTrials.gov processed this record on November 25, 2014