Flock worker's lung
- David G Kern, MD
David G Kern, MD
- Maine VA Medical Center
- Augusta, Maine
- Robert S Crausman, MD
Robert S Crausman, MD
- Clinical Professor of Medicine
- Brown University
An outbreak of work-related interstitial lung disease among employees at a Rhode Island textile plant specializing in the manufacture and application of nylon flock was described in 1998 . Based on a case definition of persistent respiratory symptoms, previous work in the flocking industry, and histologic evidence of otherwise unexplained interstitial lung disease, a cluster of eight cases of flock worker's lung was recognized among fewer than 200 at-risk workers at a single production facility . More than two dozen cases have now been reported among nylon flock workers in Rhode Island, Massachusetts, North Carolina, and Ontario [1-4].
The epidemiology, clinical features, and natural history of flock worker's lung are described here. General issues related to the diagnosis of interstitial lung disease are discussed separately. (See "Approach to the adult with interstitial lung disease: Clinical evaluation" and "Approach to the adult with interstitial lung disease: Diagnostic testing".)
NYLON FLOCK EXPOSURE
In the flocking industry, short fibers (flock) are cut from cables of synthetic monofilaments and applied to adhesive coated fabric surfaces to produce velvet-like materials often used to produce upholstery, blankets, and clothing [1-3]. Exposures common to the nylon flocking industry include nylon, tannic acid, acrylic adhesive, nonfibrous zeolite, heat transfer oil, thermal degradation products, and ammonium ether of potato starch .
Although most nylon flock manufacturers worldwide use guillotines to cut flock, two large North American companies use rotary cutters. The rotary cutters apparently generate substantial quantities of respirable-sized nylon particles [3,5]. Inhalation of these fibers resulted in pulmonary toxicity in one animal model; however, these findings were not replicated in a separate industry-sponsored experiment [6,7]. All affected nylon flock workers described thus far have had occupational exposure to rotary-cut flock .
The polycationic nature of nylon flock is reminiscent of the polycationic compounds in Acramin-based spray paint, which caused occupational outbreaks of organizing pneumonia in Spain and Algeria, and the humidifier disinfectant polyhexamethylene guanidine, which caused an outbreak of interstitial lung disease in Korea . Experimental studies in animals support the idea that the polycationic nature of these agents contributes to lung toxicity when the agents are inhaled despite apparent absence of toxicity in dermal and oral exposure studies.
- Kern DG, Crausman RS, Durand KT, et al. Flock worker's lung: chronic interstitial lung disease in the nylon flocking industry. Ann Intern Med 1998; 129:261.
- Eschenbacher WL, Kreiss K, Lougheed MD, et al. Nylon flock-associated interstitial lung disease. Am J Respir Crit Care Med 1999; 159:2003.
- Kern DG, Kuhn C 3rd, Ely EW, et al. Flock worker's lung: broadening the spectrum of clinicopathology, narrowing the spectrum of suspected etiologies. Chest 2000; 117:251.
- Turcotte SE, Chee A, Walsh R, et al. Flock worker's lung disease: natural history of cases and exposed workers in Kingston, Ontario. Chest 2013; 143:1642.
- Burkhart J, Piacitelli C, Schwegler-Berry D, Jones W. Environmental study of nylon flocking process. J Toxicol Environ Health A 1999; 57:1.
- Porter DW, Castranova V, Robinson VA, et al. Acute inflammatory reaction in rats after intratracheal instillation of material collected from a nylon flocking plant. J Toxicol Environ Health A 1999; 57:25.
- Warheit DB, Webb TR, Reed KL, et al. Four-week inhalation toxicity study in rats with nylon respirable fibers: rapid lung clearance. Toxicology 2003; 192:189.
- Nemery B, Hoet PH. Humidifier disinfectant-associated interstitial lung disease and the Ardystil syndrome. Am J Respir Crit Care Med 2015; 191:116.
- Barroso E, Ibañez MD, Aranda FI, Romero S. Polyethylene flock-associated interstitial lung disease in a Spanish female. Eur Respir J 2002; 20:1610.
- Atis S, Tutluoglu B, Levent E, et al. The respiratory effects of occupational polypropylene flock exposure. Eur Respir J 2005; 25:110.
- Antao VC, Piacitelli CA, Miller WE, et al. Rayon flock: a new cause of respiratory morbidity in a card processing plant. Am J Ind Med 2007; 50:274.
- Lougheed MD, Roos JO, Waddell WR, Munt PW. Desquamative interstitial pneumonitis and diffuse alveolar damage in textile workers. Potential role of mycotoxins. Chest 1995; 108:1196.
- Washko RM, Day B, Parker JE, et al. Epidemiologic investigation of respiratory morbidity at a nylon flock plant. Am J Ind Med 2000; 38:628.
- Weiland DA, Lynch DA, Jensen SP, et al. Thin-section CT findings in flock worker's lung, a work-related interstitial lung disease. Radiology 2003; 227:222.
- Boag AH, Colby TV, Fraire AE, et al. The pathology of interstitial lung disease in nylon flock workers. Am J Surg Pathol 1999; 23:1539.
- Kern DG, Kern E, Crausman RS, Clapp RW. A retrospective cohort study of lung cancer incidence in nylon flock workers, 1998-2008. Int J Occup Environ Health 2011; 17:345.