Toxic Treads: The Link Between Tire Fibers, Microplastics, and Interstitial Lung Disease

Abstract 26-74% of microplastics are derived from tire rubber and is a large contributor to environmental pollution. While infrastructure contributes to environmental pollution, it equally contributes to pathogenesis of pulmonary disease. Industry workers, particularly in tire manufacturing plants, are susceptible to pulmonary fibrosis and interstitial lung disease (ILD), with studies showing almost half of ILD cases secondary to microplastics. This case highlights the effect of exposure in industry workers over time. A 63-year-old gentleman with remote history of smoking presented to the emergency department with worsening shortness of breath. He was diagnosed to have chronic obstructive pulmonary disease exacerbation, imaging revealed interstitial pattern. He was treated with steroids and with improvement in symptoms. High resolution computed tomography showed evidence of interstitial lung disease. Further questioning revealed that patient reported a 20+ year history of working in a tire shop with exposure to buffed tire dust and autoshop particulates without proper protection. Patient had multiple outpatient visits for 10 years due to recurrent sinusitis. Imaging in the past demonstrated atypical lung disease, which was attributed to chronic sinobronchitis. Pulmonary function test prior to admission demonstrated obstructive disease. While signs of ILD were noted for over 6 years, due to confounding factors, there was delay in further evaluation. He was discharged on 6L oxygen. He presented again to the ED for worsening dyspnea and acute on chronic hypoxia. During this admission, he was unable to be weaned off high flow nasal cannula and discharged to long term acute care for aggressive physical therapy and oxygen management. He was intubated at the facility and returned due to inability to wean from ventilator. He subsequently passed after family decided on compassionate extubation. Talc is commonly used in the tire industry; however, exposure to this substance can cause granuloma formation and subsequent ILD. Our patient was working in the tire industry for more than 20 years with recurrent symptoms of inflammatory processes. Based on imaging, his disease process started in the upper lobe and progressed diffusely throughout the parenchyma. The pathogenesis of microplastics resulting in ILD is not well understood, but is becoming more evident that chronic inflammation from microplastic inhalation can contribute to development of severe ILD over time. Our case highlights the role of environmental tire fiber exposure in the development of ILD. Regulations on occupational hazards of exposure to microplastics need to be further explored and education to workers to be further enhanced.