Latar belakang: Selain meningkatkan produktivitas kerja karyawan, lingkungan kerja yang aman dan sehat akan membuat tenaga kerja nyaman dalam bekerja. Salah satu faktor lingkungan yang berpengaruh terhadap kesehatan kerja adalah paparan debu di tempat kerja. Paparan debu dapat menyebabkan berkurangnya kenyamanan kerja, maslah penglihatan dan gangguan fungsi paru. Penelitian ini bertujuan menganalisis hubungan antara kapasitas kerja dan penurunan fungsi paru pada pekerja di lingkungan berdebu.Metode: Penelitian adalah penelitian eksplanatory research dengan pendekatan cross sectional. Subyek penelitian sebanyak 32 orang penenun yang diambil secara purposif di desa Troso, Jepara. Variabel penelitian meliputi kapasitas kerja (umur, masa kerja, status gizi, kebiasaan merokok) dan kapasitas vital paru. Data dianalisis dengan uji chi-square. Hasil: Kadar debu tertinggi sebesar 0,64 m3/menit sedangkan kadar terendah sebesar 0,05 m3/menit; sebanyak 34.4% pekerja mengalami gangguan restriktif ringan, 56.2% mengalami restriktif sedang dan mengalami gangguan mixed sebesar 3.1%. Terdapat hubungan antara umur dan masa kerja dengan kapasitas vital paru (p< 0.05). Tidak ada hubungan antara kebiasaan merokok dan status gizi dengan kapasitas vital paru (p> 0.05)Simpulan: Kadar debu lingkungan kerja belum melampaui nilai ambang batas yang ditentukan namun terdapat pekerja yang mengalami gangguan fungsi paru berupa restriktif ringan, restriktif sedang dan mixed. Sangat disarankan bagi pekerja untuk melakukan upaya menjaga kesehatan parunya selama bekerja. ABSTRACT Title: Work Environment Dust Level and Work Capacity as A Determinant of Decreased Lung Function CapacityBackground: A safe and healthy work environment will make the worker feel comfortable and safe at work, these conditions will increase the level of productivity. One of the environmental factors that affect occupational health is dust exposure in the workplace. It can reduce comfortness and safety at work, impaired vision and impaired lung function. This study aimed to analyze the relationship between work capacity and workers’ decreased lung function in dusty environments. Method: This research is an explanatory research with a cross sectional approach. The research subjects were 32 weavers who were taken purposively in the village of Troso, Jepara. Research variables include work capacity (age, length of work, nutritional status, smoking habits) and lung vital capacity. Data were analyzed by chi-square test.Result: The highest dust level was 0.64 m3/minute while the lowest level was 0.05 m3/minute; 34.4% of workers experienced mild restrictive disorder, 56.2% experienced moderate restrictive disorder and 3.1% experienced mixed disorder. There was a relationship between age and length of work with vital lung capacity (p < 0.05). There was no relationship between smoking habit and nutritional status with lung vital capacity (p> 0.05).Conclusion: The dust level in the work environment has not exceeded the specified threshold value, but there were workers who experience impaired lung function in the form of mild restrictive, moderate restrictive and mixed. It is highly recommended for workers to maintain lung health while working.