The C-Category Mines, in the form of rocks and soil, is one type of mines of which management authority is carried out by the local government. The C-category quarry does indeed provide benefits in the form of employment and contributions to certain parties, but the mining activities conducted within produce dust that can have a negative impact on the environment and health in the form of air pollution that causes Upper Respiratory Tract Infections (URI) in workers. The purpose of this study was to determine the total dust content and the relationship between working hours, the use of Personal Protective Equipment, and workers' knowledge on the risk of URI in C-category quarry. This study was categorized as quantitative study with a cross sectional study approach. There were 76 workers of C-category quarry in Watusampu Village as the sample of study. The sampling was conducted by using simple random sampling technique. The data were analyzed using chi-square test. Total dust content was measured at two points using the LVS (Low Volume Sampler) tool. The measured total dust content was determined gravimetrically. The results showed that total dust content at both sampling points exceeded the Threshold Limit Value of Chemical Substances contained in the air at the workplace which was 125 mg/m3 at sample point I and 140,6 mg/m3 at sample point II. Threshold Limit Value for total dust content contained in the air at the workplace was 10 mg/m3. There is no relationship between working hours (ρ=1,000) and the risk of URI in workers, there is a relationship between the use of mask as a PPE (ρ=0.030) and workers' knowledge (ρ=0.012) and the risk of URI in C-category quarry workers which can cause negative impact on the environment and the health of workers.