Coupled diffusion law of windflow-dust, respiratory zone exposure levels and simulated dust reduction in industrial building re-construction

The greening and organic regeneration of cities has led to the massive reclamation of industrial buildings. However, regeneration construction in closed environments has triggered serious dust pollution, posing a serious threat to the occupational health of construction workers. This paper analyses the spatial and temporal distribution and respiratory zone exposure levels of regeneration construction dust in a typical contaminated industrial building site in Xi'an, China, and determines the optimal dust reduction location and dynamic dust reduction scheme. The results show that the initial kinetic energy and direction of motion of construction dust have an important influence on the overall distribution of dust in the regeneration construction site of abandoned industrial buildings. The instantaneous concentration of cutting dust was higher than 89 mg/m³ at 60s of continuous operation, and the high concentration of dust was mainly concentrated within 10 m from the working surface. As far as the breathing zone is concerned, L = 5 m is the best distance for pollution control. Setting up a dust reduction device with 8 MPa pressure at this place and adopting dynamic peak dust reduction method can achieve >80 % dust reduction efficiency, minimise dust pollution and ensure workers' health. The results of the study can provide certain theoretical and technical references for all kinds of construction projects, especially the dust pollution control of old building renovation projects and other work.