Impact of soldering temperatures on heavy metal and dust emissions: A LIBS-based environmental pollution analysis

Abstract

Soldering is a critical operation in various industrial sectors, however, the pollution generated by this process is emerging as a significant environmental concern. This study utilizes Laser-Induced Breakdown Spectroscopy (LIBS) for real-time analysis of contaminants produced during soldering, with a particular focus on heavy metals such as lead (Pb) and tin (Sn). The research examines the elemental composition of soldering fumes, including variations in heavy metal content, dynamic changes in carbon and particle distribution of PM2.5, PM10, and Total Suspended Particles (TSP) in workers' breathing zones. The results indicated that rising temperatures significantly enhanced the evaporation of lead and tin. Concurrently, the intensity of carbon spectral lines exhibited a pronounced upward trend. The concentrations of PM2.5 and PM10 particulate matter increased significantly with operating temperature increments. PM2.5 required substantially more time than PM10 and total particulate matter (TPM) to reach its peak concentration within the workers' breathing zone. Furthermore, Pearson's correlation analysis between temperature and elemental intensity revealed correlation coefficients exceeding 0.8 for both Pb and Sn, highlighting a strong linear relationship with temperature. This finding was further corroborated by the Principal Component Analysis (PCA)-based correlation analysis between temperature and element intensity, with the coefficient of determination (R²) reaching 0.89. This research highlights the potential health risks associated with soldering fumes, particularly regarding the presence of heavy metals and harmful gases, and underscores the importance of regulating soldering practices to mitigate environmental pollution risks.