This study develops a mathematical model using the one-dimensional advection diffusion equation (ADE) to simulate the spread of SARS-CoV-2 particles in an indoor environment. The model assumes the presence of one infected individual and focuses on the effects of ventilation and aerosol-generating activities, such as talking and breathing. This study advances previous work by employing boundary conditions and incorporating the source location and time of particle release that allow for more realistic simulation. The one-dimensional ADE is solved analytically using the Laplace transform method which then provides predictions of the distribution of the virus. One of the key findings indicates that pandemic-updated ventilation shows the lowest overall concentrations of particles across all conditions compared to poor ventilation, thereby lowering the risk of transmission. Well-ventilated spaces quickly reach stable conditions with low particle concentrations, while poorly ventilated areas maintain higher concentrations for longer periods, increasing exposure risk. Additionally, the use of masks is shown to further mitigate transmission risks by reducing the number of particles released into the air. However, breathing without a mask is better than talking with a mask. These findings can guide public health policies on ventilation standards to improve air quality and reduce viral transmission.