The present disclosure relates to a method for monitoring oxygen level of an environment. The method comprises receiving at least one image of the environment comprising plurality of users from a capturing device. Then, at least one region of interest of each of the plurality of users is detected in the at least one image. A video plethysmographic waveform is generated by analyzing the at least one region of interest. Further, Peripheral Capillary Oxygen Saturation (SPO2) based on the video plethysmographic waveform is determined. Thereafter, oxygen level of the environment is determined by averaging the SPO2 level of each of the plurality of users. The determined oxygen level of the environment is compared with predefined oxygen level of the environment and an appropriate action is performed based on the comparison.