Most pigments are made by grinding mineral materials into powder and blending oil, and those minerals are all heavy metals harmful to human body. The gas emitted by pigments is actually pigments in gaseous form evaporated by solidification and heat absorption of pigments in the picture. Once these heavy metals enter the human respiratory system from the oral cavity and nasal cavity, they will cause respiratory diseases, and you will find it difficult to breathe or even suffocate for a long time, and even cause leukemia if you stay in such an environment for a long time.