Like other dusts, coal dust mainly enters the human body through the respiratory tract, followed by skin contact, and part of the dust can be swallowed into the digestive tract when dissolved in oral saliva or adhered to food
Like other dusts, coal dust mainly enters the human body through the respiratory tract, followed by skin contact, and part of the dust can be swallowed into the digestive tract when dissolved in oral saliva or adhered to food
Like other dusts, coal dust mainly enters the human body through the respiratory tract, followed by skin contact, and part of the dust can be swallowed into the digestive tract when dissolved in oral saliva or adhered to food