Occupational diseases result from conditions of a person's work or occupation. They include diseases from exposure to toxic substances like lead, asbestos, mercury and chemicals that can cause immediate, gradual or delayed reactions in the body. Common occupational diseases are anthrax, silicosis, asbestosis, byssinosis, radiation poisoning and skin cancer. Prevention involves identifying workplace hazards, using protective equipment, monitoring health, and removing hazardous materials. Protective measures include regular health checkups, adequate treatment, compensation, and strictly following factory laws.