What happens if a person swallows small amount of cement?

"Cement" isn't just one thing -- there are an amazing number of recipes for cement. That said, I assume you're referring to the building compound. Cement, the building compound, is highly alkaline and very corrosive. As such it's a dangerous toxin. Quantities of one gram or less are likely to be harmless, but much more is not. If you have any doubt, head for an ER and/or call poison control. That said, here's the basic first aid for cement injestion: * Make sure the mouth is clear, to allow breathing. You can rinse the mouth out with water if you can do so without waching more cement down the throat. To do this, use a bulb irrigator gently, and turn the patient so that the water and cement drin from his mouth and don't wash down the throat. * Breathing is a major concern -- make sure breathing continues. If the airway is damaged, it may swell and shut down breathing so, in sufficient quantities of injestion, you should be prepared to consider a tracheostomy. * Unless you were able to clear the mouth completely, don't do CPR without a mask -- cement can burn you too. * Do NOT induce vomiting. * Do NOT make the patient drink an acidic solution in hopes of counteracting the alkalinity of the cement (this causes an exothermic reaction and adds chemical burns to situation, and can easily make them vomit). * If the patient becomes unconscious, position on his side so that any vomit runs out of hte mouth and is not aspirated. * I'd guess that the hospital will treat this with activated charcoal. However, that's beyond the realm of first aid.