The earliest this can be detected the better it is for the child because it means less damage. Lead screening is done by a blood test and if there is any level of lead in your child's blood it will be detected. If lead does show up, then a second blood test will need to be done for follow up. If the child shows high levels of lead then X-rays and other test may be ordered. In severe cases medical treatment may include hospitalization.
Vitamin C helps protect the body against lead.
Don't leave any food in open cans and put back in refrigerator for storage. Have your water tested and have a water filter inserted. Be on the look out for chipping paint. Make sure your paint is lead-free. Always have your child wash his hands before eating.