Have your child tested. Ask your pediatrician to administer a venous lead test, and request specific results: the amount of lead, in micrograms per deciliter, in the child's blood. Many doctors aren't aware of the harm lead can do at levels below 10.
Likely suspects. Keep an eye out in your home for peeling paint. Windows are a large source of lead exposure, as the friction from opening and closing a window causes lead dust to be created and scattered. Porches are also a common source of lead paint hazards because lead used to be put into paint to help surfaces withstand cold and wet weather.
Get inspected. If you suspect lead paint in your home, call 311 to schedule a lead inspection with the city. Lead test kits are also available at hardware stores, but they have limited detection capabilities and can give false negatives.
Be smart about renovation. Renovating your home can expose lead hazards that were previously covered up. Make sure that any contractor you work with tests for lead and minimizes exposure. If you hire a contractor to do lead abatement, make sure they are certified with the state to properly handle lead hazards.