The element lead is a neurotoxin that is particularly dangerous to young children. Among other uses, lead compounds were common paint additives until being phased out for safer titanium-based additives beginning in the 1960's. Lead compounds were also added to gasoline to prevent engine knocking, until being phased out beginning in the 1970's. Although paint and gasoline sold today no longer contain lead, soil can have contamination from older sources of lead, such as paint from old buildings. This project shows you how you can test soil in your neighborhood for lead contamination.