Hi Mohammed, you can only derive a protein concentration from a competitive ELISA under very special circumstances. If you are not sure whether you have these conditions in your experiment you should work with IC50 values.
About Lead-Based Paint. Lead is a highly toxic metal that may cause a range of health problems, especially in young children. When lead is absorbed into the body, it can cause damage to the brain and other vital organs, like the kidneys, nerves and blood. Lead may also cause behavioral problems, learning disabilities, seizures and in extreme cases, death.
Homes or apartments built before 1978 may contain lead paint. Exposure to lead paint dust or chips can cause serious health problems. Children and pregnant women are at higher risk. If you own rental property, it is your responsibility to repair chipping or peeling lead painted surfaces. It is important to assess the need for repairs every year or when a new occupant moves in.