The New York Times has an article in today's Science section about lead, and its historical uses. It's not hard to see why people were so enthusiastic about lead in ancient times-- it's easy to find and recover, it has a low melting point, and it's malleable. Lead also gets cozy with sulfur, which is why there are so many health problems associated with it. Some of these problems were known by Hippocrates in 400 BC, but lead was so useful that people weren't ready to do without it. The most significant problems are experienced by young children, whose brain development is affected by lead molecules which disrupt some proteins by seeking out sulfur. Other animals are also affected by ingesting lead.
In my previous career in public health, I became a Certified Lead Inspector for housing. In New England, with its older housing stock, lead paint is a persistent issue. While Europe banned the residential use of lead paint in the 1920s, the US didn't until the Consumer Product Safety Commission issued a regulation in 1978 prohibiting its use in residential settings. At first, I thought that flaking lead paint was the big problem, since kids often eat the flakes (Apparently, lead lends a sweet taste to substances, which is why the Romans used it to treat wine.), but it is also present in house dust as a result of friction on window sashes and door jambs. Lead from gasoline contributed to the environmental load as well.
Here are some UMass Library databases you can search for more information on lead in the environment and it's effects on humans and other animals. Remember that you may have to use your OIT login information if you want to connect from off-campus.
Food Science and Technology Abstracts
Kirk Othmer Encyclopedia of Chemical Technology
PubMed: UMass Amherst subscription
Web of Science
If you're interested in the biochemistry of lead, try Beilstein.