Lead toxicity is a hot topic these days, especially when it was a common component in household paint for many years. In Taiwan, there was concern that babies were being exposed to toxic levels of lead through breast milk. A study was done comparing the breast milk from women who used traditional Chinese herbs and those who did did not.   High schoolers read an article about the study and then research the sources of lead exposure in the USA. A four-step assignment accompanies the article. Note that you will need to search for the article online since the links do not work.