As part of the Science Hall Colloquium Series, Dan Brabander, an associate professor of geochemistry at Wellesley College, delivered a lecture April 27 titled “Medical Geology: The Interface between Environmental Engineering and Public Health: Case Studies from the Urban Environment.” Brabander used case studies as examples for how researchers in many disciplines – namely biology, geology and chemistry – can combine forces to positively affect human health. There are a number of different approaches that allow scientists to look at hazards to human health. One of these approaches is epidemiological, or population-based. Brabander used the situation in Bangladesh as an example. There, scientists are studying arsenic in drinking water supplied to 80 million people. Scientists often study the bioaccesibility and bioavailability of toxic molecules; these terms refer respectively to how much of a particular contaminant will dissolve in your stomach and how much of it will reach your circulatory system. Biomonitoring is a particularly inhumane way of evaluating exposure. Canaries used to be taken into coal mines to measure the level of oxygen available. When the canaries died due to a lack of oxygen, miners would know that they needed to leave. Brabander suggested that urban children are the unsuspecting canaries when it comes to testing the levels of lead in urban gardens. Brabander also addressed the two different ways in which risk is assessed. Scientifically speaking, risk is determined by the sum of toxicity and exposure. Risk here equals hazard plus outrage, or media coverage. This assessment of risk was used in the example he gave concerning his study of chromated copper arsenate wood in Boston area playgrounds. CCA was an EPA approved material used for outdoor construction in the United States for 60 years, but Brabander and his students found that the levels of arsenic in the wood were a cause for concern. When this information was presented at a conference, The Boston Globe got hold of the information and amplified the perceived level of risk. The popular reporting made the story much different from the conference, in which Brabander said, “There was no mention of risk or exposure.” For this reason, Brabander encouraged the general public to develop “quantitative reasoning skills.” To further illustrate the oddities concerning public opinion, Brabander showed excerpts from National Geographic articles from the late 1920s about children playing with lead toys. He had a few of these toys with him and passed them through the room, reminding the audience to wash their hands before eating. Currently Brabander is working with colleagues on publishing a paper that focuses on lead levels in the blood of Indians who use imported spices and religious ceremonial powders. Some children were coming to hospitals with very elevated levels of lead in their blood and were coincidentally all Indian. Brabander worked to identify products specific to that ethnic group that could be the cause of such high lead exposure. Research led him and his colleagues to Sindoor powder, which is in some cases made with large amounts of lead, lending it a red color. This type of specific research and collaboration among disciplines can significantly impact great amounts of people.