Many foods are touted for their "antioxidant" properties, such as acai berry, green tea, and coffee, which prevent cellular damage by disarming free radicals. Free radicals are highly reactive molecules naturally formed in our bodies. However, our bodies are not the only source of free radicals. To understand how pollution could create free radicals in human lungs, Jessica Charrier, a recent PhD graduate from the UC Davis Superfund Research Program (SRP), has been investigating the most reactive chemicals found in air pollution.
By researching the fine particles (called particulate matter or PM) in air pollution, Charrier hoped to identify which components were likely responsible for causing negative human health outcomes affecting the lungs. She discovered that copper metal produced the most free radicals in artificial lung fluid out of all the other particle types used in the study. Charrier used this fluid as a way to simulate the first interaction between PM and the human body once inhaled.
How does copper get into the air we breathe? Although the sources of PM copper are largely unknown, car brakes have been identified as one major contributor because they release copper particles every time they are used. Luckily, the EPA has already begun phasing out copper in response to a different concern: after a rainstorm, copper particles from various human activities wash into waterways and harm fish and other wildlife.
Charrier has presented her research at academic conferences to great acclaim, winning student poster competitions at two American Association for Aerosol Research (AAAR) conferences in 2009 and 2010, and at the 2011 NorCal Society of Environmental Toxicology and Chemistry (SETAC) annual meeting. Charrier was also awarded a very prestigious EPA Science to Achieve Results (STAR) fellowship in 2010.
To continue focusing on how the environment impacts human health, Dr. Charrier has begun working at the CA Environmental Protection Agency Air Resources Board to inventory California’s greenhouse gas emissions: one more player in the global fight against climate change.
Erika Fritsch, a Ph.D. graduate student in Dr. Isaac Pessah’s lab, received an Outstanding Poster Presentation Prize for her research on killifish and PCBs at the 25th Annual Superfund Research Program Meeting.
Fritsch’s research on killifish is something of an evolutionary puzzle. Polychlorinated biphenyls (PCB) pollute the waters home to killifish on the east coast, yet the population appears to flourish. PCBs do not break down easily, and even in degraded forms continue to cycle through water, soil, and air. Fritsch compares killifish from PCB environments with those from non-PCB contaminated environments to determine how certain populations may have evolved immunity against these toxins. Specifically, she looks at how PCB alters the fishes’ calcium signaling pathway, a mechanism crucial to cardiac and skeletal muscle function. Fritsch hopes to further our understanding of PCB’s long-term effects on humans with her research.
Fritsch’s earlier work focused on the effects of another harmful chemical, triclosan, in fathead minnows, for which she was awarded 3rd place Best Student Platform Presentation at the Society of Environmental Toxicology and Chemistry North America 32rd Annual Meeting. Her expertise regarding triclosan drew legislative attention as policy-makers from Minnesota drafted a proposal to ban triclosan in hand soap. One of Fritsch’s papers had addressed mammalian effects of triclosan, and she subsequently corresponded with legislators to lend her expertise. “It was a nice externality,” explains Fritsch. “When you do research, you hope to learn, but you also hope that your findings are translational.”
To most people, the lanthanides are just another row of bizarrely-named elements. But for Don Anderson, a Ph.D. graduate student in Dr. Ian Kennedy’s lab, two of the rare-earth elements in that row couldn’t be more important. Anderson uses the rare-earth elements, Europium (Eu) and Gadolinium (Gd), to simulate particulate matter.
Particulate matter comes from the air pollution we know as soot, dust, and car exhaust. Because it is made of the same elements commonly found in our bodies, particulate matter is difficult to detect once inhaled. While these pollution particles can trigger inflammatory responses in the body, they leave no trail of passage.
Anderson’s research aims to determine the path these particles take when inhaled. Substituting particulate matter with Eu and Gd in his experiments with mice helps Anderson track the trajectory of inhaled particles. Since Eu and Gd fluoresce, they effectively indicate where in the body particles travel to upon inhalation. Anderson has found that the particles often reach the lungs, liver, and spleen.
A pressing question that remains is whether the particles spread to the heart. Data show that greater densities of particulate matter in the air are correlated with higher rates of cardiovascular problems. But the debate over whether particulate matter inflames the heart muscle directly (through physical contact) or indirectly (while remaining in the lungs) is unresolved.
Anderson’s work is unique in that he delivers Eu and Gd particles to the mice in the same airborne fashion that particulate matter enters our bodies. In Anderson’s experiments, mice are placed in cages filled with the particles, where they breathe the matter in passively. While this method takes more time and resources than simply “force-feeding” the particles through a tube, it ensures the most realistic simulation of particulate matter inhalation.
Anderson says he loves the sophisticated level of design and analysis involved in lab research, but eventually hopes to pursue a career in teaching. Anderson is the recipient of the White Family Graduate Student Award. This award is given to students whose research will aid in the improvement of environmental health.