Despite a constant growth in numbers, the identity and nature of human-derived environmental contaminants have changed from traditional pollutants such as nutrients, trace metals, DDT and PCBs to other biologically active compounds such as endocrine disruptors, antibiotics and, more recently, a wide range of chemicals broadly classified as emergent chemicals of interest. Chemicals such as mercury, natural and synthetic estrogens, antibiotics, high-use pharmaceuticals and even natural toxins produced by algal blooms are now recognized as having significant effects both directly, in receiving ecosystems, and indirectly to humans.
Processes such as eutrophication produce a direct and striking visual response for water quality degradation often evidenced by microorganism blooms, drastic changes of water color, and in some cases, animal deaths. The causes, however, are often hidden in subtler changes of the chemical ecology of an ecosystem, triggered by chemicals (present in treated domestic effluents), contaminants (e.g. the combination of mercury and sulfate leading to mercury methylation) or natural stressors (wildfires, climatic disturbances and others) whose introduction affects the delicate balance of natural systems, particularly those in the direct path of urban development. The first signs of impact are often presented in water streams where small concentrations of these chemicals are constantly introduced and transported through multiple boundaries (air, water, soil, and organisms).
Water quality is not only the most critical driver in ecosystem sustainability, but also a major limiting factor for human development due to its effects on water scarcity. As a result, water tends to be progressively laced with anthropogenic signatures from components that elude treatment, as it continues its journey from release to recharge to reuse. With few exceptions, in surface water bodies used as sources for drinking water, contamination is largely affected by dilution, so “exposure” needs to be characterized at very low concentrations for early intervention to be effective. The remaining challenges beyond the characterization of the environmental stressor, are establishing the links between the chemical indicator (CI) and its receptors, and determining the biological conduits and physiological events that will result in an adverse outcome pathway (AOP). Addressing these two key issues is essential in producing meaningful, population-based science in support of the decision making and regulatory processes.
The CREST CAChE team has taken on these challenges using multiple approaches in creating new technologies, developing analytical methods, implementing extensive environmental assessments and characterizing the processes and mechanisms that control the “exposome” using engineering, chemistry, biology, statistics and molecular and traditional ecotoxicology. The ultimate goal of Subproject 1 is to advance the effectiveness of existing analytical approaches for the analysis of traditional pollutants, to develop novel analytical methodologies and approaches for the identification, characterization and quantification of previously unknown contaminants of concern, and to enhance and extend the applicability of molecular biology methodologies to assess environmental stressors to aquatic organisms across land-use boundaries.
The driving hypothesis for Subproject 1 is that detection of environmentally relevant levels of pollutants, contaminants or stressors using high throughput technologies with high degree of specificity and at ultra-low concentrations will lead to the recognition of important pathways, interactions, changes and transport along environmental gradients and across land-use boundaries, that could negatively affect ecosystem functioning through anthropogenic activities, natural forces and altered biogeochemical cycles.
Through CREST CAChE, Subproject 1’s research into contaminant detection and identification will:
Our team is extending technologies and approaches for measuring chemical stressors. We conduct advanced sensing of environmental exposure to anthropogenic contaminants, pollutants and other natural stressors, such as harmful algal blooms.
Piero Gardinali, Co-Lead: environmental analytical chemistry
Yong Cai, Co-Lead: environmental bioinorganic chemistry
William Anderson: stable isotope biogeochemistry
Marcus Cooke: biomonitoring genotoxin exposure
Jose Eirin-Lopez: genetic and epigenetic adaptation
Quentin Felty: estrogen-mimicking endocrine disruptors
Rene Price: hydrogeology, eco-hydrology and geochemistry
Leonard Scinto: aquatic and sediment biogeochemistry