Ecosystems Effects Research
Nanomaterials have become widely used in products ranging from clothing (which incorporates bacteria-fighting nano Silver) to sunscreen. Nanomaterials are very useful, but there is little research about how nanomaterials affect ecosystem health. Since nanomaterials are much smaller than normal (about 100,000 times smaller than the width of a human hair), they are absorbed more easily by animal’s lungs and skin. EPA is in the process of researching how nanomaterials interact with biological processes important to the health of ecosystems and wildlife species that live in these ecosystems.
EPA researchers are developing methods, models and guidelines to:
- Quantify the potential hazard of various nanomaterials.
- Characterize and quantify effects of nanomaterial properties and modifying factors.
- Determine adverse outcome pathways (AOPs) that can affect nanomaterials potential for exposure and toxicity.
- Develop rapid screening tools (high throughput screening) to evaluate nanomaterials for these adverse outcomes.
- Explain higher-level system responses (e.g. effects on soil or sediment ecological function).
Results & Impact
The results of this research will allow risk assessment of multiple different nanomaterials including:
Nano-Titanium Dioxide (TiO2)
- Testing effect of fate processes (aging) of cosmetic and sunscreen TiO2 and reactivation of photoactivity in aquatic systems. The testing includes uptake, food chain transfer, and potential for phototoxicity via those modes of exposure. It will also inform identification of adverse outcome pathways and nanomaterials indicators of hazard.
- Researching plant and earthworm response to nanomaterials exposure, whole organism lethal and sublethal responses (e.g. growth and genomic indicators) and effects on system functions performed by fungi and mycorrhizae
- Bioaccumulation of nanomaterials and responses in sediment organisms living in marine systems.
- Comparative toxicity of nanomaterials in two species, acute to chronic ratios in those two species and differentiation of particle vs. free species toxicity in aquatic systems.
- Nanomaterials bioaccumulation comparison of citrate vs. PVP-capped material and whole-community microbe genomics in marine systems.
Carbon nanotubes (SWCNT)
- Nanomaterials toxicity, bioaccumulation and food-chain transfer in model in marine systems.
- Development of methods for extraction and quantification of carbon nanotubes in water, sediments, and organisms
Nano Cerium oxide
- Effects on plants deposition via diesel combustion, on direct plant application and soil exposure of plants and earthworms in terrestrial systems.
- Four types of nano-scale copper, acute effects in water column organisms, sediment community responses and whole-community microbe genomics in marine systems.