Tracking semi-volatile organic pollutants in remote lake systems.

摘要

SOCs volatility and persistence properties cause many SOCs to become ubiquitous in the environment as well as accumulate in areas with lower temperatures such as polar or orographic regions. Many anthropogenic SOCs pose a serious risk to human and ecosystem health because of their persistent, bioaccumulative, and toxic properties in the environment. Unique and sensitive ecosystems exist in polar or orographic regions. Vast improvements in our understanding of the fate and transport of many SOCs have been made with research in polar or orographic regions located in eastern North America, Europe, and parts of the arctic and Antarctica. Advancements in our understanding of the fate and transport of SOCs in western U.S are hindered by the limited number and scope of past studies, sampling strategies, and current methodologies. Described herein, the development, validation, and as well as the demonstration of a new analytical method capable of measuring 75 SOCs including current and historic-use pesticides, polycyclic aromatic hydrocarbons, polychlorinated biphenyls in large-volume lake water and snowmelt samples. A novel solid phase extraction device containing hydrophilic and hydrophobic called a "modified Speedisk" was developed to handle large volume aqueous samples (50L), capture a wide range of SOCs, and capable of interfacing with an in situ submersible pump. In addition, this dissertation contains the development, validation, and demonstration of an analytical method capable of quantifying 98 SOCs including polybrominated diphenyl ethers from remote lake systems. Sediment core, snow, and lake water samples were collected, extracted, and quantified for SOCs using the methods above from fourteen high-altitude and/or high-latitude remote lake systems in western National Parks (NPs). Many SOCs demonstrated a significant regression between surficial sediment fluxes and snow fluxes (p0.05). These significant regressions stress the importance of winter time SOC deposition in western NPs. SOC deposition in Rocky Mountain NP and Glacier NP is dependent on regional upslope wind directions and the location of regional sources (relative to the Continental Divide). Lake water concentrations and sediment fluxes were generally lower in the Alaska's NPs and Olympic NP, due to proximity to source regions and the prevailing westerly winds.