Chlorinated aliphatic hydrocarbons (CAHs) such as vinyl chloride (VC) and 1,-2 dichioroethane (DCA), are wide-spread groundwater pollutants found at many contaminated field sites around the world. Quantitative tools are needed to determine the in situ rates of VC and DCA transformation to ethene in contaminated groundwater. The objective of this...
Many pesticides, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers
(PBDEs), and polycyclic aromatic hydrocarbons are persistent, bio-accumulative, and
toxic. These semi-volatile organic compounds (SOCs) can undergo atmospheric
transport and deposition in cold, remote ecosystems. A better understanding of their
accumulation in the fish of these ecosystems is important to better predict...
The purpose of this research was to compare four different media that were used to monitor SOC atmospheric concentrations in remote ecosystems. The accumulation of semi-volatile organic compounds, including pesticides, polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), was investigated in lichen, 2-year old conifer needles, resin-based passive air sampling...
The atmospheric transport and deposition of semi-volatile organic compounds (SOCs), including current and historic use pesticides, polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs), to mountain ecosystems may result in the exposure of tadpoles to these SOCs. This exposure has been implicated in amphibian population declines in California. Tadpoles encounter...
Halogenated Polycyclic Aromatic Hydrocarbons (X-PAHs) are ubiquitous contaminants that are thought to be generated by processes such as chemical industries and incomplete combustion, including waste incineration and electronic waste (e-waste) burning. X-PAHs are a concern for environmental and human health because they are toxic, mutagenic, and are expected to be...
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous contaminants and are mostly products of the incomplete combustion of organic material. PAHs are often found in environmental samples as a complex mixture of isomers. In addition, the same sources that produce complex PAH mixtures also produce other poorly characterized mixtures of organic compounds,...
The trans-Pacific atmospheric transport of particulate matter (PM)-bound polycyclic aromatic hydrocarbons (PAHs) to remote sites in western North America has been well documented and has triggered research questions regarding to atmospheric transformation of PM-bound PAHs and the potential impacts on human health from their inhalation exposure. In this dissertation, field...
Remote national parks of the western U.S. and Alaska are not immune to contaminants of emerging
concern. Semivolatile organic compounds (SOCs) such as pesticides and PCBs can selectively deposit from
the atmosphere at higher rates in cold, high-elevation and high-latitude sites, potentially increasing risk to
these ecosystems. In the environment,...
The objective of this research was to assess the variability of POP deposition by snow on a 10 km spatial scale by measuring the POP concentrations in fresh-fallen snow from remote alpine sites. Samples of pre-metamorphic snow were concurrently collected from three remote alpine sites, of matched altitude and exposure,...
The heterogeneous reactions of ambient particulate matter (PM)-bound polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs (NPAHs) with NO₃/N₂O₅, OH radicals, and O₃ were studied in a laboratory photochemical chamber. Ambient PM[subscript 2.5] and PM₁₀ samples were collected from Beijing, China and Riverside, California, and exposed under simulated atmospheric long-range transport conditions...