Michael O. Gaylor

We analyzed >400 particulate samples collected from throughout the Chesapeake Bay region between 1991 and 1998 for polycyclic aromatic hydrocarbons (PAHs). Isomer ratios of PAHs associated with aerosol and surface water particles demonstrate that motor vehicles are a major source of carcinogenic combustion-derived PAHs to Chesapeake Bay. Most of the benz[a]anthracene, benzo[a]pyrene, benzo[b]fluoranthene and their isomers in air, rain, and surface waters of Chesapeake Bay appear to be derived from automotive sources. Lesser, but still significant amounts (53(±5)%) of these PAHs in the sea surface microlayer near urban areas are motor vehicle-derived, with 47(±5)% being coal-derived. In contrast, PAHs in surface sediments of Chesapeake Bay are predominantly coal-derived (86(±8)%) and at most 14(±8)% motor vehicle-derived. Thus, carcinogenic PAHs input to the bay from motor vehicles are either degraded prior to deposition to the sediments or are diluted by previously deposited coal-derived PAHs in the seabed. Like anthropogenic nitrogen (NOx), which leads to coastal eutrophication, managing the impact of carcinogenic PAHs on coastal regions will need to focus on motor vehicle use, which continues to outpace population growth in areas such as Chesapeake Bay.

Polybrominated diphenyl ethers (PBDEs) were examined in fish fillets collected from two large Virginia watersheds. Emphasis was on the tetra- to hexabrominated congeners since these exhibit the greatest bioaccumulation and toxicological potentials. These congeners are dominant constituents of Penta-, a commercial PBDE product used to flame retard polyurethane foam. In 1999, North America accounted for98% of global Penta-demand. Concentrations of total tetra- to hexabrominated congeners in fillets ranged from <5 to 47,900 microg/kg (lipid basis). BDE-47, one of the two major constituents of Penta-, was detected in 89% of samples and contributed 40-70% of the total PBDEs observed. Concentrations of BDE-99, the second major constituent of the Penta- commercial mixture, were much lower in fish. While some differences in PBDE profiles between fish species were apparent, dominant congeners were consistent with those in surficial sediments from the Virginia sites and recently published data for U.S. air samples. PCB and PBDE concentrations in fish were generally associated. These factors point to exposure from nonpoint sources. Exceptions existed, likely due to inputs from local sources. The Virginia study area has historically served as a center for furniture and textile manufacturing, although polyurethane foam production here has been limited.

Twenty married chronic pain patients (pain duration > 8 mo.) consecutively admitted to a pain management program were administered a taped structured interview designed to elucidate the responses of their spouses to pain behavior. Additionally, patients were required to report their pain levels in two different observational conditions: when observed by their spouse and when observed by a "neutral observer", the ward clerk. Those patients who reported that their spouses were relatively non-solicitous in responding to pain behavior reported significantly lower pain levels in the spouse-observing condition than in the neutral-observer condition. Patients who reported that their spouses were relatively solicitous in responding to pain behavior reported marginally higher levels of pain in the spouse-observing condition than in the neutral-observer condition.