The use of semipermeable membrane devices (SPMDs) has become common in environmental sampling of nonpolar organic contaminants, yet few data exist for the uptake or sampling rates of polycyclic aromatic hydrocarbons (PAH). Two separate laboratory calibration experiments were conducted to determine the sampling rates of 28 individual PAH and 19 homologues. PAH with a log Kow > 4.5 remained in the linear uptake phase for 30 days, but PAH with a log Kow < 4.5 began to approach steady state within 15 days. Sampling rates, corrected for dissolved organic carbon, ranged from 2.11 to 6.06 L d(-1). Shear flow across the membrane had no statistically significant effect on rates over the range of 0.01-0.50 cm s(-1). Field verification of these sampling rates yielded agreement within about a factor of 2 for most PAH and a factor of 4 for all PAH. The worst agreement was for the most hydrophobic PAH, where partitioning into dissolved and particulate organic carbon pools are more important and less certain. These SPMD sampling rate data will allow quantitative estimations of freely dissolved concentrations of 47 compounds that are commonly used for PAH and petroleum product source identification and allocation.

Polybrominated diphenyl ethers (PBDEs) have been used extensively to flame-retard polymers and textiles. These persistent chemicals enter wastewater streams following manufacture, use, and disposal, concentrating in the settled solids during treatment. Land application of stabilized sewage sludge (known as biosolids) can contribute PBDEs to terrestrial systems. Monitoring sludge/biosolids contaminant burdens may be valuable in revealing trends in societal chemical usage and environmental release. In archived Chicago area sludges/biosolids from 1975 to 2008, penta-BDE concentrations increased and then plateaued after about 2000. Penta-BDE manufacture in the United States ended in December 2004. Deca-BDE concentrations in biosolids rose from 1995 to 2008, doubling on a 5-year interval. Evaluation of U.S. Environmental Protection Agency Targeted National Sewage Sludge Survey data from 2006 to 2007 revealed highest penta-BDE biosolids levels from western and lowest from northeastern wastewater treatment plants (2120 and 1530 μg/kg, respectively), consistent with patterns reported in some recent indoor dust and human blood studies. No significant regional trends were observed for deca-BDE concentrations. Congener patterns in contemporary Chicago biosolids support the contention that BDE-209 can be dehalogenated to less brominated congeners. Biosolids application on agricultural fields increased PBDE soil concentrations. However, corn grown thereon did not exhibit measurable PBDE uptake; perhaps due to low bioavailability of the biosolids-associated flame retardants.

Polybrominated diphenyl ethers (PBDEs) and hexabromocyclododecane (HBCD) are common flame retardants in polymers and textiles. Recognition of the persistent, bioaccumulative, and toxic properties of PBDEs has prompted reductions in their use. In contrast, HBCD has received less scrutiny. The U.S has historically been a dominant BFR consumer. However, the few publications on HBCD in wildlife here suggest modest levels compared to Asian and European studies. In contrast, the HBCD concentrations we detected in U.S. fish are among the highest reported in the world. The temporal trends observed suggest that HBCD use may have risen, and that of Penta-BDE declined, following the 2004 termination of its U.S. manufacture. For example, Hyco River carp collected in 1999-2002 exhibited a mean ∑HBCD (sum of α-, β- and γ-HBCD) concentration of only 13 ng/g (lipid weight basis), but was 4640 ng/g in fish collected in 2006-2007. In contrast, the mean ∑PBDE level in these same fish decreased from 40,700 ng/g in 1999-2002 to 9140 ng/g in 2006-2007. Concentrations of HBCD and PBDEs in several Hyco River fish species exceeded those from rivers less influenced by manufacturing outfalls. Results support the contention that textile-related production, relative to its BFR market share, may release disproportionately large amounts of HBCD to the environment.

No abstract

No abstract