Superfund Research Program
Sources of Airborne PCB Congeners
Title: PCB congener data of gas-phase, freely-dissolved water, air-water fugacity ratios and air-water fluxes in Indiana Harbor and Ship Canal, IN, USA.
Accession Number: 10.1594/PANGAEA.894908
Link to Dataset: https://doi.pangaea.de/10.1594/PANGAEA.894908
Data Type(s): Environmental Science Data
Experiment Type(s): Contaminant measurements
Summary: We have developed a method for measuring fluxes of PCBs from natural waters using air and water passive samplers deployed simultaneously in the Indiana Harbor and Ship Canal (IHSC). Net volatilization of PCBs was determined for 2017, and ranged from 1.4 to 2.8 g m 2 d 1, with a median of 2.0 g m 2 d 1. We confirm earlier findings that the IHSC experiences constant release of gas-phase PCBs. Gas-phase and freely-dissolved water PCB samples median were 4.0 ng m 3 and 14 ng L 1, both exhibiting increasing concentrations over the year of study, and with a strong positive correlation between them (R2 = 0.93 for PCBs). The relative concentrations of individual PCB congeners were very similar between air and water samples, and resemble Aroclor 1248, a mixture previously reported to contaminate the IHSC sediments. Monthly variability of the volatilization fluxes was primarily driven by the freely-dissolved water concentration changes (R2 = 0.87). Although different sampling methods were performed to estimate air-water fluxes between the month of August of 2006 and 2017, PCB net fluxes have decreased by more than 60, suggesting that either dredging at IHSC from 2012 to 2017 or reduction of upstream sources have decreased the freely-dissolved water concentrations of PCBs, thus reducing the air-water net volatilization in IHSC. Finally, we have shown that this passive sampling approach represents a simple and cost-effective method to assess the air-water exchange of PCBs, increase analytical sensitivity, enable measurements over time, and reduce uncertainties related to unexpected episodic events. Includes 15 datasets.Publication(s) associated with this dataset: