Modeling the Atmospheric Transport and Deposition of PCDD/F to the Great Lakes

Abstract

Atmospheric deposition is a significant loading pathway for polychlorinated dibenzo-p-dioxins and dibenzofurans (dioxin) to the Great Lakes. An innovative approach using NOAA's HYSPLIT atmospheric fate and transport model was developed to estimate the 1996 dioxin contribution to each lake from each of 5,700 point sources and 42,600 area sources in a U.S./Canadian air emissions inventory. These unusually detailed source-receptor modeling results show that deposition to each lake arises from a broad geographical region, with significant contributions from up to 2,000 km away. The source categories contributing most significantly to 1996 dioxin deposition appear to be municipal waste incineration, iron sintering, medical waste incineration, and cement kilns burning hazardous waste. Model-predicted air concentrations and deposition fluxes were consistent with ambient measurement data, within the uncertainties in each, but there may be a moderate tendency toward underestimation using midrange emissions estimates. The most likely reason for this tendency appears to be missing or underestimated emissions sources, but in-situ atmospheric formation of octachlorinated dibenzo-p-dioxin (OCDD) and heptachlorinated dibenzo-p-dioxin (HpCDD) may have also contributed. Despite uncertainties, the findings regarding the relative importance of different sources types and source regions appear to be relatively robust and may be useful in prioritizing pollution prevention efforts.

Partitioning of dioxins (PCDDs/Fs) in ambient air at urban residential locations

“…Sources of PCDD/Fs have been identified to include various man-made processes such as domestic cooking and heating, power stations, vehicle exhaust emissions, steelworks, metal refineries, municipal and medical waste incineration, and production of cement, lime, glass, and brick (Chen 2004;Cohen et al 2002;Karasek and Hutzinger 1986). In addition to these well-known local sources, it is also difficult to exclude the role of long-range transport as an additional, minor source component, especially during spring (or winter) known as periods of low precipitation (Tysklind et al 1993;Dyke and Stratford 2002).…”

Environmental and human exposure to persistent halogenated compounds derived from e-waste in China

“…For example, PCDD/Fs can be released from various sources other than e-waste handling [27][28][29][30]. In addition, only 3% of the global production of flame retardants is used in electronic apparatus [31].…”

Gridded atmospheric emission inventory of 2,3,7,8-TCDD in China

“…Under this convention, the establishment of emission inventories for POPs is mandatory for the party countries because emission inventories are necessary for the assessment of environmental fate and health risks of POPs (UNEP, 1999(UNEP, , 2001Vestreng and Klein, 2002). Emission data are also essential in POPs modeling and prediction of source-receptor relationships on regional (Van Jaarsveld et al, 1997;Cohen et al, 2002;Ma et al, 2004Ma et al, , 2005 and global scales (Wania et al, 1999;Wania and Daly, 2002).…”

“…Based on the information of large point sources of PCDD/Fs across Europe, gridded PCDD/Fs emission inventory (50 km  50 km) for these EU-27 member states were created at a national level and sectoral level for every five years from 1990 to 2010 (EEA, 2012). Cohen et al (2002) collected PCDD/Fs emission data from facilities, industry groups, and/or regulatory agencies in each significant source category and established the gridded PCDD/Fs emission inventory (100 km  100 km) over the U.S. and Canada in 1996. They implemented this emission inventory in an atmospheric dispersion model to simulate the deposition of PCDD/F to the Great Lakes.…”