Exposure phases, residential

INTRODUCTION 210 STATUS OF RESIDENTIAL MODELS 211 EXPOSURE PHASES IN RESIDENTIAL EXPOSURE 212 Mixing and Loading Phase 212 Application Phase 212 Post-Apphcation Phase 213 MODEL CONCEPTS FRAMEWORKS 214 Mass-Balanced Air Qnality Model 214 Fngacity Model 215 Flnid Dynamics Model 216 MODEL CONCEPTS SOURCES AND SINKS 216 Sonrce Evaporation of Pesticides 216 Vapor-Pressnre-Driven Evaporation 216 Chinn Evaporation 217... 

Residential exposures are no different from occupational exposures in terms of the phases of exposure. Generally, exposure can be divided into the following three phases (EC, 1998). 

Control of cancer risk from pesticides can be illustrated by the example of chromated copper arsenate (CCA), used as a wood preservative. The risk estimate was particularly contentious, but despite arguments over the specific numbers, a cancer hazard to children from the arsenic in this product used in decks and play structures could not be denied. These and other residential-related uses were finally phased out in late 2003 (ERA 2008i). CCA is still available for commercial construction. Arsenic continues to be available for household use in ant baits, although the potential for human exposure in this product is relatively low. 

Foam Furniture Foam furniture items, such as foam upholstered-PUF couches and chairs, as well as mattresses, pads and pillows, are large sources of PentaBDE and DecaBDE in homes (Table 3.2). Stapleton et al. (2012) foimd BFRs in 85 % of 102 foam samples from residential couches pmchased in the U.S. between 1985 and 2010. In couches purchased prior to 2005, PentaBDE congeners —47, —99, and —100 were the predominant BFRs in foam. High concentrations of Penta-BDE were found in mattress foam (mean 20,230 milligrams per kilogram, mg/kg). PentaBDEs were found in 17 % of the couches tested, indicating that many years after the PBDE phase-out, U.S. residents are still exposed to PentaBDE from furniture foam. Because there is currently no strategy in place for the identification or safe disposal of FR-treated furniture, in-use and discarded furniture will continue to be a source of PentaBDE exposure for the foreseeable future (Shaw and Kannan 2009). 

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