Multiphase Contaminant Distributions Inside Flooded Homes In New Orleans, Louisiana, After Hurricane Katrina: A Modeling Study

摘要

Flooding caused by Hurricane Katrina in New Orleans, Louisiana, in August 2005 resulted in contaminated sediments being deposited inside homes and businesses. As these structures sat unoccupied for weeks to months after floodwaters had been drained, volatile and semivolatile pollutants in the sediment distribute themselves between multiple indoor phases (MIPs) that include the vapor phase, mold films, and aerosolized mold spores inside the home. First responders, returning residents, and recovery workers are exposed to these pollutants by two primary pathways: dermal contact with sediments and mold films and inhalation of gas-phase pollutants and contaminated mold aerosol. The objective of this work is to offer a theoretical model for estimating chemical concentrations and human exposure in post-Katrina flooded homes. To date, measurements of contaminant levels exist for the sediment deposits only, and no data are available on indoor gas-phase contaminants, contaminated mold films, or aerosol. Based on known contaminant loadings of interior deposited sediments, an equilibrium model for estimating levels in the other media was developed. Results forecast possible types and levels of volatile and semi-volatile organic species likely to be found in the MIPs inside Katrina-flooded homes. This worst-case scenario modeling approach enumerates specific pollutant classes and phases that may be of concern to persons having contact with flooded structures as well as demolition residues. Areas of future research and exposure concerns that should be taken into account during future urban flood situations are discussed.