Total and bioaccessible metal concentrations in river flood sediment
deposits in two urban communities following Hurricane Ida
Abstract
Anthropogenic climate change has resulted in extreme rainfall and
flooding on both a global and local scale. Flooding of urban areas can
redistribute historical and present-day soil, sediment, and water
contamination across affected areas and leave behind a sediment later
laced with a suite of metals. This sediment layer poses a direct human
health risk to the residents who live within these affected communities
as well as the workers tasked with its cleanup. This study evaluated
relative differences of total (Al, Fe, Co, Cr, Ni, Zn, Cu, As, Ba, Pb)
and human bioaccessible (Zn, Cu, As, and Pb) metal concentrations in
river flood sediment deposits in two urban communities in Philadelphia,
P.A. (U.S.) (Manayunk and East Falls), which border the Schuylkill
River, and have relative differences in historical industrial land use
(Manayunk >>East Falls). Sediment deposits were
collected immediately following a near record flooding event associated
with the remnants of Hurricane Ida in September 2021. Statistically
higher concentrations of Cr, Fe, Cu, Zn, As, and Pb in the Manayunk
neighborhood suggests remobilization of contaminated soils as well as
sediments from a historical industrial canal. Statistical analysis
results also suggest the influence of roadway derived materials. Total
metal and bioaccessible lead concentrations in excess of regulatory
thresholds for residential soils suggests the sediments pose a
substantial health risk to those who live and work in these areas.
Collectively, the study results elucidate the public health risk
associated with the deposition of flood sediment in urban areas.