Road sediment, an underutilized material in environmental science
research: A review of perspectives on United States studies with
international context
Abstract
Road sediment is a pervasive environmental medium that acts as both
source and sink for a variety of natural and anthropogenic particles and
often is enriched in heavy metals. Road sediment is generally
understudied in the United States (U.S.) relative to other environmental
media and compared to countries such as China and the United Kingdom
(U.K.). However, the U.S. is an ideal target for these studies due to
the diverse climates and wealth of geo-chemical, socioeconomic,
demographic, and health data. This review outlines the existing U.S.
road sediment literature while also providing key international
perspectives and context. Furthermore, the most comprehensive table of
U.S. road sediment studies to date is presented, which includes
elemental concentrations , sample size, size fraction, collection and
analytical methods, as well as digestion procedure. Overall, there were
observed differences in studies by sampling time period for elemental
concentrations, but not necessarily by climate in the U.S. Other key
concepts addressed in this road sediment review include the processes
controlling its distribution, the variety of nomenclature used,
an-thropogenic enrichment of heavy metals, electron microscopy, health
risk assessments , remediation, and future directions of road sediment
investigations. Going forward, it is recommended that studies with a
higher geographic diversity are performed that consider smaller cities
and rural areas. Furthermore, environmental justice must be a focus as
community science studies of road sediment can elucidate pollution
issues impacting areas of high need. Finally, this review calls for
consistency in sampling, data reporting, and nomenclature to effectively
expand work on understudied elements, particles, and background
sediments.