Using community science for detailed pollution research: A case-study
approach in Indianapolis, IN, USA
Abstract
Heavy metal contamination in urban environments, particularly lead (Pb)
pollution, is a health hazard both to humans and ecological systems.
Despite wide recognition of urban metal pollution in many cities, there
is still relatively limited research regarding heavy metal distribution
and transport at the household-scale between soils and indoor dusts-the
most important scale for actual human interaction and exposure. Thus,
using community-scientistgenerated samples in Indianapolis, IN (United
States), we applied bulk chemistry, Pb isotopes, and scanning electron
microscopy (SEM) to illustrate how detailed analytical techniques can
aid in interpretation of Pb pollution distribution at the
household-scale. Our techniques provide definitive evidence for Pb paint
sourcing in some homes, while others may be polluted with Pb from past
industrial/vehicular sources. SEM revealed anthropogenic particles
suggestive of Pb paint and the widespread occurrence of Fe-rich metal
anthropogenic spherules across all homes, indicative of pollutant
transport processes. The variability of Pb pollution at the household
scale evident in just four homes is a testament to the heterogeneity and
complexity of urban pollution. Future urban pollution research efforts
would do well to utilize these more detailed analytical methods on
community sourced samples to gain better insight into where the Pb came
from and how it currently exists in the environment. However, these
methods should be applied after large-scale pollution screening
techniques such as portable X-ray fluorescence (XRF), with more detailed
analytical techniques focused on areas where bulk chemistry alone cannot
pinpoint dominant pollution mechanisms and where community scientists
can also give important metadata to support geochemical interpretations.