House Sparrows as Sentinels of Childhood Lead Exposure

Our understanding of connections between human and animal
health
has advanced substantially since the canary was introduced as a sentinel
of toxic conditions in coal mines. Nonetheless, the development of
wildlife sentinels for monitoring human exposure to toxins has been
limited. Here, we capitalized on a three-decade long child blood lead
monitoring program to demonstrate that the globally ubiquitous and
human commensal house sparrow (Passer domesticus) can be used as a sentinel of human health risks in urban environments
impacted by lead mining. We showed that sparrows are a viable proxy
for the measurement of blood lead levels in children at a neighborhood
scale (0.28 km2). In support of the generalizability of
this approach, the blood lead relationship established in our focal
mining city enabled us to accurately predict elevated blood lead levels
in children from another mining city using only sparrows from the
second location. Using lead concentrations and lead isotopic compositions
from environmental and biological matrices, we identified shared sources
and pathways of lead exposure in sparrows and children, with strong
links to contamination from local mining emissions. Our findings showed
how human commensal species can be used to identify and predict human
health risks over time and space.