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The emergence of a new form of chronic
kidney disease of unknown etiology (CKDu) in Sri
Lanka’s North Central Province (NCP) has become a
catastrophic health crisis. CKD u is characterized as
slowly progressing, irreversible, and asymptomatic until
late stages and, importantly, not attributed to diabetes,
hypertension, or other known risk factors. It is postulated that the etiology of CKDu is multifactorial, involving
genetic predisposition, nutritional and dehydration status, exposure to one or more environmental
nephrotoxins, and lifestyle factors. The objective of this limited geochemical laboratory analysis was to determine the concentration of a suite of heavy metals and
trace element nutrients in biological samples (human
whole blood and hair) and environmental samples
(drinking water, rice, soil, and freshwater fish) collected
from two towns within the endemic NCP region in 2012
and 2013. This broad panel, metallomics/mineralomics
approach was used to shed light on potential geochemical risk factors associated with CKDu. Based on prior
literature documentation of potential nephrotoxins that
may play a role in the genesis and progression of CKDu, heavy metals and fluoride were selected for analysis.
The geochemical concentrations in biological and environmental media areas were quantified. Basic statistical
measurements were subsequently used to compare media against applicable benchmark values, such as US
soil screening levels. Cadmium, lead, and mercury were
detected at concentrations exceeding U S reference
values in many of the biological samples, suggesting
that study participants are subjected to chronic, lowlevel exposure to these elements. Within the limited
number of environmental media samples, arsenic was
determined to exceed initial risk screening and background concentration values in soil, while data collected
from drinking water samples reflected the unique
hydrogeochemistry of the region, including the prevalence of hard or very hard water, and fluoride, iron,
manganese, sodium, and lead exceeding applicable
drinking water standards in some instances. Current
literature suggests that the etiology of CKDu is likely
multi factorial, with no single biological or hydrogeochemical parameter directly related to disease genesis
and progression. This preliminary screening identified
that specific constituents may be present above levels of
concern, but does not compare results against specific
kidney toxicity values or cumulative risk related to a
multifactorial disease process. The data collected from
this limited investigation are intended to be used in the
subsequent study design of a comprehensive and multifactorial etiological study of CKDu risk factors that
includes sample collection, individual surveys, and laboratory analyses to more fully evaluate the potential
environmental, behavioral, genetic, and lifestyle risk
factors associated with CKDu.
