  Kidney disease of unknown aetiology (CKDu) has been identified in many
countries extending from MesoAmerica and Egypt, to South-east Asia and China.
Although CKDu has been linked by various authors to farming, it is an artifact
of treating multi-modal disease distributions as unimodal. There is NO
correlation of CKDu with agriculture since affected farming villages are often
surrounded by other farming villages free of CKDu. Initial studies looked for a
correlation of CKDu with toxic heavy metal residues of arsenic, cadmium etc.,
or herbicides like glyphosate that may be present in the environment, as the
causative factors. There is now considerable consensus that their
concentrations are below danger thresholds, be it in Mesoamerica or south-east
Asia. The conceptual basis of a search for etiology within a systems approach
is discussed, and attempts to name the disease to bias the identification of
its etiology are reviewed. Current research has narrowed down the etiology to
geochemical electrolytic contaminants like fluorides and ionic components in
hard water, nanosilica (found in water as well as in the air), as well as renal
toxins similar to indoxyl sulphates that may arise from interactions of ions
with humic acids contained in aqueous organic matter. However, while
agrochemical toxins are increasingly considered less relevant to the etiology
of CKDu, it has become a firm public belief. In Sri Lanka this has spawned
ideology-based agricultural policies for partial and complete banning of
agrochemicals (2014-2021), followed by some back-tracking, disrupting the
economy and the food supply. A farmer's uprising in 2022 was spawned by poor
harvests. It triggered a larger popular uprising that led to the collapse of a
government wedded to romanticized eco-extremist agricultural policies in a
country already facing difficulties in the wake of Covid and Ukraine.
