Earthquake Debris May Be Leaching Metals Into Türkiye’s Drinking Wells, Study Warns

When two earthquakes of moment magnitude 7.7 and 7.6 tore through southern Türkiye on February 6, 2023, they reduced entire neighborhoods in Hatay Province to rubble. In the months that followed, mountains of building debris were dumped near villages and farmland, often just meters from the shallow wells that thousands of people rely on for drinking water. A new study published in Environmental Geochemistry and Health by Esra Taner and Abdullah Özkan of Iskenderun Technical University now provides one of the most detailed looks yet at what that rubble may be doing to the groundwater beneath it, and the results reveal a subtle but troubling picture in which the most dangerous metal may not be the one dumped by the disaster at all.

The research team sampled thirty-three distinct wells across six districts of Hatay Province in June 2024, more than a year after the earthquakes. Each sample was analyzed for fourteen elements using inductively coupled plasma mass spectrometry, an ultra-sensitive technique capable of detecting metals at concentrations down to parts per trillion, at the university’s Central Laboratory. The fourteen-element panel included the metals most commonly associated with construction debris, such as iron, lead, chromium, and nickel, alongside naturally occurring elements like lithium and calcium that serve as geochemical fingerprints of the underlying bedrock.

On the surface, the results looked reassuring. Most of the fourteen elements met Turkish and international drinking-water limits in the majority of wells. But two metals stood out. Iron exceeded the Turkish TS 266 national guideline in fourteen of the thirty-three wells, and chromium, a metal with well-documented carcinogenic potential in its hexavalent form, exceeded the guideline in nine wells. For a province still rebuilding from one of the deadliest earthquake sequences in modern history, the finding that nearly a third of tested wells carried guideline-exceeding chromium was a warning that could not be ignored.

To determine where those metals were coming from, the researchers turned to multivariate statistics, combining principal component analysis with hierarchical clustering. These techniques group elements that behave similarly in the water, which usually means they share a source. The analysis cleanly separated two distinct chemical signatures. One cluster paired chromium with lithium, calcium, and nickel, and it appeared strongest in the Iskenderun and Arsuz districts, an area underlain by ophiolitic bedrock, the fragment of ancient oceanic crust that geologists know naturally weathers to release chromium and nickel. That signature, in other words, was geogenic, written into the rocks long before any earthquake.

The second cluster told a very different story. Iron, manganese, and lead traveled together, and their signature was concentrated in the Hassa and Kırıkhan districts, precisely where debris dumps sit closest to settlements and farmland. Lead and manganese are classic tracers of anthropogenic contamination, and their association with iron in wells near demolition waste is consistent with rainwater percolating through rubble piles, dissolving metals from rebar, paint, alloys, and treated wood, and carrying them downward into shallow aquifers. The researchers formalized this pathway in a conceptual framework they call Debris-to-Groundwater Metal Transfer, or DGMT, which links debris composition, dumping location, and hydrogeology to predict which wells face the greatest exposure.

Having traced the sources, the team then quantified what the contamination might mean for human health, using a United States Environmental Protection Agency assessment that accounts for both ingestion of the water and dermal absorption during bathing and washing. Because individual exposure varies widely from person to person, they wrapped the calculation in a one-dimensional Monte Carlo simulation, running the risk model thousands of times with randomized input values to generate a probability distribution of outcomes rather than a single misleading number.

The aggregate picture was mixed. The heavy metal pollution index, a composite score that weighs each metal against its guideline value, remained below 100 in all wells, the threshold generally indicating acceptable overall water quality. Yet the more granular risk calculations told a different story. The total hazard index, which sums the non-cancer risks of all fourteen elements, exceeded unity, the level of potential concern, for children in eighteen of the samples. More striking still, the carcinogenic risk exceeded the 1 × 10⁻⁴ benchmark, above which intervention is typically considered, in most samples, and chromium was the dominant driver of that risk.

Perhaps the most counterintuitive finding was geographic. The highest hazard index did not appear in the wells closest to the debris dumps in the anthropogenic zone. Instead, it surfaced in the geogenic region, where chromium-rich ophiolitic bedrock naturally loads the groundwater. This inversion carries a critical lesson for disaster response and environmental monitoring alike: a well can pass every guideline check for most metals and still deliver a pathway-specific, chromium-dominated cancer risk that only a probabilistic, element-by-element assessment will catch. Guideline compliance, the authors conclude, does not imply the absence of risk.

The study’s authors are careful to frame their results as conservative screening estimates. The EPA model relies on default exposure assumptions, and total chromium measurements do not distinguish between trivalent chromium, which is an essential nutrient, and hexavalent chromium, which is the carcinogenic form of greatest concern. That distinction matters enormously for interpreting the health findings, and the researchers explicitly call for chromium speciation studies and continuous monitoring of the affected wells as the necessary next steps. Until those speciation data exist, the true magnitude of the chromium risk in Hatay’s groundwater remains an open question.

What the study does establish is a template for the aftermath of every future major earthquake. Collapsed cities generate staggering volumes of debris, and where that debris is dumped determines whether its metal cargo stays locked in rubble or migrates into the aquifers people drink from. By pairing high-resolution ICP-MS chemistry with statistical source apportionment and Monte Carlo risk simulation, and by packaging the logic in the transferable DGMT framework, Taner and Özkan have given public health officials in Hatay, and in every disaster zone to come, a way to identify which wells need watching before the first symptoms of contamination appear. For the residents of Hatay still drawing water from shallow wells beside the ruins of 2023, that early warning may prove to be the study’s most valuable product.

Subject of Research: Post-earthquake heavy metal contamination of well water and associated health risks in Hatay Province, Türkiye

Article Title: Post-earthquake heavy metal contamination of well waters in Hatay Province, Türkiye: source apportionment, human health risk and a debris-to-groundwater metal transfer framework

Article References: Taner, E., & Özkan, A. (2026). Post-earthquake heavy metal contamination of well waters in Hatay Province, Türkiye: source apportionment, human health risk and a debris-to-groundwater metal transfer framework. Environmental Geochemistry and Health, 48(15), Article 594. https://doi.org/10.1007/s10653-026-03488-y

Image Credits: AI Generated

DOI: 10.1007/s10653-026-03488-y

Keywords: groundwater, heavy metals, earthquake, Hatay, chromium, drinking water, debris, health risk assessment, Monte Carlo simulation, ICP-MS, Türkiye, water contamination