Abstract / Summary
Abstract Background Touching the border of the world-famous “ Esophageal Cancer Belt ” the Kashmir Valley has a high burden of esophageal squamous cell carcinoma (ESCC). The contribution of environmental exposures remains largely inconclusive. Horticulture and agriculture are considered the backbone of the Kashmir economy; however, such practices have raised concerns regarding the potential environmental toxic metal accumulation due to excessive use of pesticides, fungicides, insecticides and fertilizers. This study evaluated the distribution pattern of selected trace elements in the environment and staple food items across the Valley. Methods A total of 117 samples comprising soil (n = 30), drinking water (n = 30), collard greens (n = 30), and paddy/rice (n = 27) were collected across all 10 districts of the Kashmir Valley in this descriptive-analytical study. The samples were analysed for trace elements—zinc (Zn), selenium (Se), copper (Cu), lead (Pb), chromium (Cr), barium (Ba), cadmium (Cd), arsenic (As), and cobalt (Co)—using inductively coupled plasma mass spectrometry. Median and percentile measures were used for estimating elemental contamination. Differences across sample types and districts were assessed using Kruskal–Wallis tests and Benjamini–Hochberg false-discovery-rate correction. Spearman correlation and principal component analysis were used to assess inter-element associations and multivariate patterns. Results Trace-element concentrations varied significantly across the samples for all 9 elements (FDR-adjusted P < 0.001). Soil demonstrated high median concentrations of Zn (244.0 ppm), Cu (110.75ppm), Pb (108.4ppm), Cr (114.5ppm), Ba (396.0 ppm), Cd (12.25ppm), and As (133.0ppm). All soil samples exceeded the applied reference values for As and Cd, while 83.3%, 70.0%, and 70.0% exceeded those for Cr, Cu, and Pb, respectively. In collard greens, Pb and Cr exceeded the applied reference concentrations in all 30 samples, while As and Co exceeded them in 33.3% and 36.7%, respectively. In drinking water, Cu exceeded the applied reference concentration in 28/30 (93.3%) samples. We observed significant district-level heterogeneity for selected elements, with district Kupwara presenting substantially elevated median concentrations for multiple trace elements. Several elements presented with strong but positive correlations in collard greens and paddy samples. Conclusions The study demonstrates significant and spatially heterogeneous trace-element contamination across collected samples from high ESCC risk in the Kashmir Valley. Our study identifies potential environmental and dietary exposure pathways; however, the study findings are mainly hypothesis-generating and should not be considered as a causal relationship between heavy-metal exposure and ESCC until further investigation integrating human biomonitoring, exposure assessment, agricultural practices, and district-level ESCC incidence.