Chronic kidney disease of uncertain etiology (CKDu) has emerged with growing evidence linking it to environmental exposures. This case–control study aimed to evaluate serum and urine trace elements (TEs) in CKDu patients, comparing them with those from control groups from endemic and non-endemic regions. TEs were analyzed in 406 participants (CKDu = 75, endemic CKD (ECKD) = 82, non-endemic CKD (NECKD) = 85, endemic control (EC) = 79, non-endemic control (NEC) = 85 using Inductively Coupled Plasma Mass Spectrometry. Means ± standard deviations were compared via the t-test and categorical variables by the chi-square test. Compared to non-endemic groups, Al, Mn, Ni, Cu, Cd, and Ba in serum and urine were significantly higher in endemic areas. CKDu patients showed elevated serum V, Cr, Zn, As, and U and urinary Cr, Mn, Fe, Co, Ni, and Rb compared to ECKD. Compared to NEC, CKDu patients had higher serum Zn, As, and Ba and urinary Al, Cr, Mn, Fe, Co, Ni, and Cu. Significant increases in serum V, Zn, As, Cd, Ba, and U and urinary V, Cr, Mn, Co, Ni, Rb, and Sr were noted in CKDu vs. NECKD. Elevated serum Al, Cr, Mn, Fe, Co, etc., and urinary Be, V, Zn, Se, etc., were observed in EC vs. CKDu. Urinary TEs positively correlated with eGFR, suggesting tubular dysfunction or prolonged exposure. Serum Se, a known reno-protective TE, was low in CKDu and ECKD. This study highlights that TE levels were high not only due to exposure but also depending on kidney health. Identified group-specific TEs may be causative in CKDu, having adverse health outcomes in some groups while potentially being protective in healthy groups.

Green chili (Capsicum annuum L.) is a widely cultivated spice crop of high economic importance, playing a vital role in both global and Sri Lankan agriculture. Several factors influence the growth of green chili, and this study aimed to determine the optimal silicon (Si) concentration required to maximize its growth. The effects of two cultivation seasons (“Yala” and “Maha”) and different Si concentrations (0–300 ppm) were evaluated. Growth parameters assessed included leaf Si accumulation, plant height, number of leaves, number of pods per plant, average pod weight, pod diameter, and pod length. Univariate and multivariate statistical analyses were performed using a full factorial design with six replicates per treatment combination. The results revealed that both season and Si concentration had a significant impact on growth parameters. MANOVA results indicated that season, Si concentration, and their interaction had a significant overall effect on the combined set of growth traits. Univariate ANOVA further showed that Si concentration significantly affected all growth parameters, while season and the interaction effect influenced several traits. The optimal Si concentration was identified as 200 ppm, consistently producing the highest and most significant growth responses compared to other levels. The availability of Si in the soil solution, influenced by soil pH, was crucial for effective Si absorption. Therefore, considering soil pH is essential when determining the optimal Si content to promote plant growth. Overall, this study provides valuable insights into the interactions between seasonal variation, Si levels, and green chili growth, contributing to the development of improved cultivation strategies for enhanced yield and quality.