Occupational Biomonitoring of Heavy Metals in Brick Kiln Workers of Bahawalpur, Pakistan

Background: Brick kiln workers are chronically exposed to dust, combustion products, and industrial emissions that may contain toxic heavy metals. Prolonged exposure to metals such as cadmium (Cd) and Chromium (Cr) poses significant occupational health risks, including respiratory and systemic effects. This study assessed blood cadmium levels and screened for chromium exposure among brick kiln workers in Bahawalpur, Pakistan.Methods: A cross-sectional study was conducted from April to June 2023. Venous blood samples for heavy metal analysis were obtained from 14 workers selected from a total of 70 brick kiln workers based on sample availability and consent and digested using aqua regia. Cadmium concentrations were quantified using Atomic Absorption Spectrophotometry (AAS). Chromium was assessed using a colorimetric method based on 1,5‑diphenylcarbazide. Descriptive statistics were used to summarize metal concentrations and compare findings with international reference values.Results: Blood cadmium concentrations ranged from 0.24 to 5.12 µg/L, indicating elevated exposure among a substantial proportion of workers when compared with reference background levels. Chromium concentrations were below the detection limit of the colorimetric method in all analyzed samples. The observed cadmium burden suggests occupational exposure likely associated with kiln-related emissions, dust, and fuel combustion.Conclusions: Brick kiln workers in Bahawalpur exhibit elevated blood cadmium levels, reflecting significant occupational exposure. Although chromium was not detected above the analytical detection limit, methodological constraints preclude ruling out low-level exposure. These findings highlight the need for routine biomonitoring, improved workplace controls, and stricter enforcement of occupational health regulations in Pakistan.