Assessment of immunological status and health risks associated with endotoxin exposure in waste management workers

Throughout the waste management process, endotoxins are generated and released into the environment, posing a significant health risk to waste management workers. This study aimed to investigate the health impacts of endotoxin exposure on waste management workers by assessing their Immunoglobulin E (IgE) levels, a key indicator of allergic responses. Additionally, the study focused on quantifying the health risks associated with endotoxin exposure in a large solid waste management facility where endotoxin exposure is a concern. This study investigated airborne endotoxin exposure at a waste processing and disposal complex in Tehran, Iran. The research involved: Measuring airborne endotoxin levels at various sites including office, preprocessing, and composting, calculating daily endotoxin intake and assessing non-cancer health risks (including Monte Carlo simulations to analyze uncertainty and sensitivity), analyzing blood samples for IgE levels using electrochemiluminescence immunoassay. Results showed that the highest endotoxin concentrations were found in the granulation (14,592 EU/m 3 ) and preprocessing (5,399 EU/m 3 ) units. The estimated daily intake was highest for granulation workers (1,019.2 EU/kg·d), resulting in a hazard quotient (HQ) far exceeding acceptable limits (mean HQ = 45.6) in the granulation unit. This was attributed to the exceptionally high airborne endotoxin concentrations at this site combined with prolonged daily exposure durations indicating a significant non-carcinogenic risk. Biological monitoring showed higher serum IgE levels in exposed workers relative to the low-exposure reference group. These findings highlight the need for improved occupational health and safety measures to mitigate endotoxin exposure in waste management facilities.