Toxicity evaluation of dioxin-contaminated animal-origin foods from an Indian industrial zone in male Wistar rats

Abstract

Dietary intake of animal-origin foods (AOF) is the primary pathway for non-occupational human exposure to dioxins and dioxin-like polychlorinated biphenyls (dl-PCBs). Despite known health risks, the specific toxicological impacts of consuming locally contaminated foods remain understudied. This study evaluated the toxicity associated with the consumption of dioxin-contaminated eggs (15 pg TEQ/g), milk (10 pg TEQ/g), and fish (3 pg TEQ/g) sampled from semi-urban areas in South India. Male Wistar rats were utilised as model organisms and divided into sub-acute (n=20) and sub-chronic (n=40) exposure phases. Pathological, haematological, immunological, biochemical, and oxidative stress parameters were systematically analysed across dosing groups. The group dosed with 10 pg TEQ/g exhibited dyslipidemia—characterised by elevated cholesterol and LDL alongside decreased HDL—and concurrent elevations in SGOT, globulin, and urea. The low-dose group (3 pg TEQ/g) demonstrated similar hepatic strain, paired with elevated oxidative stress markers, including CAT and 8-OHdG. In the 15 pg TEQ/g and 10 pg TEQ/g groups, haematological deviations were observed. Biochemical profiles revealed persistent elevations in cholesterol, SGPT, and urea. Furthermore, a marked suppression of glutathione reductase activity and a decline in serum testosterone levels were observed. These findings underscore the critical need for epidemiological surveillance and long-term risk assessment in hot spot areas.