Dioxins

PCDD/F homologue profiles and 2,3,7,8 chlorine-substituted congener patterns are studied using principal component analysis and hierarchical cluster analysis. Measurement data from different industrial metallurgical processes such as iron and steel manufacturing, copper smelters and aluminium plants are compared. It appears that the PCDD/F homologue profiles from industrial metallurgical processes are similar to those from municipal solid waste incinerators. The 2,3,7,8 chlorine-substituted congener pattern from copper smelters is also very similar to that of municipal solid waste incinerators. However, the 2,3,7,8 chlorine-substituted congener pattern from an aluminum plant is very different, 2,3,7,8-TCDF being by far the most important TCDF congener.

Background and Aim: 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is a persistent organic pollutant toxic to the human reproductive system. This study aimed to evaluate the effect of α-Tocopherol administration on the male fertility parameters of a rat model exposed to TCDD.

Materials and Methods: Fifty healthy 12-week-old male rats were randomly divided into five groups. Rats in the control group were given corn oil twice daily in 4 h intervals. In the treatment groups, all rats were given TCDD at a dose of 700 ng/kg of body weight (BW)/day for 45 days. Four hours after receiving the TCDD, T0 rats were given corn oil, and T1, T2, and T3 rats were given α-Tocopherol at doses of 77, 140, and 259 mg/kg BW/day, respectively, for 45 days. On day 46, experimental animals were sacrificed to collect blood and testicular samples.

Results: TCDD exposure decreased superoxide dismutase activity, plasma membrane integrity, Leydig cell count, sperm cell count, sperm viability and motility, and increased malondialdehyde levels, serum testosterone levels, and sperm morphological abnormalities. The administration of α-Tocopherol mitigated the effects of TCDD exposure, and the 140 and 259 mg/kg BW/day treatments returned those male fertility parameters to normal levels.

Conclusion: The administration of 140 mg/kg BW/day α-Tocopherol restored male semen quality in rats exposed to TCDD. We found dynamics serum testosterone levels in rats exposed to TCDD that need to be further studied.

Passive and composite sampling in combination with in vitro bioassays and identification and quantification of individual chemicals were applied to characterize pollution by compounds with several specific modes of action in urban area in the basin of two rivers, with 400,000 inhabitants and a variety of industrial activities. Two types of passive samplers, semipermeable membrane devices (SPMD) for hydrophobic contaminants and polar organic chemical integrative samplers (POCIS) for polar compounds such as pesticides and pharmaceuticals, were used to sample wastewater treatment plant (WWTP) influent and effluent as well as rivers upstream and downstream of the urban complex and the WWTP. Compounds with endocrine disruptive potency were detected in river water and WWTP influent and effluent. Year-round, monthly assessment of waste waters by bioassays documented estrogenic, androgenic and dioxin-like potency as well as cytotoxicity in influent waters of the WWTP and allowed characterization of seasonal variability of these biological potentials in waste waters. The WWTP effectively removed cytotoxic compounds, xenoestrogens and xenoandrogens. There was significant variability in treatment efficiency of dioxin-like potency. The study indicates that the WWTP, despite its up-to-date technology, can contribute endocrine disrupting compounds to the river. Riverine samples exhibited dioxin-like, antiestrogenic and antiandrogenic potencies. The study design enabled characterization of effects of the urban complex and the WWTP on the river. Concentrations of PAHs and contaminants and specific biological potencies sampled by POCIS decreased as a function of distance from the city.