The developmental and reproductive effects of endocrine disruption on humans and wildlife rank among the most threatening of all environmental health concerns. Particularly vulnerable to chemical assaults are the hypo...The developmental and reproductive effects of endocrine disruption on humans and wildlife rank among the most threatening of all environmental health concerns. Particularly vulnerable to chemical assaults are the hypothalamic-pituitary-gonadal (HPG) axis and the hypothalamic-pituitary-thyroid (HPT) axis of the endocrine system. While the effects of endocrine disrupting chemicals (EDCs) on the HPG axis have been the subject of intense research efforts, with comprehensive elucidation, a lot remains to be clarified on the effects of EDCs on thyroid functions. For instance, there are no clear-cut biomarkers of exposure and effects of thyroid disrupting chemicals (TDCs) in intact organisms. Consequently, a number of in vitro assays have been developed, and are particularly useful for the identification and mechanistic characterization of potential TDCs considering the increasing number of EDCs that are being released into the environment. However, with the in vitro assays, studies suggest that a plausible major mode of action of TDCs, thyroid hormone receptor (THR) agonist activity, is not environmentally relevant. Here, we reviewed in vitro detection of TDCs activities in wastewater and surface waters. Data strongly suggest that cell lines may be responsible for the less frequent detection of THR agonist activity in wastewater and surface water. It was concluded that the development of reporter gene assays with thyroid hormone function related cell lines, is required.展开更多
People tend to rely upon fish as a source of cheap animal protein and a vital resource to sustain life.Oreochromis niloticus(tilapia fish)and Clarias gariepinus(cat fish)were collected from two rivers(Nworie and Otami...People tend to rely upon fish as a source of cheap animal protein and a vital resource to sustain life.Oreochromis niloticus(tilapia fish)and Clarias gariepinus(cat fish)were collected from two rivers(Nworie and Otamiri rivers)and two fish ponds(FUTO and Philip’s fish ponds in Owerri municipal).The heavy metals analyzed were mercury(Hg),cadmium(Cd),iron(Fe),nickel(Ni),zinc(Zn),lead(Pb),and chromium(Cr)using FS 240 Varianatomic absorption spectrophotometer(AAS)SpectrAA.Catfish accumulated high level of Hg concentrations(>1.40 ppm)in the sample sites,Cd concentration was also high in cat fish(8.33 ppm)sampled from Nworie river while the other sample sites recorded<1 ppm.Also,Fe recorded concentrations above 4 ppm with highest concentration of 30.8 ppm;however,tilapia fish accumulated more Fe concentrations than the cat fish.Heavy metals values in the fishes were above the maximum permissible limits of established standards for fish consumption.Data collected were subjected to t-test and analysis of variance(ANOVA),and there was no statistical difference(p>0.05)between the heavy metals contents of fishes from the rivers and fish ponds studied.The total heavy metals concentrations studied accumulated from the different sample sites were in this order:tilapia fish:Nworie river(5.96±4.36)>Otamiri river(4.87±3.32)>Philip’s pond(4.87±3.19)>FUTO pond(1.62±1.40)while in cat fish:Nworie river(4.02±1.66)>Philip’s pond(3.60±2.10)>Otamiri river(2.43±1.54)>FUTO pond(2.27±1.38).There is need for periodic monitoring and assessment of heavy metals in water bodies and various aquatic lives that serve as a source of food to human.展开更多
文摘The developmental and reproductive effects of endocrine disruption on humans and wildlife rank among the most threatening of all environmental health concerns. Particularly vulnerable to chemical assaults are the hypothalamic-pituitary-gonadal (HPG) axis and the hypothalamic-pituitary-thyroid (HPT) axis of the endocrine system. While the effects of endocrine disrupting chemicals (EDCs) on the HPG axis have been the subject of intense research efforts, with comprehensive elucidation, a lot remains to be clarified on the effects of EDCs on thyroid functions. For instance, there are no clear-cut biomarkers of exposure and effects of thyroid disrupting chemicals (TDCs) in intact organisms. Consequently, a number of in vitro assays have been developed, and are particularly useful for the identification and mechanistic characterization of potential TDCs considering the increasing number of EDCs that are being released into the environment. However, with the in vitro assays, studies suggest that a plausible major mode of action of TDCs, thyroid hormone receptor (THR) agonist activity, is not environmentally relevant. Here, we reviewed in vitro detection of TDCs activities in wastewater and surface waters. Data strongly suggest that cell lines may be responsible for the less frequent detection of THR agonist activity in wastewater and surface water. It was concluded that the development of reporter gene assays with thyroid hormone function related cell lines, is required.
文摘People tend to rely upon fish as a source of cheap animal protein and a vital resource to sustain life.Oreochromis niloticus(tilapia fish)and Clarias gariepinus(cat fish)were collected from two rivers(Nworie and Otamiri rivers)and two fish ponds(FUTO and Philip’s fish ponds in Owerri municipal).The heavy metals analyzed were mercury(Hg),cadmium(Cd),iron(Fe),nickel(Ni),zinc(Zn),lead(Pb),and chromium(Cr)using FS 240 Varianatomic absorption spectrophotometer(AAS)SpectrAA.Catfish accumulated high level of Hg concentrations(>1.40 ppm)in the sample sites,Cd concentration was also high in cat fish(8.33 ppm)sampled from Nworie river while the other sample sites recorded<1 ppm.Also,Fe recorded concentrations above 4 ppm with highest concentration of 30.8 ppm;however,tilapia fish accumulated more Fe concentrations than the cat fish.Heavy metals values in the fishes were above the maximum permissible limits of established standards for fish consumption.Data collected were subjected to t-test and analysis of variance(ANOVA),and there was no statistical difference(p>0.05)between the heavy metals contents of fishes from the rivers and fish ponds studied.The total heavy metals concentrations studied accumulated from the different sample sites were in this order:tilapia fish:Nworie river(5.96±4.36)>Otamiri river(4.87±3.32)>Philip’s pond(4.87±3.19)>FUTO pond(1.62±1.40)while in cat fish:Nworie river(4.02±1.66)>Philip’s pond(3.60±2.10)>Otamiri river(2.43±1.54)>FUTO pond(2.27±1.38).There is need for periodic monitoring and assessment of heavy metals in water bodies and various aquatic lives that serve as a source of food to human.
