Throughout history a strong correlation has been observed between the presence of environmental pollutants and adverse physiological effects on both humans and wildlife (Olea & Fernandez 2000; Kawai et al. 2003). These pollutants have the capacity to disrupt normal endocrine function, with the majority of cases involving reproductive abnormalities leading to population decline (Kawai et al. 2003). Chemicals with such effects are labelled as endocrine disruptors and can be defined as exogenous substances that alter the normal functions of the endocrine system which in turn produce adverse health effects in organisms, their offspring or entire populations (Olea & Fernandez 2000). The majority of endocrine disruption research has been focused
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Through these studies, a link was found between concentrations of TBT and the occurrence of imposex, where male sex characteristics were seen to be superimposed onto females of the same species. It is hypothesised that this process is a result of the testosterone conversion inhibiting properties of TBT. By the 1980’s numerous cases revealing susceptible species had been recorded resulting in the introduction of constraints on the previously unrestricted use of TBT (Antizar-Ladislao 2008). Despite current restrictions, concentrations of TBT are still found exceeding threshold levels by over one hundred times, with high levels of the chemical still found throughout marine environments in polluted sediments around the world (Antizar-Ladislao …show more content…
Endocrine disruption is just one of many threats faced by wildlife which can be compounded by additional stressors of a changing environment (Pottinger 2003). While the endocrine system is common among mammals, the chemical types of hormones and their physiological roles vary among species, particularly in sex steroids (Kawai et al. 2003). Response to endocrine disruptors varies greatly among species, associated with specificity of the receptors at a cellular levels and depending on their vulnerability. The vulnerability of a species or individual is determined by a number of factors including the endocrine disrupting chemical itself, the magnitude, duration and frequency of exposure, together with the capacity for absorption, dilution, distribution, transformation and elimination of such substances, and the developmental stage resulting in varying sensitivities of specific organs (Johnson & Jürgen 2003). Sex of the individual is also a major physiological factor, influencing the susceptibility to certain endocrine disrupting chemicals (Kawai et al. 2003). Varying responses seen among species and within species are not just specific to endocrine disrupting chemicals and are instead evident in response to most chemicals including both synthetic and naturally occurring substances (Kawai et al.
Through these studies, a link was found between concentrations of TBT and the occurrence of imposex, where male sex characteristics were seen to be superimposed onto females of the same species. It is hypothesised that this process is a result of the testosterone conversion inhibiting properties of TBT. By the 1980’s numerous cases revealing susceptible species had been recorded resulting in the introduction of constraints on the previously unrestricted use of TBT (Antizar-Ladislao 2008). Despite current restrictions, concentrations of TBT are still found exceeding threshold levels by over one hundred times, with high levels of the chemical still found throughout marine environments in polluted sediments around the world (Antizar-Ladislao …show more content…
Endocrine disruption is just one of many threats faced by wildlife which can be compounded by additional stressors of a changing environment (Pottinger 2003). While the endocrine system is common among mammals, the chemical types of hormones and their physiological roles vary among species, particularly in sex steroids (Kawai et al. 2003). Response to endocrine disruptors varies greatly among species, associated with specificity of the receptors at a cellular levels and depending on their vulnerability. The vulnerability of a species or individual is determined by a number of factors including the endocrine disrupting chemical itself, the magnitude, duration and frequency of exposure, together with the capacity for absorption, dilution, distribution, transformation and elimination of such substances, and the developmental stage resulting in varying sensitivities of specific organs (Johnson & Jürgen 2003). Sex of the individual is also a major physiological factor, influencing the susceptibility to certain endocrine disrupting chemicals (Kawai et al. 2003). Varying responses seen among species and within species are not just specific to endocrine disrupting chemicals and are instead evident in response to most chemicals including both synthetic and naturally occurring substances (Kawai et al.