Ecological Risk Assessment of Perchlorate in Avian Species, Rodents, Amphibians and Fish
TEXAS TECH UNIV LUBBOCK
Pagination or Media Count:
Perchlorate occurs in ground and surface waters in 44 states in the USA, primarily as a result of AP discharge from rocket fuel manufacturing facilities or from the demilitarization of missiles Urbansky, 1998. AP is highly water-soluble and, as a result of the very slow reduction of the central chlorine atom, can persist in the environment for decades Urbansky, 1998. Perchlorate is known to prevent intake of iodine from water or food and thus it is goitrogenic thyroid gland inhibitor in many animals including fishes and amphibians Miranda et al., 1996 Manzon and Youson, 1997. Ionic perchlorate also alters calcium balance in fishes and amphibians Luttgau et al., 1983 Thevenod et al., 1992 Jong et al., 1997 as well as other vertebrates. Calcium is a ubiquitous chemical messenger that is involved in the regulation of cellular function. Endocrine glands require calcium for the normal secretion of hormones and therefore contaminant-induced disruption of calcium balance can lead to systemic endocrine disruption. Because of the important role played by hormones in animal development and reproduction, endocrine disruption is likely to lead to serious impairments in growth, reproductive fitness, and consequently, amphibian and wildlife population stability as well as human health. We have previously examined aspects of growth and development and thyroid function in anuran larvae collected from AP-contaminated sites at the Longhorn Army Ammunition Plant LHAAP located in Karnack, Texas, and identified two possible cases of thyroid disruption. Bullfrog larvae collected from an AP-contaminated pond exhibited decreased hindlimb growth than larvae from a reference pond, even though the animals from both sites were of identical body length, and presumably, identical age class.
- Anatomy and Physiology
- Inorganic Chemistry