Associations between Organochlorine Contaminant Concentrations and Clinical Health Parameters in Loggerhead Sea Turtles from North Carolina, USA
Keller, Jennifer M., Kucklick, John R., Stamper, M. Andrew, Harms, Craig A., McClellan-Green, Patricia D., Environmental Health Perspectives
Widespread and persistent organochlorine (OC) contaminants, such as polychlorinated biphenyls (PCBs) and pesticides, are known to have broad-ranging toxicities in wildlife. In this study we investigated, for the first time, their possible health effects on loggerhead sea turtles (Caretta caretta). Nonlethal fat biopsies and blood samples were collected from live turtles for OC contaminant analysis, and concentrations were compared with clinical health assessment data, including hematology, plasma chemistry, and body condition. Concentrations of total PCBs ([summation]PCBs), [summation]DDTs, [summation]chlordanes, dieldrin, and mirex were determined in 44 fat biopsies and 48 blood samples. Blood concentrations of [summation]chlordanes were negatively correlated with red blood cell counts, hemoglobin, and hematocrit, indicative of anemia. Positive correlations were observed between most classes of OC contaminants and white blood cell counts and between mirex and [summation]TCDD-Iike PCB concentrations and the heterophil:lymphocyte ratio, suggesting modulation of the immune system. All classes of OCs in the blood except dieldrin were correlated positively with aspartate aminotransferase (AST) activity, indicating possible hepatocellular damage. Mirex and [summation]TCDD-like PCB blood concentrations were negatively correlated with alkaline phosphatase (ALP) activity. Significant correlations to levels of certain OC contaminant classes also suggested possible alteration of protein ([up arrow] blood urea nitrogen, [down arrow] albumin:globulin ratio), carbohydrate ([down arrow] glucose), and ion ([up arrow] sodium, [down arrow] magnesium) regulation. These correlations suggest that OC contaminants may be affecting the health of loggerhead sea turdes even though sea mrdes accumulate lower concentrations of OCs compared with other wildlife. Key words: health assessment, hematology, organochlorine contaminants, PCBs, persistent organic pollutants, pesticides, plasma chemistries, polychlorinated biphenyls, reptile, white blood cell counts, wildlife. doi: 10.1289/ehp.6923 available via http://dx.doi.org/[Online 21 April 2004]
It has been well established that organochlorine (OC) compounds, including polychlorinated biphenyls (PCBs) and OC pesticides, bioaccumulate in animal tissues and cause hepatotoxicity, wasting, immunotoxicity, developmental abnormalities, and reproductive toxicity along with endocrine disruption, neurobehavioral effects, and population declines (Fox 2001; Safe 1993). OC compounds have been detected in tissues of threatened and endangered sea turtles [reviewed by Pugh and Becket (2001)], and recently, we measured OC concentrations in the tissues of live, juvenile loggerhead sea turtles (Caretta caretta) from North Carolina (Keller et al. 2004). PCB concentrations in these loggerhead turtles were similar to those of alligators from Florida lakes (Guillette et al. 1999) and of the general human population of North America (Feeley 1995) but were much lower than those found in snapping turtles, Caspian terns, and bottlenose dolphins (de Solla et al. 1998; Grasman and Fox 2001; Lahvis et al. 1995). Although concentrations of organic contaminants have been assessed in sea turtles, health effects from these exposures remain undocumented.
In both the hospital and the veterinary clinic, assessment of clinical health parameters provides a first line of patient health evaluation. Clinical health assessments typically include a physical examination and measurements of hematology and clinical blood chemistry values. Common parameters include total and differential counts of blood cells, activities of plasma enzymes, and concentrations of plasma proteins, glucose, and electrolytes. OC contaminants have been shown to alter hematology and blood chemistry values in laboratory-exposed animals and environmentally exposed humans and wildlife (Grasman et al. 2000b; Lawton et al. 1985; McConnell 1985). …