PubMed HealthSearch

Biomedical subjects

D L Stoneburner

Publications and source records attributed to D L Stoneburner.

2 recordsLinked to original sources

Heavy metals in tissues of stranded short-finned pilot whales.

Selected tissues from four short-finned pilot whales that stranded at Cumberland Island National Seashore were analyzed for total cadmium, mercury and selenium by neutron activation. Cadmium reached a maximum mean wet weight concentration of 31.4 ppm in the kidney tissues. Maximum mean wet weight concentrations of mercury, 230.0 ppm, and selenium, 44.2 ppm, were found in the liver tissues. The lowest concentration of each metal was found in the blubber. Postmortem examination showed that the whales had no food in their stomachs. The whales must have been utilizing metabolic reserves, contaminated with residual concentrations of heavy metals, prior to beaching. This utilization of reserves probably resulted in the high concentrations of cadmium, mercury and selenium found in the liver and kidney tissues. Since the heavy metal concentrations were three to four times greater in the stranded whales, as compared to apparently healthy whales of the same species, it is suggested that heavy metal toxicosis may have been a factor contributing to this particular stranding.

Adipose Tissue

Diatom diversity as a function of insecticidal treatment with a controlled-release formulation of chlorpyrifos.

Following treatment with a controlled-release formulation of chlorpyrifos, no substantial differences between diversity estimates were evident for 6 post-treatment weeks for both treated and control plots. By post-treatment week 12, significant decreases in diversity estimates occurred in treated plots, suggesting that a directly proportional relationship exists between chlorpyrifos concentrations and reduced diatom colonization through time. Comparatively, diatom colonization progress "normally" and populations proceeded toward "maturity" in the control plots as indicated by the increase in the diversity estimates between post-treatment weeks 6 and 12. Any adverse effects due to the insecticidal treatment, however, were not considered to be environmentally deleterious in light of the restricted type of habitat (rice culture) in which the chlorpyrifos was used.

Biodegradation, Environmental