Aminolevulinic acid dehydratase activity in American dippers (Cinclus mexicanus) from a metal-impacted stream

• Published in: Environmental toxicology and chemistry Vol. 21; no. 1; pp. 115 - 120
• Main Authors: Strom, Sean M., Ramsdell, Howard S., Archuleta, Andrew S.
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Periodicals, Inc 01.01.2002; SETAC
• Subjects: Amnolevulinic acid dehydratase; Amrican dipper; Animal, plant and microbial ecology; Animals; Applied ecology; Arkansas River; Aves; Biological and medical sciences; Biomarkers; Birds - blood; Colorado; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Environmental Monitoring; Erythrocytes - drug effects; Erythrocytes - enzymology; Food Chain; Fresh water environment; Fundamental and applied biological sciences. Psychology; Hematocrit; Invertebrates - chemistry; Lead; Lead - blood; Lead - toxicity; Mining; Porphobilinogen Synthase - metabolism; Spectrophotometry, Atomic; Water Pollutants, Chemical - blood; Water Pollutants, Chemical - toxicity; United States; North America; Colorado; Arkansas River; America; Porphobilinogen synthase; Enzyme; Toxicity; Interspecific comparison; Biological marker; Lyases; Spatial variation; Blood; Biological monitoring; Feeding; Heavy metal; Aquatic environment; Trophic chain; Vertebrata; Enzymatic activity; Lead; Water pollution; Stream; Aves; Biological accumulation; Invertebrata; Carbon-oxygen lyases; Hydro-lyases; Mining waste
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620210117

Blood samples collected from adult and nestling American dippers (Cinclus mexicanus) along the Arkansas River (CO, USA), a stream impacted by discharges from historical mining operations, and a reference stream were analyzed for lead concentration and δ‐aminolevulinic acid dehydratase (ALAD) activity. Median ALAD activities of adult and nestling dippers from the Arkansas River were found to be significantly different from median ALAD activities of reference adults and nestlings (p = 0.002 and p = 0.028). Median ALAD activity for adult dippers from the Arkansas River was more than 50% lower relative to reference adults and activity approached a level close to 50% lower in nestlings from the same site. Median blood lead concentrations from adult (range 15.4–386.0 ppb) and nestling (range 12.1–323.0 ppb) dippers from the Arkansas River were found to be significantly different from median blood lead concentrations of reference adult (range 4.2–29.6 ppb) and nestling (range 4.2–8.2 ppb) dippers (p < 0.001 and p = 0.011). The median hematocrit level in adult dippers did not vary between sites (p = 0.73), whereas the median hematocrit level of nestling dippers from the reference site was significantly lower compared to Arkansas River nestlings (p = 0.042). Blood lead concentration in both adult and nestling dippers was found to be significantly correlated with invertebrate lead concentration (r = 0.81, p < 0.001 and r = 0.62, p = 0.01, respectively). Highly significant negative correlations were observed between blood lead concentration and ALAD activity in both adult and nestling dippers (r = −0.86, p < 0.001 and r = −0.84, p < 0.001, respectively). This study suggests that dippers (both adults and nestlings) from the Arkansas River have significantly lower ALAD activity and significantly higher blood lead concentrations compared to reference values. The measurement of ALAD activity may be a sensitive and accurate biomarker for environmental lead exposure in dippers.