Metal and metalloid levels in blood of semipalmated sandpipers (Calidris pusilla) from Brazil, Suriname, and Delaware Bay: Sentinels of exposure to themselves, their prey, and predators that eat them.
Environ Res
; 173: 77-86, 2019 06.
Article
em En
| MEDLINE
| ID: mdl-30901611
ABSTRACT
Identifying animals as sentinels for humans and other animal species is an excellent method for understanding exposure to environmental contamination at different times and places. Shorebirds are useful sentinels because they have a world-wide distribution, eat a range of prey, and are eaten by a range of other species, including humans. We collected blood from semipalmated sandpipers (Calidris pusilla) wintering in northern (Suriname Nâ¯=â¯71) and northeastern (Brazil Nâ¯=â¯61) South America to examine levels of heavy metals and metalloids (arsenic, selenium), and compare them to blood levels in sandpipers at a heavily used stopover site in New Jersey (Nâ¯=â¯30; Delaware Bay, NJ). Since blood represents relatively recent exposure, it can provide information on where and when the birds were exposed. Levels were highest in Brazil for arsenic and particularly selenium; highest in Suriname for cadmium and lead; and highest in New Jersey for chromium. Samples from Brazil and Suriname presented higher levels of mercury than did those from New Jersey. There were no geographic differences for cobalt. Levels of all metals were generally within an order of magnitude. The significant geographic difference for selenium was interesting because it is regulated in the body. Selenium levels in the NJ sample were directly proportional to levels found in their principle food at this migration stopover site (eggs of horseshoe crab, Limulus polyphemus). Mean selenium level was almost an order of magnitude higher in the semipalmated sandpiper blood samples from Brazil (mean of 27,500⯵g/L= ppb) compared to the other sampling locations (mean > 5330⯵g/L). This is a toxic level and cause for concern and further investigation, alerting us to look for other evidence of excess selenium exposure. Otherwise the levels of other metals are generally not high enough to cause harm to the sandpipers themselves or to predators that eat them. We discuss the implications for these birds and their exposure to contaminants at different stopover sites.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
Selênio
/
Aves
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Monitoramento Ambiental
/
Poluentes Ambientais
/
Metais
Limite:
Animals
País como assunto:
America do norte
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America do sul
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Brasil
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Caribe ingles
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Suriname
Idioma:
En
Ano de publicação:
2019
Tipo de documento:
Article