Uptake, elimination and toxicity of an arsenic-based pesticide in an avian system

Monosodium methanearsonate (MSMA), an arsenic-based pesticide, has been used to control Mountain Pine Beetle (Dendroctonus ponderosae) populations throughout British Columbia for the past ten years. Cavity nesting forest birds have been shown to forage and breed in MSMA treated pine stands. This study examined the effects of MSMA using the Zebra Finch (Taeniopygia guttata) as a model passerine. The objectives were to determine the distribution as well as any sub-lethal toxic effects of this compound in both adults and nestlings. Zebra Finches were exposed to environmentally relevant concentrations of this pesticide. Adults showed dose-dependent trends in accumulation of arsenic in the blood and specific tissues, and weight loss occurred in adults in the two highest dose groups. Nestlings accumulated more arsenic in tissues than adults, and exhibited a high mortality rate at higher doses, which suggests high sensitivity to this pesticide in early life stages.