The concentrations of butyltin (summation operatorBT=TBT+DBT+MBT) and mercury (Hg) were determined in the liver of 35 harbour porpoises (Phocoena phocoena), which were found dead along the coastlines or caught as by-catch in the Danish North Sea and the Inner Danish waters. In addition, three harbour porpoises hunted in West Greenland were analysed. High levels of butyltin and mercury, within the range of 68-4605 mg BT/kg ww and 0.22-92 mg Hg/kg ww, were found in the liver of the Danish harbour porpoises and both substances tend to accumulate with age. The levels in the harbour porpoise from West Greenland were 2.0-18 mg BT/kg ww and 6.3-6.9 mg Hg/kg ww, respectively. The concentrations of butyltin and mercury were both found to be higher in stranded than in by-caught harbour porpoises but only the butyltin concentration was significantly higher in stranded porpoises in the age group 1-5 years. These substances are suspected of inducing adverse effects on immune and endocrine systems in mammals and they may thereby pose a threat to the animals. This study suggests that organotin compounds are also important, when assessing the risks of contaminants on the health and viability of harbour porpoises in Danish waters.
Organotin compounds (OTs) including mono- to tri-butyltins, -phenyltins, and -octyltins were determined in the liver of adult sea otters (Enhydra lutris) found dead along the coasts of California, Washington, and Alaska in the USA and Kamchatka, Russia. Total concentrations of OTs in sea otters from California ranged from 34 to 4100ng/g on a wet weight basis. The order of concentrations of OTs in sea otters was total butyltins>total octyltins> or = total phenyltins. Elevated concentrations of butyltins (BTs) were found in some otters classified under 'infectious-disease' mortality category. Concentrations of BTs in few of these otters were close to or above the threshold levels for adverse health effects. Total butyltin concentrations decreased significantly in the livers of California sea otters since the 1990s. Based on the concentrations of organotins in sea otters collected from 1992 to 2002, the half-lives of tributyltin and total butyltins in sea otters were estimated to be approximately three years.
Organotin compounds (OTCs) are a large class of synthetic chemicals with widely varying properties. Due to their potential adverse health effects, their use has been restricted in many countries. Humans are exposed to OTCs mostly through fish consumption.
The aim of this study was to describe OTC exposure through fish consumption and to assess the associated potential health risks in a Finnish population.
An extensive sampling of Finnish domestic fish was carried out in the Baltic Sea and freshwater areas in 2005-2007. In addition, samples of imported seafood were collected in 2008. The chemical analysis was performed in an accredited testing laboratory during 2005-2008. Average daily intake of the sum of dibutyltin (DBT), tributyltin (TBT), triphenyltin (TPhT) and dioctyltin (DOT) (SigmaOTCs) for the Finnish population was calculated on the basis of the measured concentrations and fish consumption rates.
The average daily intake of SigmaOTCs through fish consumption was 3.2ng/kgbwday(-1), which is 1.3% from the Tolerable Daily Intake (TDI) of 250ng/kgbwday(-1) set by the European Food Safety Authority. In total, domestic wild fish accounted for 61% of the SigmaOTC intake, while the intake through domestic farmed fish was 4.0% and the intake through imported fish was 35%. The most important species were domestic perch and imported salmon and rainbow trout.
The Finnish consumers are not likely to exceed the threshold level for adverse health effects due to OTC intake through fish consumption.