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Organic mercury in Greenland birds and mammals
The Science of the Total Environment, 95 (1990) 41-51 Elsevier
41
ORGANIC MERCURY IN G R E E N L A N D BIRDS A N D MAMMALS
R. DIETZ, C.O. NIELSEN, M.M. HANSEN and C.T. HANSEN Greenland Environmental Research Institute, Tagensvej 135, 4, DK-2200 Copenhagen N (Denmark)
(Received October 2nd, 1989; accepted October 4th, 1989)
ABSTRACT Muscle, liver and kidney samples of 20 species of birds, seals, whales and polar bear were analyzed for total and organic mercury. Organic mercury concentrations varied considerably between individuals. A general tendency towards age accumulation was found, together with log-linear correlations between organic mercury concentrations in the three tissues. The major part of the muscle mercury was organic (maximum concentration found was 1235#g kg-1 wet wt). This also applied to liver of birds, while in mammal liver organic mercury concentrations approached a level of 2000pgkg -1 wet wt, which was not exceeded even when the total mercury concentration was > 100000~gkg -~ wet wt. The percentage of organic mercury in relation to total mercury in kidney of seals and whales was 10-20% (maximum 982 pg organic mercury kg- 1wet wt), while in polar bear it was < 6% (maximum 217 ~g kg-1 wet wt). For the monitoring of local food in the Arctic, the simpler and less expensive analysis of total mercury suffices when testing muscle, whereas liver and kidney should be tested for organic mercury as well.
INTRODUCTION Mercury exists in several interchangeable forms in the biosphere. Total m e r c u r y c o n c e n t r a t i o n is a p o o r i n d i c a t o r o f t o x i c e f f e c t s , a s o r g a n i c m e r c u r y seems to be considerably more toxic to higher animals than inorganic mercury. Accumulation of organic mercury through food chains poses a potential hazard to organisms of higher trophic levels. Published results of analyses of methylmercury concentrations in various tissues show that they, as well as the ratio of methylmercury to total mercury, vary considerably. T h e p u r p o s e o f t h e p r e s e n t s t u d y is t o p r o v i d e i n f o r m a t i o n o n t h e c o n c e n t r a tions of organic mercury and on the organic-inorganic mercury relations in Greenland marine mammals and birds. The animals were sampled in areas which are not believed to receive mercury from man-made sources. Emphasis was on marine mammals which contribute the bulk of the local human consumption and which, due to their high levels of mercury, are of greater concern to health authorities.
0048-9697/90/$03.50
© 1990 Elsevier Science Publishers B.V.
41
ORGANIC MERCURY IN G R E E N L A N D BIRDS A N D MAMMALS
R. DIETZ, C.O. NIELSEN, M.M. HANSEN and C.T. HANSEN Greenland Environmental Research Institute, Tagensvej 135, 4, DK-2200 Copenhagen N (Denmark)
(Received October 2nd, 1989; accepted October 4th, 1989)
ABSTRACT Muscle, liver and kidney samples of 20 species of birds, seals, whales and polar bear were analyzed for total and organic mercury. Organic mercury concentrations varied considerably between individuals. A general tendency towards age accumulation was found, together with log-linear correlations between organic mercury concentrations in the three tissues. The major part of the muscle mercury was organic (maximum concentration found was 1235#g kg-1 wet wt). This also applied to liver of birds, while in mammal liver organic mercury concentrations approached a level of 2000pgkg -1 wet wt, which was not exceeded even when the total mercury concentration was > 100000~gkg -~ wet wt. The percentage of organic mercury in relation to total mercury in kidney of seals and whales was 10-20% (maximum 982 pg organic mercury kg- 1wet wt), while in polar bear it was < 6% (maximum 217 ~g kg-1 wet wt). For the monitoring of local food in the Arctic, the simpler and less expensive analysis of total mercury suffices when testing muscle, whereas liver and kidney should be tested for organic mercury as well.
INTRODUCTION Mercury exists in several interchangeable forms in the biosphere. Total m e r c u r y c o n c e n t r a t i o n is a p o o r i n d i c a t o r o f t o x i c e f f e c t s , a s o r g a n i c m e r c u r y seems to be considerably more toxic to higher animals than inorganic mercury. Accumulation of organic mercury through food chains poses a potential hazard to organisms of higher trophic levels. Published results of analyses of methylmercury concentrations in various tissues show that they, as well as the ratio of methylmercury to total mercury, vary considerably. T h e p u r p o s e o f t h e p r e s e n t s t u d y is t o p r o v i d e i n f o r m a t i o n o n t h e c o n c e n t r a tions of organic mercury and on the organic-inorganic mercury relations in Greenland marine mammals and birds. The animals were sampled in areas which are not believed to receive mercury from man-made sources. Emphasis was on marine mammals which contribute the bulk of the local human consumption and which, due to their high levels of mercury, are of greater concern to health authorities.
0048-9697/90/$03.50
© 1990 Elsevier Science Publishers B.V.