Investigations on the radiocaesium contamination of wild boar (Sus scrofa) meat in Rhineland-Palatinate: a stomach content analysis

Abstract

To substantiate the pathways of radiocaesium contamination in wild boars in parts of RhinelandPalatinate, we analysed radiocaesium-activityconcentration of 2,433 wild boars shot in an area covering 45,400 ha in the western part of the Palatinate Forest between January 2001 and February 2003. Also, for a fraction of 689 animals shot between May 2002 and February 2003, we collected their stomachs for the examination of content and Cs-activity concentration. Wild boar meat contamination followed a seasonal curve with maximum proportions exceeding accepted levels in the summer (21-26%) and minimum levels in winter (1-9.3%) indicating a higher consumption of a contaminating source during the vegetation period. The autumn decline is obviously attributed to the extensive consumption of low-contaminated beech nuts. An exact analysis of food composition in 18 stomachs with maximum Cs-activity concentrations [345-1,749 Bq/kg (fresh matter: fm)] and 18 with low Cs-activity concentrations ( £ 20-199 Bq/kg) was carried out in the summer of 2002. Deer truffles (Elaphomyces granulatus) were found in significantly higher proportions in stomachs with maximum contamination levels than in stomachs with lowcontamination levels. This fungus was found in the Palatinate Forest, by a trained dog, in average densities of 1 truffel/20 m 2 primarily in spruce stands, showing an average Cs-concentration of 6,030 Bq/kg (fm). On the basis of our findings we stress the hypothesis that deer truffles function as a main Cssource for the wild boar in Rhineland-Palatinate.

137Cs activity concentration in wild boar meat may still exceed the permitted levels

“…Even lower levels were measured in animals from the vicinity of Belgrade [17]. However, considerably higher values up to 40,000 Bq kg −1 were noted in some areas of Germany [5,13,14].…”

“…Dyes from its cap cuticle can complex caesium ions [1]. Moreover, deer truffle (Elaphomyces granulatus), also containing particularly high levels of radiocaesium, could be another radionuclide source for wild boars [5,13,14]. These mushrooms grow in a depth of 6-8 cm in spruce forest soil, which corresponds to a Oh/Ah (organic layer/mineral layer) horizon where high 137 Cs activities are still observed [12].…”

Transfer of Radiocesium into Wild Boar Meat

“…The above mentioned specific activities exceeded at least by one order the specific activities measured in all other above-ground fruiting bodies and other plant and animal samples (Hohmann and Huckschlag 2005). Seasonal variations of the 137 Cs specific activities in muscle samples of boars in forests in the south Rhineland (50% pine forests and 20% spruce forests representing 90% of the land area) were revealed between January 2001 and February 2003.…”

“…Cs specific activity of 25,660 Bq·kg -1 was detected in the fruiting bodies found in a Bavarian forest (Felitz 2005) whereas the specific activities reached their maximum between 800 to 18,800 Bq·kg -1 in less contaminated regions, e.g., in Rhineland, Germany (Hohmann and Huckschlag 2005). The above mentioned specific activities exceeded at least by one order the specific activities measured in all other above-ground fruiting bodies and other plant and animal samples (Hohmann and Huckschlag 2005).…”

Deer truffles – the dominant source of radiocaesium contamination of wild boar

“…In the Bavarian Forest, for instance, activity levels ranged between 82 and 40,000 Bq kg −1 FW in 2004, with maximum and minimum values occurring at almost the same location within one week [1]. Whereas radiocaesium levels of roe deer (Capreolus capreolus) and red deer (Cervus elaphus), apart from seasonal variations, are continuously decreasing, those of wild boar are either remaining fairly constant or even increasing [1][2][3].…”