*5.3.2. Herbs*

3.5 Bq/kg for radiostrontium. Mushrooms of a special region in the canton of Aargau (Swit‐

Wood soils build their own biosphere: dead leaves, pins, etc., build the humic fraction of the soil. The plants take up the radioactivity from the soil. The radioactivity is recycled to the soil

In 1986, the State Laboratory Basel-City analysed approximately 30 berry samples from Switzerland. Strawberries showed a quite low activity (2.7 Bq/kg radiocaesium), whereas currants, raspberries, elderberries, and gooseberries showed significantly higher activities (51±27 Bq/kg). The reason is that strawberries are cultivated in greenhouses, in the shelter. Only in 2009 was our focus set on blueberries and other wild-grown berries. These products are imported in big charges of tons from East European countries, such as Ukraine, Poland, Russia or Hungary. From 16 analysed samples, we registered eight violations because of too high activities of radiostrontium. In the following years, we analysed more than 100 samples with 10 further violations for products from Austria, Ukraine, or Poland. The products were blueberries and blueberry products, such as marmalades. Violations were mostly because of radiostrontium (>1 Bq/kg) and radiocaesium (>100 Bq/kg) [45]. Wild berries grow in woods. The soil is more acid and promotes the uptake of the contaminants. Because of the cycle soilplant-soil, the residues in the plants are reduced only slowly compared to berries grown on

Leafy vegetables were, besides milk, the most contaminated food. Depositions from washouts on spinach and salad cultures happened just before harvest. Radioiodine level reached almost 4000 Bq/kg in spinach. Therefore, it was advised that small children, pregnant women, and nursing women should not consume this kind of food. The investigation of mother's milk showed considerable amounts of radioiodine (up to 35 Bq/L). We tried to reduce the contam‐ ination on salads with washings but with only poor success. In May 1986, leafy vegetables were most affected by radioiodine (131I and 132I): radioiodine was 65% of the measured total dose. Radiocaesium (134Cs and 137Cs) was 25% and other short-lived radionuclides, such as 103Ru, 140Ba, 140La, and 99Mo, gave approximately 10% to the total dose. We noticed many violations of the limit values for radioiodine and radiocaesium (24 and 10 violations for baby food from a total of 40 samples analysed). This survey focused on food with higher radiation levels as a screening before the γ-analyses were done. The investigation of deep-frozen vegetables did not show any elevated radiation. These products were produced before 1986 [46]. After 2010, we started up again with controls of leafy and root vegetables. The contami‐ nation level was low and caused by the fallout from the bombs. Radiocaesium is normally below the detection limit of 0.1 Bq/kg. Radiostrontium is detectable in small amounts of 0.05

zerland) show a continuous fall of the activity from 1986 to 2014 [44].

through the fall of the leaves and pins.

*5.2.4. Wild-grown berries*

142 Radiation Effects in Materials

farmland.

*5.3.1. Vegetables*

to 0.5 Bq/kg [47].

**5.3. Vegetables and fruit**

Herbs of 1986/1987 showed the highest contamination with radiocaesium of all investigated food. In 1986, 35 of 42 herbs contained up to 3.200 Bq/kg. In the following year, the contami‐ nation level was even higher: 12.300±32.000 Bq/kg [38].
