**5.14. Charcoal and briquettes**

In 2009, more than 10,000 tons of wood pellets had to be withdrawn from the Italian market. The product was from Lithuania and was contaminated with radiocaesium (300 Bq/kg). The fact that such products and barbecue coals are imported from countries such as Ukraine or Poland motivated us to conduct this investigation. Charcoal is produced either by charcoal burning of wood (possibly contaminated by the fallout of Chernobyl) or from coal mining. The survey of barbecue coals over the last 6 years showed that there is some contamination with radiocaesium (13±20 Bq/kg). We could not verify the high values from Italy; instead, one also has to consider some radiation of the coals derived from natural radionuclides, such as radium, uranium, thorium, and lead (210Pb). The latter is present in activities of around 65±68 Bq/kg, which is over the limit of 10 Bq/kg of the ordinance of radioprotection. The thorium activity concentrations also reach the permitted limit of 6 Bq/kg [88, 89]. Barbeque experiments with steaks grilled over charcoal showed only a slightly contamination of the meat. The main activity remains in the barbeque ashes [90].

#### **5.15. Estimation of internal doses by the consumption of contaminated food in 1986/1987**

Based on the results presented from our own investigations in 1986/1987, we estimated a received dose by ingestion of 4.6 mSv. A main contribution came from contaminated vegeta‐ bles. It is not clear if the population followed an appeal and the recommendations by the government to avoid the consumption of such contaminated vegetables. If so, the dose would have been reduced to approximately 2.4 mSv. Our estimations seem to be too high. The basis of our calculations was dominantly on the first months after the Chernobyl accident. Thus, our mean values are not representative of the whole years 1986 and 1987. **Table 3** gives an overview of these investigations.


Radioactivity in Food: Experiences of the Food Control Authority of Basel-City since the Chernobyl Accident http://dx.doi.org/ 10.5772/62460 151

enclosed would lead to 0.1 mSv/year. Healing earths, and also silica-based chemicals of

In 2009, more than 10,000 tons of wood pellets had to be withdrawn from the Italian market. The product was from Lithuania and was contaminated with radiocaesium (300 Bq/kg). The fact that such products and barbecue coals are imported from countries such as Ukraine or Poland motivated us to conduct this investigation. Charcoal is produced either by charcoal burning of wood (possibly contaminated by the fallout of Chernobyl) or from coal mining. The survey of barbecue coals over the last 6 years showed that there is some contamination with radiocaesium (13±20 Bq/kg). We could not verify the high values from Italy; instead, one also has to consider some radiation of the coals derived from natural radionuclides, such as radium, uranium, thorium, and lead (210Pb). The latter is present in activities of around 65±68 Bq/kg, which is over the limit of 10 Bq/kg of the ordinance of radioprotection. The thorium activity concentrations also reach the permitted limit of 6 Bq/kg [88, 89]. Barbeque experiments with steaks grilled over charcoal showed only a slightly contamination of the meat. The main

**5.15. Estimation of internal doses by the consumption of contaminated food in 1986/1987**

Based on the results presented from our own investigations in 1986/1987, we estimated a received dose by ingestion of 4.6 mSv. A main contribution came from contaminated vegeta‐ bles. It is not clear if the population followed an appeal and the recommendations by the government to avoid the consumption of such contaminated vegetables. If so, the dose would have been reduced to approximately 2.4 mSv. Our estimations seem to be too high. The basis of our calculations was dominantly on the first months after the Chernobyl accident. Thus, our mean values are not representative of the whole years 1986 and 1987. **Table 3** gives an overview

**Origin Activity levels 1986/1987 Activity levels 1990/2015**

Sheep <1–30 <1–624 <1–22 N/A N/A Mother <1–30 <1 N/A N/A N/A

Milk, CH Cow <1 <-1025 35 <0.05–0.2 0.04–0.2

Milk powder CH <1 <1–19,000 <1–22 N/A N/A Baby food CH <1 <1–5400 N/A <0.05–0.5 0.03–0.3

Chocolate CH, D <1 6–80 N/A N/A Nuts TR <1 100–17,100 0.1–30 N/A

CH 0.4–2 1–2 0.05–1.1

**131+132I 134+137Cs 90Sr 134+137Cs 90Sr**

chemical laboratories, remain a source for natural radionuclides [87].

**5.14. Charcoal and briquettes**

150 Radiation Effects in Materials

activity remains in the barbeque ashes [90].

of these investigations.

Milk products


**Table 3.** Summary of the artificial radioactivity levels found in different food of 1986/1987 compared to the data of 1990/2015. All data were generated at the State-Laboratory Basel-City.

No dose estimation was possible for 90Sr. There were not sufficient 90Sr data available for most of the food categories. Most Swiss agencies believe that 90Sr activity was low in the fallout from Chernobyl.

The Federal Office of Public Health estimated the dose commitment for the Swiss population to be 0.2 mSv/year in 1986. The estimation was based on the results of the food categories milk, vegetables, and meat only. Other food categories were not taken into account (e.g., cereals or 90Sr data of milk). According to the estimated dose from radioiodine in milk, they estimated that, for children, 75 new cases of thyroid cancer with seven or eight fatal cases would occur. For adults, there was no risk seen [91]. The genetically based radiation risk, which causes genetically anomalies, was estimated at 2 to 22 new cases between 1986 and 2086 [92]. The Swiss Federal Nuclear Safety Inspectorate (former HSK) published a more profound study. They came to the following conclusions: for children of age 1 year, children up to 10 years, and adults, a whole body dose of 0.6 to 1.6, 1.0, and 1.1 mSv was calculated, respectively [93]. The Association for Radioprotection of Germany and Switzerland calculated somewhat lower doses (0.4–1.0 mSv for children and 0.4–0.8 mSv for adults) [94]. The Swiss Federal Office of Public Health compared the calculated doses to the whole-body countings of Swiss people. They calculated 10-fold lower doses according to the whole-body countings [95].

In 2014, the Federal Office of Public Health estimated the mean dose through the consumption of food to be 0.35 mSv. The main contribution came from 40K (0.2 mSv/year) and from natural radionuclides of the uranium and thorium series. The remaining contamination from the bomb fallout was less than 0.1 mSv/year [96].

The listed dose estimations fluctuate because of the use of different radioactivity concentra‐ tions in food and different assumptions of the consumption rates. All these estimations are based on the dose coefficients for inhalation and ingestion of the International Commission for Radiation Protection (ICRP). However, there are other commissions such as the European Committee on Radiation Risk (ECRR), which conducts more assessments on the effects of low doses. Their dose coefficients are different from ICRP data for some important radionuclides. The ingestion dose factors of the ECRR for 137Cs and 90Sr are 5- and 320-fold higher than the ICRP factors. The ECRR attaches more importance to aspects such as DNA damage by radionuclides [97]. The application of these dose factors would result in higher doses by ingestion of 137Cs and 90Sr. Furthermore, by respecting these dose factors, the limit values for radionuclides in food should be considerably lower for 90Sr and 137Cs.

Different countries have different limit values, even using the same dose coefficients from ICRP. This led to confusion in 1986 and was also a problem in 2011. Policymakers and the general public do not understand such differences. Why are there different threshold values for the same radionuclide in the same food? In Switzerland, the Government has the intention to let fall most limit values for radionuclides in food in "times of non-crisis". In times of crisis, the Government should enact ad hoc specific limit values, as was done in 1986 and 2011.

It is not clear how the state laboratories can sustain their activities and conserve their knowhow in the field of radioactivity monitoring of food without limit values. However, we must always be prepared for emergency cases.
