Natural and Anthropogenic Radioactivity Content and Radiation Hazard Assessment of Baby Food Consumption in Italy

Abstract

The natural (⁴⁰K) and anthropogenic (¹³⁷Cs) radioactivity concentration in four different typologies of early childhood (up to two years old) foods, i.e., homogenized fruit, homogenized meat, childhood biscuits and baby pasta, produced in Italy and sold in Italian large retailers, was investigated through High Purity Germanium (HPGe) gamma spectrometry. The present study is carried out with the aim to: (i) evaluate the background levels of the investigated radionuclides in the analyzed early childhood foods, (ii) identify whether the twenty analyzed samples were appropriate for infant consumption and (iii) contribute to construct a database on the radioactivity of early childhood foods sold in Italy.

1. Introduction

The main source of exposure to ionizing radiations for individuals of the population is natural radioactivity [1,2,3,4]. In particular, with reference to internal exposure, it is worth noting that radionuclides can enter the human body by the inhalation of gas in the air, by feed ingestion or through the skin (transcutaneous absorption) [5,6]. As widely reported in the literature, the major contribution to the average worldwide annual effective dose per capita (2.4 mSv) [7] is from the ingestion of food and water [8,9,10].

In light of this, it can be easily understood that the consumption of food that contains radionuclides can constitute a serious health threat for human beings [11,12] and, in particular, for infants, since they are at a high risk for foodborne illness and related health complications because they are under developing immune systems and cannot fight off infections such as adults [13].

Thus, in order to fill the knowledge gap related to the radioactivity content of baby food produced in Italy and sold in the Italian large retailers, four different typologies of early childhood (up to two years old) foods, i.e., homogenized fruit, homogenized meat, childhood biscuits and baby pasta, were analyzed in the present study in terms of natural (⁴⁰K) and anthropogenic (¹³⁷Cs) radioactivity concentration. In particular, regarding the first, we investigated only ⁴⁰K since natural radioactivity in food mainly comes from this radioisotope [14,15,16,17]. Potassium assumes a fundamental role in regulating many body functions [18,19]. Natural potassium contains 0.012% by weight of ⁴⁰K, and its content in the body is therefore also constant. Typically, adults and children receive annual doses of 165 μSv and 185 μSv, respectively, from ⁴⁰K naturally present in their bodies [1]. The higher dose received by children is due to a higher potassium concentration in their diet in relation to body mass [20].

The assessment of the ingestion dose levels was also performed in order to identify whether the twenty analyzed early childhood foods were appropriate for infant consumption, by comparing them with the internationally recommended level [16].

2. Materials and Methods

2.1. Sample Description

The investigated samples, collected during the year 2020, were divided into four groups (G#, # = 1, 2, 3, 4), according to what is reported in

Table 1. Group identification code (ID), typology and number of samples for each group.

Group ID	Typology	Number of Samples
G1	Homogenized fruit	5
G2	Homogenized meat	5
G3	Childhood biscuits	5
G4	Baby pasta	5

. The five samples in each group belong to Italian brands and different batches.

Homogenized fruit and meat are early childhood foods with a mixed consistency between solid and liquid, frequently used for infant weaning. They do not require chewing, and therefore they are very useful in the case of an incomplete dental structure and represent transition foods between the liquid feeding of the infant and the solid one of the weaned infant [21]. The nutritional composition of homogenized foods varies significantly depending on their typology. In theory, they should be produced from raw materials and water alone, without adding anything else; however, several simple sugars are added to various fruit ones [22]. Those based on meat, on the other hand, are rich in proteins with a high biological value.

As for the non-energetic nutrients, the homogenized foods fully satisfy the needs of mineral salts and vitamins. In addition, they also show low levels of cholesterol and saturated fat, and provide a few grams of dietary fiber [23].

Childhood biscuits, commonly used for weaning children under one year of life, are not much different from a common dry biscuit in terms of nutritional composition, neither in sugar content nor in saturated fat content. They are a source of complex carbohydrates, which provide slow-release energy that can therefore be used over time, and of simple carbohydrates, which immediately enter into the circulation and are burned [24]. They are also enriched with protein, both of animal and vegetable origin, which are fundamental elements for the growth of the cells and tissues of the child’s body [25]. Childhood biscuits are also integrated with vitamins, i.e., those of group B, essential for calcium absorption and cell renewal, and vitamin C, which stimulates the body’s natural defenses and promotes iron absorption. In addition, they also contain minerals, such as calcium and phosphorus (for the development of the skeletal system and teeth), copper (for the nervous system), iron (for the formation of red blood cells) and zinc (to strengthen bones and muscles in addition to the immune system) [26].

Baby pasta should be given to the children at the beginning of weaning, taking into account that it has very specific characteristics [27]. First of all, it is gluten-free, so it can be given even before six months of age. Then, it is prepared with soft wheat, more digestible and easily chewable than that used for pasta commonly consumed by adults. Finally, it is obtained with diastased flour, which is subjected to a specific procedure following which the starch is broken down into simpler elements making it easier for the early children to digest, while still maintaining the right nutritional values [28]. After one year of age, durum wheat pasta in a larger format can be given to children, even combined with legumes in order to constitute a complete meal from the point of view of protein [29].

2.2. Radioactivity Measurements

For High Purity Germanium (HPGe) gamma spectrometry measurements, early childhood food samples were inserted in Marinelli containers of 1 L capacity and counted for 70,000 s [30]. The obtained spectra were then analyzed with the aim to assess the ¹³⁷Cs and ⁴⁰K specific activity [30].

A positive biased Ortec HPGe detector (GEM) was employed for the analysis [31]. In order to perform efficiency and energy calibrations, a Eckert and Ziegler Nuclitec GmbH traceable multinuclide radioactive standard (AK-5901), energy range 59.54 keV–1836 keV, reproducing the exact samples geometries in a water-equivalent epoxy resin matrix, was employed [31].

The specific activity (Bq kg⁻¹) of the investigated radionuclides was calculated as follows, by using the Gamma Vision (Ortec) software [32,33]:

$$C=\frac{N_E}{{\epsilon }_{E}t{\gamma }_{d}M}$$

(1)

where N_E accounts for the net area of a peak at energy E; ε_E and γ_d indicate the efficiency and yield of the photopeak at energy E, respectively; M is the mass sample (kg); and t is the live time (s).

The quality of the results was certified by the Italian Accreditation Body (ACCREDIA) [34,35].

2.3. Evaluation of the Radiological Hazard

The radiological health risk was estimated as follows [36]:

$$D_{ing }\left(Sv y^{-1}\right)=h_{ing,K-40}\times J_{ing, K-40}$$

(2)

where h_ing,K−40 accounts for the coefficient of effective dose for insertion unit for ingestion of ⁴⁰K (5.2 × 10⁻⁸ Sv Bq⁻¹ and 4.2 × 10⁻⁸ Sv Bq⁻¹ for the age categories of 0–1 and 1–2 years old, respectively), as reported in [1], while J_ing,K−40 is the annual intake of ⁴⁰K (Bq year⁻¹), calculated by multiplying the early childhood food consumption (kg) for the specific activity of the investigated radionuclide (Bq kg⁻¹).

3. Results and Discussion

3.1. Activity Concentration

Table 2. Massic activities (Bq kg⁻¹) of ⁴⁰K and ¹³⁷Cs in the analyzed early childhood food samples.

Group ID	Specific Activity
	40K (Bq kg−1)	137Cs (Bq kg−1)
G1	111 ± 13	<0.11
	95 ± 11	<0.12
	68 ± 9	<0.10
	160 ± 19	<0.09
	51 ± 6	<0.11
Mean value	97 ± 12	<0.11
G2	171 ± 19	<0.09
	202 ± 23	<0.11
	182 ± 19	<0.12
	188 ± 20	<0.08
	142 ±16	<0.13
Mean value	177 ± 19	<0.10
G3	120 ± 14	<0.11
	72 ± 9	<0.12
	130 ± 14	<0.10
	75 ± 9	<0.13
	55 ± 7	<0.09
Mean value	90 ± 11	<0.11
G4	106 ± 12	<0.19
	83 ± 9	<0.18
	96 ± 11	<0.13
	79 ± 9	<0.14
	78 ± 9	<0.17
Mean value	88 ± 7	<0.10

reports the massic activities of ⁴⁰K and ¹³⁷Cs for all the analyzed early childhood food samples. For each group, the mean value (±standard deviation) is also reported.

First of all, a good agreement between the results shown in Table 2 and those reported in the food radioactivity database of the “Italian Institute for the Environmental Protection and Research” (ISPRA) [37] was found.

In the case of the ¹³⁷Cs specific activity, the obtained results revealed no residual contamination from artificial radioactivity, with the radiocaesium activity concentration being lower than the minimum detectable activity in all cases.

Finally, the activity concentration of ⁴⁰K, measured for each sample, does not allow a proper assessment of the radiological hazard for early children, and hence, to evaluate it, additional factors have to be taken into account [38], as reported in the following section.

3.2. The Annual Effective Dose for Early Childhood Food Ingestion

The dose estimation due to the ingestion of radionuclides through food consumption was performed for infants up to two years old. In order to evaluate the radiological health risks for early children, we estimated the annual effective dose due to the ingestion, D_ing.

Table 3. The annual effective dose for early childhood food ingestion.

	Effective Dose for Ingestion, Ding (mSv y−1)
Group ID	0–1 Year Old	1–2 Years Old
G1	0.23	0.19
G2	0.27	0.22
G3	0.02	0.01
G4	0.17	0.13

reports the obtained results, which take into account the annual average consumption of homogenized fruit (three 80 g jars per day), homogenized meat (one 80 g jar per day), childhood biscuits (four per day) and baby pasta (about 100 g per day), per infant in Italy [39,40].

The ingestion dose for the selected age categories, due to the intake of ⁴⁰K, thus ranges from 0.02 mSv y⁻¹ (for G3) to 0.27 mSv y⁻¹ (for G2) for the age category of 0–1 year old, and from 0.01 mSv y⁻¹ (for G3) to 0.22 mSv y⁻¹ (for G2) for the age category of 1–2 years old, respectively. Noteworthily, the obtained values were found to be always lower than the ICRP recommended limit of 1 mSv y⁻¹ for all ages [16]. Moreover, such dose values account for 0.8–11.2% (age category of 0–1 year old) and 0.4–9.1% (age category of 1–2 years old) of the average annual effective dose to the world population (2.4 mSv y⁻¹) [41].

These results show the importance of determining the radioactivity level in early childhood foods in order to ensure their safety and suitability, considering that they are typically consumed during a vulnerable period of human life.

4. Conclusions

In this work, the activity concentration of natural and anthropogenic radionuclides (⁴⁰K and ¹³⁷Cs, respectively) was evaluated for early childhood food samples of four different typologies (homogenized fruit, homogenized meat, childhood biscuits and baby pasta), produced in Italy and collected from Italian large retailers.

The HPGe gamma spectrometry results indicate that the ¹³⁷Cs specific activity was lower than the minimum detectable activity in all cases, thus excluding anthropogenic radioactive contamination. Moreover, the ⁴⁰K activity concentration was employed in order to evaluate the radiological health risk for the selected age category, by assessing the effective dose for food ingestion. The calculated values turned out to be lower than the ICRP recommended limit for all ages. They were also compared with the total natural radioactivity value for humans, resulting to be equal to the 0.8–11.2% (age category of 0–1 year old) and 0.4–9.1% (age category of 1–2 years old) of the average annual effective dose.

Finally, the results reported in this article can be used to develop a database on the radioactivity in early childhood foods sold in Italy.