# Evaluation of the Radiological and Chemical Risk for Public Health from Flour Sample Investigation
## 1 Introduction  
Natural radioactivity occurs in the environment due to the presence of cosmogenic and primordial radionuclides in the Earth's crust [1]. The first radionuclides were produced by cosmic-rays' interaction with atomic nuclei in the atmosphere, while primordial radioisotopes were generated by the nucleo-synthesis process during the Earth's formation [2]. Anthropogenic radioactivity is due to radionuclides, such as \({}^{137}\)Cs, mainly derived from nuclear accidents and global nuclear tests conducted between the mid-1940s and the 1980s [3]. Human beings can be exposed to ionizing radiations through external gamma rays, the inhalation of radon and other radioactive nuclides, and ingestion of radioisotopes through food and water [4]. In particular, for the latter, the natural radioactivity in food comes mainly from \({}^{40}\)K; uranium and thorium daughter products are usually present in traces [4; 5; 6; 7; 8]. The presence in food of anthropogenic radionuclides, as well as of heavy metals, is a significant issue, involving contamination of the food chain and harm to public health [9]. The danger associated to heavy metals is especially severe, because they are not chemically or biologically degradable [7]. Once released into the environment, mainly due to industrial or mining activities, they can remain for hundreds of years, polluting the soil and accumulating in plants and organic tissues. Moreover, their concentration in living beings increases as they move up the food chain [10]. Among all sources of the food chain contamination, pollution of the soil (from which foods are produced) due to the radioactive fall-out, residual muds, chemical fertilizers, and pesticides used in agriculture appear to be the most significant [11]. Having this contamination in so many different sources, there is a wide range of foods potentially contaminated by anthropic radionuclides and heavy metals, including products of plant origin, such as cereals, rice, wheat, edible roots, mushrooms, etc., as well as animal origin foods, such as fish, crustaceans, mollusks, etc. [6]. Flour is a plant origin foodstuff consumed daily by inhabitants of Italy [12]. The average annual consumption of flour is of about 85 kg per person, taking into consideration its use to produce bread, pizza, and baked goods, so the analysis of flour in terms of chemical and radioactive contamination is extremely important to safeguard human health [13]. The consumption of contaminated food increases the amount of radioactivity and chemical contamination inside an individual, and therefore increases the health risks associated with radiation exposure and heavy metal pollution. The exact health effects depend on the type and quantity of ingested radionuclides and metals [14]. Consumers have an increasing interest towards safe foodstuffs and protection [15; 16]. For this reason, studies focused on food authenticity and traceability are in constant increase to preserve costumers against fraud and commercial disputes [17]. In particular, botanical and geographical origins of various foodstuffs have been verified by developing quali-/quantitative methods with subsequent multivariate analysis [18; 19]. In this article, eleven different types of flour (five samples for each one), i.e., wholemeal, semolina, rice, coconut, almond, chestnut, Mallorcan wheat, oat, corn, rye, and pistachio, coming from large retailers and employed by people for different altimetry purposes, were analyzed. The analysis was to identify and quantify, on the one hand, natural (\({}^{40}\)K) and artificial (\({}^{137}\)Cs) gamma-emitting radionuclides with HPGe gamma spectrometry, in order to evaluate any possible radioactive contamination and estimate the effective dose due to the flour ingestion.