**3. A Case of nuclear analytical application in animal sciences: Uranium in rock phosphates and rabbit muscles from animals receiving uranium determined by neutron activation analysis**

Sedimentary ore deposits have provided about 80%–90% of world production of phosphate [6]. Oppositely, in Brazil igneous deposits represent 80% of the national reserves of phosphate rocks. The major Brazilian phosphate rock reserves are concentrated in the states of Minas

Nuclear Analytical Techniques in Animal Sciences: New Approaches and Outcomes

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In 2009, the Brazilian phosphate-related products market was shared as phosphate fertilizers (89.12%), animal feed – mainly dicalcium phosphate (6.91%), soil amendment (1.01%), and the

**Ingredient (tons.year-1)** *2005 2011 2012***<sup>∇</sup>**

Dicalcium Phosphate 216.400 404.761 560.274

Limestone 634.000 1.247.016 1.276.388

Bone Meal 225.400 n.i. n.i.

**Products Quantity (tons) FOB x U\$1,000.00**

United States n.a. 33.31 30.59 Algeria 20.90 n.a. n.a. Morocco 63.80 24.54 27.74 Israel 10.30 8.97 9.08 Tunisia 4.71 7.95 7.68 Russia n.a. 6.74 6.19 Spain 0.13 n.a. n.a. Others 0.16 18.49 18.71

**Table 3.** Brazilian imports of phosphates by countries, raw and industrialized products. Total pondered by the price

**Industrialized Material (%)**

**Total (%)**

Raw material 915.449 84.040 Industrialized 2.861.719 945.170 Total 3.777.168 1.029.210

Gerais, Goiás and São Paulo [17].

remaining was not informed (2.96%) [17].

n.i., not informed., <sup>∇</sup> forecasted in 2012, May for the entire year

**Table 1.** Phosphorus and calcium sources used in the Brazilian Feed Industry [8]

**Table 2.** Brazilian imports of phosphates, raw and industrialized products [17]

**Raw Material (%)**

**Country**

FOB, DNPM [17]

Nuclear applications in Animal Sciences are not a novelty. It could be considered as the two first studies from 1949 using rabbits to assess the biological consequences of the uranium ingestion: Decreased body weight was reported for rabbits exposed to 11 mg U/ m3 as uranium tetrachloride dust for 35–40 days [9]. Rabbits lost 22% of their body weight during a 30 days exposure to 0.9 mg U/m3 , dogs and cats lost approximately 25% of their body weight during a similar exposure to 9.5 mg U/m3 . Similar effects were observed with uranium tetrafluoride [10].

**Introduction**: Phosphorus (P) deficiency in crops is an important constraining factor n plant and animal yields, especially in hot humid tropics where soils are predominantly acidic and often extremely P deficient with high P fixation capacities [11,12].

Phosphorus combines with oxygen forming oxides called phosphates. Phosphates are defined as compounds, which contain phosphorus-oxygen (P-O) linkages. The P-O bond has a length of 1.62Å with bond angles of 130° at the oxygen atoms and 102° at the phosphorus atoms at the pentoxide P2O5, the only oxide of phosphorus that is produced commercially [13].

Phosphate rock denotes the product obtained from the mining and subsequent metallurgical processing of phosphorus bearing ores. By flotation of phosphate rock it is formed apatite concentrates. These phosphate products are the major phosphorus sources in soil nutrition, also plenty used in animal formulations by industries [14].

*they cremated some one. Now they recover over ninety-eight per cent of it. More than a kilo and a half per adult corpse. Which makes*

*the best part of four hundred tons of phosphorus every year from England alone." Henry spoke with a happy pride, rejoicing whole-*

*heartedly in the achievement, as though it had been his own. "Fine to think we can go on being socially useful even after we're dead.*

*Making plants grow.'…} Brave New World, Aldous Leonard Huxley [15].*

This text above was extracted from the 1932 fictional worldwide bestseller *Brave New World* [15]. It could sound so fantasist back when it was firstly published. Maybe it will sound reality in a future not far ahead. Currently, a reduced and shortening number of phosphate sites are mined around the world. Based on current phosphate extraction rates and economic trends in the 1990s, more than half of main phosphate producer countries will have exceeded the life of their reserves up to 2024 [16].

Phosphate ranks second (coal and hydrocarbons excluded) in terms of gross tonnage and volume of international trade [16].

*<sup>…&#</sup>x27;On their way up the chimney the gases go through four separate treatments. P2O5 used to go right out of circulation every time*

Sedimentary ore deposits have provided about 80%–90% of world production of phosphate [6]. Oppositely, in Brazil igneous deposits represent 80% of the national reserves of phosphate rocks. The major Brazilian phosphate rock reserves are concentrated in the states of Minas Gerais, Goiás and São Paulo [17].

In 2009, the Brazilian phosphate-related products market was shared as phosphate fertilizers (89.12%), animal feed – mainly dicalcium phosphate (6.91%), soil amendment (1.01%), and the remaining was not informed (2.96%) [17].


n.i., not informed., <sup>∇</sup> forecasted in 2012, May for the entire year

**3. A Case of nuclear analytical application in animal sciences: Uranium in**

Nuclear applications in Animal Sciences are not a novelty. It could be considered as the two first studies from 1949 using rabbits to assess the biological consequences of the uranium ingestion: Decreased body weight was reported for rabbits exposed to 11 mg U/ m3 as uranium tetrachloride dust for 35–40 days [9]. Rabbits lost 22% of their body weight

**Introduction**: Phosphorus (P) deficiency in crops is an important constraining factor n plant and animal yields, especially in hot humid tropics where soils are predominantly acidic and

Phosphorus combines with oxygen forming oxides called phosphates. Phosphates are defined as compounds, which contain phosphorus-oxygen (P-O) linkages. The P-O bond has a length of 1.62Å with bond angles of 130° at the oxygen atoms and 102° at the phosphorus atoms at

Phosphate rock denotes the product obtained from the mining and subsequent metallurgical processing of phosphorus bearing ores. By flotation of phosphate rock it is formed apatite concentrates. These phosphate products are the major phosphorus sources in soil nutrition,

*…'On their way up the chimney the gases go through four separate treatments. P2O5 used to go right out of circulation every time*

*they cremated some one. Now they recover over ninety-eight per cent of it. More than a kilo and a half per adult corpse. Which makes*

*the best part of four hundred tons of phosphorus every year from England alone." Henry spoke with a happy pride, rejoicing whole-*

*heartedly in the achievement, as though it had been his own. "Fine to think we can go on being socially useful even after we're dead.*

This text above was extracted from the 1932 fictional worldwide bestseller *Brave New World* [15]. It could sound so fantasist back when it was firstly published. Maybe it will sound reality in a future not far ahead. Currently, a reduced and shortening number of phosphate sites are mined around the world. Based on current phosphate extraction rates and economic trends in the 1990s, more than half of main phosphate producer countries will have exceeded the life of

Phosphate ranks second (coal and hydrocarbons excluded) in terms of gross tonnage and

the pentoxide P2O5, the only oxide of phosphorus that is produced commercially [13].

, dogs and cats lost approximately 25% of their

. Similar effects were observed with

**rock phosphates and rabbit muscles from animals receiving uranium**

182 Imaging and Radioanalytical Techniques in Interdisciplinary Research - Fundamentals and Cutting Edge Applications

**determined by neutron activation analysis**

body weight during a similar exposure to 9.5 mg U/m3

often extremely P deficient with high P fixation capacities [11,12].

also plenty used in animal formulations by industries [14].

*Making plants grow.'…} Brave New World, Aldous Leonard Huxley [15].*

their reserves up to 2024 [16].

volume of international trade [16].

during a 30 days exposure to 0.9 mg U/m3

uranium tetrafluoride [10].

**Table 1.** Phosphorus and calcium sources used in the Brazilian Feed Industry [8]


**Table 2.** Brazilian imports of phosphates, raw and industrialized products [17]


**Table 3.** Brazilian imports of phosphates by countries, raw and industrialized products. Total pondered by the price FOB, DNPM [17]

Data in table 1 demonstrate the economic relevance of the products under consideration in this study for the Brazilian feed industry. Foreign products are also of concern, as long Brazilian crops and animal yields rely on a great amount of imported phosphate prod‐ ucts (tables 2 and 3).

Practically every rock phosphate contains uranium in its structure [16,24]. The amounts of this and others hazardous substances vary widely among phosphates sources and it may vary even in the same deposit. Thus, mining, milling, industrializing and using phosphate products in soil and animal nutrition are anthropogenic activities increasing the potential for human

German studies in the 1970´s pointed-out the evidence for a raising uranium presence in rivers and groundwater in regions with intensive use of phosphate fertilizers in agriculture (figure 1). Uranium derived from phosphate fertilizers is likely to be adsorbed on the uppermost soil

Uranium content can be determined by the nuclear method of the Neutron Activation Analysis. This is a precise, fast (short turn-around), sensitive and non-destructive method [2].

*Phosphate sample preparation*: phosphates were acquired in the local market of Minas Gerais. Aliquots of 100 grams were randomly taken for each product pack to be grounded to obtain a particle size of 200 Tyler mesh (75 μm) establishing similar conditions for all samples (99% of conformity of the particle size of each product). Aliquot of 1000 mg of each grounded product

*Animal breeding:* Two groups of twelve (6 females and 6 males) New Zealand white rabbits (30 days of life) were selected and separated in two groups housed individually receiving a

Two rabbit feeds were designed to allow the introduction of the P source and to offer sufficient nutrient intake to meet rabbit nutritive requirements. Each one of the feeds had the same 98 percent (dry basis) of fiber, energy, and amino acids. Both formulations were based in raw materials as %, dry basis: Alfalfa meal 34.63, Soy oil 1.00, Sugar cane 2.00, Salt 0.50, Lysine 0.25, Methionine 0.04, Limestone 1.0, Premix 0.40, Maize 6.05, Wheat straw 25.0, Soybean meal 12.13, Maize by products 15.00 and the remaining 2.0 from the selected P source – dicalcium

Feeds were processed in order to turn the mixed products into a compact mixture. After that, the meal was conditioned by mixing it on dry steam in a conditioner; this conditioned product was pressed by rolls to pass through the holes of the pelleting die which shapes the meal into the final pellet shape of 3.00 mm to permit a good balance between pellet quality and good

Animals were housed in stainless steel cages with a fenestrated floor to allow feces to drop through into a pan. Absorbent material was placed in the pan to collect urine and minimize

Good quality water was provided through a nipple-drinking system that provides water at all times. Food was provided by a J-hopper attached to the front of the cage. J-hopper

different phosphorus source (dicalcium phosphate and bovine bone meal).

phosphate and bone meal, both materials analyzed in first part of the experiment.


Nuclear Analytical Techniques in Animal Sciences: New Approaches and Outcomes

content in the river [25].

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layers and its content on the water is correlated to the HCO3

was weighted and sealed in small polystyrene capsules.

ammonia release due to the bacterial breakdown of urea.

exposure to uranium [24,25].

**4. Material and procedures**

intestinal motility.

Indeed, any phosphate mined worldwide may contain accessory-gangue minerals and impurities that can be hazardous to man and animal such: Cd, Hg, Pb and V [16].

The United States Agency for Toxic Substances and Disease Registry [19] publishes the CERCLA Priority List of Hazardous Substances that includes substances, which have been determined to be of the greatest public health concern [19]. Uranium is the 97th substance ranked in the list (table 4).


\*The ranking of hazardous substances on the CERCLA Priority List is based on three criteria (i,ii,iii). They form altogether the Total Score = Σ (i) Frequency of Occurrence + (ii) Toxicity + (iii) Potential for Human Exposure = Σ (i) up to 1.800 Points + (ii) up to 600 points + (iii) up to [300 concentration points + 300 exposure points] [20]

**Table 4.** Compilation of some hazardous substances (including uranium) in the CERCLA List [19, 20]

This study deals with the uranium, since to face the main constraints low inherent P in soil and plants, rock phosphates are likely to be more extensively disseminated in the agriculture and these phosphorus sources carry uranium from their structures to the environment and human food chain as well [21].

Uranium is the heaviest natural element in the nature; it is hazardous element in man and animal health, not just it presents radioactivity but also it presents metallotoxicity once it is a heavy metal. Furthermore, uranium presents many radionuclides with high radioactiv‐ ity and energy [22].

Health implications of human exposure to uranium are well documented: cancer, liver and kidney diseases and reproduction impairment [21,22].

Uranium in nature is more plentiful than silver (Ag) and about as abundant as arsenic (As). It is found in very small amounts in the form of minerals, especially in rocks, soil, water, air, plants and animal tissues that could be consumed as food containing varying amounts of uranium [23].

Practically every rock phosphate contains uranium in its structure [16,24]. The amounts of this and others hazardous substances vary widely among phosphates sources and it may vary even in the same deposit. Thus, mining, milling, industrializing and using phosphate products in soil and animal nutrition are anthropogenic activities increasing the potential for human exposure to uranium [24,25].

German studies in the 1970´s pointed-out the evidence for a raising uranium presence in rivers and groundwater in regions with intensive use of phosphate fertilizers in agriculture (figure 1). Uranium derived from phosphate fertilizers is likely to be adsorbed on the uppermost soil layers and its content on the water is correlated to the HCO3 content in the river [25].

Uranium content can be determined by the nuclear method of the Neutron Activation Analysis. This is a precise, fast (short turn-around), sensitive and non-destructive method [2].
