Presence of natural radionuclides and toxic elements in monocalcium phosphate, complete feed and pig manure.

Naturally occurring radionuclides and toxic elements are ubiquitous in the environment and can pose a great risk to animals' health. Control of these toxic substances in animal diet is essential for animal's welfare, human nutrition risk management as well as environmental protection. Our study addresses these issues by determining a content of natural radionuclides (40K, 238U and 226Ra), and toxic elements (Cd, Cr, As) in total of 108 samples: 36 monocalcium phosphate, 36 complete feed and 36 pig manure samples that were collected from 6 different commercial farms in the Republic of Serbia. In monocalcium phosphate the content of 40K, 238U and 226Ra ranged from 7.6-23.4 Bq kg-1, 13.2-1778 Bq kg-1 and 3.6-13.5 Bq kg-1, respectively. In complete feed samples, 40K ranged from 170 to 306 Bq kg-1, 238U from minimum detectable activity (MDA) to 9.1 Bq kg-1, and 226Ra from MDA-5.5 Bq kg-1, while in pig manure 40K ranged from 146 to 531 Bq kg-1, 238U from MDA-30.1 Bq kg-1, and 226Ra from MDA-10 Bq kg-1. The concentrations of Cd, Cr and As in monocalcium phosphate were 0.26-14.9 mg kg-1, 10.3-497 mg kg-1, and 4.2-5.5 mg kg-1, respectively. In complete feed, the content of Cd, Cr and As ranged from minimum detectable concentration (MDC) - 0.78 mg kg-1, 0.30-7.41 mg kg-1, and 0.09-0.31 mg kg-1, respectively. In pig manure Cd, Cr and As ranged from 0.8-2.3 mg kg-1, 2.3-22.2 mg kg-1, and 0.51-5.45 mg kg-1, respectively. The obtained results showed that Cd concentration in monocalcium phosphate exceeded the maximum permissible legislative concentrations for phosphate additives. Monocalcium phosphate is the main source of 238U and Cr in complete feed, while Cd derives from other sources. For that reason excessive use of monocalcium phosphate can lead to high levels of these pollutants in complete feed and consequently in manure.

Toxicity of high uranium doses in broilers and protection with mineral adsorbents.

The aim of this study was to determine the uranium distribution and histopathological changes in broiler organs (kidney, liver, and brain) and muscle after 7 days of contamination with high doses of uranyl nitrate hexahydrate (UN), and the protective efficiency of three different mineral adsorbents (organobentonite, organozeolite, and sepiolite). During the 7 days, the UN administration was 50 mg per day, and administration of adsorbents was 2 g per day immediately after UN. In control group where broilers received only UN, histopathological changes such as necrosis of intestinal villi, oedema, vacuolisation and abruption of epithelial cells in renal tubules, oedema and vacuolisation of the cytoplasm of hepatocytes, and dystrophic changes in the neurons of the medulla oblongata were observed. In contrast, when the adsorbents organobentonite, organozeolite, and sepiolite were administered, no histopathological changes were observed in liver and brain. The investigated adsorbents showed the highest protective effects in liver (80-92%), compared to the kidney (77-86%), brain (37-64%), and meat (31-63%).

Natural and anthropogenic radioactivity in the environment of Kopaonik mountain, Serbia.

To evaluate the state of the environment in Kopaonik, a mountain in Serbia, the activity concentrations of (4) K, (226)Ra, (232)Th and (137)Cs in five different types of environmental samples are determined by gamma ray spectrometry, and radiological hazard due to terrestrial radionuclides is calculated. The mean activity concentrations of natural radionuclides in the soil are higher than the global average. However, with an exception of two sampling locations, the external radiation hazard index is below one, implying an insignificant radiation hazard. Apart from (40)K, content of the natural radionuclides is predominantly below minimum detectable activities in grass and cow milk, but not in mosses. Although (137)Cs is present in the soil, grass, mosses and herbal plants, its specific activity in cow milk is below minimum detectable activity. Amongst the investigated herbal plants, Vaccinium myrtillus L. shows accumulating properties, as a high content of (137)Cs is detected therein. Therefore, moderation is advised in consuming Vaccinium myrtillus L. tea.

Efficiency of sepiolite in broilers diet as uranium adsorbent.

The use of phosphate mineral products in animal nutrition, as a major source of phosphor and calcium, can lead to uranium entering the food chain. The aim of the present study was to determine the protective effect of natural sepiolite and sepiolite treated with acid for broilers after oral intake of uranium. The broilers were contaminated for 7 days with 25 mg/uranyl nitrate per day. Two different adsorbents (natural sepiolite and sepiolite treated with acid) were given via gastric tube immediately after the oral administration of uranium. Natural sepiolite reduced uranium distribution by 57% in kidney, 80% in liver, 42% in brain, and 56% in muscle. A lower protective effect was observed after the administration of sepiolite treated with acid, resulting in significant damage of intestinal villi in the form of shortening, fragmentation, and necrosis, and histopathological lesions on kidney in the form of edema and abruption of epithelial cells in tubules. When broilers received only sepiolite treated with acid (no uranyl nitrate), shortening of intestinal villi occurred. Kidney injuries were evident when uranium concentrations in kidney were 0.88 and 1.25 µg/g dry weight. It is concluded that adding of natural sepiolite to the diets of broilers can reduce uranium distribution in organs by significant amount without adverse side effects.

137Cs and 40K in some traditional herbal teas collected in the mountain regions of Serbia.

Herbal teas are an important part of traditional medicine in Serbia. The objective of the present study was to determine the activity concentrations of (40)K and (137)Cs in herbal tea, using the gamma spectroscopy method. The samples were collected during the period 2011-2012 in three mountain regions in Western and Central Serbia. The activity concentrations of (40)K and (137)Cs were found to be in the range of 130-1160 and 0.7-124 Bq kg(-1), respectively. The average annual effective dose equivalents from ingestion of (40)K and (137)Cs for an adult person consuming one cup of herbal tea daily were found to be 588.4-5250.2 nSv for (40)K and 4.0-706.1 nSv for (137)Cs. Our investigation showed that the herbal teas originating from Maljen, Zlatibor and Tara mountains are radiologically safe for human consumption.

Uranium distribution in broiler organs and possibilities for protection.

The aim of the present study was to investigate the distribution of uranium (uranyl nitrate hexahydrate, UN) in muscle and organs (kidney, liver, and brain) of broilers, after a 7-day contamination with UN and administration of two different adsorbents (organobentonite and organozeolite). The birds were contaminated during 7 days with 25 mg/UN per day. Adsorbents were given via gastric tube, immediately after contamination with UN. In group 1 that did not receive any adsorbents, histopathological changes in the contaminated broilers were observed in small intestine, liver, and kidney in the form of necrosis of intestinal villi, oedema and cytoplasmic vacuolation of hepatocytes, and dystrophic changes in the kidney tubules epithelium. Organobentonite administered via gastric tube (group 2) reduced uranium distribution by 66 % in kidney, 81 % in liver, and 34 % in brain. In group 3, administration of organozeolite reduced uranium distribution by 67 % in kidney, 68 % in liver, and 49 % in brain. In groups 2 and 3, where the broilers received adsorbents immediately after the UN contamination, no histopathological lesions were observed.

Comparative study of (137)Cs distribution in broilers and pheasants and possibilities for protection.

The aim of the present study was to investigate distribution of (137)Cs in leg and breast meat of broilers and pheasants following single alimentary contamination and administration of two protectors (AFCF and clinoptilolite). The birds were administered a single dose of (137)CsCl, with an activity of 750 Bq. Protectors were given via gastric tube or mixed in the forage pellets. AFCF given via gastric tube decreased the (137)Cs concentration by a factor of 7.8 in broilers leg meat and 7.4 in broilers breast meat. When AFCF was mixed in pellets, the (137)Cs concentration was 19.5 times lower in broilers leg meat and 22.1 times lower in broilers breast meat, than in the control group. In pheasants, AFCF administered via gastric tube decreased the (137)Cs concentration by a factor of 12.4 in leg meat and by a factor of 13.7 in breast meat, respectively. In group 4, where pheasants were administered AFCF mixed in pellets, the (137)Cs concentration was 3.7 times lower in leg and breast meat, than in the control group. For comparison, clinoptilolite administered via gastric tube decreased the (137)Cs concentration 1.8 times in broilers leg meat and 2.0 times in breast meat, compared to the control group. In pheasants, (137)Cs concentration was 2.9 times lower in leg meat and 2.6 times lower in breast meat. Clinoptilolite mixed in the feed had relatively low efficiency of protection in broilers ((137)Cs concentration was 1.4 times lower in leg meat and 1.6 lower in breast meat). A similar trend was observed in pheasants ((137)Cs concentration was 1.6 lower in leg and breast meat).