Andreja Prevendar Crnić

Cadmium, Lead, and Mercury Exposure Assessment Among Croatian Consumers of Free-Living Game

Abstract Free-living game can be an important source of dietary cadmium and lead; the question is whether exposure to these two elements is such that it might cause adverse health effects in the consumers. The aim of this study was to estimate dietary exposure to cadmium, lead, and mercury from free-living big game (fallow deer, roe deer, red deer, wild boar, and brown bear), and to mercury from small game (pheasant and hare), hunted in Croatia from 1990 to 2012. The exposure assessment was based on available literature data and our own measurements of metal levels in the tissues of the game, by taking into account different consumption frequencies (four times a year, once a month and once a week). Exposure was expressed as percentage of (provisional) tolerable weekly intake [(P)TWI] values set by the European Food Safety Authority (EFSA). Consumption of game meat (0.002-0.5 % PTWI) and liver (0.005-6 % PTWI) assumed for the general population (four times a year) does not pose a health risk to consumers from the general population, nor does monthly (0.02-6 % PTWI) and weekly (0.1-24 % PTWI) consumption of game meat. However, because of the high percentage of free-living game liver and kidney samples exceeding the legislative limits for cadmium (2-99 %) and lead (1-82 %), people should keep the consumption of certain game species’ offal as low as possible. Children and pregnant and lactating women should avoid eating game offal altogether. Free-living game liver could be an important source of cadmium if consumed on a monthly basis (3-74 % TWI), and if consumed weekly (11-297 % TWI), it could even give rise to toxicological concern.

Malondialdehyde and heavy metal concentrations in tissues of wild boar (Sus scrofa L.) from central Croatia

The aim of this research was to assess the degree of heavy metal (cadmium, lead and mercury) contamination of wild boars from central Croatia and thereby conduct further tests to connect the contamination to oxidative stress occurrence. The highest cadmium concentration was noticed in the kidneys of older boars, the lead concentration was approximately the same in the liver and kidneys, but it was much higher than the concentration in the muscles, while the highest mercury concentration was measured in the kidneys of all wild boars. The correlation between the malondialdehyde (MDA) and the heavy metal concentrations was higher in tissue samples taken from younger animals (1 to 3 years of age) than in the tissue samples taken from older animals (5 to 6 years of age). In the kidneys of all wild boars there was a statistically significant connection between the MDA and cadmium concentration; in the kidneys of younger wild boars there was a statistically significant connection between the MDA and lead concentration. Further research on this topic should focus on MDA potential to find its use, not only as a contamination biomarker in the area of ecotoxicology, but also in the evaluation of the hygienic acceptability of animal products.

Mercury in hares organs (Lepus europaeus Pallas) in the vicinity of the mercury-contaminated natural gas treatment plant in Croatia.

In the last two decades (1990–2008), as part of a comprehensive monitoring of the eco-system, hares were collected in the vicinity of the mercury contaminated natural gas production and treatment plant Molve, Croatia. Their organs (muscle, liver, kidney and brain) were analyzed for total mercury concentration by cold vapor AAS. The range of the median mercury concentration values (wet weight) in hares organs were 0.001–0.005, 0.007–0.045, 0.022–0.126 and 0.0006–0.015 μg/g for muscle, liver, kidney and brain, respectively. The results of mercury measurements in hares organs during the period of last twenty years demonstrate a small but constant decline in concentration values. Comparing the results obtained in this study with results published in available data and literature on mercury concentration in hares tissue it can be concluded that area investigated in this research belongs to low mercury contaminated region. Nevertheless, further eco-monitoring and mercury measurements in various hares organs are valuable and necessary and will be continued.

Cadmium, lead and mercury concentrations in selected red deer (Cervus elaphus L.) tissues from north-eastern Croatia

Concentrations of cadmium, lead and mercury were determined in muscle, liver and kidney tissue from three different age groups of red deer (young animals aged 6 or 7 months, middle-aged animals aged 3 to 5 years, old animals aged over 8 years) from the Baranja region of Croatia. Median cadmium concentrations were low in the muscles of all investigated age groups (0.0002; 0.0009 and 0.0020 μg/g), higher in the liver (0.0279; 0.0656 and 0.1463 μg/g) and highest in the kidneys (0.4792; 2.8531 and 6.1657 μg/g). A positive correlation was established between cadmium concentration and age. In all analyzed tissues the median lead concentration was higher in young (muscle 0.0024; liver 0.0364 and kidney 0.0618 μg/g), compared to middle-aged animals (muscle 0.0001; liver 0.0184 and kidney 0.0160 μg/g). In contrast to cadmium, mercury had a negative correlation to age but median concentrations were very low (in muscle: 0.0011; 0.0001 and 0.0006 μg/g; in liver: 0.0051; 0.0037 and 0.0022 μg/g and in kidney: 0.0145; 0.0183 and 0.0106 μg/g) especially compared to cadmium. From the hygienic point of view all the examined tissues are edible since concentrations of the analyzed metals do not exceed values proposed by the official regulations, with the exception of a few kidney samples, which contained cadmium above the recommended value. Furthermore, mercury concentrations are no longer (since 2008) a matter of legislation.

A case of a brown bear poisoning with carbofuran in Croatia

Abstract We provide the first known documentation of a fatal brown bear (Ursus arctos) poisoning with carbofuran (an acetylcholinesterase inhibitor) in Croatia. Diagnosis using liquid chromatography–mass spectrometry confirmed the presence of high concentrations of carbofuran in liver and kidney tissue (12.650 and 2.695 ppm, respectively). These measurements, combined with the very small distance between poisonous baits and the brown bear carcass, provided the basis on which we concluded that the animal consumed a lethal dose of carbofuran and succumbed to acute poisoning soon thereafter. We believe this mortality was caused by the illegal placement of this poison probably to eliminate perceived pests, such as jackals (Canis aureus) or foxes (Vulpes vulpes). Our documentation may help identify similar cases and raise awareness of the risks posed by illegal poisons for non-target species, particularly scavengers such as bears.

Mercury in pheasant (Phasianus colchicus) organs in Podravina, Croatia

Since 1995 the concentrations of total mercury were analyzed in the pheasant organs (liver, kidney, brain and muscle) that live freely in an area that was exposed to elevated levels of mercury as a result of industrial activity (mercury contaminated natural gas production and processing which began in 1980). The range of the median mercury concentration values (wet weight) in pheasant organs in Podravina, Croatia were 0.0004–0.024, 0.0001–0.034, 0.0002–0.016 and 0.0001–0.025 μg/g for liver, kidney, brain, and muscle, respectively. Results of these studies confirms that in the study area in the observed period there was no significant mercury contamination which can be linked to anthropogenic activities (hydrocarbon production)‥ On the contrary, systematic measurements demonstrate a small but constant (barely noticeable) decline in mercury concentrations in pheasants organs. Primarily, this is the result of the significant improvement in the technological process which involves the removal of mercury from the natural gas that was designed and implemented in 1993. However, due to the need for reliable control of mercury contaminated natural gas production and the importance for better understanding of long-term exposure to low levels of mercury, and assessment of their possible harmful effects on the environment, human and animal health, research will be continued.

Stimulation by levamisole of cell-mediated immunity in weaned pigs

Abstract Commercial crossbred pigs weaned at four weeks were allocated into three equal groups. The experimental group 1 was primed intramuscularly, and the experimental group 2 was primed per os, with levamisole at an immunostimulatory dose of 2.5mg/kg once daily, for three consecutive days, and controls received saline. Venous blood samples from all pigs were collected after the last levamisole or saline dose was given (day 0), and 35 days later (day 35) for flow cytometry analysis. The results obtained by immunophenotyping of isolated circulating lymphocytes on day 35 indicate that priming by levamisole of weaned pigs selectively recruited CD4+, CD8+ and CD4+CD8+, but not CD21+ cells in the systemic circulation.

Mercury in Eisenia fetida and soil in the vicinity of a natural gas treatment plant in northern Croatia

ABSTRACT In the last two decades (1990–2012), as part of a mercury monitoring programme, earthworms and soils have been collected from four locations in the vicinity of a natural gas production and treatment plant near the village of Molve, Croatia. The aim of this study was to determine the concentration of mercury in the collected samples, monitor its changes over a longer period of time and determine the bioaccumulation of total mercury in earthworms (Eisenia fetida) from the soil. Total mercury concentrations in earthworms from the surroundings of four boreholes (Molve 9–12) ranged within 0.195–1.050, 0.129–1.0, 0.229–1.236 and 0.223–0.799 μg g−1 dry weight, while total mercury concentrations in different soil types at the same locations within 0.055–0.350, 0.035–0.250, 0.031–0.240 and 0.071–0.475 μg Hg g−1 of soil. The calculated mercury bioaccumulation factor ranged between 0.9 and 17.5. Mercury levels in soil and earthworms, as a tool for soil pollution assessment, suggested low mercury exposure and risks for human health in the monitored area.

Pharmacokinetics of an immunomodulating dose of levamisole in weaned pigs

Levamisole has been shown to stimulate the immune response in immunocompromised humans and animals. However, its use as an adjuvant in immunocompromised weaned pigs prone to colibacillosis has only been experimentally tested but not yet officially approved. Therefore, the aim of these studies was to study the pharmacokinetics (PK) of an immunomodulating dose of levamisole in weaned pigs. For that purpose, 20 weaned crossbred pigs were divided into two treatment groups. In this parallel-design study, a single dose of levamisole (2.5 mg/kg body weight) was administered by the intramuscular (i.m.) or oral (p.o.) route. Statistically significant differences between the i.m. and p.o. routes in terminal beta rate constant (β), maximum plasma concentration (Cmax), area under the curve (AUC) for plasma concentration-time curve from time zero to infinity (AUC0-inf), area under the plasma concentration-time curve from time 0 to the last quantifiable time point (AUC0-t) were determined. Further research is needed to establish a relationship between the PK and the immunomodulating effect of levamisole in pigs.