The aim of this article was to evaluate the influence and effects of chosen bioaccumulative substances i.e. heavy metals, pesticides, and polychlorinated biphenyls (PCBs) on fish, as well as provide information on time trends and potential threat to human health. Chemical substances which pollute water may affect living organisms in two ways. First of all, large amounts of chemical substances may cause sudden death of a significant part of the population of farmed fish, without symptoms (i.e. during breakdown of factories or industrial sewage leaks). However, more frequently, chemical substances accumulate in tissues of living organisms affecting them chronically. Heavy metals, pesticides, and polychlorinated biphenyls are persistent substances with a long-lasting biodegradation process. In a water environment they usually accumulate in sediments, which makes them resistant to biodegradation processes induced by, e.g., the UV light. These substances enter the fish through direct consumption of contaminated water or by contact with skin and gills. Symptoms of intoxication with heavy metals, pesticides, and PCBs may vary and depend on the concentration and bioavailability of these substances, physicochemical parameters of water, and the fish itself.

The transfer of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and polychlorinated biphenyls (PCBs) from a contaminated environment into the food chain is a serious consumer safety problem. As part of the Polish National Surveillance Program of PCDD/Fs and PCBs in food of animal origin, a concentration of PCDD/Fs of 4.61 ± 0.75 pg WHO-TEQ/g fat was determined in a sample of free-range eggs, which exceeded the permitted limit of 2.5 pg WHO-TEQ/g. The aim of the study was to investigate the source of the egg contamination and the risk for the eggs’ consumers. Eggs, muscles, feed and soil from the place where backyard waste burning had been carried out in the past and ash from a household stove tipped onto the paddock were analysed using the isotope dilution technique with high-resolution gas chromatography coupled with high-resolution mass spectrometry. The concentration in ash was low at 0.20 pg WHO-TEQ/g and the congener profile did not indicate the source of contamination. The dioxin content in soil from the backyard waste-burning site was 2.53 pg WHO-TEQ/g dry matter (d.m.) and the soil’s profile of PCDD/F congeners matched the profile of the contaminated eggs. By reason of the congener profile similarity, the investigation concluded, that the cause of the contamination was the backyard waste-burning site soil which the animals had access to. Frequent consumption of contaminated eggs from the analysed farm could pose a health risk due to chronic exposure, especially for vulnerable consumers.

This paper reports polychlorinated dibenzo-p-dioxin (PCDD), polychlorinated dibenzofuran (PCDF), and polychlorinated biphenyl (PCB) concentrations in fish collected from Polish and Vietnamese farms and the related risk for consumers. Altogether, 160 samples were analysed using an isotope dilution technique with high-resolution gas chromatography coupled with high-resolution mass spectrometry (HRGC-HRMS). To characterise the potential health risk associated with PCDD/F and dioxin-like polychlorinated biphenyl (DL-PCB) intake, doses ingested in two 100 g portions of fish by adults and children were calculated and expressed as the percentage of the tolerable weekly intake (TWI) newly established by the EFSA in November 2018 at 2 pg WHO-TEQ kg⁻¹ b.w. Generally, levels in fish muscles were low in relation to maximum limits (4), being in the range of 0.02–3.98 pg WHO-TEQ g⁻¹ wet weight (w.w.) for PCDD/F/DL-PCBs and 0.05–24.94 ng g⁻¹ w.w. for NDL-PCBs. The highest concentration was found in eel muscles. The least polluted were pangas and zanders and the levels were at the limits of quantification. Consumption of two portions of fish per week results in intakes of 9– 866% TWI by children and 4–286% TWI by adults. Frequent consumption of some species (for example eel and bream) can pose a health risk to vulnerable consumers and especially children and pregnant women.

The aim of this article was to evaluate the influence and effects of chosen bioaccumulative substances i.e. heavy metals, pesticides, and polychlorinated biphenyls (PCBs) on fish, as well as provide information on time trends and potential threat to human health. Chemical substances which pollute water may affect living organisms in two ways. First of all, large amounts of chemical substances may cause sudden death of a significant part of the population of farmed fish, without symptoms (i.e. during breakdown of factories or industrial sewage leaks). However, more frequently, chemical substances accumulate in tissues of living organisms affecting them chronically. Heavy metals, pesticides, and polychlorinated biphenyls are persistent substances with a long-lasting biodegradation process. In a water environment they usually accumulate in sediments, which makes them resistant to biodegradation processes induced by, e.g., the UV light. These substances enter the fish through direct consumption of contaminated water or by contact with skin and gills. Symptoms of intoxication with heavy metals, pesticides, and PCBs may vary and depend on the concentration and bioavailability of these substances, physicochemical parameters of water, and the fish itself.

OBJECTIVE To determine the optimal anatomic site and directional aim of a penetrating captive bolt (PCB) for euthanasia of goats. SAMPLE 8 skulls from horned and polled goat cadavers and 10 anesthetized horned and polled goats scheduled to be euthanized at the end of a teaching laboratory. PROCEDURES Sagittal sections of cadaver skulls from 8 horned and polled goats were used to determine the ideal anatomic site and aiming of a PCB to maximize damage to the midbrain region of the brainstem for euthanasia. Anatomic sites for ideal placement and directional aiming were confirmed by use of 10 anesthetized horned and polled goats. RESULTS Clinical observation and postmortem examination of the sagittal sections of skulls from the 10 anesthetized goats that were euthanized confirmed that perpendicular placement and firing of a PCB at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear, resulted in consistent disruption of the midbrain and thalamus in all goats. Immediate cessation of breathing, followed by a loss of heartbeat in all 10 of the anesthetized goats, confirmed that use of this site consistently resulted in effective euthanasia. CONCLUSIONS AND CLINICAL RELEVANCE Damage to the brainstem and key adjacent structures may be accomplished by firing a PCB perpendicular to the skull over the anatomic site identified at the intersection of 2 lines, each drawn from the lateral canthus of 1 eye to the middle of the base of the opposite ear.

Polychlorinated biphenyls (PCBs) are synthetic organic compounds with two benzene rings and well known environmental pollutants. This study examined the effect of persistent exposure to 2,3',4,4',5-pentachlorobiphenyl (PCB118) on the proinflammatory and proapoptotic factors in male rats. Male Sprague Dawley rats were administered weekly intraperitoneal injections of either PCB118 (20 mg/kg) dissolved in corn oil or corn oil alone. One week after 2 and 5 administrations, the rats were sacrificed by a pentobarbital injection. The effect of PCB118 on the expression of cyclooxygenase 2 (COX-2), cytosolic phospholipase A2 (cPLA2), peroxisome proliferator-activated receptor gamma, Bcl and Bcl-2-associated X protein (BAX) was investigated. The level of COX-2 and cPLA2 expression was higher in the PCB118-treated rats than the control. These results suggest that PCB118 has a proinflammatory effect in rats.

This study was performed to examine the effect of 2,3',4,4',5-pentachlorobiphenyl (PCB#118) on testis of male rats. PCB#118 (20 mg/kg/week) in corn oil was intraperitoneally injected to adult male rats for 2, 5, 8 weeks. The body and testicular weights were measured at 3, 6, 9 weeks of PCB treatment. The morphological changes in the rat testes were then analyzed by light microscopy (LM) and transmission electron microscopy (TEM). The results showed that PCB#118 caused significant change in the body weights and testicular weights. Moreover, the morphological studies that were conducted on the PCB-treated rats revealed that the number of spermatocytes and spermatids in their seminiferous tubules decreased than control group (LM). The nuclear membrane was damaged when PCB was administered to them for 9 weeks (TEM). These results suggest that the reproductive function of the adult male rats is sensitive to PCB#118, and that may affect the testicular morphology of adult male rats.