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Marek Walczak and Michał Reichert

Abstract

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.

Open access

Katarzyna Walczak, Jerzy Olszewski and Marek Zmyślony

Abstract

The aim of the study was to determine the radon permeability coefficient of insulating building materials. Eleven insulating materials were tested. A research setup was developed and it was as follows: a tested material was tightly set on the receiver box’s hole and placed into the radon chamber. The measurements showed that for various insulating materials, radon permeability coefficient varies from 1.26 × 10−10 m2/s for film-like materials to 9.95 × 10−8 m2/s for roofing papers. According to our calculations of all insulating materials, the foil-type insulating materials to ensure the best protection against radon flow from the ground. Comparison of different types of building materials shows that the insulating building materials ensure better radiological protection than regular building constructions materials.

Open access

Małgorzata Juszkiewicz, Marek Walczak and Grzegorz Woźniakowski

Abstract

African swine fever (ASF), caused by African swine fever virus (ASFV), is currently one of the most important and serious diseases of pigs, mainly due to the enormous sanitary and socio-economic consequences. It leads to serious economic losses, not only because of the near 100% mortality rate, but also through the prohibitions of pork exports it triggers. Currently neither vaccines nor safe and effective chemotherapeutic agents are available against ASFV. The disease is controlled by culling infected pigs and maintaining high biosecurity standards, which principally relies on disinfection. Some countries have approved and/or authorised a list of biocides effective against this virus. This article is focused on the characteristics of chemical substances present in the most popular disinfectants of potential use against ASFV. Despite some of them being approved and tested, it seems necessary to perform tests directly on ASFV to ensure maximum effectiveness of the disinfectants in preventing the spread of ASF in the future.