Coronaviruses are causative agent of many human and animal diseases. Since the first observations made by Beaudette and Hudson in 1933, describing “gasping disease” of chickens as a deadly respiratory disease, to modern
times dominated by information about the global COVID-19 pandemic, the importance of this group of pathogens for the health and safety of both the general and the working populations has been constantly growing.
Nowadays, the modern methods of molecular analysis and precise recognition of immunological reactions related to the activity of pathogens from this group allow not only a more complete understanding of the biology of coronaviruses, but also the pathogenesis of the diseases caused by them. This article describes the taxonomy of Coronaviridae family, characterizes the structure of the virion and methods of its multiplication, presents the methodology of clinical and environmental samples testing used to confirm the presence of coronaviruses, and describes the pathogenicity of this group of microorganisms along with a brief description of the largest epidemics caused by SARS and MERS coronaviruses. A special emphasis in this paper is given to SARS-CoV-2 coronavirus, which is responsible for the currently observed global pandemic, familiarizing the potential readers with the health effects of infection caused by this virus, activities used in antiviral prophylaxis, works related to the development of vaccines and the risk caused by its presence in the most vulnerable sectors of the economy.

Acrylonitrile is a highly flammable, volatile, colorless or pale yellow transparent liquid with a pungent odor. It is chemically very reactive and undergoes spontaneous polymerization. It is mainly used in the production of artificial fibers and plastics. Acrylonitrile is toxic (harmful to nervous system during chronic exposure), irritating and sensitizing. It is classified as a carcinogen category 1B based on animal studies (no evidence from epidemiological studies). The proposed TLV value for acrylonitrile was based on a quantitative risk assessment of CNS tumors in rats exposed by inhalation. The MAC value of 1 mg/m3 has been proposed, at which the additional risk of CNS cancer, assuming a 40-year period of occupation, is 2.2 · 10-4 – 6.2 · 10-4. To prevent peak concentrations, the STEL value of 3 mg/m3 has been proposed. The BLV value was proposed at 60 μg/l (2-cyanoethyl)valine (CEV) in blood collected after 3 months of exposure. Due to its carcinogenic, irritating, sensitizing effects and absorption of acrylonitrile through the skin, it should be labeled: Carc. 1B (carcinogenicity category 1B); A (sensitizing substance); I (irritant) and „skin” (skin absorption may be just as important as inhalation). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

C.I. Basic Red 9 is a dye used in histological preparations (the basic component of Schiff ’s reagent). This compound is ranked 25th in the Top 50 carcinogenic substances based on the number of workers exposed in Poland, and the data from the Central Register of Data on Exposure to Carcinogenic or Mutagenic Chemical Substances, Mixtures, Agents or Technological Processes shows that in 2018, 645 people (mainly employees of chemical and medical laboratories) were exposed to this compound. The main route of occupational exposure to this substance is the respiratory system.
The MAC value was based on the slope factor of the dose-response curve derived from a two-year carcinogenicity study on female mice (liver cancer). With the assumed risk of additional cancer of 10-4 and 40 years of occupational exposure to this compound by inhalation, it was proposed to set a value of 0.02 mg/m3 as the MAC for C.I. Basic Red 9. There is no basis for setting the STEL and BEI values. Due to the lack of data on the absorption of C.I. Basic Red 9 by dermal route, there is also no basis to label this substance with the symbol „skin”. However, because of the supposed carcinogenic effect on humans, it is proposed to label this substance with the symbol „Carc. 1B”. This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

Furan is used in the organic synthesis, in the production of varnishes, drugs, stabilizers, detergent substitutes, chemicals used in agriculture, temperature-resistant laminates, as a solvent for resins and in laboratories. Furan is classified as a carcinogen category 1B. In 2005-2017, the number of enterprises reporting furan to the Central register of occupational carcinogens or mutagens increased. In 2017, 9 enterprises reported 183 exposed people. So far, the MAC value for furan has not been established in Poland. Under occupational exposure conditions, furan is absorbed into the body by inhalation and dermal route. The hepatotoxic effect was assumed as a critical effect of exposure to furan. The OEL value at the level of 0.05 mg/m3 should also protect employees against carcinogenic effects. The additional risk of leukaemia in people exposed to furan at a concentration of 0.05 mg/m3 for 40 years is less than 10-3 and does not exceed the acceptable risk value in the working environment. The STEL value was proposed at the level of 0.1 mg/m3. The substance should be labeled: “Carc. 1B ”(carcinogenicity category 1B), “I” (irritant) and “Skin” (skin absorption can be as important as inhalation). This article discusses the problems of occupational safety and health, which are covered by health sciences and environmental engineering.

In Poland, until now it has not been necessary to determine the elemental carbon (EC) concentrations because Polish NDS values are set for a respirable fraction of diesel exhausts. No data on the level of EC concentrations in workplace air are available although the exposure to this hazardous factor concerns a large population of workers. The exposure concerns people working in underground mines and tunneling, firefighters, lorry and bus drivers, and car service station workers. The introduction of 0.05 mg/m3 BOELV value for diesel exhaust gases in working environment, measured as elemental carbon into the Directive 2019/130 of the European Parliament, requires the adjustment of the national legislation. The aim of the study was to develop a method for determining EC in workplace air at the level of 0.005 mg/m3. As a result, a method for determination EC in workplace air using a thermo-optical analyzer with a flame ionization detector was developed. The method consists in passing the tested air containing diesel exhaust gases through a quartz filter placed in a cassette and its analysis in an appropri­ate temperature program. An EC determination of 0.0027 mg/m3 was obtained. The total accuracy of the method was 5.6%, a relative total uncertainty was 11.2% and an expanded uncertainty was 22.4%. This article discusses problems of occupational safety and health, which are covered by health sciences and environmental engineering.