Viruses are harmful biological agents, which can pose a risk for workers from different occupational groups. Information regarding the occurrence of viruses in occupational environment is still scarce, primarily due to analytical difficulty of their routine detection. Hygiene control applied for microbiological contamination are not effective in case of viruses, so the occupational risk for workers exposed to biological agents is still underestimated. Such a state of affairs fundamentally precludes a proper management of occupational safety. The effectiveness of virus detection in the environmental samples depends on methods of sampling and transport, and isolation and identification method.

The aim of this paper is an attempt to critically review the literature of the subject, determination of the best and the most effective method of virus detection and identification in the occupational environment, which could be used as a routine methodology for assessing the risk of viruses in various workplaces. The article discusses methods of viral samples collection, viral nucleic acid isolation, and, their detection based on vi­ral activity, molecular biology and immunoenzymatic assays.

Chloroethene (vinyl chloride) does not occur in nature. It is obtained exclusively in chemical synthesis. Under normal pressure and temperature conditions it is a gas. At 40–70 °C, it polymerizes to form polyvinyl chloride (PVC). It is a large-volume compound. Its annual global production exceeds 40 million t/year. About 98% of the total production is used to produce polyvinyl chloride (PVC) and copolymers. Chloroethene is also used in the synthesis of 1,1,1-trichloroethane (methyl chloroform).

Exposure to chloroethene occurs during its synthesis and polymerization and during plastification and processing of polymers and copolymers that take place in many industries, including plastics, footwear, rubber and pharmaceutical industries.

The main route of occupational exposure to chloroethene is inhalation. After cessation of exposure, the levels of chloroethene in blood fall sharply. Absorption of the compound through the respiratory tract is very rapid. Deposition of chloroethene in the body is limited due to its rapid metabolism and excretion. The largest amount of absorbed chloroethene accumulates in liver, where it undergoes biotransformation. The intermediate products of chloroethene metabolism, chloroethylene oxide and 2-chloroacetaldehyde, are the most reactive metabolites of this compound. The detoxification process takes place in the liver and relies on their conjugation with glutathione. As a result of further metabolism, final metabolites are formed which are excreted mainly with urine. In low concentrations, this is the main route of excretion. With the increase in the exposure concentration, the amount of chloroethene excreted by the lungs in the unchanged form increases.

Chloroethene has a very low acute toxicity, which has been found in both volunteer and animal studies. In volunteers as a result of acute inhalation exposure to high concentrations, neurological and psychiatric disorders only were observed. In animal studies, depressive effects on the central nervous system were observed, and histopathological examination revealed damage of liver, lung, kidney, heart and blood clotting disorders. In workers chronically exposed to high concentrations of chloroethene, a syndrome of vinyl chloride disease was found, which includes symptoms of Raynaud's syndrome (pain, numbness and tingling in the upper and lower limbs, cold feeling in the limbs), pseudoscleroderma, acroosteolysis, allergic dermatitis, peripheral polyneuropathy, neurological disorders, and hepatotoxic effects.

In animal studies chronically exposed by inhalation to chloroethene, the hepatotoxic effect of the compound is well documented. This effect has been found at a relatively low concentration of 26 mg/m³ (10 ppm). In addition, there is evidence that chloroethene affects the vascular and respiratory system. The effects of the compound on bones, kidneys, spleen, blood and animal skin are less documented.

Chloroethene has mutagenic/genotoxic properties, as observed in in vitro tests both with and without metabolic activation, and in in vivo tests. In in vitro tests on bacterial strains, the activity of chloroethene was much stronger with the participation of an exogenous metabolic system. Epidemiological studies in workers exposed to chloroethene showed an increased incidence of chromosomal aberrations, sister chromatid exchanges, micronuclei in lymphocytes and DNA damage in peripheral blood lymphocytes. The highest frequency of genotoxic effects was observed among operators of polymerization reactors subject to periodic exposure to very high concentrations of chloroethene.

Chloroetene has been classified as a carcinogen by the International Agency for Research on Cancer, IARC (Group 1) and the European Union (Category 1A). It was concluded that there was sufficient evidence of a carcinogenic effect of chloroethene in humans and sufficient evidence of carcinogenicity in experimental animals.

Carcinogenic effect of chloroethene has a genotoxic basis and results from the formation of reactive metabolites, mainly chloroethylene oxide and 2-chloroacetaldehyde, which in reaction with DNA act mutagenically on somatic cells, mainly endothelial cells and thus play a significant role in the etiology of angiosarcoma.

Epidemiological studies have demonstrated a significant causal link between exposure to chloroethene and the incidence of hepatic cancers: angiosarcoma of the liver (ASL) and hepatocellular carcinoma (HCC). Epidemiological studies have shown a correlation between the number of deaths from liver tumors and the duration and magnitude of exposure and the length of latency, which in the case of ASL ranges from 10 to >30 years. Carcinogenic effects of chloroethene on the lungs, brain, lymphatic and circulatory systems, skin and digestive system (cancers other than liver cancer) are less documented and ambiguous.

There are reports of the effect of chloroethene on the reproductive functions of women and men and the defects of their offspring. Existing data do not provide unambiguous evidence of teratogenicity and reproductive effects in the case of occupational exposure. In animal studies, chloroethene affected fertility and prenatal development of rats at high concentrations,

with a NOAEL of 2860 mg/m³ (1100 ppm).

Available data indicate that the target organ of chloroethene toxicity in chronic exposure in humans is the liver, and the critical effect of exposure is the development of liver tumors.

In epidemiological studies, the effect of occupational cumulative exposure dose (CED) on the development of angiosarcoma of the liver (ASL) is best documented. The SCOEL Scientific Committee using PBPK models estimated the risk of ASLs at 3 · 10^-4 as a result of 40 years of occupational exposure to chloroethene in a concentration of 2.6 mg/m³ (1 ppm).

Taking into account the above calculations, and the accepted level of occupational risk for carcinogens in the range from 10^-4 to 10^-3, the TWA of chloroethene at the level of 2.6 mg/m³ (1 ppm) has been proposed. This means an increase in the incidence of 3 liver cancers (ASL) per 10,000 people. There is no substantive basis to determine a short-term exposure limit (STEL) and acceptable concentration in biological material (DSB). It is proposed to label the compound as "Carc. 1A " – carcinogen category 1A.

The proposed value is in line with the value adopted by ACGIH and in Canada and the binding value proposed by SCOEL for this compound, and the binding value included in Directive of the European Parliament and of the Council (EU) 2017/2398 of 12 December 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work.

o-Toluidine is a substance produced in large amo­unts and used in rubber, dyeing and pharmaceutical industries and in the production of herbicide and other chemical compounds. The estimated number of people occupationally exposed to o-toluidine in EU is 5 500, half of them is employed in chemical industry in the production of chemical fibers and rubber products.

In the conditions of occupational exposure, o-toluidine is absorbed by skin and by inhalation. Regardless of route of exposure this compound is excreted in urine.

The effects of acute inhalation exposure to high con­centrations (> 25 mg/m³) of o-toluidine are irritation of upper respiratory tract, irritation of eyes and skin, which is manifested by face, eyes and pharynx burning, cough, shortness of breath, weakness, nausea, vomit, headache and dizziness, tinnitus, methemoglobinemia, hematuria and hemorrhagic cystitis.

In epidemiological studies, the mostly analyzed gro­up of substances was aromatic amines (including o‑toluidine). Available data mainly refer to exposure in dyeing and rubber industries. Described effects of chronic exposure are methemoglobinemia, hematuria and damage of bladder epithelium leading to malignant tumor of this organ.

Carcinogenicity of o-toluidine was confirmed in tests on experimental animals, including rats and mice. Oral exposure to o-toluidine results in bladder cancer, pri­marily in female rats, to a lesser extent in male rats. In female rats F344 exposed to o-toluidine with feed, increase of the incidence of cancer from the bladder transitional cells was observed. Furthermore, in mice and rats fibromas and fibrosarcomas in subcutaneous tissue, angiomas and angiosarcomas in abdominal ca­vity and bladder, mesotheliomas of various organs, an­giosarcomas in various organs, hepatocellular carcino­mas and adenomas were observed.

In experimental animals, o-toluidine exhibits moderate acute toxicity, LD50 values for intragastric administra­tion are within the range 670 – 2951 mg/kg bw. In acute toxicity studies, rats exposed by inhalation to o-tolu­idine had cyanosis, contractions and muscle tremor, difficulty in breathing, red-brown rhinorrhea, corneal opacification, body weight loss, body temperature de­crease, lethargy and extreme exhaustion. The effects of subchronic and chronic exposure of experimental ani­mals to o-toluidine described in the literature include changes in the spleen, hematopoietic system, kidneys and bladder.

Most of the mutagenicity tests in bacterial systems do not confirm mutagenicity of o-toluidine. A few works only described positive test result after metabolic ac­tivation. Both in vitro and in vivo studies confirmed induction of DNA damage by o-toluidine.

o-Toluidine has harmonized classification in the EU as a category 1B carcinogen with assigned phrase H350 – may cause cancer. SCOEL experts classified it to group A of carcinogens, which means carcinogens with genotoxic properties. In Germany, DFG has ranked o-toluidine into category 1 of carcinogens, so substan­ces that cause cancer in humans and substances that are believed to significantly affect the risk of cancer. IARC classified it into group 1, compounds with confirmed human carcinogenicity.

On the basis of a quantitative assessment of the risk of cancer as a result of occupational exposure, it has been estimated that at a 40-year exposure period to o-toluidi­ne at a concentration of 1 mg/m3, the additional risk of bladder cancer ranges from 2.4 – 3.1 · 10^-4 (depending on the estimation method).

The values of the determining exposure limits of o-toluidine applicable in the EU member states and in the world are 0.5 – 0.9 mg/m³; 4.5–8.8 mg/m³ and 22 mg/m³. In Poland, the applicable OEL value is 3 mg/m³. In SCOEL, no BOELV had been proposed, considering o-toluidine as a genotoxic carcinogen. Directive 2017/2398 of the European Parliament and of the Council (EU) of 12 December 2017 amending Directive 2004/37/EC on the protection of workers from the risks related to exposure to carcinogens or mutagens at work, a concentration of 0.5 mg/m³ was adopted (0.1 ppm) as a binding value for o-toluidine (based on socio-economic analysis, environmental risk assessment and risk of bladder cancer in professionally exposed workers).

It has been proposed to reduce the OEL value of o-toluidine to 0.5 mg/m3, which will affect a nearly tenfold reduction in the risk of bladder cancer wor­kers. In addition, according to CSI (Chief Sanitary Inspectorate) data in Poland, no exposure to o-toluidine in concentrations > 3 mg/m³ and > 1.5 mg/m³ (0.5 OEL values) have been found in years 2015–2016, while in conditions of exposure to concentrations from within the range of 0.3 – 1.5 mg/m³ (0.1 – 0.5 of the OEL value), a dozen or so people only worked.

There is no basis for determining the short-term exposure limit value (STEL). As a value of biologi­cal exposure index (BEI) of o-toluidine, it has been proposed to leave 2% level of the MetHb in the blo­od. The standard was labeled “skin” (the absorption of substances through the skin may be as important as in inhalation) and “Carc. 1B” (carcinogenic substance of category 1B).

Phenolphthalein at room temperature is present in a form of solid, odorless, white or yellowish crystals. It is commonly used in analytical laboratories as a pH indicator. It is also used to determine the depth of concrete carbonation or for metal surface preparation in galvanizing and powder painting processes. Exposure to phenolphthalein can cause skin irritation. In the European Union, phenolphthalein has been classified as carcinogenic category 1.B and mutagenic category 2. It is also suspected to have a negative effect on human fertility.

The aim of this study was to develop and validate a sensitive method for determining phenolphthalein concentrations in the workplace air in the range from 1/10 to 2 MAC values, in accordance with the requirements of Standard No. PN-EN 482.

The study was performed using a liquid chromatograph with spectrophotometric detection. All chromatographic analysis were performed with Supelcosil LC 18 150 × 3 mm analytical column, which was eluted with mixture of methanol, water and acetic acid.

The method is based on the collection of phenolphthalein on glass fiber filter, extraction with methanol, water and acetic acid mixture, and chromatographic determination of resulted solution with HPLC technique. The average extraction efficiency of phenolphthalein from filters was 99.9%. The method is linear (r = 0.9997) within the investigated working range 0.008–0.4 mg/ml (0.33–16.7 mg/m³ for a 240-L air sample). Calculated limit of detection (LOD) and limit of quantification (LOQ) were 0.33 μg/ml and 0.99 μg/ml, respectively.

The analytical method described in this paper enables determination of phenolphthalein in workplace air. The method is precise, accurate and it meets the criteria for procedures for measuring chemical agents listed in Standard No. PN-EN 482+A1:2016-01. The method can be used for assessing occupational exposure to phenolphthalein and associated risk to workers’ health. The developed method of determining phenolphthalein has been recorded as an analytical procedure (see appendix).

The metallurgical, mining and tanning industries are, among others, very important sources of chromium compounds emission to the environment. Moreover, chromium is widely used in the production of dyes, pigments, paints and wood preservatives. Welding processes are one of the sources of exposure to chromium compounds under occupational conditions. Long-term occupational exposure to Cr(VI) chromium compounds increases the risk of developing lung or nasal cancer.

The aim of the study was to develop a method for selective determination of Cr(VI) compounds in the workplace air with a combination of ion chromatography technique and post-column derivatisation.

The method is based on separating the inhalable fraction of chromium(VI) compounds on a filter using an I.O.M. type probe, extraction with 10 mL of 2% sodium hydroxide/3% sodium carbonate solution and further analysis with ionic chromatography with a post-column reaction of Cr(VI) with 1.5-diphenyl carbazide (DPC) and spectrophotometric determination of the formed Cr(VI)-DPC complex.

The measuring range for chromium (VI) compounds is 0.072–1.44 μg/mL. Precision, chromium recovery from filters, limit of detection and quantification were calculated. The overall uncertainty was 12.2%. The expanded uncertainty for Cr(VI) was 24.3%. The developed method enables the separation and quantification of Cr(VI) compounds in the presence of Cr(III) compounds in air samples (avoiding adverse reactions of one form of chromium to another) at a level of 0.0009 mg/m³ for Cr(VI) compounds converted into Cr at 720-L intake of air. The procedure for determining chromium(VI) compounds is included in the annex.