This article discusses harmonizing methods of measurements done in real conditions at workstations in the context of assessing exposure and occupational risk and selecting appropriate protection measures. It is important to harmonize the analysis, evaluation and reporting of data on exposure to nano-objects during measurements done in real conditions and to determine procedures for calibrating equipment for measuring emission of nano-objects in real time. In the context of the development of the database, it is also very important to store information on exposure to nano-objects and on risk assessment related to the presence of nano-objects in the working environment. This information can provide a basis for future development, calibration and validation of models or for building exposure scenarios.

1,2-Dichloroethane is a colorless liquid with an odor   typical  of   chlorinated   hydrocarbons.   1,2-Dichloroethane has been used as an inter-mediate in the manufacture of vinyl chloride; as a scavenger in leaded gasoline; and a solvent. It is also used in paint removers, wetting and penetrating agents, ore flotation, and soaps and scouring compounds. Animal studies have uniformly indicated liver and kidney injury from exposure to 1,2-dichloroethane. 1,2-Dichloroethane vapor is irritating to the eyes, nose, throat (mucous membranes) and skin. Human exposure to 1,2-dichloroethane results in CNS depression. This paper reports symptoms such as nausea, vomiting, and dizziness. 1,2-Dichloroethane has been classified by the International Agency for Research on Cancer as possibly carcinogenic to humans based on limited human epidemiological data and sufficient animal toxicity (IARC category 2b). Under the classification and labelling legislation in Europe it is classified as a carcinogen Cat. 1B. Information about the hazard from 1,2-dichloroethane is limited. Animal toxicity studies have shown a range of tumors induced from ingested 1,2-dichloroethane. However, human epidemiological evidence for occupational exposure causing cancer is weak. There is no basis to identify a suitable risk estimate. To determine MAC value for 1,2-dichloroethane systemic effect was adopted as a critical effect. The Expert Group for Chemical Agents has recommended TWA of 10 mg/m³ and STEL of 20 mg/m³. It has been also proposed to label the substance with “I” (irritant), Skin (substance can penetrate skin) and a carcinogen Cat. 1B.

Crystalline silica is the name of a group of minerals composed of silicon dioxide. Quartz and cristobalite are the most common forms of crystalline silica. Siliceous raw materials are widely applied in the production of building materials, glass, ceramics, silicon and ferrosilicon, organosilicon compounds, and many others. Workers in the following industries are exposed to crystalline silica: mining, fuel and energy, chemical, foundry, metallurgical, building materials, glass and construction.
In Poland, according to data of the Central Statistical Office, about 50,000 people are occupationally exposed to dust causing pulmonary fibrosis (mainly containing crystalline silica). The median concentrations of respirable dust containing 2 to 50% crystalline silica, calculated on the basis of the results of almost 50,000 measurements made in 2001-2005, was 0.56 mg/m³. Every year in Poland about 100new cases of silicosis are recorded. The harmful effects of quartz and cristobalite in humans results mostly from long (over 10 years) inhalation of dust, which can enter the area of gas exchange in the lungs, where it can be toxic to macrophages, pneumocytes and other cells, causing a chronic inflammation and nodular (focal) or diffused pulmonary fibrosis. The development of silicosis and, in many cases, of lung cancer follows those processes. Autoimmune diseases, chronic kidney disease, bacterial and fungal complications of silicosis and systemic silicosis are other health effects of exposure to crystalline silica. Epidemiological studies of people exposed to crystalline silica have shown that the risk of silicosis is proportional to the dose of dust. After 40 to 45 years of exposure it is to 2–3% up to the concentration level of 0.025 mg/m³ from a few to several percent when concentration is 0.05mg/m3, and from a few to about 70 percent at 0.1 mg/m³. On the basis of the results of epidemiological and experimental studies, the Working Group of the International Agency for Research on Cancer (IARC) has classified quartz and cristobalite as group 1 (carcinogens to humans). The relative risk of lung cancer in workers exposed to crystalline silica is usually estimated at 1.3–1.4. However, among workers with silicosis it is 1.7–2.4, and in those exposed without radiological changes in the lungs it is 1.0–1.2. Experimental studies in rats have confirmed carcinogenic effects of quartz and cristobalite. Studies with other animal species did not produce similar results. The test results of genotoxic effects of crystalline silica are also not clear. Taking into account the results of epidemiological studies on the fibrotic effect of quartz and cristobalite, and no NOAEL or LOAEL values, adopting occupational exposure limit value (OEL) for respirable crystalline silica of 0.1 mg/m³ has been proposed. Compliance with this OEL will greatly help to improve the working conditions of people exposed to crystalline silica.

This method describes how to measure acetic anhydride in workplace air using highperformance liquid chromatography (HPLC) with a diode array detector (DAD). Samples are collected onto glass fiber filters coated with 3,4-di-methoxybenzylamine and di-n-octyl phthalate. Samples are extracted with aqueous ammonium hydroxide and analysed with HPLC. The determination was carried out in the reversephase system (mobile phase: acetonitrile : phosphoric acid) using an Ultra C18 col-umn. The measurement range was 1.2 – 24 mg/m³ for a 7.5-L air sample. Limit of detection (LOD): 3.1 ng/ml; limit of quantification (LOQ): 9.3 ng/ml. The developed method of determining acetic anhydride has been recorded as an analytical procedure, which is available in the Appendix.

A method for the analysis of  4-chloro-3-methylphenol by gas chromatography with flame ionization detector (GC-FID) was described. This method is based on the adsorption of 4-chloro-3-methylphenol on a polypropylene filter, extraction with acetonitrile and chromatographic analysis of the obtained solution. The working range is 0,5 to 10 mg/m³ for a 90 l air sample. The developed method of determining 4-chloro-3-methylphenol has been recorded as an analytical procedure, which is available in the Appendix.