Modern industrial facilities emit a wide variety of harmful pollutants into the atmosphere. The concentrations of hazardous substances are monitored using special environmental standards. Using maximum permissible concentrations (MPCs) allows us to analyze the quality of not only air but also water and soil. To accurately assess environmental conditions, maximum permissible concentrations (MPCs) are calculated for each element or substance.
Explanation of the concept of MPC
The maximum permissible concentration (MPC) of chemical elements and their compounds in the environment is established by law. This standard defines the permissible concentration of substances at which no pathological changes in the body or disease are observed.
The definition of MAC values is arbitrary and subject to periodic revision. MAC values may also vary in individual countries, as they are based on the maximum exposure limit for a particular zone, at which exposure is considered safe. MAC values are measured in different units, depending on the type of object containing the substance.
Alternatively, milligrams per cubic decimeter are used to analyze the condition of water bodies, milligrams per cubic meter for air, and milligrams per kilogram for soil.
Existing classification
Various MAC classifications are used to assess environmental pollution. The following standards for harmful substance content are most commonly analyzed:
- The maximum permissible concentration (MPC) of a working area is the standard for pollutants that do not cause illness or adverse health effects, based on an 8-hour workday and a 40-hour workweek over the entire working period. MPC values for ambient air and for air in industrial premises are considered separately.
- The average daily parameter determines the concentration of pollutants in the air of populated areas that do not cause negative indirect or direct effects on the human body. MAC analysis is conducted to prevent mutagenic, carcinogenic, and general toxic effects;
- The maximum single-time MPC assumes short-term exposure to the human body (less than 20 minutes). This standard is established to prevent reflex reactions (changes in olfactory function, brain activity, and eye sensitivity to light).
When interpreting the indicators, it is important to remember that the standards will differ for individual harmful substances.
Methods for determining the MAC value
To control the content of hazardous elements in the environment, various methods are used, depending on the objectives:
- Conducting laboratory tests requires a significant amount of time, but ensures accurate analysis. Several types of work area testing are used (infrared and ultraviolet spectroscopy, gas chromatography);
- The express method allows you to quickly determine the concentration of harmful substances in the atmosphere. Simply pump air through an indicator tube containing a reagent. Of course, this method is not accurate;
- The indicator method is appropriate to use for the rapid detection of toxic substances in the air, even in small quantities.
Monitoring of the content of certain substances in the working area (for example, ethylbenzene) is carried out using special methods approved by the Ministry of Health.
Safety precautions
To ensure normal working conditions (safe for health), it is important to continuously assess the air quality in the work area. Monitoring of maximum permissible concentrations of harmful substances is carried out at the most typical workstations. Sample collection takes 15-20 minutes. Measurement results are recorded in a special log. The frequency of monitoring is determined by several factors (the hazard class of the harmful substance, the length of time personnel spend in the workplace, the nature of the technological process, and others).
To minimize exposure to harmful impurities, workers use personal protective equipment. Prolonged exposure to areas with elevated concentrations of hazardous substances can lead to serious health problems. Therefore, a properly designed and installed ventilation system is key to maintaining health. Production facilities also install systems to capture and dispose of harmful impurities.
To ensure safe living conditions for humans and preserve the environment, it is important to monitor the levels of harmful substances in water, air, and soil. To objectively assess the maximum permissible concentrations of hazardous elements, it is recommended to use various data collection methods.
