Air and water are two very important factors for the survival of living things. In addition to a number of substances that allow the living organisms to breathe in the air, there are many particles of various sizes. These particles are composed of impurities and microorganisms. The microorganisms may be present in the air in free form or due to other substances.
Since air is ubiquitous, microbial contamination in the air easily reaches foodstuffs and workers in this area, thus posing health risks to consumers. Depending on the number and variety of these microorganisms, food spoilage increases and causes workers and consumers to experience food-borne discomfort. Therefore, it is important to keep the ambient air under control in terms of air microbiology, especially in the production, packaging and storage areas of the food sector.
Microbial contaminants in the air are living things such as bacteria, fungi, viruses and mites. The most common of these are fungi and bacteria. Yeasts and mold spores are particularly important in terms of air microbiology. They find a very comfortable living space, especially in humid environments. Humid environments can provide the pH and water activity necessary for their reproduction. In the meantime, bacterial spores can survive much longer and pose a health risk. Factors such as humidity of the environment, air flow, location and sections of the enterprise, area of activity, structural characteristics also affect the microbial load of the air.
Which microbiological analyzes are performed?
Food production, packaging and storage are ideal environments for the growth of fungi and bacteria, both in terms of temperature and humidity. Mold spores in the air affect the respiratory, nervous, immune, skin and blood systems of people and threaten many organs of the body for human health.
In this respect, the air of the areas where food is produced, packaged or stored should be kept under control, air intake from outside should be prevented in various ways and measures should be taken to ensure that fresh air is contained inside.
Within this framework, support should be sought from authorized testing and inspection laboratories to measure and reduce the microbial load of these areas. Possible risks should be identified with the measurement, test and analysis studies to be carried out in this direction and enterprises should take the necessary measures in this direction.
Several microbiological analyzes are performed in these laboratories to detect microbial contamination. The main analyzes performed in this context are as follows:
- Salmonella detection
- Listeria spp. and detection of listeria monocytogenes
- Total coliform bacteria count
- Enterobacteriaceae count
- Count of coagulase positive staphylococci
- Yeast and mold count
- Bacillus cereus count
- Eshericia coli count
- Total colony count
- Total colony count on food contact surfaces
There is no standard for mold density in ambient air. However, there is still a limit value accepted in laboratory studies. Accordingly, if 1 is a colony forming unit (cfu) between 150-1000 per cubic meter, it is considered to be harmful to human health.
Bioaerosol is all organic substances originating from biological air, including fungi, fungal spores, viruses, bacteria, pollen and their components. Bioaerosols originate from water, soil, animals and humans and can be ubiquitous. They are of different sizes. Their length varies between 0,3 and 100 millimicron. Viruses are smaller than 0,3 millimicron. Bacteria in the air are found on pollen, dust particles or spores. A bioaerosol in the air moves depending on the movement, shape, density of the air. They are usually invisible to the eye and may remain suspended in the air for a long time.
Reproduction of various microorganisms in indoor environment depends on temperature, nutrient availability, moisture content, oxygen and light amount. High humidity means that bacteria and fungi can easily reproduce. If the humidity in the environment is higher than 70 percent, the probability of mold growth increases.
The limit values accepted by the European Union for bioaerosols in indoor environments are 5000 cfu / m3 for bacteria and fungi.
Airborne microbial contamination causes serious economic losses for food businesses. Furthermore, if spoiled food is placed on the market, it is also a danger to human health. This situation is also risky for the health of the employees. Bioaerosols are also a very important issue in terms of air purification of hospitals and health institutions.
Some volatile compounds produced by molds are mixed directly into the air. These are called microbial volatile organic compounds (VOCs). Workers exposed to these compounds will have symptoms such as headache, dizziness, excessive fatigue, and nausea. Volatile organic compounds testing in the air sample is important for determining the type and intensity of mold contamination. Mold spores are microscopic organisms that live in open spaces as well as indoors. Some types can fly through the air with a very gentle breeze. Some types adhere to the surface and are effective only through contact. Sports can survive for years. Mold spores cause food degradation with enzymes and mycotoxins that they leave on foods.
Various microbiology test methods are available to measure the microbial density of air. Using the test equipment, the microbial load is measured in cfu / m3. Another method is the petri dish. Sometimes the counting method is also used under a microscope.
It is important to reduce the microbial density in the air and improve the quality of the air after these measurements. After this, the tests and measurements should be repeated again.
To summarize, periodical measurement of air quality and certain limit values of products and services that have a direct impact on human health, especially in food and pharmaceutical production facilities, health centers and residences, and in public areas such as hospitals, schools, kindergartens and public offices. measures should be taken to correct this situation, which threatens the health of people.
