**Author details**

**•** The isolated bacteria were Micrococcus sp., S. aureus, Streptococcus pyogenes, Bacillus sp.,

**•** The isolated fungi were *Cladosporium* sp., *Alternaria* sp., *Penicillium* sp., and *Aspergillus* sp. The microbiological quality of air in the investigated rooms in the Bucharest school as well as in the Giurgiu school changed significantly during the school day. The highest levels were found around 11:00 a.m. in classrooms with large numbers of persons inside. Most of the levels

measurement in the school in Bucharest and four measurements in the school in Giurgiu City. Also, the presence of *Streptococcus* beta hemolytic and coliform bacteria in classrooms air represents a threat to the health of children. This threat appears to be greater in the school in

The fungi levels identified in offices and archives were over the limit accepted in Romania.

In the case of the shop with only a ground floor and the supermarket, it is obvious that the size of the shop, the numbers of floors, and the numbers of departments in the shop can induce a high bacteriological contamination of air due to the high number of people visiting the shops. The air contamination in the supermarket was found to be higher at the ground floor and at the third and fourth floors. The high level of bacteriological contamination at the ground floor is probably due to the large number of visitors, while at the third and fourth floor it is probably due to the accumulation of bacteria coming from the first and second floors. In the shop with only a ground floor, the levels of air contamination in the evening were lower than in the morning. It is probable that this type of shop has better ventilation. High levels of staphylococci and the presence of *Streptococcus* in air can be dangerous for human health, and it is necessary

**a.** Biological contamination (bacteriological and fungal contamination) represents a constant

**b.** All results showed that the levels of bacteria in indoor air are higher than the allowed limit (2, 500 CFU/m3 air for bacteria at 37°—limits admitted in Romania for rooms in a house). In schools, the levels of bacteriological contamination of air must not exceed 1, 500 CFU/

**c.** Concerning the indoor air pollution with fungi, the results showed a high level of

**d.** Biological contamination of air in schools can represent a threat for children health. This

contamination exceeding the allowed limit in Romania of 550 CFU/m3

situation is obvious especially in schools outside Bucharest.

for bacteria at 37°. The presence of coliform bacteria and hemolytic bacteria are not

Isolated fungi species include *Cladosporium*, *A. flavus*, *A. niger*, and *Penicillium* sp.

, with the exceptions of one

for fungi in air.

identified in the study were under the limit of 1, 000 CFU/m3

and Neisseria sp.

510 Current Air Quality Issues

Giurgiu City.

**9. Conclusions**

m3

to have a very strong disinfection action.

From this study, several conclusions can be drawn:

allowed in the air inside education units).

element that was identified in all Romanian houses.

Anca Maria Moldoveanu1,2

Address all correspondence to: anca.moldoveanu@gmail.com

1 Carol Davila University of Medicine and Pharmacy, Bucharest, Romania

2 National Institute of Public Health, Bucharest, Romania
