Ambient air quality in urban areas

Thematic area - Air

Name of Indicator - Ambient air quality in urban areas

DPSIR - S = states

Indicator type - A = descriptive indicator

Definition of the indicator The indicator shows the annual average concentration of NO2 and SO2 and numbers of the days with exceed of NO2 and SO2 limit value during a year in urban area (3 biggest cities).

Units - µg/m3

Policy relevance of the indicator Legal framework includes: Law #1515 from 16.06.1993 on environment protection, Law #1422 from 17.12.1997 on air protection, Law #1536 from 25.02.1998 on hydrometeorological activity.

Strategic framework includes: Environmental Strategy (Government Decision #301 from 24th April 2014), Association agreement between Republic of Moldova and European Union (Law #112 from 02.07.2014).

Targets Environmental strategy establishes as a target reduction of pollutants emissions into the atmosphere by 30% by 2023.

Key question What is the trend in the concentration of NO2 and SO2 in urban area?


In urban area, the main source of NO2 is the cars traffic, especially diesel cars. Also, the concentrations of NO2 are dependent on season and meteorological conditions.

According to monitoring data, in Chisinau, capital city, the annual average concentration of NO2 is the highest and has a stabile ascendant trend, the highest concentration of NO2 being registered in 2011 – 58,2 µg/m3 (see Figure #1). In Balti, starting with 2011, a descending trend is registered, for 2014 the annual average concentration of NO2 being 22,9 µg/m3. Tiraspol registers an ascendant trend.

Figure #2 shows the number of the days with exceeded of maximum allowable concentration (daily average). So, for Chisinau situation is alarming, where, in the period of 2010-2014, more than 200 days with exceeded of MAC (daily average) have been registered. In Balti, in the period 2010-2012 there were registered a growing trend, but starting with 2013 it goes down, last data showing a number of 39 days with exceeded of MAC (daily average). For Tiraspol, during the observed period, only 2013-2014 registered more than 50 days with exceeded of MAC, all other years registered less than 10 days with exceeded of MAC.

The main sources of SO2 are fixed sources (major thermal power plants, small and medium size boilers for coal combustion in urban environments). The main anthropogenic sources include coal and oil combustion. Also, SO2 emissions depend on season and meteorological conditions. So, during the heating period/winter emissions of SO2 will be higher that other period of the year.
Table #1 shows that the situation with the SO2 annual average concentration by cities is not as alarming as in case with NO2. Figure #3 shows a descendent trend of SO2 annual average concentration for all 3 cities, the highest annual average concentration being recorded in 2006 in Balti - 41 µg/m3.

Only in Balti were registered in 2005-2006 days with exceeded of MAC (daily average) of SO2. For Chisinau and Tiraspol no days with exceeded MAC have been registered (see Figure #4).

Key messages In the period 2005-2014 for NO2 was registered a negative trend, with a weak fluctuation, while for SO2 the trend is positive. There is not a continue monitoring, monitoring is sporadically (3 times per day).

Data coverage - 2005-2014

Data source - Ministry of Environment, State Hydrometeorological Service.

Methodology: Monitoring of the air quality in urban areas is performing using manual technical approach at the fixed monitoring stations (6 stations in Chisinau, 2 in Balti and 3 in Tiraspol). Samples are collected by approved programs 3 times during 24 hours (07.00, 13.00, 19.00). For estimation of air quality in the territory of Moldova, we use the Guidance “Руководство по контролю загрязнения атмосферы РД 52.04.186-89 б Москва 1991 г.”, approved in ’90ns by Ministry of Health. The target value was approved by Ministry of Health because is related only to human health, but do not contain the value related to vegetation, ecosystem and other aspect, stipulated in EU Directive 2008/50. To estimate the air pollution in the Republic of Moldova are in force the next approved norms: - Maximum allowable concentration (maximum momentary) - MACmm, which represents the approved concentration norms during short time - 20 minutes and is 85 µg/m3 (for NO2) and 500 µg/m3 (for SO2), - Maximum allowable concentration (daily average) – MACda, , which represents the approved concentration norms during 24 hours and represents 40 µg/m3 (for NO2) and 50 µg/m3 (for SO2). In the normative acts of Moldova there is not in force the principle of annual concentration. For annual concentration is used the same approved daily norms and represents 40 µg/m3 (for NO2) and 50 µg/m3 (for SO2).

Reporting obligations: Annual National Report Daily and monthly bulletins
Advertisement on high level of air pollution.

Recommendations: Adopting of the legislation approximated to EU Directive 2008/50 Improving of the monitoring system by continues monitoring in urban area (including traffic, industrial and background stations), as well as for rural areas monitoring and indicative approach of air pollution estimation is suitable to be used mobile laboratory.

Date și Resurse

Informație Adițională

Cîmp Valoare
Maintainer Violeta Balan
Date noi da
Frecvența de actualizare anual
Instituția sau direcția responsabilă State Hydrometeorological Service