<s>[INST] The next text is a question of a member of the European parliament:"According to official sources, the discharge of gases in the city of Stara Zagora and the region began in 2004. Numerous studies have found that the city has been exposed to hydrogen chloride, hydrogen sulphide and nitrogen dioxide. Research has demonstrated the presence of heavy metals and chemicals in plants, animals and in the soil. An increase in the incidence of serious respiratory and pulmonary diseases has been registered in the city and its surroundings.  The various ministries and institutions contradict each other in their statements regarding the source of the discharges. As early as 2004 an ad hoc parliamentary committee of inquiry was set up, but its report was inconclusive.  Ministers from the Sax-Coburg Gotha cabinet pointed to the Maritsa Iztok energy complex as the culprit. Residents of the region, however, as well as representatives of political and non-governmental organisations, suggest that at the Zmeevo military base (which is in the immediate vicinity of Stara Zagora) conventional arms tests are carried out, as well as the unregulated disposal of fuels and ammunition, both of which result in the escape of gases.  The current government has not finalised its investigations either and the causes of the pollution remain unclear.  The subject of this gas pollution in Stara Zagora is of the utmost importance, as it affects the health and the future of a region with more than 500000 residents.  Can the Commission set up an independent expert committee whose task it would be to accurately establish the causes of the release of gases in Stara Zagora, with a view to finding a national solution for their elimination?"
Analyze carefully the text and assign it to the most relevant policy area among those listed below. Do not explain your answer and return only a number.
Policy area numbers: 1 = Macroeconomics
2 = Civil Rights, Minority Issues and Civil Liberties
3 = Health
4 = Agriculture and Fisheries
5 = Labour, employment and pensions
6 = Education
7 = Environment
8 = Energy
9 = Immigration
10 = Transportation
12 = Law and Crime
13 = Social welfare
14 = Regional and Urban issues and Planning
15 = Banking, finance and domestic commerce issues
16 = Defence
17 = Space, science, technology, and communications issues
18 = Foreign trade
19 = International affairs and foreign aid
20 = Governance and government
21 = Public Lands, Water Management and Territorial Issues
23 = Culture and media
[/INST]. Answer = [7]. </s>
According to official sources, the discharge of gases in the city of Stara Zagora and the region began in 2004. Numerous studies have found that the city has been exposed to hydrogen chloride, hydrogen sulphide and nitrogen dioxide. Research has demonstrated the presence of heavy metals and chemicals in plants, animals and in the soil. An increase in the incidence of serious respiratory and pulmonary diseases has been registered in the city and its surroundings.  The various ministries and institutions contradict each other in their statements regarding the source of the discharges. As early as 2004 an ad hoc parliamentary committee of inquiry was set up, but its report was inconclusive.  Ministers from the Sax-Coburg Gotha cabinet pointed to the Maritsa Iztok energy complex as the culprit. Residents of the region, however, as well as representatives of political and non-governmental organisations, suggest that at the Zmeevo military base (which is in the immediate vicinity of Stara Zagora) conventional arms tests are carried out, as well as the unregulated disposal of fuels and ammunition, both of which result in the escape of gases.  The current government has not finalised its investigations either and the causes of the pollution remain unclear.  The subject of this gas pollution in Stara Zagora is of the utmost importance, as it affects the health and the future of a region with more than 500000 residents.  Can the Commission set up an independent expert committee whose task it would be to accurately establish the causes of the release of gases in Stara Zagora, with a view to finding a national solution for their elimination?