Air pollution has become a pressing concern as the number of cars has increased to over 300,000 in the capital Tirana. These are mostly 1990s and early 2000s diesel cars, while it is widely believed that the fuel used in Albania contains larger amounts of sulfur and lead than in the European Union. Albania is probably one of the few countries in Europe where vehicles imported from the United States, and from left hand traffic jurisdictions (for example the United Kingdom) can be found on the streets without any modifications brought from expats living abroad.