The halt of traffic on Israel's roads during the Jewish holy day of Yom Kippur led to a significant improvement in the quality of air across the country, the Environmental Protection Ministry said Tuesday. Ministry officials, who measured the quality of air before and during Yom Kippur, reported of a dramatic drop in the air pollution from the very beginning of the fast. The ministry's air quality department noted that as Yom Kippur began, there was a drastic drop in the concentrations of nitrogen oxides, which are a key indicator of air pollution from vehicles, particularly in transportation stations in the Tel Aviv metropolitan area and in Jerusalem. For the sake of comparison, the concentrations of nitrogen oxides on Yom Kippur in the Tel Aviv metropolitan area stood at 1-8 ppb (parts per billion) compared to concentrations of up to 125 ppb on an average day. In Jerusalem, which suffers from a lot of pollution, the concentrations of nitrogen oxides dropped from 283 ppb at 12:30 pm to 2-16 ppb during the holy day. Dr. Levana Biezuner, the scientific director of the air quality monitoring network at the Ministry of Environmental Protection, said this phenomenon was unique to the State of Israel and is made possible due to the halt in traffic during Yom Kippur. According to Dr. Biezuner, the most significant improvement is felt in the Tel Aviv metropolitan area and in Jerusalem – areas which are greatly affected by air pollution from vehicles. Ministry officials noted that the significant improvement felt in the quality of air during Yom Kippur demonstrates the great effect of vehicles as a major source of pollution in big cities.