‘It’s possible that changes in climate conditions contributed to the drop,’ Environment Ministry allows
Zafrir Rinat | Mar. 23, 2020 | 12:32 AM

The concentration of a key air pollutant has fallen by 30 percent over the past few weeks, most likely “thanks” to the coronavirus.

The pollutant in question, nitrogen dioxide, is mainly emitted by cars. Because of the severe restrictions on movement imposed to slow the spread of the coronavirus, traffic has dropped, and that has presumably caused the lower air pollution, the Environmental Protection Ministry said.

Nevertheless, it added, more time is necessary to be certain that there’s a causal connection.

The ministry compared air quality measurements taken over the past week to the average of the past few months. It found that concentrations of nitrogen dioxide had fallen by almost a third, from an average of 35.5 micrograms per cubic meter between January 1 and March 11 to just 25.0 micrograms per cubic meter between March 12 and March 16.

“We can’t say unequivocally at this stage that the reason for the drop in concentrations of nitrogen dioxide over the past week was due solely to a reduction in air polluting emissions from transportation,” the ministry said in a statement. “It’s possible that changes in climate conditions contributed to the drop.

“Nevertheless, the reduction in concentrations of nitrogen dioxide is consistent, clear, sharp and significant, and it occurred at all the monitoring stations that were checked,” it added.

Climate conditions could have contributed to the decline by affecting the speed at which this pollutant spreads through the air. The monitoring stations where the data was tested were located in the greater Tel Aviv area, Haifa and Jerusalem.

The ministry also measured emissions of fine particulate matter (PM 2.5), an air pollutant caused mainly by human activity such as transportation and industry, but also by the desert conditions in the Middle East and North Africa region.

In contrast to the decline in nitrogen dioxide, concentrations of PM 2.5 actually rose last week, to 20.0 micrograms per cubic meter, compared to an average of just 13.6 micrograms per cubic meter during the previous two months. But that increase was most likely due primarily to dust blowing in from the east and south, especially on the night between March 12 and 13, the ministry said.