The coronavirus lockdown has seen air pollution levels drop significantly in Bath.

With all but essential journeys banned, air monitoring sites across Bath have noticed a significant dip in harmful gasses caused by fuel-burning vehicles.

Already in the first few weeks of lockdown we reported a 50% drop in air pollution levels along the Bath A4 roadside.

And it appears nitrogen dioxide (NO2) levels have remained low during lockdown.

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Research done previously by the BBC Shared Data Unit found levels of nitrogen dioxide (NO2) at the Bath A4 Roadside station averaged 24.6 micrograms per cubic metre between March 17 and 24.

That was down from an average of 45.5 micrograms per cubic metre between March 19 and 26 last year.

Yet Bath local Steve Cross has been looking at the levels of NO2 along the same road during lockdown for the following weeks, which shows the same trend.

He said: "The graphs speak for themselves and show how less traffic since early/mid March has reduced pollution."

Charts reveal how much air pollution has dropped in Bath

"Yesterday (Tues 26th May) was one of the highest days since shut-down at 48 µg/m3 average (the same figure as on Friday 15th May, Friday 3rd April and Wed 1st April). 

"The next highest level was recorded on Thursday March 26 at 73 µg/m3.

"The average weekly level has been 40 µg/m3 or below since the last week in March.

"Prior to that the lowest average weekly level this year was 51 µg/m3 and the highest was 213 µg/m3. 

"The 4 weekly average has dropped from a high of 120 µg/m3 for the first 4 weeks of the year to 30 µg/m3 for the latest 4 week period (ending on May 19)."

NO2 primarily gets in the air from the burning of fuel, usually as emissions from cars, trucks and buses and power plants.

The UK Air Quality Strategy (2000) sets an objective that the annual average NO2 should not exceed 40 micrograms per cubic metre across a year.

There is evidence that high levels of NO2 can inflame the airways in our lungs and, over a long period of time, affect how well our lungs work. This can cause problems such as wheezing, coughing, colds, flu and bronchitis.

Mr Cross said: "I just thought that these graphs might encourage people to consider how they travel."

Whats the latest on Bath's Clean Air Zone?

The clean air zone has been delayed due to the coronavirus outbreak.

Following lobbying from businesses who wanted to keep goods moving during the outbreak and advice from government, the start date of the clean air zone has been pushed back to January 2021 at the earliest.

Bath and North East Somerset Council was due to hear back in March if Government would cover the £18 million implementation cost - just as the coronavirus pandemic took hold. 

It had planned to activate Bath’s clean air zone on November 4, with charges for the worst polluting vehicles - except for private cars.