Timaru saw its 21st high pollution day on Tuesday – one more than the number of breaches recorded by the same time last year and the eighth consecutive time air quality standards were breached this month.
On Tuesday the 24 hour average PM10 concentration was 56 micrograms of suspended particulate per cubic metre of air.
PM10 refers to particulate matter in the air that is smaller than 10 micrometres in diameter. A reading over 50 micrograms indicates “high” pollution under the national environmental standard.
Since 2006, between 21 and 36 days of high pollution were recorded at the Anzac Square site by this date.
So far this year, the Timaru station has recorded the most high pollution days of all centres monitored by the regional council.
Kaiapoi has had seven high pollution days, Rangiora has had six, Christchurch has had five, and Ashburton has had two. The Geraldine and Washdyke stations recorded one breach this year. Waimate has not had a high air pollution night so far this year.
All but two of Timaru’s breaches this year happened in June and July.
ECan’s Canterbury Air Regional Plan, which will become operative later this year, ultimately aims for Timaru to have fewer than three high pollution nights per year.
Timaru’s PM10 readings this year:
July 26: 56mcgs (11C, -3C)
July 22: 51mcgs (12C, -4C)
July 12: 69mcgs (10C, -4C)
July 11: 57mcgs (8C, 4C)
July 4: 60mcgs (19C, 2C)
July 3: 88mcgs (16C, 0C)
July 2: 62mcgs (11C, -5C)
July 1: 58mcgs (9C, -4C)
June 29: 57mcgs (12C, -1C)
June 22: 67mcgs (15C, 4C)
June 21: 56mcgs (10C, 5C)
June 18: 58mcgs (11C, 0C)
June 17: 74mcgs (17C, -3C)
June 16: 55mcgs (14C, -2C)
June 9: 70mcgs (16C, -2C)
June 8: 70mcgs (10C, -5C)
June 7: 73mcgs (11C, -3C)
June 6: 59mcgs (13C, -2C)
June 4: 51mcgs (15C, -2C)
May 2: 51mcgs
March 10: 55mcgs
(Sources: Environment Canterbury, Metservice)
Source: Timaru’s 21st high air pollution day | Stuff.co.nz