Timaru had its 18th high pollution day for 2016 on Monday, four more than the number of breaches recorded by the same time last year and the fifth time air quality standards were breached for the month.
The latest breach recorded by Environment Canterbury’s (ECan) monitoring station at Anzac Square showed the 24 hour average PM10 concentration for July 11 was 57 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.
Timaru had 14 high pollution days by July 11 last year. Since 2006, there have been anywhere between 15 and 32 days of high pollution by the same day.
So far this year, the Timaru station has recorded the most high pollution days of all centres monitored by the regional council.
Kaiapoi and Rangiora have had six high air pollution days, Christchurch has had five, and Ashburton has had two. The Geraldine and Washdyke stations recorded one breach 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 11: 57 micrograms of suspended particulate per cubic metre of air. The temperature high was 8 degrees Celsius, and low was minus 4 degrees Celsius.
July 4: 60 micrograms (19C, 2C)
July 3: 88 micrograms (16C, 0C)
July 2: 62 micrograms (11C, -5C)
July 1: 58 micrograms (9C, -4C)
June 29: 57 micrograms (12C, -1C)
June 22: 67 micrograms (15C, 4C)
June 21: 56 micrograms (10C, 5C)
June 18: 58 micrograms (11C, 0C)
June 17: 74 micrograms (17C, -3C)
June 16: 55 micrograms (14C, -2C)
June 9: 70 micrograms (16C, -2C)
June 8: 70 micrograms (10C, -5C)
June 7: 73 micrograms (11C, -3C)
June 6: 59 micrograms (13C, -2C)
June 4: 51 micrograms (15C, -2C)
May 2: 51 micrograms
March 10: 55 micrograms
(Sources: Environment Canterbury, Metservice)