Differences over air pollution readings

Press, Volume CXIII, Issue 33413, 20 December 1973, Page 16

Differences over air pollution readings

The air pollution committee of the Regional Planning Authority says it is dissatisfied with the Health Department’s air pollution monitoring system in Christchurch.

Mr D. F. Caygill, the committee’s chairman, said in a statement yesterday that the standards selected for measurements last winter have given a wrong impression of the amount of pollution. The committeee welcomed an undertaking by the Clean Air Council to have the procedures and standards of reference for daily air pollution figures reviewed before a monitoring scheme was adopted for use next year. "Most of the metropolitan local authorities have now signified approval of the committee’s earning out an air pollution monitoring pro-

gramme early next winter,’’ (Mr Caygill said. This would provide data to -indicate pollution trends in different sections of the city, and of the degree to which the Clean Air Act was succeeding. The Health Department’s earlier measureemnts have been very restricted and it was expected that the local authorities’ new programme would give far more useful and reliable information, Mr Caygill said. COMPUTER FIGURES Mr D. R. Pullen, the department’s air pollution monitorling supervisor, did not comment yesterday on Mr Caygill’s assertions. He said, however, that a detailed computer analysis of last winter’s readings would

be ready at the end of January. This would relate the readings to those of previous years so that an over-all picture of Christchurch pollution could be obtained.

It is known that antipollution organisations ip Christchurch were partly responsible for the publication of the winter’s air pollution figures, by urging the Minister of Health to have the readings given regularly to the news media.

They expected Christchurch’s normal winter pollution readings to cause a furore, especially when the readings were compared with World Health Organisation recommended levels. In previous winters, readings have been well in excess of the levels—up to 1000 micrograms for smoke on some days. A minimum level is between 50 and 80 micrograms.

But Christchurch had an abnormally clean winter this year. Winds blew much of the pollution away and newspaper readers and television viewers wondereo what the pollution “thing" was all about when “low,” and only very occasionally, “high” readings were supplied by the department. The department is believed to be upset about Mr Caygill’s assertions of unreliable readings and wrong impressions.

It considers that its monitoring stations were carefully chosen to give a realistic picture of the pollution problem in Christchurch. The station on the third floor of the Reserve Bank building was criticised by clean-air campaigners because they thought it too high above the city pavements where people breathed. However, other station sites included a large garden near Bealey Avenue, a street-level site in Manchester Street, and a street in Avonhead.