Christchurch has its dirtiest day: a pollution record

Press, 15 June 1977, Page 1

Christchurch has its dirtiest day: a pollution record

Pollution in Christchurch yesterday was the worst recorded in the citv since levels were first monitored in 1959.

Sulphur dioxide levels remained relatively low, but the figures for smoke 8.30 a.m. ’» °

and nitrous oxides have never before been as high, according to the Health Department’s pollution monitors.

Smoke peaked at 750 micrograms per cubic metre about 2 p.m., the highest yet recorded during the day, although it is often higher at night. The figure was 1320 on Monday night, for example. Nitrous oxides peaked at 1800 about 8.30 a.m.. It has reached this mark for seconds at a time in the past, but has never averaged as high as 1000 for a long period, which it did for the two hours between 8 a.m. and 10 a.m.

From 10 a.m. to 2 p.m. it fell slightly to 900, and then rose to average 1200 for the next half-hour. A 24-hour average of 200 is rated as high pollution. Levels began to fall in the afternoon as the wind grew to drive the pollution away. Dr J. McLeod, r.n expert on pollution and respirator’ problems, said that the levels yesterday would acutely aggravate the conditions of people with asthma, bronchial problems, and severe heart disease.

He said that at a rough estimate about 10,000 people in Christchurch came into this category. They should stay indoors. If they did go outdoors, he said, they should avoid doing anything strenuous at all costs. They should not do anything that

would force large quantities of the heavily polluted air through their lungs. Mr H. T. Thompson, a cardio-thoracic surgeon, said that the people in this category should’ undoubtedly stay at home when pollution was as bad as yesterday morning. The levels found yesterday would be likely to make their ailments worse for a little while, and if the same levels were experienced for a few weeks they would be made permanently worse. Pollution like yesterday’s damages and irritates the lining ’of the bronchial tubes and makes them become smaller. This reduces the amount of oxygen getting in and the amount of carbon dioxide getting out, which affects all the body tissues, and especially the heart and lungs.

Smoke levels have to be considered in conjunction with sulphur dioxide levels to gauge these effects. Nitrous oxides cause the same sort of symptoms, and at yesterday’s levels could damage sensitive plants. The long-term effects of such nitrous oxide levels would be significant, but the short-term effects are unknown, except that they contribute to the hazards of people with respiratory diseases. Mr D. F. Caygill, chairman of the Regional Planning Authority’s air-pollu-tion committee, said that

the high smoke levels were directly attributable to the domestic fire. He said there was no evidence that shortages of any forms of energy need occur, and said that electricity was at once the cheapest and most efficient source of heating. “The present situation is not one of energy shortage but of conservation, which is completely different, although the Government is not keen to trumpet the fact” Mr Caygill said. The most effective means of conservation was to use only efficient heating appliances for all fuels. Some 80 per cent of coal burnt in an open fire went straight up the chimney unburnt, whereas electrical efficiency was 100 per cent, he said.

People thought electrictiy was more expensive because they were aware of price rises. In fact, when the heating portion of the bill was extracted, it was much lower than the running or capital costs of using coal, gas. or oil. Yesterday’s levels were significant because they proved that pollution was not only a night problem in Christchurch. Mr Caygill said. The city figures consistently exceeded the World Health Organisation’s recommended levels.

“We have a .significant problem, although it cannot be compared to that of other cities, such as Tokyo, Los Angeles, or London.” Mr Caygill said.