OPEN FIRE POLLUTION: II WINTER SMOKE LEVELS CAI BE EXPENSIVE TO ECONOMY

Press, Volume CXV, Issue 33803, 27 March 1975, Page 18

OPEN FIRE POLLUTION: II WINTER SMOKE LEVELS CAI BE EXPENSIVE TO ECONOMY

In their final article on open fire pollution in Christchurch, Professor A. M. Kennedy and Dr N. -1. Peet, of the department of chemical engineering. University of Canterbury, refer to the effect of concentrations of smoke and sulphur dioxide on sufferers from respiratory diseases, and the cost of damage by air pollution.

The Department of Scientific and Industrial Research quoted in 1966 a figure of one to two million dollars as the estimated annual cost of damage by air pollution in Christchurch. Professor Kennedy and DiPeet say that more recent data from the United Kingdom indicate that the real cost may be up to four times greater.

Average winter levels of smoke, measured by the Department of Health, have decreased steadily in recent years (very much in line with the decline in domestic coal sales). Consideration of average values obscures the fact that the main danger to health arises from high-level peak concentrations, not the relatively low average concentrations.

For example, although the average daily smoke reading during June, 1974, at the central city (Reserve Bank) site was 80 micrograms a cubic metre, daily mean concentrations for the period June 5 to 9 were 143, 193, 295, 204 and 123 micrograms. Over this same period, values recorded at the Linwood monitoring station were, respectively, 136, 255, 479, 307 and 71 micrograms. These readings, taken over I a single five-day period, ! stand out unfavourably in i the light of the World Health Organisation’s recommendation (based on present knowledge of the adverse health effects of pollution) that a mean daily smoke level of 120 micrograms per cubic metre should not be exceeded on more than seven days a year. Variations throughout the day are even more pronounced. Thus, on June 7-9, the two-hourly average values from 4 p.m. to 2 a.m. were 259, 688, 828, 388 and 147 micrograms a cubic metre. These levels are extremely high and, on the best available overseas evidence, would adversely affect human health. In contrast to smoke levels, measured concentrations of sulphur dioxide in Christchurch are seen to be less significant when viewed against the World Health Organisation’s, recommended standard of 200 micrograms a cubic metre (to be exceeded on not more than seven days in a year). Thus sulphur dioxide levels during the June 5 to 9. 1974, episode were 71, 103, 161, 78 and 46 micrograms for the central city site. However, it is important to note that the principal adverse effects of smoke and sulphur dioxide occur when they are present together in the atmosphere, and low sulphur dioxide readings should not be viewed in isolation. From evidence in the W.H.O. report and elsewhere, the concentrations of smoke and sulphur dioxide quoted above will almost certainly aggravate asthma, bronchitis, and other preexisting respiratory and cardiac diseases, and will considerably increase the severity of infectious diseases of the respiratory system.

Cost of damage

The 1966 D.S.I.R. report quoted a figure of ■ one to two million dollars as the estimated annual cost of damage by air pollution in Christchurch. It was based on direct costs of laundry and domestic cleaning, the cleaning, painting and repair of buildings, corrosion and protection of metals, and so forth, as well as indirect costs associated with reduced human efficiency due to illness. More recent data from the United Kingdom indicate that the real cost may be up to four times greater than the earlier est ; - mate in terms only of losses that can be given a monetary value. Much of the recent debate concerning the banning of the open fire has centred on the undesirable consequences this would have for the New Zealand electricity generating system at large. In fact, of the total useful energy supplied to Christchurch households in 1973. only 4.5 per cent came from coal, an amount equivalent to only one-quarter of one per cent of the country’s electrical generation in that year. However, since most of the domestic coal is used for peak evenings, the peak electrical demand to replace

I Quite obviously, cases of I financial hardship will be !encountered during the five Ito 10-year phasing-out | period for existing open

| this would be dis-1 I proportionately high and! other forms of energy sub-, jstitution (and conservation)! may have to be considered, ( Low efficiency | Because of its low thermal j efficiency, the open fire is 'the most expensive of the! Icommon means of home I heating, quite apart from the I pollution it causes when| operated with any fuel other! I than coke (the only smoke-! ! less solid fuel obtainable in; l !Christchurch or any other; ! part of the country). ; Relatively non-polluting,! downdraught coal-burning; space heaters are now obrai-li able and the Clean Air Council will amost certainly 11 grant them the status of “an approved means of heating” ! for clean air zones. They are L quite a lot more expensive! to purchase and install then ! the equivalent gas or elec- i trical heaters, but less ex-h pensive to run. Oil can be! burnt at high efficiency and,(despite its relatively high!; (price, offers a form of heating that is only slightly!' (more expensive to run than!; electricity or gas and is still i cheaper than the open fire. The cost of putting an open fire into a new house i is not much less than the cost of most alternative • forms of heating. This has i not escaped the vast major- 1 ity of new home-builders in recent years. They have ; shown themselves quite will- ] ing to defy the maxim that 1 “any house without a fire in < the winter time is not really i a home” in order to install a i costly (in the long-term) < more efficient and less i form of heating. Replacement costs for 1 existing houses are more of a problem — although a;< Christchurch-wide survey well conducted in August, 1972, I showed that only 6 per cent < of houses were entirely 1 dependent on solid fuel for > home heating, while 88 per < cent used electricity for i complete or supplementary < heating. Therefore the prob- j lem may not be such a uni- t versal one as seems com- i monly to be assumed. i

; fires. Financial assistance (will be needed to enable some householders to make | the change from their ; present open fire to a nonpolluting form of heating A decision from the Governj ment on this question has j been anxiously awaited by (the Clean Air Council for many months. ( We have indicated that ; domestic coal-burning on ! open fires, and the low-level ! smoke pollution thereby proIduced, have diminished since the peak levels recorded at (the time of the Regional 1 Planning Authority survey. It is debatable whether this decline will continue naturI ally, especially in the coni text of possible electricity ! shortages and increased oil prices. i Certainly, the Clean Air , Council believes that imple- , mentation of the clean air | zoning provisions of the Clean Air Act, 1972, will be (needed to ensure the demise of the open fire and that, without such action, the people of Christchurch will continue to be exposed to levels of smoke pollution well beyond the limits recommended by the World Health Organisation. This is not to ignore the significance of motor vehicle pollution, as a reading of the council’s 1974 report quite clearly shows Nor is it to overlook the fact that other practices, such as cigarette smoking, may be more injurious to the individual if not the public at large. In the final analysis, the (decision whether or not to I create clean air zones .is basically up to the citizens of Christchurch, acting through their elected representatives on the local councils. How’ever, the decision must be made on the basis of known facts and logical judgments, not the emotional and often irresponsible opinions that have been aired in recent weeks.