Research Letter #9

WHERE THERE’S SMOKE ...

... THERE’S A HEALTH ISSUE

Most of the concern about the smoke from fires is about health effects. We hear heaps about the smoke from tobacco but much less about the health effects of other sources. In building fires the main smoke problems seem to be caused by: lack of visibility; carbon monoxide; and, arguably, toxic gases from the breakdown of synthetic materials (Terrill et al. 1978; Drysdale 1985). Particulates in tobacco smoke may be highly toxic too (U.S. Surgeon General 1979). What about smoke from natural fuels?

Recently, Schwela (1998), of the World Health Organization (WHO), wrote about the health effects of smoke from natural fuels. The following points are from his article.

By way of contrast the values of PM-10 for Canberra in 1997 averaged about 20 units (ACT Government Analytical Laboratory). Note that this is about half the minimum of the range of values recorded for urban areas by Schwela (1998), above. In the ACT, measurements are made at Civic, Woden and Gowrie every 6 days. Maximum values in Canberra in 1997 reached 56 units (Gowrie). Values for the ACT are published every 3 months.


Conclusions

Any raised level of particulate matter in the air can cause a health problem for someone, especially if they have a history of respiratory disease or are elderly. Setting a logical standard for air quality, therefore, is very difficult. Setting realistic standards in relation to fires could be based on background levels in the area and documented medical effects of any increased values associated with bushfire smoke. Thus a "standard" may be set at different levels in different places. An alternate approach is to set guidelines for the smoke management of prescribed fires in which the aim is to disperse the smoke away from urban areas.

Literature cited

ACT Government Analytical Laboratory. ACT Air and Recreational Water Quality Data (published every 6 months).

Drysdale, D. (1985). An Introduction to Fire Dynamics. Wiley, Chichester.

Schwela, D. (1998). Forest fires and their public health impacts: global aspects. In: D.X. Viegas (ed.) Third International Conference on Forest Fire Research and 14th Conference on Fire and Forest Meteorology Proceedings I, 23-37.

Terrill, J.B., Montgomery, R.R. and Reinhardt (1978). Toxic gases from fires. Science 200 (4348), 1343-1347.

U.S. Surgeon General (1979). Smoking and Health. U.S. Department of Health, Education and Welfare Publication No. 79-50066.

Malcolm Gill
18 February 1999