The purpose of the Society is to preserve clean air in Australia and New Zealand. Schroder was introduced to the guests by Mr Hans Hartmann of the Gas and Fuel Corporation of Victoria. Professor Kirov and the other members of the organizing committee are to be congratulated on a job well done.
The proportioning of the raw materials and grinding them, in ball mills, to a certain size. One of the problems in the preparation of oven feed is to proportion the raw materials to achieve the desired accuracy of chemical composition. In a wet process, the performance of the electrostatic precipitator is greatly enhanced by the water vapor present with the exhaust gases.
Figure 2 shows that air coming from the mill rises to the separator. In open circuit, the material coming out of the discharge end of the mill is a product. Other parts of the grinding circuit where water vapor is likely to be present are also discharged to the dust trap.
At Berrima, this is eliminated under the new bulk silos by blowing air from the trucks into the dust collection system at the top of the silos.
M C PHERSONS LTD
Some Arguments Suggesting a Causative Relationship Between Air Pollutants
Since cigarette Table 2 compares consumption between urban and rural areas in the two areas, the incidence and mortality rates for different groups are roughly parallel. The Sydney: Rest of New South Wales mortality rate for men (1.93:1) was similar to comparable studies in the United States, but the equivalent ratio for women was much higher in Sydney (1.93:1) than in the United States States. In the United States,4 South Africa,21 New Zealand22 and Australia2 it has been shown that immigrants from Great Britain have a higher mortality rate from lung cancer than native men.
They produced sarcomas in mice by subcutaneous injection of a benzene extract obtained from the atmospheric dust of eight cities in the United States. Extracts of atmospheric soot samples were also used to produce sarcomas in mice by Kotin et al26. In other work, Kotin and Falk35 produced pulmonary tumors in mice by exposing them to ozonated gasoline.
Since the carcinogenic polynuclear hydrocarbons reported in atmospheric samples were also identified in many soot and tar samples, the observed biological activity of the crude extracts could be largely attributed to the carcinogenic potency of the polycyclic hydrocarbons present. It should be emphasized that other carcinogenic organic substances, such as epoxides and peroxy compounds and some phenols and quinones, may also be present in very small amounts associated with the fraction of atmospheric soot particles.36 Epoxides, hydroperoxides and peroxides are of particular interest, as it is possible that these could be formed by autoxidation or photochemical oxidation of definitions in air. However, as pointed out by van Duuren36, the study of the carcinogenicity of these compounds is of interest mainly because it could provide information on the early stages of the metabolism of aromatic carcinogens.
The small number tested in different animal species has produced results that make it clear that there are pronounced differences in the response of different species to the action of carcinogenic compounds in the case of the mouse. In addition, there is evidence that some compounds that were negative in mice may cause tumors in other species. Moreover, it is now abundantly clear in the mouse itself that different tissues respond differently to the same substance.
Media of a complex nature, such as lard or sesame oil, may contain anticarcinogens or cocarcinogens and even chemically homogeneous carriers may produce different results when the same dose of the same carcinogen is administered to the same tissue of the mouse. Because some compounds that were negative during the first year gave rise to tumors during the second year of the experiment, it is possible that a compound that produced negative results in the mouse could produce positive results if its lifespan were longer. Conclusions about the potency of a particular compound must therefore be interpreted in light of the data on which they are based.
AIR POLLUTION PROJECTS
July Meeting of the New South Wales
Emissions from Large Municipal Incinerators and Control of Air Pollution
HOWARD COCK,
Consulting Chemist
Alderman Parkinson concluded his remarks by suggesting that the problem of disposal in Sydney can only be efficiently executed by the joint action of the various Councils. Basden, who noted that knowing the composition and characteristics of waste is desirable as it is a prerequisite for planning for its efficient disposal by methods such as sanitary landfill, composting or incineration. The paper also provided a number of tables summarizing existing data on waste composition, its values and calorific values, seasonal variations and projected trends, etc., for a number of cities around the world.
Modern refuse collection vehicles of the side, rear and rotary drum type used to compact the waste material were discussed, and this was followed by some comments on bulk handling of refuse, its removal from high-density housing, disposal by bag collection and the bulk - transfer of waste by road vehicles. It is believed that the application of these modern developments to local conditions may have the effect of assisting in the improvement of current practices in Australia. Watkins in the introduction of his paper, and particular emphasis was placed on the precautions that must be taken to protect the health and comfort of the community.
Judell said that the pollution of streams and coastal waters is a matter of increasing public concern, and that control of the pollution of streams and coastal waters has become one of the main problems facing modern civilization. The results of a number of tests listed in the paper were described and some important relevant aspects of the Clean Air Act were discussed. Professor Kirov stated that for several reasons, as detailed in his paper, the incineration of municipal waste by modern high-temperature techniques has become the preferred method of waste disposal in most of the major cities of the world.
The objectives of high temperature combustion were described, followed by considerations of waste as fuel and of the basic requirements for its efficient combustion. The introduction was illustrated with an excellent film depicting a particular type of modern incinerator and its operation in a number of major cities around the world. Basden stated in the introduction to this article that the subject was only a minor one and was included in the program of the Conference to complete the description of modern high-temperature combustion plants described by Professor Kirov in the previous article. so aptly illustrated in the films shown earlier that morning and the day before.
The purpose of this paper was to briefly outline the nature and operation of the most important instruments and control systems for this type of incinerator. The performance of various types of gas cleaning equipment was examined and it was concluded that for large municipal incinerators, fabric filters, wet gas scrubbers and electrostatic precipitators are capable of achieving the high collection efficiencies required to control within the requirements of the NSW Clean Air Act. Pottinger described four industrial situations in which incineration was used to destroy industrial odors.
A range of topics were discussed, covering the whole field of the conference and presenting points of view not raised during the previous discussions (which followed each one or two papers). At the close of the conference, Professor Fowler thanked the organizing committee and all others who had contributed to its success, and invited delegates who had any suggestions for a possible second waste disposal conference, which might be held in two or three years' time, to he sends them to the members of the organizing committee or the honor.
