Francis Murray

Indicators of air quality (AQ) in the largest cities of Asia show that although many of these cities are among the most polluted in the world, AQ in many cities has generally been improving over the past few years. To improve AQ further, Asian cities must respond to the combined pressures of rapid growth in urban population, transport, economic development, and energy consumption. Asia is expected to account for most of the growth in world economic activity to 2025. Asia currently has about one billion people living in urban areas, and this number is growing at an average of 4% per year. The major sources of air pollution in cities in Asia are vehicles, large stationary sources such as power stations and other major industries, small stationary sources such as domestic sources and small industries, and area sources such as open burning. Introduction Fine particulate matter (PM), or particles with diameter not more than 2.5 microns (PM2.5), clearly presents the greatest health risk for air pollutants in ambient air—estimated to cause 520,000 premature deaths and more than 4 million years of lives lost annually in Asia (Cohen et al. 2005). The projected increases in ozone concentrations in East Asia may lead to substantial crop losses and damage to natural areas in the near future. Acid deposits and other pollutants also present health and environmental challenges in some countries. Despite these challenges, the strong economic growth of many Asian economies is providing the resources necessary to meet the costs of effective air quality management (AQM), fuel changes, emissions control technologies, industrial restructuring, and modernization of transport systems.

A study attempted to gain insight into the attitudes, perceptions and values of Perth inhabitants directed toward the environment. This document attempts to summarise the major findings drawn out in a series of more detailed reports generated at the conclusion of an initial study. Over 1300 responses were obtained to core questions investigating the significance of environmental management to these Western Australians. Ten specific areas received the attention of a proportionately smaller number of the public, and the literature, activities and policies of the relevant authorities were critically reviewed. These areas were the natural environment, air pollution, land degradation, toxic waste, water, urban waste, transport, energy, urban expansion, and economic incentives for guiding industry. The environment was perceived to be worsening in Perth, in Australia, and world-wide, and to exceed unemployment and economic issues as a problem in the near future. Land degradation is considered the most important environmental issue by Western Australians, although closely followed by pollution in an unspecified form while the more specific terms, air pollution and water pollution, are also considered important. Other environmental issues include our forests, ozone, urban waste, and the natural environment. A service gap model is advanced as an appropriate conceptual structure to examine the stewardship role that the government and its authorities have with respect to various areas of the environment. Education and information issues appear to be the major limitations in closing the service gap. One clear exception to this is the political motivation of the proposed coal-fired base load power station where the public sentiment away from the coal option is well founded in public understanding of the issue and well known to the government. This study confirmed this sentiment. The community acceptance of and involvement in major government programs associated with the issue of land degradation appears to be a case of effective focussing of community attention, with closure of a service gap. Although there is no clear understanding of more technical or 'invisible' concepts such as groundwater, there appears to be a strong intuitive feel for returning land to a forested state as a repairing process. The community often has only limited understanding of environmental issues. As a result, close but distinct issues, for example air pollution and toxic waste, can map together in respondents perceptions. In this situation, the individual tends to respond with a common level of concern be it high or low on both.

Natural vegetation in Europe and North America has been damaged by emissions of nitrogen oxides, but there are no published studies of effects of nitrogen oxides on Australian native vegetation. To determine the potential for emissions of nitrogen oxides from gas-fired power stations to affect Australian native vegetation, eight economically or ecologically important tree species were exposed to nitrogen oxides at various concentrations and frequencies of exposure. The experiments were conducted in open-top chambers under field climatic conditions, and under realistic exposure conditions. The results showed that although there were some species differences, concentrations of up to 200 nL L-1 for 2 hour/day, 3 days/week, stimulated height and weight by about 10-20%. However, a decrease in height and weight of up to 15% resulted from exposure to 100-500 nL L-1 for 2 hour/day, days/week, depending on the species. There was no visible injury. Changes in the frequency of exposure had little effect on plant response, but there were interactions with sulphur dioxide, cold and possibly drought, which can accentuate the effects of nitrogen oxides. The symptoms of nitrogen dioxide injury to leaves of Australian native plants have not been previously described, but are described in this report. They are unlikely to be found in the field as they only occur at very high concentrations, such as would only be found around the sites of large accidental releases.

Dose-response relations for the effects of S02 and NOx (NO and N02) on Australian vegetation were developed using open-top chamber fumigation. This information was used, in conjunction with review of the literature, to formulate secondary ambient air quality criteria for the protection of human welfare in Australia. A simple linear regression of S02 concentration versus response best described the effects of long term, frequent exposures to S02 on the growth or yield of Australian vegetation. This regression predicted zero yield or growth loss at 25 nLL -1 S02 as a 4-h average. Exposure length and frequency were of little importance in determination of the dose-response relationship. Leguminous species and Eucalyptus species showed a no-threshold response due to simultaneous exposure to S02 and NOx. Both NO and N02 were phytotoxic. To protect human welfare in Australia it is recommended that a one hour arithmetic mean value of 200 nLL -1 S02 not be exceeded, a four hour arithmetic mean value of 25 nLL-1 S02 not be exceeded more than once per week and that the sum of the NO and N02 concentrations be no higher than 25 nLL-1 as a four hour arithmetic mean in the presence of the same levels of S02.