The long vapour trail of health consequences of air pollution

In London on December 4^th 1952, the still, moist air of an anti-cyclone combined with the sulphur dioxide and smoke of coal used for domestic heating to create a five-day ‘smog’. It is estimated that this led to an extra four thousand deaths. Smogs are local events.

By contrast, the Earth Policy Institute in Washington DC calculated that at least 35,000 extra deaths occurred throughout Europe during the August 2003 European heatwave. Hurricane Katrina is said to be the costliest hurricane in American history.

The changing climate of Europe and the growing intensity of hurricanes are seen by many scientists as portents of serious fuel-fired climatic change that are global in their reach. They have in common their relationship to the way we generate and use energy.

Add to this toll the consequences of the April 1986 disaster at the Chernobyl nuclear power plant in the Ukraine and it is clear that energy generation and human health interlock. Rising global temperatures and ocean levels, with the risk of inundation of low lying, generally poor, cities, changing disease patterns and other disturbances mean that human health is at serious risk from our generation activities.

Emission control technology and restrictions on the use of coal for domestic heating have rendered the sulfurous and particulate London smogs a distant memory. But that is not all there is to coal, and the carbon dioxide released from our ever-growing use of fossil fuels is set to create health consequences that are no longer under the control of one country.

The advent of human-generated global warming

Global warming calls for a global approach that starts with the realities of global energy requirements, the development of alternative fuels that do not produce greenhouse gases and the support of technology that would control the carbon emissions from burning coal.

The Prime Minister’s growing but cautious interest in nuclear energy for Australia is welcome, especially if it can form part of a considered response to both the global energy and environmental health needs of this century.

If current projections are accurate we will need all energy sources — fossil fuel, solar, wind and nuclear — to meet demand. It is, therefore, not a question of which source of energy to develop but more one of achieving the best balance among these energy sources. Their effects on human health must form part of this calculation.

That human-generated global warming has been occurring slowly for decades is now widely understood. In the most recent issue of The Harvard Magazine, environmental scientist Daniel Schrag projects that by 2100 the energy demands of an increasing prosperous world, driven especially from the economic growth of China and India, will have increased fourfold.

While alternative energy sources, including nuclear power, are projected to be almost equal to today’s total energy consumption, Schrag projects that it will be coal that will grow immensely as a source of energy to meet an annual increase in demand for energy of 1.5%, contributing half of all our energy by century’s end.

Thanks to Scratch

Given that global warming is a slow process, and that it can only be controlled and not eliminated or reversed, Schrag supports the view that new technology will be needed to trap carbon from the exhaust of coal-fired electric power stations.

One form of entrapment would require it to be stored as a liquefied sludge under the huge pressures and cold temperatures 3000 metres down on the ocean floor. Here it would remain relatively inert, and Schrag estimates that the oceans could accommodate the toxic waste created over thousands of years.

The health consequences of nuclear power generation include the Chernobyl syndrome in case of a nuclear accident, the risk of terrorist attacks on nuclear power plants, the risk of mischievous acquisition of enriched uranium to make nuclear bombs and the hassle of storage of nuclear waste. None of these are trivial but they are not out of range of technological innovation to confront.

Unfortunately, Schrag writes, modeling suggests that even a tenfold increase in nuclear power generation over the next 100 years would barely reduce the predicted atmospheric burden of CO2 — from 900 ppm (parts per million) to 820 ppm. The level today is 320 ppm.

The likely health problems that will follow from global warming

The health effects of global warming are largely indirect and follow from its effect on forests and farmland. As regions become either warmer and wetter or warmer and drier the distribution of diseases due to mosquitoes, especially but not exclusively malaria, will change, but knowledge is not at a stage where global predictions can be made confidently.

Increases in temperature of our cities that are already carrying substantial air pollution burdens could mean trouble for people for people with respiratory disorders. More droughts may be handled in Australia, but what of the effects of these events upon less economically advanced nations where some of the world today’s 800 million malnourished people? (See Sid Perkins article in Science News.)

Coastal communities are threatened by global warming. Most of the world lives in such communities. Bangladesh is a country that will face severe problems. Crowding, already a problem in many developing world cities, is likely to increase with predictable rise in infectious and chronic disorders such as diabetes associated with sedentary, urban living.

Policy responses to global warming and health

Despite the potential significance of global warming for global health, individual action is needed by all countries if the problem is to be solved, even if those countries, like Australia, may not stand at great risk of consequences.

Policies conceived in a vacuum of public and political indifference will not go far. That is what makes the campaigns of Al Gore, in person and through his recent movie, so important. Without a background of rising citizen concern, we cannot expect political or policy action. With it, we can.

In considering the long term, and developing health services for the future, a realistic estimate of the likely consequences of global warming, especially surveillance for vector-borne diseases, climatic monitoring for major disruptions (impending heat waves), and contingency plans for serious agricultural disruption need to be put in place. These policies are best linked with similar initiatives for our near neighbours whose vulnerability to the effects of global warming — for example, disappearing Pacific atolls — is far greater.