Hot times, summer in the city.

Even if the skeptics are right and reducing [CO.sub.2] emissions does not have much of an effect on global warming it could give a big boost to local air quality

Smog. Most big cities have it. And it's not surprising that it affects the health of city folks. For that reason alone, it's worth cleaning up our air. And that means cutting greenhouse gases, whether they affect climate in a big way or not.

In a speech in June 1998, Christine Stewart, Canada's Minister of the Environment, said 64% of Canadians believe their health has already been affected by the environment, while 93% believe environmnental problems will affect the health of their children and grandchildren. And, their main concern is pollutants reaching us all by air.

Researchers have found that death rates rise, hospital admissions increase, and asthma symptoms are aggravated when air pollution is high.

"We know that air pollution accounts for 80% of the smog in the southern portion of the Maritimes," said Ms. Stewart. "Montreal has already had two smog alerts this year (1998). When smog levels are high in the Montreal region, hospitalization of respiratory-disease cases rises to 14%.

"We know that children exposed to air pollution lose some of their lung function. We know that there is no healthy level of exposure to smog. Improving our air quality is an important step in ensuring the health of future generations... Reducing air pollutants will be a major factor in public health at the turn of this century."

Our love affair with the car creates a hefty chunk of smog-producing pollutants -- formed when hydrocarbons mix with nitrogen oxides in sunlight. A recent issue of Canadian Geographic points out that sulphur is also a big culprit. In 1995, the average sulphur level in Canadian gasoline was 343 parts per million (PPM) compared to the 30 PPM allowed in California, the world leader in clean fuels. Cleaning up Canadian refineries to California's standards would cost oil companies $1.8 billion. According to one calculation that would mean consumers spending one to 1 1/2 cents a litre more at the gas pumps. But, it would prevent an estimated million cases of acute respiratory illness in Canada and 82 premature deaths a year. It could also save $281 million a year in health care and other costs in seven major Canadian cities.

Within Canada, Ontario has the worst gasoline in terms of sulphur content, with more than 500 PPM; some has as much as 668 PPM. That's about twice the sulphur content of gas sold in Atlantic Canada, Quebec and the West because the province relies on old refineries that use more high-sulphur crude as a raw material.

The health cost is high. The Ontario Medical Association estimates that air pollution from all sources causes 1,800 premature deaths in the province each year.

People who live in Mexico City understand. With millions of cars and thousands of factories, the city is one of the unhealthiest places in the world.

The pollution gets worse as the temperatures rise, and they're setting records. In May 1998, Mexico City had its hottest day ever when temperatures reached 44.4 [degrees] C. Over the past 100 years, the average daily temperature has gone up by two degrees Celsius, more than four times the average increase at the other 6,000 locations scientists monitor around the globe. As the largest city in the world, it is suffering from car emissions, as well as vast energy usage, lots of heat-capturing surfaces such as metal, concrete and glass, and not much open land.

Urban Mexicans complain of not being able to sleep, exercise, or work because of the heat. Experts predict Mexico City's temperatures will continue to rise at a rate outpacing almost everywhere else on Earth.

In mid-January 1996, Mexicans were breathing so many gasoline fumes they had to park their cars. Ozone levels in Mexico City reached unheard of heights even for this heavily polluted city. When the ozone hit 2.5 times the level considered safe, officials banned driving for half the city's cars for two days.

In Mexico's case, one of its main problems is location. The city of 20 million -- about one-fifth of the total population of Mexico -- sits at 2,255 metres (7,400 feet) above sea level and is surrounded by mountains which trap heat and pollution -- they reduce the flow of winds that otherwise might help disperse atmospheric pollution.

The Metropolitan Area of Mexico City is home to 30,000 heavy to light industries. Among the industries in the valley, 250 handle hazardous wastes and 4,000 use combustion or transformation processes which generate major atmospheric emissions. Air pollution has grown along with the area's population, which stood at 1.7 million in 1940 and is expected to be around 26 million by 2000. Some of the air pollution is natural dust from unvegetated and unpaved areas on the outskirts of the city. The main source though comes from the consumption and use of fossil fuels. Motor vehicles account for 44% of the total energy consumption in the area. In 1992, they burned 40,000 barrels of diesel and one million barrels of leaded gas each day, according to the World Health Organization. Private cars produce about 63% of total transport emissions and up to 99% of carbon monoxide emissions.

In addition to a comprehensive long-term pollution control program started up in 1990, the city has taken steps to alleviate the immediate problem. During prolonged periods of high pollution levels, these measures include restrictions on highly polluting industries and vehicle use. In extreme cases, primary schools are temporarily closed to prevent potential damage to children's health.

The city of Toronto also embarked on a smog-reduction plan in May 1998 when unseasonable temperatures (27 [degrees] C) put a damper on air quality. The public-health department warned asthmatics and others with heart and lung diseases to stay inside. Under the plan, city staff will be asked to stop paving roads, spraying pesticides, and using gasoline-powered equipment such as lawn mowers and leaf blowers when a smog alert is issued.

While the plan is seen as more of a well-meaning gesture than a cure for air pollution, it's also seen as a good first step.

Cleaning up air pollution could save the city dollars as well as lives.

One 1993 study estimated that people in the Toronto area could save $74 billion simply by curtailing their use of cars. On an individual basis, the study said each car owner could save $2,000 to $10,000 a year in fuel and repairs. As alternatives, the report saw commuters using an expanded subway system, light-rail transit, bicycles, and foot power.

Then, we could all breathe easier.

SUGGESTED ACTIVITIES:

1. In June 1998, the Canadian Institute for Environmental Law and Policy released a scathing report on the Ontario government's environmental performance. According to the report, fines against polluters in Ontario declined to $955,000 in 1997, the lowest total in more than a decade and less than one third of the 1995 amount. It also found that the number of provincial pollution investigators fell 28% between 1995 and 1998, and that the Environment Ministry's operational budget fell by 45% while staff dropped 32%. Research and report on your province's record on dealing with environmental problems. Ontario students can find more information that confirms or disputes the findings of the report.

2. Check out the air quality where you live and identify what makes some areas cleaner than others.

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Tests in the U. S. have shown that lawn mowers produce 11.5 times the polluting emissions of a car; leaf blowers, 35 times car emissions.

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In Mexico City, the U.S. air quality standard of 207 micrograms per cubic metre is commonly exceeded 80100 hours per month.

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The highest smog concentrations in Canada are in the Lower Fraser Valley in British Columbia and in Southern New Brunswick.

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A week-long smog in London' England, in 1952 caused more than 4,000 deaths and led to new limits on coal burning in factories and homes.

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Only 1% of Canadians cycle to work and about 10% use public transportation.

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Each car pool saves about 2,000 litres of gasoline a year and cuts [CO.sub.2] emissions by about five tonnes.