Clean Air Partnership

Air Pollution and Your Health

WHAT IS THE CONNECTION BETWEEN AIR POLLUTION AND YOUR HEALTH? 

Air pollution affects our health in many ways, particularly our lungs, heart and blood vessels.Research has linked air pollution to a number of health concerns like:

  • Asthma;
  • Chronic obstructive pulmonary disease;
  • Cardiovascular disease;
  • Lung cancer;
  • Endocrine system effects;
  • Neurological effects; and
  • Allergies.

In addition, air pollutants typically increase the severity or frequency of common respiratory and cardiovascular medical conditions or illnesses.

According to the most recent scientific research, there is no “safe level” for air pollution. In other words, there is no level below which air pollution poses no adverse health effects.Air pollution poses a health risk all year long, not just in the hot summer months. These health impacts severely impact our quality of life and place unnecessary strain on the health care system.

Poor air quality reduces quality of life for all GTA residents, especially for children and the elderly, and for those with respiratory and cardiovascular problems. Negative health effects increase as air pollution worsens. Studies show that even modest increases in air pollution can cause small, but measurable, increases in emergency room visits, hospital admissions and death.

The harmful effects of air pollution are primarily the result of exposure to five common air pollutants:

  • Nitrous oxide;
  • Ozone (ground-level ozone is not directly emitted but is produced when sunlight combines with hydrocarbons and nitrogen oxide, two compounds produced by cars, trucks, industrial processes, and power-generating plants, and found wherever gasoline, diesel fuel, kerosene, oil, or natural gas are combusted);
  • Fine and ultrafine particulates;
  • Sulfur dioxide; and
  • Carbon monoxide.

These pollutants contribute to the air pollution mix commonly known as smog. They arise from the combustion of fossil fuels in vehicles, from heating of buildings, and from the production of electricity. Depending on exposure time, health status, genetic background, and the concentration of pollutants, air pollution can:

  • Make it harder to breathe
  • Irritate your eyes, nose and throat
  • Worsen chronic diseases such as bronchitis, emphysema and asthma
  • Cause heart attacks, heart failure and other forms of heart disease due to constricted blood vessels, altered heart rates and rhythms, and blood clotting
  • Lead to premature death

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WHAT IS THE CONNECTION BETWEEN AIR POLLUTION AND CARDIOVASCULAR HEALTH?

While many people are aware of the connection between air pollution and respiratory illness, over the last decade a growing body of evidence has led to increased concern of the effects of air pollution on heart disease and stroke. 

Of special interest are several environmental air pollutants that include carbon monoxide, oxides of nitrogen, sulfur dioxide, ozone, lead, and particulate matter (PM10 and PM2.5). These pollutants are associated with increased hospitalization and mortality due to cardiovascular disease, especially in persons with congestive heart failure, frequent arrhythmias, or both.

Air pollution is thought to increase the inflammation of blood vessels which is of particular concern for people who suffer from poor cardiovascular health as their ability to handle the inflammation is already compromised. Below is a diagram of the impact of inflammation from air pollution on a blood vessel. The healthy blood vessel on the left has ample room for the flow of blood; the images as you move to the right illustrate increased inflammation and reduced blood flow as a result of air pollution.

Figure 1: Inflammation of Blood Vessels Caused By Air Pollution

 blood vessels and inflammation

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WHAT ARE THE REAL IMPACTS OF AIR POLLUTION ON HUMAN HEALTH? HOW MANY DOCTOR/HOSPITAL VISITS AND DEATHS CAN BE DIRECTLY ATTRIBUTED TO AIR POLLUTION?

Air pollution exacerbates health conditions in people who already suffer from chronic conditions such as heart and lung disease, or makes those who are vulnerable to its effects--such as children and the elderly--more susceptible to illness. 

Air pollution may also contribute to the development of new cases of heart and lung disease. 

Ontario Medical Association  

In 1998, the Ontario Medical Association (OMA) declared air pollution “a public health crisis”. This statement was based on strong scientific evidence linking air pollutants like ozone, nitrogen oxides, carbon monoxide and tiny airborne particulates and acid droplets to various illnesses and breathing problems.

According to the OMA’s report, The Illness Cost of Air Pollution in Ontario, particulate matter (one type of air pollution) is responsible for almost 900 premature deaths per year in the Greater Toronto Area and almost half a billion dollars in health care costs (not including visits to family doctors) and lost productivity (as employees were too sick to come to work due to smog). 

Toronto Public Health  

Research undertaken for Toronto Public Health in 2005 found that, in any given year, the mix of six common air pollutants1 is associated with 1,700 premature deaths and 6,000 hospitalizations in Toronto. (Note, this figure is higher than that in the Ontario Medical Association model above because it includes the health impacts of more pollutants). These severe health outcomes are only the tip of the iceberg. Air pollution is also responsible for health impacts such as chronic bronchitis in children and the triggering of asthma attacks. The study estimates that in Toronto, exposure to fine particles in the air contributes to about 6,000 emergency room visits, 12,000 cases of childhood bronchitis and 72,000 days of asthma symptoms each year. 1. (Pollutants included in study are: ozone, nitrogen dioxide, carbon monoxide, sulphur dioxide, and fine particles - PM2.5 and 10)

Environment Canada’s Air Pollution Death’s Report  

Environment Canada’s Air Health Effects Division (AHED) was mandated to estimate the annual number of excess deaths due to current air pollution levels in Canada. The results are based on non-accidental mortality counts and National Air Pollution Surveillance (NAPS) data for the years 1998 to 2000, and pollutant-mortality concentration response functions (CRFs) from epidemiological studies. These estimates can be viewed as the number of deaths which could be prevented each year if air pollution from human sources within North America were eliminated. The overall estimate is determined as the sum of the estimated number of excess deaths associated with both short- and long-term exposure to air pollution.

The annual excess number of deaths in 11 major Canadian cities associated with short-term exposure was estimated to be 1,800. The annual excess number of deaths associated with long-term exposure was estimated to be 4,200.

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WHAT ARE THE SOURCES OF AIR POLLUTION IN SOUTHERN ONTARIO?

A number of sources are responsible for a large proportion of the emissions of major air pollutants in the GTA. The major air pollutants include:

  • nitrogen oxides (NOX),
  • sulphur dioxide (SO2),
  • volatile organic compounds (VOCs),
  • fine particulate matter (PM10 and PM2.5); and
  • carbon monoxide (CO).

The primary sources of these pollutants are:

  • On-road vehicles and off-road equipment that use diesel and gasoline;
  • Residential and commercial use of oil, natural gas and wood;
  • The generation of electricity;
  • Industrial operations;
  • Road dust and construction activities; and
  • Use of solvents and surface coatings such as paints.

Transportation is a major source of the emissions that contribute to both air pollution and climate change. In the Greater Toronto Area transportation is responsible, according to 2005 Environment Canada data, for about:

  • 27% of PM2.5
  • 18% of SO2
  • 75% of NOx
  • 34% of VOCs
  • 87% of CO
  • 30%1 of CO2 (carbon dioxide) emissions

Ground-level ozone is also an air pollutant but is not directly emitted, rather it is produced when sunlight combines with hydrocarbons and nitrogen oxides. 

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WHAT IS THE CONNECTION BETWEEN AIR POLLUTION AND CLIMATE CHANGE?

There are immediate connections between climate change and local air quality. Air temperature and ground-level ozone formation are directly correlated. The warmer the temperature, the faster ground-level ozone is formed and the worse air quality becomes. Secondly, as temperatures increase, so does air conditioning use; both in homes and in vehicles. In southern Ontario, much of the electricity used by air conditioners is produced through the burning of coal, which releases more air pollutants and further deteriorates our air quality.

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WHAT IS THE DIFFERENCE BETWEEN THE OZONE LAYER AND OZONE POLLUTION?

Ozone can be good or bad for us depending on where it's located.

Ozone is in the upper reaches of the sky, about ten to fifty kilometers above ground level is stratospheric ozone. It's better known as the "ozone layer." Akin to a protective blanket, it helps protect us from the developing cataracts and skin cancer by reducing the sun's biologically damaging ultraviolet rays (UV-B) that otherwise would bring genetic damage and harm marine life. Ground-level ozone is the main ingredient in cough-inducing, eye-stinging smog. It can cause rubber to crack and people's lungs to scar.

In cities, it results when sunlight combines with hydrocarbons and nitrogen oxides causing a chemical reaction that forms ozone. Some people use the term "smog" and "ozone" interchangeably. The hotter the day and the more intense the sun, the more ozone is formed.

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WHAT ARE THE CONNECTIONS AND THE DIFFERENCES BETWEEN AIR POLLUTION AND HEAT ALERTS?

Poor air quality can often accompanies heat waves, as high pressure (which often accompanies heat waves) parked over a region creates a stagnant environment due to light winds and lack of precipitation.

This stagnation prevents the atmosphere from dispersing pollutants, allowing them to build up near ground level.

When there is a heat wave those with respiratory ailments should exercise caution outdoors especially if poor air quality is expected to accompany the high temperatures. At greatest risk is a subset of the population most susceptible to air pollution (the same group that is also likely to be more vulnerable to high temperatures - such as the elderly, young children and those with respiratory and heart ailments).

Those with medical conditions or taking certain medications may also be vulnerable to heat stress. Healthier adults who exert themselves too much while outdoors could also find themselves impacted.

Heat Alerts and higher air pollution levels result is a double-whammy of health concerns, particularly for young children, the elderly and anyone with breathing or heart problems. On days when there is more heat and more sunlight, there is more ozone formation and on hot, humid days, sulfate particulate matter forms more readily in the atmosphere. Generally, the health consequences are the sum of the heat hazard plus the pollution's effects. But at very high temperatures and very high levels of ozone, the effect is more than additive.

Most heat-related deaths result from heart or lung complications, usually lagging a day or two after the hot spell, rather than happening from immediate overheating. Air pollution targets the same organs: ozone (the main ingredient in "smog") and particulate matter can penetrate the lungs, aggravating asthma and other breathing problems, and extend their harm to the heart and blood vessels. During heat and/or smog alerts, those at highest risk for asthmatic attacks or other cardiovascular conditions should limit their time outdoors, while the rest of the population should reduce exertion levels as much as possible while drinking plenty of fluids.

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WHAT ARE THE SHORT TERM EFFECTS OF AIR POLLUTION ON MY HEALTH?

People already suffering from respiratory or cardiac problems are the most likely to feel the short term effects of air pollution. These effects can arise after exposure to high levels of pollutants over a period ranging from several minutes to several weeks.

Exposure to pollution can exacerbate preexisting health problems in those who are vulnerable and in serious cases lead to hospitalization or death. Symptoms are those of the preexisting illness, including:

  • Irritation and inflammation of the respiratory tract
  • Wheezing
  • Tightness in the chest
  • Pain while deep breathing
  • Difficulty breathing
  • Increased shortness of breath on exertion

You will not necessarily experience all these symptoms, and you may have symptoms that are not on the list. For this reason you should be alert to the symptoms you have already learned to recognize due to your health condition.

The onset of these symptoms may also be caused by a host of other factors that you should also watch for, including heat, humidity, viruses, seasonal pollen (e.g., ragweed), and misuse of medication.

  • People with existing illnesses may have the following specific symptoms:
  • People with asthma or COPD may notice an increase in cough, wheezing, shortness of breath or phlegm. 
  • People who have suffered from heart failure may experience increased shortness of breath or swelling in the ankles and feet. 
  • People with heart rhythm problems may notice increased fluttering in the chest and feeling lightheaded. 
  • People with angina or coronary artery disease may have an increase in chest or arm pain.  

Note: You should always consult your doctor concerning medical issues. People who have existing respiratory or cardiovascular illness should follow their doctor's usual advice on management of their condition. Use of the following guide is an additional tool that can be used

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WHAT ARE THE LONG TERM EFFECTS OF AIR POLLUTION ON HEALTH? 

Most epidemiological investigations have looked at the effects of short term rather than long term exposure. Studies have shown an increased risk of lung cancer or cardiovascular and cardiopulmonary disease in populations living in highly polluted cities. What’s more, long term exposure could interfere with pregnancy (low birthweight and premature birth) and lung development in children.

In addition to respiratory and cardiovascular vulnerabilities, a 2010 national epidemiologic study found a correlation PM2.5 exposure and increased rates of adult diabetes (even after adjustment for other risk factors like obesity and ethnicity on diabetes rates).

A Government of Canada study assessed the annual number of excess deaths due to current air pollution levels in Canada associated with both short- and long-term exposure to air pollution.

Estimated Number of Excess Deaths in Canada Due To Air Pollution (10 pages, Air Health Effects Division, Health Canada, and Meteorological Service of Canada, Environment Canada, Gatineau, Quebec, April 2005).

Results found that based on non-accidental mortality counts and National Air Pollution Surveillance data and pollutant-mortality concentration response functions from epidemiological studies the annual excess number of deaths associated with short-term exposure was estimated to be 1,800, with long term exposure was estimated to be 4,200, resulting in a total excess deaths estimate of 5,900 people. 

To mitigate these effects, we must work together to decrease current air pollution levels, for example by ensuring reductions of industrial air pollutants, reducing energy use from buildings and ensuring increased use of public transit. Our efforts would also protect the health of those who are most vulnerable to the effects of air pollution.
 

 airpollutiondeathschart

 

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