Adverse Impacts of Road Traffic exhaust on Human Health and Mitigation measures:

Adverse Impacts of Road Traffic exhaust on Human Health and Mitigation measures:

Automotive vehicle engines produce a number of air pollutants that pose risks to human health. Road vehicles such as cars, buses and trucks are a source of air pollution. When their engines burn fuels (gasoline or diesel), they produce large amounts of chemicals that are emitted in engine exhaust. In addition, some of the gasoline used by engines vaporizes into the air without having burned, and this also creates pollution.

A. Recent study shows that those who reside near major highways had worse indoor air pollution than those in more rural settings, with respect to PAHs (polycyclic aromatic hydrocarbons), a class of compounds that contain known cancer-causing toxins.

Although, stringent regulations on engine performance and fuel formulation have brought about a decline in the amount of air pollution produced by individual vehicles, but due to increase in number of vehicles the air pollution level in urban areas have not come down. Automobile exhaust remains a major source of pollution and the pollutants cause local changes in the air quality, which affect the human health adversely.

B. This causes us great concern on health front of public, especially, children who pose risk to various hazards. Children exposed to high levels of air pollution during their initial years of life run a greater risk of developing asthma, pollen allergies, and impaired respiratory function.

Another group of people those are greatly affected due to vehicular exhaust are traffic personnel - men and women. It has also been reported in many countries that, due to high exposure to toxic fumes of vehicular exhaust among traffic personnel, induced impaired reproductive system observed.

C. The following is a summary of the main pollutants produced by road traffic and the way they may affect our health:

Nitrogen oxides: These are created when vehicle engines burn nitrogen that is present in the air and nitrogen compounds found in fossil fuels. Nitrogen oxides can irritate airways, especially your lungs.

Carbon monoxide: This gas is produced by incomplete combustion of gasoline and diesel fuel. All engine exhaust contains a certain amount of carbon monoxide, but the amount will increase if your vehicle engine is poorly maintained. Carbon monoxide decreases the ability of your blood to carry oxygen.

Volatile organic compounds (VOCs): These are a large family of carbon-containing compounds that evaporate easily. Engine exhaust contains a number of different VOCs. Some of them, such as benzene and 1,3-butadiene, are cancer-causing agents, although the risk at current levels in the environment is small.

Fine particulate matter: These tiny particles contain many substances, including metals, acids, carbon, and polycyclic aromatic hydrocarbons. Some of these particles are emitted in vehicle exhaust, while others are formed in the atmosphere through chemical reactions between the various pollutants found in exhaust. Particulates are known to aggravate symptoms in individuals who already suffer from respiratory or cardiovascular diseases.

Ground-level ozone: This is not emitted directly by vehicle engines, but is formed by chemical reactions between nitrogen oxides and VOCs. These reactions are stimulated by sunlight, and this is why concentrations of ground-level ozone are higher during the summer months. Ground-level ozone irritates airways and can trigger reactions in people who have asthma (Ground-level ozone should not be confused with the ozone layer in the stratosphere, which provides protection from the sun's ultraviolet rays.).

The air pollution from road traffic causes two types of effects on health:

Acute Effects: These effects occur rapidly (in a few hours or days) following exposure to high levels of pollutants. In certain cases, air pollution may worsen symptoms for people with existing heart and lung conditions. Scientific research carried out in some countries has shown that the number of deaths and hospitalizations related to respiratory and cardiac conditions increases when the levels of ground-level ozone or fine particulate matter increase.

Chronic Effects: These occur over time following extended exposures (months or years). Scientific studies in Europe have shown that children living in areas with higher traffic density have more respiratory symptoms than other children.

In general, traffic exhaust pollutants are a major source of air pollution especially in urban areas, and are a major source of greenhouse gas emissions as well. Vehicles run on conventional or diesel engines. Although diesel engines are more efficient, they emit more fine particles than conventional engines. According to many, diesel exhaust is responsible for 70 percent of the cancer risk that the average urban population faces from breathing toxic air pollutants.

Potential health effects from being exposed to traffic-exhaust pollutants include respiratory illnesses (including asthma), cardiovascular disease, adverse reproductive outcomes, cancer, and shortening of the life span.

D. We can help to minimize risks by taking steps to reduce traffic-related air pollution. (a) Whenever possible, use public transit, bicycle or walk instead of using your vehicle. (b) Take fuel efficiency into account when you buy a vehicle. (c) Turn off the engine of your car when you stop for more than 10 seconds, unless you are in traffic or at an intersection. (d) Keep your vehicles well maintained. (e) In addition, you can take steps to help minimize your risk of health effects from traffic-related air pollution, such as,

(i) Pay attention to air quality forecasts in your community, and tailor your activities accordingly.

(ii) Avoid or reduce strenuous outdoor activities when air pollution levels are high, especially in the afternoon during summer months when ground-level ozone reaches its peak.

(iii) Choose indoor activities instead.

(iv) Avoid or reduce exercising near areas where traffic is heavy, especially during rush hour.

(v) If you have a problem of heart or lung, consult health care professional about additional ways to protect your health when air pollution levels are high.

E. Governments can encourage the reduction of vehicular use by:

a. Promoting Voluntary abstention,

b. Increase Public Transit - diversify options and limit access to existing roads.

c. Separate commercial and private traffic to increase efficient use of roads,

d. Stop building car-oriented roads and highways,

e. Replace 30% of the existing roads designed for cars with a variety of transportation options,

f. In cities, build more walking paths, bicycle routes and paths for small electric vehicles, g. Reduce commuting - link residence and business activities by rezoning and rebuilding cities,

h. Reward car-pools and car-sharing plans,

i. Redefine road use by defining access privileges - no longer a right,

j. Road Tolls and increased gasoline and vehicle registration taxes,

k. Base car license fees on fuel consumption in the previous year. Use exponential fee rate increase for high fuel consumption individuals,

l. Provide generous development grants and tax incentives for all non-polluting transportation alternatives.