Traffic significantly reduces the quality of air, especially in urban environments. Drivers should make sure that their vehicles’ fresh air filters are working properly.

Over the past few decades, car emissions have decreased. This decrease in emissions has been partly due to the introduction of catalytic converters, particulate filters, and cleaner fuels. Rising traffic volumes, however, cancel out the positive effects of these factors on air quality.

Busy traffic and congestion are the main causes of poor air quality in urban environments. Vehicles emit undiluted exhaust fumes right at breathing height, which further increases our exposure to pollutants.

Different particles and nitrogen oxides are a particular threat to the air we breathe. Exhaust fumes also contain carbon monoxide, different hydrocarbons, and carbon dioxide. Ozone is formed through the reaction of hydrocarbons and nitrogen oxides.

The weather has a significant impact on how much traffic fumes are diluted. The situation is the worst on calm, crisp mornings when the temperature is below zero. Cold air is heavier than warm air. This is why different air masses do not mix in calm weather. The layer of air nearest to the ground cools more rapidly than the layer above it. In the morning rush hour, the pollution levels rise high as the exhaust fumes gather in the cool, bottom layer of air near the ground.

In winter, the situation is even worse due to cold start emissions, engine idling, and the fact that catalytic converters are less efficient in cold weather.

Drivers should make sure that their vehicles’ fresh air filters are working properly, especially during the street dust season and the coldest months.

The problems created by traffic-related airborne particles are at their worst in spring. Street dust is formed by asphalt dust and grit, which has been crushed under studded winter tyres.

Urban air quality can be improved by functional public transport, efficient street cleaning, and low-emission vehicles.